[GeoJournal Library] Mountain Geoecology and Sustainable Development of the Tibetan Plateau Volume 57 ||

Mountain Geoecology and Sustainable Developmentof the Tibetan Plateau

The GeoJournal Library

Volume 57

Managing Editors: Herman van der Wusten, University of Amsterdam,The NetherlandsOlga Gritsai, Russian Academy of Sciences, Moscow,Russia

Former Series Editor:Wolf Tietze, Helmstedt, Germany

Editorial Board: Paul Claval, FranceR.G. Crane, U.S.A.Yehuda Gradus, IsraelRisto Laulajainen, SwedenGerd LOttig, GermanyWalther Manshard, GermanyOsamu Nishikawa, JapanPeter Tyson, South Africa

The titles published in this series are listed at the end of this volume.

Mountain Geoecology and Sustainable Development of the Tibetan Plateau editedby

DUZHENG

QINGSONG ZHANG

and

SHAOHONGWU Institute о( Geographical Sciences and Natural Resources Research, Chinese Academy о' Sciences, Beijing, P.R. China

SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.

A C.I.P. Catalogue record for this book is available from the Library of Congress

ISBN 978-94-010-3800-3 ISBN 978-94-010-0965-2 (eBook) DOI 10.1007/978-94-010-0965-2

Printed on acid-free paper

Cover illustration: Photo taken bij Zheng Du. Published by the State Survey Bureau 1989 at a scale of 1 :2.5 million.

AII Rights Reserved © 2000 Springer Science+Business Media Dordrecht Originally published by Kluwer Academic Publishers in 2000 Softcover reprint of the hardcover 1 si edilion 2000 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording or by any information storage and retrieval system, without written permission from the copyright owner.

CONTENTS

Foreword ixPreface xi

Chapter 1 Introduction 11.1 A Unique Geographic Unit.. 11.2 Basic Geo-Ecological Features 31.3 Retrospect of Scientific Expeditions 61.4 Main Progress in Studies of Tibetan Plateau 101.5 Framework of the Book 13References 15

Chapter 2 Uplift and Environmental Changes of the Tibetan Plateau 192.1 Tectonic Evolution of the Tibetan Plateau 202.2 Uplift Processes of the Tibetan Plateau ,,242.3 Quaternary Glacial Evolution of the Tibetan Plateau 282.4 Lake Evolution 322.5 Climatic and Environmental Changes in Holocene Age 38References 42

Chapter 3 Three Dimensional Differentiation of Natural Zonation 473.1 Comparative Studies on the Altitudinal Belt 473.2 Some Unique Geo-Ecological Phenomena 513.3 Physical Regional Differentiation 563.4 Physic-Geographical Regional System 60References 66

Chapter 4 The Population Changes and Urban Development 714.1 Evolution of Administative Regionalization 714.2 Historical Population Change 714.3 Population Growth Since 1951 724.4 Main Reasons of Rapid Population Growth 744.5 Nationality Structure 784.6 The Restrict Resources and the Threat of Over-Population 794.7 Population Quality and Education 824.8 Religion and Monk Population 844.9 Urbanization 85References 87

Chapter 5 Climate: Past, Present, and Future 895.1 Uplift of the Tibetan Plateau and Monsoon System 895.2 Climatic Change during the Historical Periods 935.3 Tibetan Plateau as Heat Source and Sink 1055.4 Moisture Transportation Pathways and its Geo-Ecological Significance .. 1055.5 Sensitive Regions for Climatic Changes 109References 111

Chapter 6 Permafrost: Status, Variation and Impacts 113

vi CONTENTS

6.1 Distribution and Characteristics of Permafrost.. 1136.2 Periglacial Processes and Landforms 1216.3 Permafrost and Geoecological Effects 1246.4 Permafrost and Global Change 1296.5 Summary and Conclusion 133References 134Acknowledgements 134

Chapter 7 Biodiversity: Biota and Biocoenose 1397.1 Composition and Characteristics of the Biota in the Tibetan Plateau 1397.2 Main Types and Characteristics of the Biocoenose 146References 156

Chapter 8 Human Health Aspect in Geoecology 1598.1 Influence of High Altitude on Health 1598.2 Effects of Life Elements in Geo-Ecosystem on Health 1628.3 Impacts of Landscape Bio-Factors on Health 176References 178

Chapter 9 Land-Use and Agricultural Development 1819.1 Introduction 1819.2 Characteristics of Land-Use 1839.3 Farm Land and Crop Production 1869.4 Grazing Land 1919.5 Forest and Horticulture Land 1959.6 Other Lands 1999.7 Spatial Distribution of Agricultural Land-Use 199References 20 I

Chapter 10 Natural Hazards and Environmental Issues 20310.1 Natural Hazards 20310.2 Environmental Issues 21410.3 Discussion and Conclusion 218References 220

Chapter 11 Nature Conservation 22311.1 An Outline of Nature Conservation 22311.2 Nature Reserves and Type Classification 22511.3 Typical Nature Reserves 22811.4 Rare and Precious Wildlife 235References 239Attach List ' .240

Chapter 12 Regional Social-Economic Sustainable Development.. 24312.1 Sustainable Strategic Objects and Policies 24312.2 Fiscal Concern with Central Govemment... 24912.3 Industrial Restructure Orientation and Allocation 257References 264

Chapter 13 Geo-Ecology of Mts. Namjagbarwa Region 26513.1 Moisture Corridor Areas 26513.2 Geo-Ecological Observation in Vertical Natural Belts 269

CONTENTS vii

13.3 Structure and Regional Differentiation of Vertical Zonation 27213.4 Land Utilization and Conservation 275References 281

Chapter 14 Dry Valleys in Hengduan Mts Region 28314.1 Geo-Ecological Features and Type Classification 28314.2 Formation and Regional Differentiation 28614.3 Resources Utilization and Environment Management... 29414.4 Highland and Lowland interaction 299References 302

Chapter 15 High-Cold Scrubs and Meadow Zone 30315.1 Geoecological Features 30515.2 The Three-Dimensional Distribution and Geo-Ecological Analysis 30915.3 Grassland Resources and Degradation Problems 31515.4 Countermeasures for Sustainable Use of Alpine Meadow Grassland 319References 323

Chapter 16 Hinterland of Qiangtang Plateau 32716.1 Natural Environment.. 32816.2 Ecosystem 33216.3 Utilization and Protection 34116.4 Cold and Dry Core Region 345References 348

Chapter 17 Kunlun Mountains Region 34917.1 Introduction 34917.2 Physical Environment 35017.3 Altitudinal Zonation of Landscape 35817.4 Regional System 36517.s Land Use and Sustainable Development 366References 372

Acknowledgements 373Contributors .375Subject Index .377

FOREWORD

Intense uplift of the Tibetan Plateau in Late Cenozoic Era is one of the mostimportant events in geological history of the Earth. The plateau offers an idealregion for studying of lithospheric formation and evolution, probing into themechanism of crustal movement, and understanding of changes in environmentsand geo-ecosystems in Asia. Intense uplift of the plateau resulted in drastic changesof natural environment and apparent regional differentiation on the plateau properand neighboring regions. The plateau therefore becomes a sensitive area of climatechange in Asian monsoon region, which is closely related to the global change. As aspecial physical unit, its ecosystems occupy a prominent position in the world. Dueto its extremely high elevation and great extent, natural types and characteristics ofphysical landscapes on the plateau are quite different from those in lowlands atcomparable latitudes, and environments are also different from those in highlatitudinal zones. Consequently, the Tibetan Plateau has been classified as one ofthree giant physical regions in China and considered as a unique unit on Earth.

Scientific surveys and expeditions to the Tibetan Plateau on large scale beganfrom 1950's. Amongst them, a number of comprehensive scientific expeditions tothe Xizang (Tibet) Autonomous Region, Hengduan Mts. areas, Karakorum andKunlun Mts. regions, as well as the Hoh Xii Mts. areas, have been successivelycarried out by the Integrated Scientific Expedition to Tibetan Plateau, sponsored byChinese Academy of Sciences since 1973. "Studies on the Formation, Evolution,Environmental Changes and Ecosystems of Tibetan Plateau", as a key State Project,initiated by the State Science and Technology Commission of China and ChineseAcademy of Sciences in 1992-1997, has been fruitfully accomplished. Progress ofthese studies have been made both on basic theoretical issues and major applicationfields, such as in geological history, earth dynamics, formation and evolution,uplifting process and environmental changes, biological diversification, naturalenvironment and its regional differentiation, nature conservation, rational utilizationof natural resources and regional sustainable development of the plateau, and so on.

The book of " Mountain Geo-Ecology and Sustainable Development of theTibetan Plateau ", edited and written by Professor ZHENG Du and his colleagues,is one part of major achievements resulted mainly from those integrated researchprojects on Tibetan Plateau, especially in the last two decades. It represents ourcurrent knowledge of fundamental issues regarding in mountain geo-ecology andmountain development of the Tibetan Plateau. In which, a general viewpoint inevolution and differentiation of physical environments, human dimension ofmountain development of the plateau is dealt with in the first part. The second partconsists of special thematic issues of environments, ecosystems and development ofthe plateau. The third part includes several case studies, selected to representenvironment and development issues from various regions in the Tibetan Plateau.

ix

x FOREWORD

As regards in study field of mountain geo-ecology and development, severalmonographs have been published in 1990's, such as "The State of the World'sMountains--A Global Report" (Edited by Peter B. Stone, 1992), "Mountains of theWorld--A Global Priority" (Edited by B. Messerli and J. D. Ives, 1997), etc.Unfortunately, most of research results of the Tibetan Plateau conducted by Chinesescientists in last decades do not sufficiently include in the above mentionedpublications. I do hope this book may fill up the gaps in studying of mountain geoecology and development of the world.

I trust that the book would present a great contribution to those interested inissues of environments and development on the Tibetan Plateau. I would like toexpress my gratitude to Professor ZHENG Du and his colleagues to compile thisvaluable book, and also to thank Kluwer Academic Publishers, who offered anopportunity to publish this book for the series of GeoJournal. I am hoping todevelop cooperation with scientists both at home and in abroad to make moreefforts for mysteries discovering and regional sustainable development in theTibetan Plateau.

Prof. SUN HonglieAcademician ofChinese Academy ofSciences

President ofChina Society on the Tibetan Plateau

PREFACE

Two years ago, I received a letter dated on 27 April 1998 from Petra D. VanSteenbergen, the publishing editor for the Geosciences programme of KluwerAcademic Publishers. The editor invited me to prepare a timely treatmentconcerning the field of mountain geo-ecology and sustainable development for theseries of GeoJournal Library.

After discussing with some ofmy colleagues I preferred to prepare a book withthe title of "Mountain Geo-Ecology and Sustainable Development of the TibetanPlateau". It will focus on the issues of environment and development of the TibetanPlateau, and by which we hope to fill the gaps between the Tibetan Plateau and theglobe in mountain geo-ecology and sustainable development.

There are two reasons for editing this volume. One is that several monographsregarding the global mountains have already been published. For examples, "TheState ofthe World's Mountains--A Global Report" (Peter B. Stone, 1992) was one ofthe Mountain Agenda's achievements and included in the Chapter 13 (ManagingFragile Ecosystems: Sustainable Mountain Development) in Agenda 21, UNCED'sprimary product. "Mountains ofthe World--A Global Priority" (B. Messerli and J. D.Ives, 1997) was another important volume which had huge influence. The other oneis that most of the research achievements of the Tibetan Plateau, known usually as"the Roof of the World", published by Chinese scientists in last two decades werestill not sufficiently known in the study fields of mountainous areas in the world.

The authors of the book have studied mainly on various issues concerningmountain geo-ecology and geography in the Tibetan Plateau since 1960's and 1970's.We participated in the Integrated Scientific Expedition to the Tibetan Plateausponsored by the Chinese Academy of Sciences and relevant surveys andexpeditions in different stages in the last several decades.

It is emphasized that this is a book produced by individuals. In no way can itbe regarded as an official document. At the beginning to editing the book, anoutline of framework was offered to all contributors. Each chapter was prepared bythe author(s) who is familiar with the issue and its focus. The overall presentation,statements, opinions, especially their conclusion and recommendations, are personaland reflect the author's own convictions and their expertise. There were editorialexchange and discussion in some degree between authors and editors. Editorialinput has entered into the development of several chapters, and into the finalizationof every chapter. Generally the input has been confined to style and efforts toreduce repetition of the manuscripts.

I convinced that the book would be a contribution to the study field ofmountain geo-ecology and sustainable development of the world. I would like to

xi

xii PREFACE

express my sincerely gratitude to Professor van der Wusten, the Series Editor of theGeoJournal Library, Ms Petra D. van Steenbergen, the Publishing Editor of KluwerAcademic Publishers, for their advice, remarks and efforts of preparing the book. Isincerely hope that the readers would give their remarks for the insufficient of thebook. I would also like to appreciate all authors of the book for their contributions.Professors ZHANG Qingsong, WU Shaohong, Dr.ZHU Liping and Mm ZHANG Liof the Institute had given their hard work for editing the book, very truly thanks tothem.

Prof. ZHENG DuInstitute ofGeographical Sciences and Natural Resources

Chinese Academy ofSciences

CHAPTER 1 INTRODUCTION

ZHENG Du and ZHANG Qingsong

The Tibetan Plateau, known as the" roof of the world", with an averagealtitude of over 4,000 m asl and surrounded on all sides by high mountain rangeswhich descend to adjacent plains and basins, is the highest, youngest and largeststructural landform unit on earth. Rising of the plateau is one of the importantevents in geological history in late Cenozoic Era. The uplifting of the plateau exertsgreat influence not only on the plateau itself, but also on the physical environmentsand human activities in adjacent regions. Tibetan Plateau has long been theattraction for Chinese and foreign scientists owing to its magical dynamics offormation, amazing geographic features, unique landscapes, special geo-ecosystemsand vast potential of natural resources.

1.1 A Unique Geographic Unit

1.1.1 LOCATION AND RANGE OF THE TIBETAN PLATEAU

The Tibetan Plateau, starting from the Pamirs in west to the Hengduan andQinling Mts. in east, stretching across 31 degrees of longitude with a distance of2,700 km, and from the Kunlun, Altun and Qilian Mts. on north to the Himalayason south, acrossing 13 degrees of latitude with a distance of 1,400 km, covers anarea of about 2.5 million km2 within the boundaries of China. The range of TibetanPlateau is corresponded with the "High Asia" described by European geographers(Schlagintweit, 1865; Wissmann, 1960/1961). Tibetan Plateau includes all ofXizang Autonomous Region and Qinghai province, northwestern Yunnan province,western Sichuan Province, a part of southern Gansu province and southern andsouthwestern Xinjiang Uygur Autonomous Region. It has a total population about10 million, of which, Tibetans, who have been well adapted to the uniqueenvironment of high altitude, accounting for 25%.

Formation of various geographic features and physical environments on theTibetan Plateau are closely correlated with geological and geomorphologicalevolution of the plateau, therefore, landform is a base for defining the scope of theTibetan Plateau (LI Bingyuan, 1987). From geomorphic view of point, thefollowing aspects should be basically considered.

ZHENG Du. ZHANG Qingsong and WU Shaohong reds.). Mountain Geoecology and Sustainable Development ofthellbetan Plateau. 1-17.©2000 Kluwer Academic Publishers.

2 ZHENG D., ZHANG Q. S.

Feature ofgigantic structural landform

Extremely high Tibetan plateau is a gigantic landform umt In continentalproper, reflecting characteristics of crust structures and neo-tectonics. The plateau issurrounded on all sides by high mountain ranges, which, on southern and northernsides, are confined by active fault zones, resulting in steep slopes and great relief onfrontiers of these mountain ranges. Such unique structure of tectonic landform invery large scale differs from other landform unit elsewhere. Therefore, relationshipbetween landform and geological structure, especially between geomorphicboundary and active fault zone should be considered in defining the boundaries ofthe plateau.

Plateau surface

High altitude is the main feature of the plateau landform and a key criterion fordemarcating the plateau. Distribution of various types of landforms reflected certainlevels in altitude, such as basins and broad valleys, summit surface, and theextremely high mountains. They might be differentiated from initial plateau surface,reflecting differences in uplifting process of the plateau. The uplifted plateausurface, as a whole, may be considered as a main symbol of structural landform inthe plateau. So, distribution ofthe plateau surface is an important basis for definingthe scope of the Tibetan Plateau, because uplift of the plateau has beencharacterized by a considerable magnitude with alternated strong uplift and relativestable periods since the end of Pliocene.

Integrity ofthe highlands

In demarcating the range of Tibetan Plateau, an altitude of above 4,000 m aslis usually taken as a criterion for delineation, but we do not simply delineate anoutline along the contour line of 4,000 m as!. In consideration of integrity of thehighlands, a base line on piedmont of high mountains, boundaries between middlelower mountains and hills, plains in peripheral areas of the plateau should be alsotaken as the boundaries of the plateau (Fig. 1-1 ).

It is quite clear that the Kunlun Mountain range extending in northwestdirection and the Himalayas stretching in east-west, both as peripheral mountains,consist of northern and southern rims of the Tibetan Plateau. And these two giganticmountain systems meet at the Pamirs to be mountainous knots as the western end ofthe plateau. Eastern boundary of the plateau stretches along with eastern peripheriesof middle and north Hengduan Mountains. Qaidam Basin, situated in betweenQilian and Kunlun mountains, is the only one portion, which was relativelydescending in the uplifting process of the plateau. In general, all boundaries of theplateau at north, east and south are controlled by a large scale active fault zones,which are coincidentally situated in gradient zones of gravity anomaly and crustthickness. Accordingly, steep steps appear on peripheries of the plateau with a

INTRODUCTION 3

relative elevation of 1,OOO~3,OOO m, forming a striking contrast to the surroundingplains and basins, and then becoming such a unique landform unit (SUN andZHENG,1996).

Fig.I-1 Sketch map of the Tibetan Plateau

1.2 Basic Geo-Ecological Features

According to the studies on physic-geographical elements of the TibetanPlateau, such as landforms (YANG et al., 1983), climate (GAO el al., 1984),glaciers (SHI et al., 1981; LI et al., 1986), rivers and lakes (GUAN et al., 1984;GUO Jinghui et al., 1985), soils (GAO et al., 1985), vegetation (ZHOU Xingmin etal., 1987; ZHOU Lihua et aI., 1987; ZHANG Jingwei et al., 1988) and animals(ZHANG Rongzu et al., 1985), as well as the integrated researches on physicalgeography (ZHANG Rongzu et al., 1982,1987; ZHENG Du et al., 1979, 1985; L1UDongsheng et al.1990), some basic features of natural environments on the plateau,which are mainly determined by its intensive uplift, high elevation, large area andmiddle-lower latitudinal location, could be summarized as follows.

1.2.1 HIGH ALTITUDE AND YOUTHFULNESS OF PHYSICAL PROCESS

Surrounded the highest and youngest plateau, extremely high mountain rangesare suffering from intensive denudation, erosion, even periglaciation and glaciationunder various of external forces. Gorges and deep cut valleys are commongeomorphic features on marginal regions of the plateau. Where intensive


rejuvenation of rivers and streams corresponded to uplifting resulted in theoccurrence of huge knick points along longitudinal profiles of large rivers andshaping of "valleys in valley" in transversal sections. These features typically occurin lower reaches of the Yatung Zanbo River, upper reaches of the Yangtze andYellow Rivers. Owing to prominent spatial differentiation in moisture regimes fromSE to NW, and consequently, great divergence in intensity of erosion, deeplydissected southeastern and eastern parts of the Tibetan Plateau are dominated byfluvial erosion process in contrast strongly with interior northwestern plateau.Where the undulating high plateau surface prevails under frigid and arid conditions,and drainage systems turn from exterior to interior due to lack of water supply.Lakes in the interior of the plateau are being intensively contracted. In most part ofthe plateau, soil-forming process has been young which is indicated by slightlydevelopment of soil profiles and weakly weathered soil minerals. Most of the soilshave thin layers, coarse texture, low weathering degree, the strong freezing-thawingaction, etc. All these features, interlaced and interconnected by stable, developing,degrading and remnant factors, demonstrate the youthfulness of the physicalprocesses on the Tibetan Plateau.

1.2.2 HIGH RADIATION WITH LOW TEMPERATURE AND LARGEDIURNAL RANGE

Because of thinned and purified atmosphere, the annual global radiation of540-790kJ/cm2·yr on the plateau is 500/0-100% higher than that at lowland in thesame latitude. Central and western part of the plateau is a high value area with anannual global radiation of over 670kJI cm2·yr, usually the direct solar radiationaccounts for 600/0-70% of the global solar radiation. Low temperature and coldnesscaused by high elevation is obvious. Northern Qiangtang plateau is the coldest areaon the plateau with a mean temperature of <6-IOoC in July. Mean temperature ofthe warmest month in most part of the plateau is 15-20°C, being lower by 12-16°Cthan that at the eastern lowlands in the same latitude. Annual range of temperatureon the plateau is lower than eastern China because of the existence of lowertemperature in warm season. Diurnal range of temperature is quite large, beingabout 10-1 2°C in southeastern part of the plateau, and 12-20°C on the proper ofthe plateau. In comparison with lowlands in high latitudes, the same temperatureson the plateau signify different meanings, so far as the physical processes and plantgrowth are concerned due to intense solar radiation and heating effects of theplateau.

1.2.3 WIDE SPREAD NIVAL AND PERMAFROST PROCESS

The Tibetan Plateau is the largest center of modern glacial ice and snow coverwith a total area of about 49,200 km2 in low-middle latitude regions. Topography,temperature and precipitation are main factors for the formation of glaciers. Twotypes of modern glaciers, maritime glacier in southeastern plateau and continental

INTRODUCTION 5

glacier in northwestern plateau, are found, which are bounded roughly along theline of Songpan, Dege, Dengqen, Lhari, Gongbo, Gyanda and Comai. There are twocontemporary modern glacial development centers on the plateau, the first, i.e.temperate maritime type glacier, is concentrated in the eastern sector ofNyainqentanglha Mountains, and the second, i.e. cold continental type glacier ispositioned in west Kunlun Mountains. Glacial landforms are widely spread in highmountainous areas, playing a significant role in local landscapes. Permafrost,80-120m thick, with an area of about 150x I04km2

, is continually distributed innorthern and middle part of the plateau, which is a huge frozen island in low andmiddle latitudes (TONG, 1981). Periglacial (freeze-thawing) processes and frigidfreeze weathering extensively exist in vast area of the plateau, which play animportant role in many aspects, such as formation of soils, micro-landforms, andeven in distribution of local vegetation. Verieties of periglacial landforms can beseen elsewhere on the plateau (CUI, 1981). Nivation process dominates in placeswhere permanent or seasonal snow patches are preserved, especially in the zonesnear snow line on the plateau.

1.2.4 UNIQUE FAUNA AND FLORA

Both components of fauna and flora in Tibetan Plateau belong to differentsystems. As concerns the fauna, Zhang Rongzu et al. (1985) has pointed out that thePalaearctic and Centro-Asiatic elements prevail over the plateau, while the Orientalspecies are confined to the southeastern margin of the plateau. In respect to the flora,WU Zhengyi et al. (1981), LI Heng et al. (1983, 1984) and ZHENG Du (1983)maintained that the plateau pertains respectively to the Tibetan Plateau Subkingdomand the Sino-Himalayan Subkingdom of the Holarctic Kingdom, while the lowlandof the southern flanks of the Himalayas belongs to the Indo-Malaysian Subkingdomof the Palaeo-tropical Kingdom. In general, the warm-hygrophilous species ofancient elements with relic species are confined to the southeastern part, which is apresent center of speciation of several groups, while the frigid-xerophilous speciesof young elements occur on the plateau proper with endemic species of their own.The extremely lofty Himalayas in west-east orientation and southern marginallocation serve as an effective barrier between the plateau and Indian subcontinent.They bar practically all tropical and subtropical elements of fauna and flora. Westeast trending Kunlun-Altun-Qilian Mountain ranges are also a barrier between theplateau and Central Asia. However, the barrier action is not so effective as theHimalayas. The Hengduan Mts., consisting of a series of parallel N-S trending highmountain ranges and deep river gorges, facilitate migration and interminglingamong different species of fauna and flora. Due to the great relief and conspicuousaltitudinal belts, as well as being an excellent asylum for fauna and flora duringQuaternary glaciations, this area is called as the richest species center of highmountainous areas on earth.


1.2.5 ALTITUDINAL BELT CONNECTED CLOSELY WITH HORIZONTALZONE

Altitudinal belts occur everywhere in Tibetan Plateau, either on the margin orin the interior of the plateau. Based on basic belt, spectrum-structure, dominant belt,as well as temperature and moisture conditions, two systems of altitudinal belts maybe recognized, i.e. monsoon system, which includes humid and sub-humid types,and continental system, which consists of semiarid, arid and super-arid types(ZHENG and LI 1990,1994; SUN and ZHENG, 1996). On the plateau proper,horizontal zone consists mainly of alpine meadow, alpine steppe and alpine desert,which differ substantially from corresponding one in low altitudes. Therefore, thecombination and interlacement of horizontal zones and altitudinal belts of theplateau reflects unique characteristics of physic-regional differentiation of theplateau itself, which is incomparable with plateau and montane areas in a smallscale. Natural zones of the Tibetan Plateau may be considered as a variety of thecorresponding one outside the plateau, as it has been raised onto an extremely highelevation. Temperature-moisture conditions caused by altitudes and atmosphericcirculation are dominant factors for the formation of the varieties (ZHENG Du et at.,1979, 1981).

1.2.6 LOW DENSITY OF POPULATION WITH WEAK HUMAN IMPACT ONNATURAL ENVIRONMENTS

Limited by physic-geographical conditions, mean density of population inTibetan Plateau is less than 4 person/km2

• Human impact on natural environmentsof the plateau in historical period was much insignificant than those not only inEastern Monsoon Region, but also in Northwest Arid Region. Therefore, regionaldifferentiation of the plateau may be directly recognized from various types ofnatural vegetation, owing to its shorter period of development, limited districts ofhuman activities, less population, poor transportation facilities and lower economicdevelopment level. Human activities in the plateau mainly include extensivestockbreeding and cultivation, which has light effects on environments both inscope and degree. With recent social-economic development and increasing ofpopulation, irrational utilization of renewable natural resources brought about asevere stress on nature, and then caused environmental deterioration rapidly incertain areas (SUN Honglie, 1981; ZHENG Du et at., J988; LI Mingsen, 1996;SUN and ZHENG, 1996).

1.3 Retrospect of Scientific Expeditions

The scientific expeditions to the Tibetan Plateau can be divided into twoperiods in recent history. The first period includes expeditions and surveys on theplateau carried out by a number of geographers, geologists, botanists and explorersbefore second half of the 20th century. After 1950 is the second period. A large

INTRODUCTION 7

number of scientific expeditions, aiming at surveying and assessing naturalenvironments and resources, and at controlling and preventing natural hazards, havebeen organized by the central and local governments of China, as well as theaffiliated departments for scientific research and industrial production.

1.3.1 EXPEDITIONS BEFORE THE 1950'S

A number of geographers and explorers initiated expeditions and surveys intothe plateau begun from late 19th century. They surveyed mapped landforms,gathered quite a lot of data and samples, and reported geographical facts andphenomena of the plateau. They were interested in geology, geography, climate,hydrology, glaciology, animals, plants, as well as native custom and religions of theplateau region. Amongst them, W. Moorcroft, Sven Hedin, H. H. Hayden, H. deTerra, E. Norin, E. Trinkler, F. K. Ward and N.M. Przewalskii, et al. were wellknown scientists and explorers in that period (SUN and ZHENG, 1996). Scientificmaterials collected in that period are of great values for understanding environmentsand nature of the Plateau. Among the mentioned above scientists and explorers, theworks ofSven Hedin and F. K. Ward deserve highly commendation (SUN, 1984)

Sven Hedin had begun his expeditions to the Pamirs, Central Asia, and TibetanPlateau since the 1890's. He traveled to the west, north and south of the TibetanPlateau three times, and published more than 50 articles and monographsconcerning the Tibetan Plateau. The works of "South Tibet" in 9 volumes describedcomprehensively natural phenomena, especially in geological and geographicalfields. According to his surveyed data on elevation of nearly a hundred lakes on theplateau, and 6 transect profiles from south to north in western plateau (78°-92°20'),he concluded some general topographic features of the plateau. He mapped severalmountain ranges to the west and north of the plateau, described initially theGandise-Nyainqentanglha Range and named it as "Trans-Himalayas", and surveyedheadwater areas of the Yarlung Zangbo River in detail.

F. K. Ward visited east Himalayas and "the Gorge Country" in southeasternTibetan Plateau 20 times from 1909 to 1956. His studied areas include theHengduan Mts. in west Sichuan and north Yunnan, south and north flanks of eastHimalayas, southern Tibet, the gorge area at lower reach of the Yarlung Zangbo,watersheds of Zayu River and Yi'ong Zangbo River. He published more than 70articles and monographs relevant to the Tibetan Plateau. He collected a largenumber of plant specimens and demarcated divisions of the plateau flora. Climateon the plateau, geomorphology and hydrology along the "big bend" gorge in lowerreach of the Yarlung Zangbo River, as well as the strong earthquake of Zayu in1950 were dealt with in detail in his articles and monographs, some records areexpensive for studying of the environmental changes in the plateau.

A few Chinese scientists, such as LIU Shen'e, XU Jinzhi and SUN Jianchutraveled to the Tibetan Plateau and made surveys and investigations in the1930s-1940s. Based on data obtained from the Kunlun and Karakorum Mts.,Aksayqin and Kashmir regions, botanist LIU Shen'e published his article "Outline


of phyto-geography in western and northern parts of China" in 1934 and discussedseveral issues of plant geography. Geographer XU Jinzhi established an earliestmeteorological observatory in Lhasa in 1934, and made survey to Nam Co in 1935.His articles, "The Lake of heaven in Tibet "and" Climate of Lhasa is earlierpublications relevant to natural sciences of Tibet written by Chinese scientists.

1.3.2 SCIENTIFIC EXPEDITIONS AFTER THE 1950S

For the sake to accumulating basic information, understanding some basictheories concerning geological evolution, environmental changes corresponded tothe uplift and dynamics of the Tibetan Plateau, and of finding out scientific basesfor exploration and utilization of natural resources, as well as mitigating of naturalcalamities, a number of large scale scientific expeditions and comprehensiveinvestigations to the plateau, sponsored by the Chinese Academy of Sciences (CAS)and other departments of Central Government of China, have been carried out in theTibetan Plateau and its adjacent regions since 1950 (L1U Dongsheng etal., 1981,1990; L1U Dongsheng, I992; SUN Honglie et al.,1986). Which may bedivided into following three stages:

• Scientific expeditions in the 1950's -1960'sMain scientific expeditions carried out during this period are as follows:a) 1951-1953, expedition in geology, geography and agriculture to eastern and

central parts of Tibet;b) 1958-1960, Qinghai-Gansu comprehensive expedition, the CAS;c) 1959-1960, scientific expedition to Mt. Qomolangma district (the first time);d) 1959-1961, comprehensive scientific expedition to investigate of water flow

transferring from south to north in the gorge country of western Sichuan andnorthern Yunnan;

e) 1960-1961, comprehensive expedition to central and southern Tibet;t) 1964, scientific expedition to Mt. Xixabangma district;g) 1966-1968, scientific expedition to Mt. Qomolangma district (the second

time).In the early stage, scientific surveys and expeditions are characterized with

gathering and accumulating basic data and information in various disciplines, andfilling in gaps in some fields of science and technology.

• Comprehensive scientific expeditions in the 1970s-1980sAccording to "the long term program of comprehensive scientific expeditions

to Tibetan Plateau in 1973-1980" of CAS, the Comprehensive ScientificExpedition to Tibetan Plateau, CAS was established in 1973 and a new stage ofintegrated survey to the plateau was then started. Its major tasks are focused oncollecting basic data and information, for investigating some basic theories relevantto formation, evolution and uplift processes and dynamics of the plateau and theirimpacts on environments and human activities, and investigating scientific bases for

INTRODUCTION 9

rational utilization of natural resources and prevention of natural hazards. A numberof comprehensive scientific expeditions were systematically carried out at this stage.They are:a) Integrated scientific expeditions to the Xizang Autonomous Region in

1973-1980;b) Scientific expedition to the Mt. Qomolangma (the third time) in 1975;c) Integrated scientific expeditions to the Hengduan Mountains in 1981-1985;d) Mountaineering and scientific expedition to Mt. Namjagbawa in 1982-1984;e) Integrated scientific expedition to the Karakorum and the Kunlun Mountains

region in 1987-1992;f) Integrated scientific expedition to the Hoh XiI Mountain region in 1989-1990.

Besides the above-mentioned activities, some related institutions of industrialministries and local governments also organized expeditions and surveys to theplateau at this stage. Which include: a) survey on geography and biology inwestern Sichuan and Mt. Gongga district in the 1970s; b) investigation of agronatural resources and studying of agricultural regionalization in Qinghai province in1982-1985; c) scientific expedition to Altun and middle Kunlun Mountains in 1984;d) surveying of land assessment, land use, soils and pasture resources in 1984-1991;and e) survey in middle reaches of the Yarlung Zangbo River for exploitation andplanning design.

Since the International Symposium on the Qinghai-Xizang (Tibetan) Plateauheld in Beijing in 1980, international cooperation and exchanges concerningresearch of the Tibetan Plateau have been promptly developed, resulting in aworldwide "Tibetan Plateau fever". Some large scale surveys and expeditions werejointly carried out as followings: a) Sino-French cooperative survey on theHimalayas in 1980-1982; b) Chinese-British cooperative comprehensive geologicalsurvey along the highway from Golmud to Lhasa in 1985; c) China - USAcooperative survey on natural environments in Mt.Yulong district of northwesternYunnan province in 1985; d) Sino-West Germany scientific expedition to westKunlun Mountain ranges in 1981 and 1985-1989; e) Chinese-Japanese cooperativeexpedition to the west Kunlun Mts. in 1987; f) Sino-French cooperative study onwest Kunlun-Karakorum Mountains in 1989-1990; etc.

• Integrated scientific survey and investigation in the 1990sA project of "the formation, revolution, environmental changes and

ecosystems of the Tibetan Plateau" was approved in 1992 by the Science andTechnology Commission of China, which is one of "the Climbing Projects"-- thestate key project for fundamental research. It led scientific expedition to the TibetanPlateau to a new period. As compared with research work in previous stages, aimedat frontiers of present international development tendency in the research domain,and the weakness of previous regional route investigation, the new projectemphasizes studies of process, quantification, dynamics and mechanism in variousspecial subjects and issues. As concerns approaches, traditional regional routesurveys in field are being correlated with remote sensing, experiments in


laboratories and field stations. In addition, the integrated studies of inter-disciplinesare stressed, and the focuses in study of environments are closely related withglobal change.

Contents of the new project include: 1) Lithospheric structure, evolution anddynamics of the Tibetan Plateau; 2) Environmental changes of the Tibetan Plateauin Late Cenozoic Era; 3) Contemporary climatic variations over the Tibetan Plateauand their influences on environments; 4) Ecosystems of the Tibetan plateau andapproach for their sustainable management; 5) Uplift of the Tibetan plateau and itsimpact on resources, environments and human activities (SUN and ZHENG, 1998).

1.4 Main Progress in Studies of Tibetan Plateau

Some main achievement and progress in studies of the Tibetan Plateauconducted by Chinese scientists in recent decades can be summarized in thefollowing five aspects.

1.4.1 LITHOSPHERIC STRUCTURE, FORMATIOM AND EVOLUTION OFTIBETAN PLATEAU

A regional structure of geological evolution in the whole plateau has beensystematically set up with some well known typical geological profiles across theplateau. Meanwhile, basic features of crust structure and deep crust-mantle structure,and spatial distribution rules of varieties of magmatic zones and terrene zones wereexamined. In the early 1970s, a theoretical model for illustrating tectonic evolutionof the Tibetan Plateau by use of plate theory was firstly proposed by Chinesegeologist (Chang Chengfa et al., 1973). From which several terrenes put together indifferent geological times in the plateau was initially separated from the ancientGandwana Continent on south. Since then this model has been revised anddeveloped based on new discoveries and thus deepened studies. Several conceptionsand models in formation and evolution of the plateau and its uplifting dynamic,such as " lamination-heat dynamic model" (Pan Yusheng et al., 1990; DengWanming, 1998) have been suggested properly. Plate tectonics of the plateau havethe following characteristics: firstly, prossess huge thickness with multi-layer cruststructure interlaced with high and low speed layers (Li Tingdong et al., 1995);secondly, consist of six terrenes which linked by five suture zones; thirdly, the eastTethys Ocean can be spatially divided into three parts coordinated with younger inage successively from north to south, which indicated sequences of plate tectonicmovement, following break of Gandwana Continent, the Asian continent expandedsouthward successively ( Pan Yusheng, et al., 1990 ); fourthly, huge magmaticzones in ages, spatial distribution and lithological characters are closely and directlyrelated with plate subdution and collision ( Deng Wanming, 1998 ); fifthly, crust inthe plateau had been suffered large scale shortening, thickening and thrusting(Wang Qingmin and Zhang Qingsong, 1993); finally, forced by Indian Plate andblocked by Eurasian Plate, crust of the plateau is under compensation, and now is

INTRODUCTION 11

still keeping its active motion ( Zhang Qingsong et at., 1991; Zhang Qingsong andLi Bingyuan, 1991; Zhong Dalai et al., 1996).

1.4.2 UPLIFTING PROCESS AND ENVIRONMENTAL CHANGES

Since the collision between Indian and Eurasian plates in Eocene age, theplateau had been uplifted unevenly in several periods with different speed. Theplateau might witness three periods of rising and two times of peneplanation (ShiYafeng et aI., 1998, 1999). A vast penenplain, formed before 3.4 Ma on the plateau,was about 1000 m high with gentle relief and sub-tropic montane forest or foreststeppe features. Started from 3.4 Ma (from end of Pliocene to early Pleistocene),violent rising of the plateau as a whole resulted in dissection of the penenplainsurface and a large number of faulting basins and valleys formed. Since then a totalamplitude of about 3500 m was uplifted, and then plateau monsoon in relativethickness occurred (Tang Maochang et al., 1995). Around 600 ka BP, when theplateau surface might rise up to 3000-3500 m high and mountain ranges exceed4000 m asl, such critical elevation could cause abrupt climatic change on theplateau. This was marked with strengthening of winter plateau monsoon andweakening of summer plateau monsoon. Temperature decrease caused by upliftingin this period coincided to global abrupt cooling originated by turn of orbital motionin middle Pleistocene, resulted in the whole plateau entered into the creosphere, andthen the largest glaciation appeared, but an united ice sheet never existed on theplateau. Due to coldness and dryness, interior river and lake systems expanded,large lakes were separated into small isolated ones, and then great number ofvarious salts deposited in saline or salt lakes. Meanwhile, wind blowing sandy loessdeposited in large scale on northern slopes of the Kunlun Mountains (SHI Yafeng etal., 1998; ZHANG Qingsong and LI Bingyuan, 1999).

Around 150 ka BP, one more intensive neo-tectonic movement occurredresulted in further uplift and violent volcanic eruptions which were mainlydistributed in northern plateau. Where climate became extremely dry and cold andthen the" Cold and Arid Core" formed. With 350,000 km2 of glacial ice cover inthe Last Glacial Maximum period (18 ka BP), climatic variation was extremelyradical since 150 ka BP. When most part of the plateau prevailed montane desertand forests retreated towards eastern and southern peripheries. Climatic changes inthe Tibetan Plateau revealed by ice cores, lake cores and loess profiles have its ownregionality and speciality in global changes. They are characterized by roughvariation, very warm in warm periods, fast entry into ice age and slow warmingprocess.

1.4.3 ECOSYSTEM AND HUMAN ADAPTED TO ENVIRONMENTS OF THEPLATEAU

The uplifted plateau not only preserved some ancient biological species, butalso reproduced a lot of new species and genus. Up to now, it has been known that


there are 1047 species of vertebrate, which include 206 species of mammals and678 species of birds in the plateau. Flora components are rich and complicated, inwhich species of higher plant are more then 12,000. Ferns, bare and sheeted seedbearing plants are all account for more then 40% in species. It has been confirmedthat biota did not become extinct in Quaternary ice ages. The rising plateau causedsome plants to specify to be new species. The Hengduan Mountain region is one ofthe distributional center for diversified plants.

The Tibetan Plateau is a special biogeochemical area with low content ofoxygen. High mountain illness may influence health of immigrants, tourists, locallabors, and even imported livestock, which is an obstructer for development of theplateau. Investigation shows that geochemical anomalies influence significantly theformation of some of high mountain illness. Distribution of Keshan c1isease andKaschin-Beck disease in the plateau is closely related with bio-geochemcal features.Based on comparative observations in physiological differentiation of residentsbetween lowland and highland, adaptation of physiological index of immigrants inthe plateau has been discussed in detail.

1.4.4 NATURAL ENVIRONMENTS AND REGIONALIZATION

Tibetan Plateau has its own unique natural environments and spatialdifferentiation rules. It has been studied in detail on types, characteristics,distribution, formation and evolution in terms of each natural element. Based onbasic belt, spectrum-structure, dominant belt, and temperature-moisture regimes,two systems of altitudinal belts with nine types in various mountain ranges of theplateau have been recognized (ZHENG and LI 1990,1994; SUN and ZHENG,1996). Distribution model of spectrum-structure in altituainal belts on the plateaureflects huge mountainous effect, which relates with heat source of the plateau.Caused by geomorphic structure and atmospheric circulation, it is featured bywarm-humid climate in southeast and becomes cold-arid northwestwards,correspondently, appearing in zonal changes of mountainous forest-alpine meadowalpine/montane steppe-alpine/montane desert. According to the features of physicalregional differentiation of the plateau surface, some ten of natural zones, located inplateau temperate and plateau sub-cold regions respectively, with differentcharacters have been identified (ZHENG and L1, 1994). In addition, some uniquephenomena and features on the plateau, such as moisture transit, dry valleys, highcold scrubs and meadow zone, and the high cold-arid core, have been investigatedin detail.

1.4.5 NATURAL RESOURCES, HAZARDS AND REGIONAL DEVELOPMENT

To meet demands for regional development, investigations and surveys havebeen carried out on types, characters and distribution of renewable natural resources,and some principles and index for adjustment of land use in agriculture, foresty andhusbandry on the plateau were suggested. In addition, maps of land type, land

INTRODUCTION 13

resource, and land use in some regions, as well as a series of maps of agriculturenatural resources in key areas have been compiled. It has been recognized thatgrassland on the plateau has varieties of types, with high quality and low productionof grass, and unbalanced distribution, which limited the raise of carrying capacity oflivestock. Farmland is concentrated in plateau temperate zones with low potential inexpanding cultivation as limited by natural conditions. Forest is relatively rich insoutheastern plateau, arrangement for forest industries, which are emphasized onintegrated use and renewal, must be put into practice. Vast potential in waterpower,geo-thermal energy, salt and mineral deposits, as well as tourism resources in theplateau have been adjusted. They can play very important rules in regionaldevelopment.

To predicate and prevent disasters, distribution and classification maps oflandslide and debris flows at different scales of the plateau have been compiledbased on detailed investigations and observations in key areas. Research work hasplaid important roles in preventing different degrees of land degradation andecological deterioration, as well as planning and establishing of natural reserves.

Agricultural regionalisation has been done. According to the regionalization,the plateau is divided into three regions, Le. (l) agriculture-forestry region insoutheastern plateau; (2) agriculture-animal husbandry region in northeasternQinghai and southern Tibet; and (3) pure animal husbandry region in central andnorthwestern plateau. Planning for sustainable development of the plateau has beencarried out. According to the existing basis and advantages of natural resources ofthe plateau, regional economy of the plateau must be set up on the basis ofagriculture, and then efforts should be made to strengthen reconstruction of energyand transportation, and develop food, leather processing, mining and touristindustries. Planning work has been carried out in detail in middle reaches of theYarlung Zangbo River and Qaidam Basin in recent years.

1.5 Framework of the Book

A series of monographs and several thousands of articles have been publishedbased on the discussed above expedition, surveys and research projects. Authors ofthis book participated in studies on various issues of the Tibetan Plateau. From theviewpoint of mountain geo-ecology and sustainable development, this book onlycontains a part of the major achievements obtained from those integrated researchprojects on the Tibetan Plateau, especially in the last two decades. It represents ourcurrent knowledge on natural processes and human activities in this uniquemountainous region. It covers a fundamental issue on mountain geo-ecology andsustainable development of the plateau.

The present book consists of three parts in 17 chapters. Following anintroduction and overview to the study area, the first part, contained three chapters,deals with evolution and differentiation of physical environments, uplifting andenvironmental changes, three dimensional differentiation of natural zonation on theplateau, as well as human dimension of mountain development of the plateau.


Intensive uplift of the plateau in late Cenozoic Era, especially in Quaternaryage, brought about tremendous environmental changes. A series of issues includingtectonic evolution and uplifting process, the Quaternary glaciations, lake evolution,climatic and environmental changes in Holocene age are dealt with in Chapter 2.Three-dimensional differentiation of natural zonation includes aspects such ascomparative studies on altitudinal belts, unique geo-ecological phenomena, physicalregional differentiation, and eco-geographical regional system of the TibetanPlateau (see Chapter 3). The Plateau is the home of Tibetan people, issues relatedwith resources, population, present economic and social development, as well ascultural background of the plateau are described in Chapter 4.

The second part consists of seven chapters, focusing respectively on specialissues of environments, ecosystems and development of the Tibetan Plateau. Thepast, present and future climate of the plateau are dealt with in Chapter 5. In which,uplifting and plateau monsoon system, climate change in historical times, heat andcold sources of the plateau, moisture transportation pathways and geo-ecologicaleffects, as well as the sensitive areas of climate change are discussed. Chapter 6describes a special issue of permafrost. Its status, variation and impacts onenvironments are presented with issues related to periglacial processes andlandforms, permafrost and geo-ecological effects, permafrost and global change.Chapter 7 deals with biota and biocoenose diversity of the plateau, which containscomposition and features of the biota, characteristics and main types of thebiocoenose, and marginal effects in eco-geography of the plateau.

On Tibetan Plateau, there exist some particular environmental conditions /stresses which influence human health, such as reduced atmospheric oxygenpressure, the abnormal geo-chemical features, as well as the especial landscape andanimal reservoir (Marmota himalayana). They may cause the occurrence of someendemic diseases, which is a potential threat to human health. Chapter 8 elaboratessuch special geo-ecological problems as human health related with environmentalfactors/stresses on the plateau. Vast land exploration in low level is one of thecharacteristics in the plateau region. Chapter 9 deals with features of land use andagricultural development of the region, focussing on characteristics and strategies ofland-use related to farmland and crop production, grazing land and livestockhusbandry development, forest and horticulture land, as well as spatial distributionof agricultural land-use.

Mountain hazards and environmental issues of the plateau, which restrictedmountain development, have been given great attention by geographers and localgovernments recently. A number of mountain hazards such as earthquakes,landslides and debris flows, heavy snow accumulation, and land desertification andland degradation as well as countermeasures are discussed in Chapter 10. Natureconservation is an important issue for development of the plateau. Main types anddistribution of nature reserves on the plateau are described in Chapter 11. In which,a preliminary assessment of nature reserve in Mt. Qomolangma district, and someparadises for rare animals and plants are introduced. Regional socio-economicsustainable development, including the regional specialty and issues, sustainable

INTRODUCTION 15

strategic objectives and policies, industrial restructuring orientation, fiscal concernwith central government, as well as index of regional sustainable development ofthe plateau are dealt with in Chapter 12.

The third part covers six chapters, consisting of several case studies, such asMt. Namjabarwa region in southeastern part of the plateau, dry valleys in HengduanMts. Region in eastern plateau, high-cold scrubs and meadow zone in middle andeastern part of the plateau, Qiangtang Plateau in the interior of the plateau, KunlunMts. Region at northern periphery of the plateau, are selected as representatives ofvarious types of mountainous regions in the plateau.

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INTRODUCTION 17

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CHAPTER 2 UPLIFT AND ENVIRONMENTAL CHANGES OFTHE TIBETAN PLATEAU

ZHANG Qingsong

Uplift and formation of Tibetan Plateau was an important event in Asia in lateCenozoic Era, which has not only changed natural environment of the plateau itself,but also exerted a tremendous effect upon its surrounding areas. Uplift of theplateau created Asian monsoons (Manabe and Terpstra, 1974), which enrichedMonsoon Asia with high unit yields of biomass, where occupying one tenth of landon earth, sustaining more than half population of the world. However, extremelyhigh altitudes, steep mountain slopes, frequent tectonic movements and changeableclimate also promote varieties of disasters, such as earthquakes, landslides, debrisand mud flows, floods and frosts etc.

According to the available data obtained by the Integrated ScientificExpedition to the Tibetan Plateau, Chinese Academy of Sciences since 1964 (SHIand LIU, 1964; XU R, 1972; LI J J et al., 1979; ZHANG Q S et al., 1981; LI J J etaI., 1981; LI B Y et al., 1983; ZHANG Q S et al., 1991; LI J J et al., 1995; DING Let al., 1995; ZHONG 0 L et al., 1996; SHI, LI and LI (eds.), 1998; SHI Y F et al.,1999), some main conclusions are summarized as follows:

1) The plateau might be twice peneplained after collision of two continents,India and Eurasia in 40 Ma BP and the second episode of Himalayan movement in20 Ma BP. Throughout most of Pliocene times (circa 5.3 Ma-2.5 Ma BP), thesurface of the plateau kept in an elevation of about 1,000m. When the Hipparionfauna existed in Tibet and migrated across the plateau from North China to SouthAsia, and subtropical vegetation and Karst landforms were well developed in theplateau.

2) Violent uplift occurred by the end of the Pliocene and Beginning of thePleistocene. Which resulted in an unconformity appeared in between of Neogenelacustrine deposits and early Pleistocene conglomerates on the northern slope ofKunlun and Qilian Mountains, southern slope of Himalayas, as well as in theplateau. The early Pleistocene conglomerates from hundreds to 3,000 m in thickness,indicating the existence of high relief between these mountain ranges and forelands.

3) Uplift periodically appeared in three stages, i.e. 1.8-1.6 Ma, 1.0-0.8 Ma, and150 ka BP in Quaternary. Uplifting amplitude in total is about 3,500-4,000 m.Uplift in the east end of the Himalayas was relative slow before 3.0 Ma BP and thenaccelerated in 3.0 Ma-1.0 Ma BP from 1-2 mm/yr. tolO-30 mm/yr. The average

19

'ZHENG Du, ZHANG Qingsong and WU Shaohong (eds.). Mountain Geoecology and Sustainable Development o/theTibetan Plateau, 19-45.©2000 Kluwer Academic Publishers.

20 ZHANGQ. S.

uplift speed of the whole plateau at present time is 5.8 mm / yr.However, some geologists and geophysicists found it is difficult to approve

them and they cannot understand what tectonic mechanism is in forcing the violentuplift since the end of Pliocene-early Pleistocene. Some other geologists andgeophysicists recognized that the plateau might reach to the highest elevation 7 Ma8 Ma BP (Harrison et a!., 1992) or 14 Ma BP (Coleman et aI., 1993; Molnar et al.,1993), since then the plateau was collapsed and reduced its height. Molnar andEngland (1990) disagree that large quantity of data related to plant and animalfossils, pollen, and so on, which have been used in examining the uplift of theplateau, are valuable. Ruddiman et al. (1989) believe that based on pollen data oflate Cenozoic Era, uplifting amplitude of the plateau must be more than 2,000msince 10 Ma-5 Ma BP, because vegetation in surroundings of the plateau, includingSouth China, South Asia and India, did not experience any change in the coldecosystems 10 Ma-5 Ma BP. The best explanation to the formation of coldecosystem vegetation in the plateau is the violent uplift of the whole plateau since 5Ma BP. Some geologists pay more attention to newly formed graben about 8 Ma BPin north-south direction originated by east-west extension, like Yangbajing graben,which is considered to be a best example to explain geo-mechanic process in lateCenozoic Era (PAN et ai., 1992; Harrison et al., 1992). In fact, the north-south andeast-west direction grabens and fault basins existed in many places and in differentgeological ages since 40 Ma BP, originated by intra-continental subduction (LI J Jet aI., 1981; DENG W M, 1998). As mentioned in section I of this chapter,existence of grabens and fault basins coincides with tectonic evolution of theplateau, and does not only mean the beginning of collapse of the plateau.Furthermore, the present uplift situation also does not approve the conception of thecollapse. According to repeated measurement data of precise leveling network inthe 1960s and the 1980s along the main highways with a total distance of 8,000 kmin Tibetan Plateau, an average uplift speed is examined to be 5.8mm / yr., lower innorth and higher in south, the highest being more than 10mm/yr. in the Himalayas(ZHANG Q Set. al., 1991). This is supported by studies of FT works on igneousrocks both in Mt. Nangaparpat and Mt. Nangapawa regions (Zeitler, 1982; DING Let al., 1995; ZHONG D L et aI., 1996). All these mentioned above show that upliftprocess of the Tibetan Plateau and its mechanism need to be further studied.

2.1 Tectonic Evolution of the Tibetan Plateau

2.1.1 FRAME OF TECTONIC EVOLUTION

Geological history of Tibetan Plateau actually was an evolution process fromocean (Tethys) to land. According to the recent studies (PAN Y S, 1990; DENG WM, 1998; SHI Y F et ai, 1998), there are five ophiolite zones existed in the plateausubsequently from north to south. They are of the north Qilian suture zone, theKunlun suture zone, the Hongshan-Jinsha River suture zone, the Bangong Co- NuRiver suture zone and the Indus-Yalung Zangbo suture zone. Which represent

UPLIFT AND ENVIRONMENTAL CHANGES 21

boundaries between the six terrenes in different times. All these five ophiolite zonesare the remains of ancient crusts of palaeo-ocean basins in different geologicaltimes (Figure 2-1).

•New Delhi

• •Kathmandu

~~. s,:lqQ

Iz0......_'--40.....~km qtt>

Figure 2-1 Tectonic frame and present motion of terrains in the Tibetan Plateau(after LI T D et al., 1995 and DING G Y et aI., 1989 and revised)

Legend: I.Late Pliocene-early-Pleistocene Molasse deposits;2. Motion speed of plate and terrain against Siberian plate (mm/a);3. Mean press rate (mm/a);4. Mean expansion rate (mm/a);5. Mean strike-slip rate (mm/a)

The north Kunlun terrain was a margin of Eurasian continent in the earlyPaleozoic age, middle Kunlun terrain was a double deformed zone which sufferedCaridonia and Varician-Indus-China movements; Tashikolgan-Tianshuihai terrainwas a palaeo-Tethys zone developed from the basis of early Paleozoic arc basin;Karakorum-Qiantang terrain was a part of palaeo-Gandwana continent whichseparated from it in Jurassic time; Gangdise terrain was a fore arc basin and islandsystem of new Tethys; and Himalayas terrain was fore thrusting and faulting zoneof Indian continent. All of these suture zones and terrains between them aresubsequently newin age from north to south (PAN Y S, 1990).

The New Tethys began to appear by the end of Permian Period, and formed areal one by the end of Triassic. By the early Jurassic period, northern ocean crustsubducted northward under the Asian continent resulted by spreading of the oceanridge and enhanced formation of split systems on the fore and back arcs in the

22 ZHANGQ.S.

Shiquanhe-Lhasa terrain, some of them spread to be comparatively big ones, suchas the back arc basins at Bangong Co, Dongqiao, Dingqing, etc. Developing periodof these basins were relatively short, and all closed at the late Jurassic time.

The Neo-Tethys accelerated subduction in mid-Cretaceous period, and closedby the mid-Eocene time when Indian subcontinent collided and put together withAsian continent, resulted in the disappearance of the Neo-Tethys from Tibet. Andthen the Tibetan Plateau came into a new stage of terrestrial evolution, stage of theHimalayan movement. After collision between Indian and Eurasian plates by thetime of 40 Ma BP (mid-Eocene), the Indian plate on south of Yarlung Zangbosuture zone has not stopped but continued its northward subduction, in the form ofintracontinental subduction, to the Gangdise Mountains (DENG W M, 1992, 1995,1998).

2.1.2 HIMALAYAN MOVEMENT

Himalayan movement is defined as a tectonic movement in Cenozoic Era,which is characterized by mountain building, faulting and magmatic activities. Aspointed by Professor Huang Jiqing (1987), the most important episodes ofHimalayan movement are of in the following three stages: (I) between early andlate Eocene periods marked by Gangdise Molasse deposition; (2) between middleNeocene and Pliocene periods marked by Molasse deposition of lower Siwalikgroup; and (3) between late Pliocene and early Pleistocene periods marked by mainmolasse (Boulder Conglomerate) deposition of upper Siwalik group.

First stage of Himalayan movement occurred in Eocene age (40 Ma BP). Thecollision of the Indian Plate with Eurasian Plate, resulted in the building ofGangdise Mountains and rising of Tibet terrain, which marked by the disappearanceof neo-Tethys and Molasse deposition at front of Gangdise Mountains. Meanwhile,Molasse deposits in reddish color in Oligocene age formed at southern and northernsides of Qilian Mountains, which indicated an intensive rise of the Qilian after thisepisode.

Second stage of Himalayan movement occurred in mid-Neogene age (20 MaBP), was a main episode of the Himalayan mountain building (Gansser, 1977,1981). The latest metamorphism, a large scale faulting and igneous activities alloccurred in the Himalayan terrain in this period. The main central thrust (MCT) andmain nappe thrust (MNT) between high and low Himalayas and the main boundarythrust (MBT) between the low Himalayas and Siwalik hills, as well as many othersouthward nappes were formed in that stage. Meanwhile, Molasse like deposits oflower Siwalik group (Kamril and Chingji strata) which filled in to the foredepressions on the south of the Himalayas, and synorogenic tourmaline-granites 10Ma-20 Ma in age accompanied within the thrusts. All these features indicate thatafter mid-Neogene the south slope of the Himalayas became northward subductionzone of the Indian terrain by means of "non-subsequent intra-continental subductionzone" (DENG W M, 1995, 1998). By mid-Neogene time, a system of faulted basins,which was resulted by east-west expansion like Jilong and Dati Basins, or north-


south expansion like Zhada Basin, were formed in north of the Himalayas. In thesebasins Molasse like deposits were fluvial and lacustrine sediments filled in middlelate Neogene times. Meanwhile, volcanic eruption occurred in forming of severalhundred meters thick of andicite and volcanic ash in Namlin Basin and Basu Basinin Gangdise range. While in Qiangtang Plateau alkalic volcanic rocks were formed10 Ma-40 Ma BP, which are similar to that in East Africa Rift (DENG W M, 1995,1998).

Third stage of Himalayan movement began from late Pliocene (3.4 Ma). Sincethen the Tibetan Plateau entered in a new stage of violent uplift periodically in greatamplitudes. Due to its great significance in forming of the plateau itself, the thirdstage is independently set out in name of " Qingzang Movement " (L1 J J et al.,1992, 1996), which is coincided with geological and geomorphologic evolution ofthe plateau and the concept of Neotectonic movement (ZHANG Q S, 1983). Alsothis stage was the greatest event in affecting modern tectonic deformation andgeomorphologic development in China and Asia. Intraplate movement in Chinacontinuously followed the basic structural frame conducted since the end ofPliocene period (DING G Y, 1989). Neotectonic movement in Quaternary periodsviolently occurred at the frontiers of the plateau. The main boundary thrust (MBT)at the southern foot of the Himalayas, for instance, thrusts southward in low angle,overlaying on Holocene deposits, reaches 20-30 km of thrusting displacement(Gansser, 1964). Faulting and folding frequently appear in the middle and lowerSiwalik group. Moreover the fore depressions were shifted southward to theGangise River valley, in which filled up typical Molasse deposits, the upper Siwalikgroup, in huge thickness (Gansser, 1964). All these indicate the Indian terrainsubducted strongly into the Himalayan terrain along BMT in Quaternary period andforced Himalayas uplift in great amplitudes. Inside the Himalayas and its northslopes, a system of expansion fault basins in north-south direction, such as TakholeMusdam Basin in Nepal, Pulan Basin, Jilong Basin, Dati Basin and Dingre Basin insouthern Tibet, newly formed, or further developed from their former bases. TheWacha-Bandi Basin in Tashkolgan in west Karakorum Mountains and theAyakkumkule Basin in middle Kunlun Mountains, as well as the Lumpola Basin inHoh Xii, are all filled up by Molasse deposits in hundreds of meters thick andstrongly folded and faulted. Shortage of upper crust in the Ayakkumkule Basin isestimated to be about 60 km in late Pliocene-early Pleistocene period (WANG andZHANG, 1994).

Molasse deposition zone of 1-3 km thick distributed at the northern foot of theplateau stretches from west Kunlun, Altun Tag to the Qilian Mountains. Theirfeatures are almost the same to that of upper Siwalik group at the south of theHimalayas, catalogued in fanglomerate resulted by fast rise of the frontiermountains of the plateau. The shortage of upper crust in north of Qilian range isestimated to be 6.4 km in last 2.5 Ma (CHEN J, 1996).

2.2 Uplift Processes of the Tibetan Plateau

24 ZHANGQ. S.

2.2.1 EARLY TERTIARY PLANATION SURFACE AFTER COLLISION

After collision between Indian plate and Eurasian plate along the YarlungZangbo suture zone in late Eocene, the Kailas Molasse deposits formed on southslope of the Gangdise ranges. Fossil plants of Eucalyptus. Fagus, Myrica,etc. werediscovered from the formation, which indicate that prevailing climate was warmand humid and altitude was very low. Pollen data obtained from the Lumpola Basinin north Tibet show that Sequoia and Taxodium etc. were rich in the early Tertiarydeposits, and in Qaidam Basin and Gansu Corridor, Magnolia, Kingo, andProteacea were found in Oligocene strata. All these species grow in relativelywarm and low altitude areas representing a tropical environment (LI J J et at., 1995).Figure 2-2 shows the sites in and out the Tibetan Plateau, where Giant Rhinocerosfossils and early Tertiary tropical vegetation are found. Giant Rhinoceros was thelargest terrestrial animal in Cenozoic Era. Numerous remains of this animal werefound in the marginal areas of the plateau, like Pakistan, and Chinese provinces ofYunan, Gansu and Xinjiang. As Grabau (1927) pointed out, " this wide distributionin Asia of an animal of this size and bulk, clearly indicates that during its existencebarriers between these different regions were wanfing". During the period ofexistence of Giant Rhinoceros. planation surface might be well developed in awarm climate with tropical vegetation.

o Giant Rhinocero.~

• Tropical vegetation

Figure 2-2 Sketch map showing distribution of Giant Rhinoceros and tropical vegetation inEurasia in Eocene period (after LI, J.J et aI., 1995)

UPLIFT AND ENVIRONMENTAL CHANGES

2.2.2 RISE OF HIMALAYAS AND FORMATION OF MAIN PLANAnONSURFACE IN NEOGENE

25

Molasse like deposits, the Siwaliks began to accumulate following the rise ofHimalayas. The Siwaliks, however, are different from the Murree group in earlyMiocene age, in which the iron-bearing Purana formation was originated fromIndian Shield to south (Wadia, 1962). And the Siwaliks are derived solely from therising Himalayas. However, the d Boulder Conglomerate did not exist until earlyPleistocene, and the Neogene sediments are composed mainly of clay and clayeysandstone. Sediments in Utter Pradesh of middle Siwalik were formed in sluggishstreams and the main load seems to have a long history of sorting, which indicatinga long period of tectonic stability (Sahni et al., 1980).

Figure 2-3 shows grain size analyses of Siwalik in Himachal Pradesh, India(Johnson, 1972) and Baiyanghe group and Shulehe group in Gansu Corridor, China(LI J J et al., 1995). The two graphs are quite similar, a lot of fluvial depositionalcycles with dominate content of clay (accounting 61 % of the Baiyanghe group and45 % of the Shule group) existed in both sections of Siwalik and Yumen,representing a gentle relief on the margin and slow subsidence basins at theforelands in which meandering rivers well developed. The main planation surface iswell preserved and normally in the forms of low and gentle sloping ridges or tabularuplands (Figure 2-4). On the east margin of the plateau, dissected remnants of thesurface becomes high tableland interflives, due to deep incision of large rivers.

('SiwolikGroup I

~~;~I~:,ral'

N~ Q1·2 B1iy1ngh, Group,_ Shul,he Group_\ Yum,na ~ NI I N2 >.Iconglomera,e

'@ i- co I .~ Ql

1 L. i5 ~ a.!l 20 I ;:J

G

Cycle number

Legend • ail11nd cl.y 0 tine "nd II grovel .nd buuld"

A. H.riulyongcr, H.P., Indio (.ft" Johnson,C.D.,1912) I B. Yurnen. Gansu, China (.fter Li, J.J.,cl.l, 1995)

Figure2-3 Comparison of fluvial depositional cycles of late Cenozoic Era on the southern andnorthern sides of the Tibetan Plateau (after Johnson C.O., 1972 (A) and LI J.J et ai, 1981(8))

Reasonably, the main surface was formed in tropical or subtropical warm andhumid climate. Hipparion fauna contained lacustrine and fluvial deposits, ascorrespondent sediments adjacent to the main surface, distribute in and surrounding

26 ZHANGQ. S.

the plateau (ZHANG Q S et aI., 1981; JI H X et al., 1981). Hipparion fauna inMiocene and Pliocene age have been discovered in many places in China and SouthAsia (11 H.X.et aI., 1981; GU Z G et aI., 1995) (Figure 2-5). Varieties of pollen,Cedar, Palm and Oak etc., which often exist in subtropical zone, were found inPliocene strata in many places in Tibet, Gansu and Yunan. Reports have revealedthat FT dating ages in 8-10 Ma of calcite crystals collected from ancient karst cavesin the plateau, which are similar to that in present South China (CUI Zh J et aI.,1996). In addition, Hipparion fauna unearthed in the karst depression at southernGansu, has a paleomagnetic age of6.1 Ma-5.3 Ma BP (LI J J et aI., 1995). All thesedata indicate that the main planation surface was widely developed in MiocenePliocene times. Hipparion fauna could migrate freely over the whole Asia withoutbarriers on the Tibetan Plateau before 5.3Ma. Elevation in Tibetan region at thattime might be no more than 1,000 m asl (LI J Jet aI., 1979).

Figure 2-4 Main planation surface is widely distributed and well preserved in the QiangtangPlateau in the north of Tibetan Plateau. This photo, taken near North Heishi Lake on south 0

west Kunlun Mountains, shows a flat plateau surface with tabular hills overlaid by hundredmeters of basalt. (Photo by Li Bingyuan, 1987)

2.2.3 VIOLENT UPLIFT OF TIBETAN PLATEAU SINCE 3.4 MA BP

As mentioned before, the Xiyue and Yumen conglomerate on the northernslopes of Kunlun and Qilian Mountains, and the Boulder Conglomerate on thesouth of Himalayas, in early Pleistocene age, are of indicators showing rapid upliftof the Himalayas and Tibetan Plateau. This neo-tectonic event, according to resentstudies, is named as " Qingzang Movement", which is divided into three (A, B, C)episodes, occurred 3.4 Ma, 2.48 Ma and 1.8 Ma BP respectively (LI J J et aI., 1995).


The Yangtze, Yellow, and other big rivers began to form systematically followedthe intense uplift of the plateau. After the" Qingzang Movement ", the plateau hadstill being uplifted, resulted in fluvial incision and formation of riverine terraces.Lanzhou area, as a key research area, has been studied, where some seven terracesof the Yellow River in ages of 1.6 Ma, 1.5 Ma, 1.2 Ma, 0.6 Ma, 150 ka, 50 ka and10 ka BP respectively are reported (LI J J et ai, 1996; LI J J et ai, 1995). It shouldbe pointed out that the ages of 2.48 Ma (Qingzang Movement B), 1.6 Ma, 1.2 Maand 150 ka may be more important in coupling climatic and environmental changesin plateau itself and in China and Asia. Some 2,000 m in height, the so-called" halfmountain" (Ruddiman, 1989), as the first critical altitude, might be reached at 2.48Ma-l.6 Ma BP. When the Asian Monsoon was induced and the loess deposition inNorth China subsequently followed by. When the plateau entered in the cryosphere,which was estimated on elevation of 3,500 m, the second critical altitude, by thetime of 1.2 Ma-0.8 Ma BP, climate and environment in and out of the plateauchanged greatly, as its huge impacts both from topography and thermal anddynamic motion of the plateau. The third critical altitude about 4,000 m high of theplateau might be reached by the time of 150 ka BP, when the plateau, especially itsinterior and northwestern part, became extremely cold and dry and to be " the coldand dried core of Asia"(ZHENG D (ed.), 1999). All these show that a couplingmechanism between tectonic events and climatic changes may exist in Asia inQuaternary age. Doubtlessly, without intensive uplift of the plateau periodicallysince early Pleistocene, the tripartite division of major landforms in China could notbe formed, the Asian Monsoon system could not so strongly exist, and the loess inhuge thickness could not be deposited in North China.

o Hipparioll fauna

Figure 2-5, Sketch distribution of Hipparion fauna in Eurasia in Miocene-Pliocene ages

28 ZHANGQ. S.

2.3 Quaternary Glacial Evolution of the Tibetan Plateau

2.3.1 DISTRIBUTION OF QUATERNARY GLACIERS

Although the Tibetan Plateau is the highest plateau on earth, averaging up tomore than 4,000 m, Quaternary glacial relics occurred only in extremely highmountains and their surroundings. Furthermore, precipitation was a decisive factorfor the glacial development. Figure 2-6 outlines distribution pattern of Quaternaryglaciers on the plateau. In terms of high mountain locations and different climaticcondition on the plateau, some Quaternary glacial regions can be classified asfollows:

.ancient 'glacier _modern glacier

~IIII

Figure 2-6 Distribution of Quaternary and modern glaciers on the Tibetan Plateau(after LI J J e/ ai, 1995)

KARAKORUM-KUNLUN REGION

Karakorum-Kunlun Region is located at southwestern part of Tibet whereconcentrated most modern glaciers on the plateau. Three stages of glaciations havebeen recognized in this area (Figure 2-7). Amongst them, the most extensiveglaciation appeared in the middle Pleistocene. At that time large glaciers, 30-50 kmin length, formed on the southern slopes of the west Kunlun Mts. ending to thenorth shore of Guozha Co Lake (Figure 2-8) (ZHENG B X et al., 1991).

Glacial development in southwestern part of the Tibetan Plateau is mainlycontrolled by Mediterranean type climate, in which precipitation, e.g. snowfall,prevailed in the winter season and mainly sources from the Arabian Sea (LI J J etaI., 1995).


Figure 2-7 Three stages of Quaternary glaciations can be clearly distinguished atthe west of Mt. Gongule, the highest peak of the west Kunlun Mountains, namelKlayayik (last), Kalakule (penultim) and Subashi (last but two) glaciation. Thisphoto is taken near the Kalakule Lake (3600 m asl) facing to the northeast toMt.Gongule (photo by ZHANG Qingsong, 1989)

29

Figure 2-8 Distribution of Quatermuy glaciers in the west Kunlun Mountains(after ZHENG B X, 1991)

30 ZHANGQ.S.

HIMALAYAS-NIANQINGTANGLHA REGION

Four glaciations in Pleistocene ages were suggested by Shi Yafeng and ZhengBenxing (1968) which are: the Xixiabangma glaciation in early Pleistocene, theNieniexiongla glaciation in middle Pleistocene, and the two stages of Qomolangmaglaciations in late Pleistocene (Figure 2-9) (SHI and ZHENG, 1968). Trellis andvalley glaciers are dominant types in the Mt. Qomolangma area. Glacial extents inPleistocene therefore are limited.

The Nianqingtanglha Mountain was a center of glacial development in TibetanPlateau. Although modem glaciers are limited in scales there, extent of the glaciersof middle Pleistocene age was approximately 10 times than that experienced today.In Pomi County, for instance, glaciers of middle Pleistocene age, as a trellis glaciertype, were up to 100 km in length. Three stages of glaciations can be recognized onthe southern slope ofthe western Nianqingtanggula Mts. near Yangbajing.

The Himalayas-Nianqingtanglha region is climatically controlled by the southAsia monsoon. In particular, humid current brings abundant precipitation into thisarea from the Bay of Bengal through the lower reach the of Yarlung Zangbo Rivervalley. It can be deduced that precipitation was more advantageous in the middlePleistocene for the development of glaciers.

Figure 2-9 Sketch map of Quaternary glaciers in Mt.Qomolangma area(after SHI and ZHENG, 1968)

HENGDUAN-BAYAN HAR REGION

Located in the eastern part of the Tibetan Plateau, the Hengduan Mountainsand Bayan Har Mountains are influenced climatically by both of southeast and

UPLIFT AND ENVIRONMENTAL CHANGES 3\

southwest monsoon. Against a few modern glaciers barely existed in this area,Pleistocene glaciers were extensively distributed here in the forms of ice cap, oreven small ice sheet. In between of the upper reaches of the Yangtze River andYalongjiang River, there is a vast and well-preserved paleo-planation surface, overwhich covered typical glacial sediments and featured glacial landforms. Twoancient ice caps, Daocheng ice cap and Xinlong ice cap extended respectively tomore than 3,000 km2 and about 2,000 km2

, have been reported (LI J J et at., 1995).A small ice cap in middle Pleistocene age in extent of approximately 80,000

km2 existed at the surroundings of Bayan Har Mountains in the source area of theYellow River (LI J J and LI B Y, 1991; LI J J et al., 1995) (see Figure 2-4). Wherestreamlined landforms such as roches moutnnees, whale back drumlins and troughlike glacial lakes are well developed. Based upon field investigations, four glacialstages can be recognized in this area: the Huanghe glaciation (the last but two,which is the largest), the Yematan glaciation (penultimate), Galala and Bayan Harstage (both the last).

QIILIAN MOUNTAINS REGION

The Qilian Mountains extended about 800 km in NW-SE direction, constitutesthe northeast margin of the Tibetan plateau. Where modern glaciers covering a totalarea of 1972 km2 existed (LI J J et al., 1995). The Mongolian high air pressurecontrols climatic conditions in this area in winter and subtropical high air pressurein summer. As a result, annual precipitation at the snowline (4,000 m asl) is 700800 mm/a in the east and 300 mm/a in the west respectively.

Three stages of glaciations have been recognized in the Qilian Mountains. Theolder erratic are scattered on the planation surfaces. Recently substantial evidencesofthe three glaciations have also been gathered on the south slope of the East QilianMountains (LI J J et al., 1995).

HINTERLAND OF THE PLATEAU

The hinterland of the plateau, namely Qiangtang Plateau, is located innorthwest Tibet (32-36° N, 82-94°E) with mean elevation of 5,000 m as!. Whereannual precipitation is less than 100 mm/a, so the area is the driest and coldest partof the plateau, hence" the dried core of Asia" was proposed (ZHENG 0 et al.,1999).

Above the high plateau, there existed some flat massive mountains, uponwhich covered small modern ice caps. However, the extent of the ancient glacier isquite limited (see Figure 2-4) due to its extremely dry and cold climate. From whichwe can say that the monsoon both from southeast or southwest had a very littleimpact on the glacial development in this hinterland since late Pleistocene.

32 ZHANGQ. S.

2.3.2 GLACIAL SEQUENCES IN THE TIBETAN PLATEAU

In summary, glacial sequences in Tibetan Plateau can be listed inTable 2-1.Table 2-1 Glacial Sequences in different places of the Tibetan Plateau

(after Lt, et al., 1995 and revised)

Region/Sequence

QomolangmaGangdiseNianqingtanggulaKarakorumTanggulaWest KunlunBayan Har

Last glaciation(25ka-18ka)Rongbu TempleGangrenboqiHailongcongKlayayikBasicuoBingshuigouGalahai

Penultimate(150ka-200ka)Jilong TempleSelongYebagouKalakuleZhajazangbuQuanshuigouYematan

Last but two(800ka-600ka)NieniexionglaGangdiseLiuhuangshanSubashiTanggulaKunlunHuanghe

Last but three(Early Pleist.)Xixiabangma

2.3.3 CONCLUSION

1) Quaternary glaciers were only developed in the extremely high mountainsof the Tibetan Plateau. They were limited in extent and appeared in the forms ofmountain glaciers, such as cirque glacier, trellis and valley glacier, pedimont glacierand ice cap that restricted in a few places like Daocheng and Maidika inNianqingtanggula Mountains. Only one small ice sheet with an area about 50,000km2 in the middle Pleistocene age examined at the source area of the Yellow River.However, the imaging united ice sheet of the late Pleistocene did not exist on theplateau.

2) Three of four stages of glaciations have been confirmed in different localnames on the Plateau (see Table 2-1). Amongst them, the Nieniexuoangla glaciation,the last but two, was most extensive both in size and distribution, in features ofmaritime glaciers. Glaciations in later stages were subsequently decreasing in sizeand distribution area, and in features of continental glacier, due to accelerateddesiccation resulting from the uplift of the plateau (ZHANG Q S et aI., 1995).While the oldest glaciation, the last but three stages, is still unclear in itsdistribution, except Mt. Xixiabangma area.

3) Development of glaciers in marginal mountains was more favorable than inhinterland, which is evidenced by increasing of snowline elevation from margin tothe hinterland, because of decreasing of monsoon precipitation. For example,elevations of modern snowline in Mt. Anymaqin (34.40oN, 99.500 E), Kunlun Pass(35.40oN, 94.000 E) and in Hoh Xii Mountains are 5,000 m, 5,300 m and 5,600 mrespectively.

2.4 Lake Evolution

The Tibetan Plateau is the largest distribution area of present lakes that cover atotal area of 36,900 km2 or 52% of lake area in China. Amongst them the QinghaiLake, the Nam Co Lake, the Sylin Co Lake, the Zhaling and Erling Lakes, and the


Bangong Co Lake etc., are well known in the world. Most of the lakes aredistributed above an elevation of 4,000 m as!.. In origin, lakes can be distinguishedin three categories: structural, glacial and dammed lakes. Caused by uplift of theplateau and climatic changes, lake evolution significantly occurred since lateCenozoic Era. Started from Oligocene age (YANG, 1986), some four stages of lakeevolution can be distinguished

2.4.1 OLIGOCENE-LATE NEOGENE (38 MA-? MABP) STAGE

Lake distribution in Oligocene-late Neocene (38 Ma-? Ma BP) stage is shownin Figure 2-10.

Lakes in Oligocene age were well developed in features of gypsum and saltdeposits under arid and hot climatic conditions. In mid-Neocene age, developmentof ancient lakes basically was followed by, except some differences in lake'sextents and salinity. However, saline and salt lakes appeared and enlarged in area inmid-Neocene in the Qaidam Basin. Gypsum and salt did not occur in southern partof the plateau in Oligocene age when lakestnainly concentrated in GangdiseMountains and its northward area at Lumpola Basin. Lakes in Gangdise Mountainsin early and mid-Neocene ages was similar to those in Oligocene age, from whichwe can see that climatic condition in Neocene age was more humid than that inOligocene both in southern and northern part of the plateau.

I~I"""'"['" I~l fresh wlltcr 1.ak..:

Figure 2-10 Lake distribution in Oligocene-late Neocene (38 Ma-? Ma) (after LI BY 1998)

34 ZHANGQ. S.

2.4.2 LATE NEOGENE-EARLY PLEISTOCENE STAGE (7 MA-l.7 MA BP)

Hepparin fauna have been discovered in many Neogene lake basins both insouthern and northern Tibet since 1975 (LI B Y et aI., 1983; JI H X et aI., 1981;ZHENG S H et al., 1985). Palaeo-magmatic ages of those lake deposits are of 7Ma-1.6 Ma, 6.54 Ma-1.67 Ma, 2.5 Ma-0.7 Ma and >2.48 Ma-1.9 Ma respectively(QIAN F, 1990, 1991; SENG X H et al., 1996; CUI Zh J et aI., 1996). From whichit can be confirmed that those lake deposits contained with fossils of Hepparinfauna are of in late Neocene-early Pleistocene ages. Such ancient lakes are widelydistributed in Tibetan Plateau (Figure 2-11)

I~ I Pliocene·PleistO<enOlal:. I~ Pliocene dried .a1t lake

Figure 2-11 Lake basins of Tibetan Plateau in late Neogene-early Pleistocene period(after LI B Y, 1998 )

Apart from a few salt and gypsum deposits appeared in some lake in QaidamBasin and Guide Basin, most of them are fresh water lakes (L1 B Y et al., 1983;HUANG B R, 1982, 1984; PANG Q Q, 1982a, 1982b; ZHANG P X et aI., 1987).However, the period of Pliocene-early Pleistocene was an important stage for saltformation in Qaidam Basin (Zhang P X, et al., 1987; YANG Z L, 1986). In hence,the formation of lakes in this period can be divided into two sub-stages:

Sub-stage 1 (late Neocene-Pliocene, 7 Ma-2.5 Ma):Most of the lakes in Tibetan Plateau were fresh except those in Qaidam Basin.

Affected by both tectonic movement and climatic changes, lakes in large areachanged from fresh water in early and middle of this period stage to semi-saline and


saline in late Pliocene. This indicated that the climate in this stage could be humidwith relative abundant precipitation.

Sub-stage 2 (early Pleistocene, 2.5 Ma-1.7 Ma):By the time of 2.5 Ma, effected by neo-tectonic movement, many ancient lakes, inroughly north-south direction, were newly formed both in the interior and onperiphery of the plateau. Because of more intensive neo-tectonic movementhappened by the time of 1.7 Ma, a large number of former ancient lakesdisappeared, as the lake basins were cut and dried up by source streams.

2.4.3 LATE PLEISTOCENE-PRESENT (50 KA-O KA BP) STAGE

Under background of the global and regional climatic changes, lake evolutionunderwent a complicated process: lake water rise and decline, and late areaextension and shrinkage. Great expansion of lake water body appeared in the lastglacial interstadial (50 ka-25 ka BP) and fast shrinkage and separation and evensearing of lake happened since 3 ka are of most notable features in the plateauwhich impacted significantly to the present geo-ecosystems (Figure 2-12).

•.' A,lIci(''fIt like

'" t..in~~ lut-intcrll~cial)

...,,~rnlakc

l,l .1 OOk 111

Figure 2-12 Paleo-lakes since last interglacial stadual period and modern lakes in TibetanPlateau ( after LI B Y, 1998 )

Northwest part of Tibetan Plateau was a most sensitive area in lake evolution.For instance, the highest beach (33 ka-40 ka BP) in ancient Tianshuihai Lake inbetween west Kunlun and Karakorum Mountains is 100 m above present lake level,and the extent is 1,403km2

, when Tianshuihai Lake unified with Aksaiqing Lakeand Kushui Lake to be a combined lake, which is 7.7 times larger than that ofpresent (Li B Y et al., 1991; SHI Y F et al., 1998).

36 ZHANGQ. S.

Since 17-15 ka BP the ancient lake has begun to shrink and separate followingthe drop of the lake level. Lungmu Co Lake and Sumxi Co Lake at northern side ofKarakorum Mountains was a united lake at 30 ka-25 ka BP, when the highestelevation of the lake water was 150-160 m higher than present with an extent of635km2, 4.7 times that of the present. Separation of the ancient lake started from 15ka BP and then lake level dropped down subsequently (LI B Y et al., 1991) (Figure2-13). Same phenomena existed at Bangong Co Lake and Zhabuye Chaka Lake aswell as Qinghai Lake etc. in southwestern, northwestern and central part of theplateau(LIBYetal., 1991;ZHENGMPetal., 1989;QI, Wetal., 1995;CHENKZ et al., 1990). From which it can be confirmed that those lake basins in southernand northern part of the plateau were not glaciated during last glaciation. Thismeans the" united ice sheet" in Tibetan Plateau in last glaciation, suggested byKuhle, M. (1987), did not exist (LI B Y and LI J J et al., 1991; LI J J et al., 1992;SHI Y F et aI., 1997).

Figure 2-13 Geomorphologic map of Lungmu Co Lake area in west Tibet (after LI B Y, 1998)

Lakes in Holocene age were mainly shrinking in extent and increasing insalinity, except mid-Holocene time (7.5 ka-3 ka) when area of lakes was expandingand water level re-rising (LI B Y et al., 1982; GU Z Y et aI., 1993; Guy et aI., 1991;Gasse et al., 1996). Violent shrinkage in late Holocene (30 ka-) appearedeverywhere in south and north Tibet (Figure 2-14). Larger lakes were separated intoseveral small lakes due to substantial drop of water level, such as the ancientTianshuihai lake and the ancient Lungmu Co lake mentioned above (see Figure 213)(LIBYetal., 1982, 1991; Gasseetal., 1991;GUZYetal., 1991).


Figure 2-14 North Tianshuihai Lake separated from the South Tianshuihairecently due to substantial drop of lake level (Photo by LI Bingyuan, 1994)

37

2.4.4 RELATIONSHIP BETWEEN LAKE EVOLUTION AND RISING OF THEPLATEAU

Lake development in the plateau is resulted by both tectonic movement andhydrologic factors. Lake evolution, therefore, must relate with rise of the plateau,which evidenced in the following two aspects:

(1) Lake evolution coincides with marcro-tectonoclimatic cycle.As described above, lake well developed in four periods, these periods and / or

sub-stages roughly coincide with tectonic-climatic cycles. Die out of the lakes relatein part with rapid tectonic or climatic changes. Dried up of the lakes relate toclimatic changes, while vanishing due to source ward incision, relate closely tointense tectonic uplift of the plateau, which is evidenced by disappearance of thelakes in marginal areas of the plateau in the periods of 3.4 Ma, 1.7 Ma, 0.7 Ma, and40 ka BP (LI B Y, 1998).

(2) Evolution oflake water bodies affected by uplift of the plateau.Appearance of time-spatial differentiation of lake evolution followed by uplift

of the plateau represent, in somewhat, the periodicity of uplift. Aquaticenvironments of paleo-lakes in Oligocene were quite different from north to south,which infer that the Qinghai-Tibet area was still in low elevation, prevailed byplanet wind system, and latitudinal climatic zones exited clearly. Lakes welldeveloped in vast areas in late mid-Neogene-middle early-Pleistocene period, whenthe difference of aquatic environments of lake water bodies was small. This inferredthat the plateau might reach the first critical elevation of about 2,000 m (LIU X D etal., 1996).

38 ZHANGQ. S.

In late early Pleistocene-middle late Pleistocene, fresh and saline lakesalternately appeared in the margin of the plateau and closed saline lakes began toexist in the hinterland, showing that the plateau reached a considerable height andimpacted climate in the plateau significantly. The vanishing of lakes in margins ofthe plateau was mainly caused by source ward incision.

Lake development since late Pleistocene is much complicated in differentareas and changing periodically with climatic variations, which effected by bothglobal and regional inferences.

2.5 Climatic and Environmental Changes in Holocene Age

The main features of Holocene climate and environment in Tibetan Plateau arecharacterized by occurrence of rapid variation periodically, and apparent zonaldifferentiation appeared in the plateau. Based on available data taken from ice core,lake core, pollen and tree ring etc., climatic and environmental change in theplateau in Holocene times can be divided in three stages. Early Holocene (10.8 ka7.0ka) was in feature of rapid temperature rising and sharp increasing inprecipitation. Middle Holocene (7.0 ka-3.0 ka) was the warmest period in theHolocene times and the late Holocene (3.0 ka-) became cooling down significantly(Figure 2-15).

-10.0.-----"-------------------,

10 9 8 7 6 5 4Time scale ( ka)

3 2 (J

Figure 2-15 Temperature variations in Qilian Mountains in Holocene times recordedby Dunde ice core (after YAO T 0 et aI., 1992 )

2.5.1 CLIIMATE AND ENVIRONMENT IN EARLY HOLOCENE PERIOD(lO.8 KA-7.0 KA BP)

Climate in early Holocene was quite unstable. According to the ice core recordfrom Dunde ice cap in Qilian Mountains, temperature in period of 10.2 ka-9.8 kaBP reached to the average level of Holocene after consequent rise began from post


glaciation in 10.7 ka, and then it was much higher in period of9.2 ka-9.0 ka. Sincethen temperature significantly decreased and went down to the lowest level ofHolocene times in 8.7 ka. Temperature rise rapidly again since 8.6 ka and reachedits highest during 8.5 ka-8.4 ka which was the warmest period in Holocene (SHI, LIandLI,eds., 1998; YAOTDetal., 1992).

Followed by rapid temperature increase and strengthening of summer monsoon,precipitation increased greatly, which resulted in rise up of the lake water level,freshening of the lake water bodies, and also favorite the vegetation grow. TheBangong Co area was in a desert environment before 9.6 ka, and grass vegetationappeared and lake water level raised around 9.5 ka which indicated a temperaturerise and precipitation increase (Fontes et aI., 1996; Fan et al., 1996; Gasse etal.,1996). However, some characteristics of vegetation in early Holocene are asfollows (TANG and SHEN, 1996).

Major vegetation in southeastern plateau in the period of 10.0 ka-9.1 ka IS ofbroad-leaved and needle-leaved forests and sub-alpine montane needle-leavedforests. Meadows appeared in Zoige Basin in period of 11.0 ka-7.0 ka, whichindicate a relative cold and humid climate. Savana like vegetation of temperate andsemiarid climate prevailed in southern plateau in the period of 11.0 ka-8.0 ka. Innorthern plateau, main vegetation was Chenopodiaceae, Artemisia, and sub-alpinemontane steppe, which inferred a cold and relative humid climate 11.0 ka-8.0 ka BP.While in the western plateau, the major component of vegetation such as Artemisiaoccurred 10.0 ka-7.7 ka BP, indicated a relative cold and humid climate. Summermonsoon affected significantly on the Qinghai Lake area in 9.1 ka-8.8 ka resulted inrapid forests growth (DU N Q et al., 1989).

2.5.2 CLIMATE AND ENVIRONMENT IN MIDDLE HOLOCENE(7.0 ka-3.0 ka)

Climate in middle Holocene in terms of " climatic optimum ", or " hightemperature stage", was the best period in the whole Holocene times. The highesttemperature occurred in the period of 7.0 ka-6.0 ka was about 4.5 °C higher than themean annual temperature in Holocene (YAO T D et al., 1992). According to thevariation of 180 in Dunde ice core, the warm period between about 7.2 ka and 3.0ka can be divided in to three sub-periods (Figure 2-16) (YAO T D et al., 1992): a)7.2 ka-6.1 ka was the warmest period amongst the three; b) 6.1 ka-4.9 ka wasrelative cold; c) 4.9 ka-2.9 ka was alternated by warm periods and cold periods(YAO T D et al., 1992).

Affected by stronger summer monsoon, most of the lakes in Tibetan Plateauhave water levels raised, extents expanded and water bodies freshened in middleHolocene (Li B Y et aI., 1982; GU Z Y et al., 1993). However, closed lakes in theinterior of the northern plateau, due to less supplement of fresh water, were beingcontinuously concentrated, and then mirabilite and gypsum were formed in deposits(LI B Y et aI., 1982).

Vegetation in middle Holocene was well developed. Sub-alpine montane

40 ZHANGQ.S.

needle-leaved forests prevailed which inferred a temperate and humid climate inQinghai Lake area in northern plateau. Zoige Basin in southeastern part of theplateau witnessed further development of the evergreen sub-alpine montane needleleaved forests by 7.0 ka, which inferred a rise of temperature. Forests increased insouthern part of the plateau where the vegetation was composed of forest-shrub andmeadow in 8.0 ka-3.0 ka, showing a warm and sub-humid climate. In most part ofthe central plateau in 7.5 ka-3.0 ka, Chenopodiasia and varieties of trees increased,showing climate was getting warmer and humid. While in the western part of theplateau in 7.5 ka-5.5 ka, pollen data indicated that the major component ofgrassland was Artemisia, infering more precipitation and humid climatic conditionin the area (TANG L Y et aI., 1996).

Based on pollen data, some tentative figures of mean annual/monthlytemperatures and precipitation in middle Holocene in different areas of the plateauare listed in Table 2-2.

Table 2-2 Mean annual/monthly temperatures and precipitation in middle Holocene(6.0ka-7.0ka) in different areas of the plateau

37°N,1000E -4°--1°C(Jan.)/+8°C12-14°C(Jul.)/+2°C

33.5°N,103°E Annual /+3-4°C31.5°N,84°E Annual/+4-5°C29°N,85.5°E Annual /+5°C28.3°N,92°E annual/3.5-4.0°C

Area

Qinghai Lake

Zoige BasinZabuy ChakaPegu CoNareyum Co

LocationMean temperature /higher than today

Precipitation/ morethan today600mm/yr. (+7080%)

References

Kong, et aI., 1990

Wang,et aI., 1990Li, et aI., 1983Wang,et aI., 1992Wang,et aI., 1992

All these data show that mean annual temperature on the plateau surface,especially in south and east, in 7.0 ka-6.0 ka was about 3-5°C higher than that oftoday and mean annual precipitation was 100-200 mm/yr. more than present. Suchwarm and humid climate was favorite for human activities (L1 B Y et al., 1982).Table 2-2. Mean annual/monthly temperatures and precipitation in middleHolocene (6.0ka-7.0ka) in different areas of the plateau

2.5.3 CLIMATE AND ENVIRONMENT OF LATE HOLOCENE

Climate in late Holocene is featured by coldness. A cold sub-stage in 2.8 ka2.7 ka was recorded with Dunde ice core record (YAO T D et al., 1992) and pollenrecords (SUN X J et aI., 1993). Coincidence with the cold sub-stage, glacialadvances appeared in many localities, which is referred to as Neoglaciation, andgreat expansion of permafrost also existed. Southern margin of the permafrostshifted southward by about 200 km to Dangxiong-Yangbajing area. Where meanannual temperature is 2°C, while the mean annual temperature at the presentsouthern margin of permafrost is -2°C~ -3°C, from which temperature inNeoglaciation was about 4°C lower than that of present (WANG F B, 1985). Thus,


temperature difference between the climate optimum period of middle Holoceneand the neoglaciation (2.8 ka-2.5 ka) may reach to 8-9°C, which is much larger thanthe pleteau existed.

Coincided with temperature drop, the monsoon precipitation decreasedsignificantly, inducing sharp drop of lake water level of 10-20 m in southern andnorthern part of the plateau. As a result, large lake was separated into several smalland shallow ones, like Chen Co and Bajiu Co being separate from Yangzoyum Coin southern Tibet. On the other hand, most of the lakes became saline or salt lakesdue to salt accumulation. Some of the lakes developed into the last stage of salt lake,such as Zhacang Chaka, in which deposits mainly consist of marabilite and sodiumchloride. So late Holocene was a main stage for the formation of salts in lake basinsin the plateau (ZHANG P X et al., 1994; CHEN K Z et al., 1990; GU Z Y et al.,1993).

~oJi IOOl-.~·.,----~.~-;----;:;'";:'~'-;-----:;:(lnf,

SOO 1000 ISOO 2000

Time scale (II AD)

Figure 2-16 Variations of 0180 (temperature) andsnow accumulation (precipitation) in the past 2000years recorded by Gulia ice core ( after YAO T D etal., 1996a)

2000ISOO1000

b

a

SOO

-10

;i -13

C

'«1 400ee......"

=300o·.~

"3e::s 200~

Vegetation degradation iscombined with arid climate inlate Holocene. Subalpine steppe,mainly consisting ofChenopodiasia and Artemisia,appeared in Qinghai Lake areasince 3.0 ka. Reduce of needleleaved forest and increase ofCyperaceae in meadow at Zoigearea at stage of 3.0 ka-1.7 ka BPshowing cold down, while after1.7 ka BP needle-leaved forestand swampy meadow expanded,showing relatively warm andhumid again. Alpine steppe,showing a cold and arid climate,exists in 3.8 ka-l.2 ka BP incentral portion of the plateau,while shrub and alpine steppe,showing a temperate-cool andarid climate, existed in southernTibet after 3.0 ka BP.

Some features of climaticchanges in the past 2000 years inthe Tibetan Plateau wererevealed in detail by Gulia ice

core record (YAO T D et al., 1996, 1996). Figure 2-16 shows variations of 0180(temperature) and snow accumulation (precipitation) in the past 2000 years. Fromwhich we can see climatic changes between cold dry and warm-humid in westKulun ranges.

42

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66. ZHANG Qingsong, LI Bingyuan and JING Ke, 1981. Palaeogeography of Qinghai-Xizangarea in Pliocene age and uplift. In: The period, amplitude and type of the uplift of theQinghai-Xizang Plateau. Beijing: Science Press, 26-39 (in Chinese).

67. ZHANG Qingsong, TAO Junrong and HUANG Cixuan et al., 1990. Discovery of fossilplants of late Cenozoic Era in middle Kunlun Mountains. Chinese Science Bulletin, 35( I):51-53.

68. ZHANG Qingsong, ZHOU Yaofei and LU Xiangshun et al., 1991. On the present upliftspeed of Tibetan Plateau. Chinese Science Bulletin, 36(21): 1820-1824.

69. ZHENG Du (Chief ed.), 1999, Physical Geography of Karakorum-Kunlun Mountains.Beijing: Science Press, 190 (in Chinese).

70. ZHENG Mianping and XIANG Jun et aI., 1989. Saline lakes in Tibetan Plateau. Beijing:Science and Technology Press, 14-33,203-219 (in Chinese).

71. ZHONG Dalai and DING Ling, 1996. A discussion on uplift processes and mechanism ofTibetan Plateau. Science in China (D). 26 (4): 289-295.

CHAPTER 3 THREE DIMENSIONAL DIFFERENTIATION OFNATURAL ZONATION

ZHENGDu

With its highest elevation, unique physical environment and rule of spatialdifferentiation, the Tibetan Plateau is a gigantic geomorphologic region on the earth.As a result of high elevation and large area, the type, characteristics and naturalhistorical process of physical landscapes on the plateau are quite different fromthose of lowlands at the same latitudes as well as high latitudinal regions. Inconsequence, it has been labeled as high hierarchic regional unit, being one of thethree largest physical regions in China. Comparable studies on altitudinal belt, someunique geo-ecological phenomena, physical regional differentiation and ecogeographical regional system of the Tibetan Plateau are dealt with in this chapter.

3.1 Comparative Studies on the Altitudinal Belt

The Tibetan Plateau is surrounded by a series of lofty mountains, includingKunlun, Altun and Qilian Mts. on the north, Himalayas on the south, Hengduan Mts.to the southeast, and Karakorum Mts. to the west, in between; there are a series ofmountain systems stretching on the plateau. Special attention has been paid to thestudy of altitudinal belt, its characteristics, structure-types and regionaldifferentiation in the expeditions to the high mountainous regions on the plateau,such as the Himalayas (ZHENG Du et al., 1981), the Hengduan Mts. (ZHENG etal., 1984; ZHENG Du et al., 1985a), the Karakorum and the Kunlun Mts. (ZHENGDu et al., 1988a, 1989a, 1999), as well as to the well known Mounts, such as Mt.Qomolangma (ZHENG Du et al., 1975), Mt. Namjabarwa (LI Bosheng, 1984;PENG, 1984, 1986,1987) and Mt. Gongga (ZHONG,1984).

From global point of view, classification of structure-type of altitudinal beltdepends mainly on temperature belt and zonal moisture r~gime. However, asconcerns the Tibetan Plateau, a unique unit of physic-geographical region,monsoonal and continental systems of structure-type of the altitudinal belt may beidentified based on spectrum-structure, base-belt, dominant belt and pattern ofaltitudinal belt (ZHANG Rongzu et al., 1982).

Monsoonal system of the altitudinal belt is mainly confined to the southern andthe southeastern parts of the plateau. This area is influenced by wet and dry seasons,alternated with Asian monsoons. The altitudinal belt composes chiefly of montane

47

ZHENG Du. ZHANG Qingsong and WU Shaohong (eds.). Mountain Geoecology and Sustainable Development ojtheTibetan Plateau, 47-69.©2000 Kluwer Academic Publishers.

48 ZHENGD.

forest belts, including broad-leaved forest and coniferous forest, and alpine scruband meadow belt appeared above the upper forest limit. It is characterized bydominant bio-chemical weathering, montane forest soils with acid soil reaction, aswelI as mesophytic types of vegetation. The altitudinal differentiation mainlydepends on temperature. It can be subdivided into three groups of structure types:humid, sub-humid and high-and-cold sub-humid.

Humid group of structure-type of altitudinal belt occurs on southern flanks ofthe Himalayas. With tropical rainforest or monsoonal rainforest as base belt andmontane evergreen broad-leaved forest as dominating belt, a relatively completespectrum-structure was formed. Upwards appear the following belts in succession:montane broad-leaved and needle mixed forest belt, montane coniferous forest,alpine scrubby and meadow belt, and subnival and nival belts. With regard to soils,in the montane forest belt developed ferrallitic soils and sialIisols, upwards occuraltocryic isohumisols (including sub-alpine meadow soils and alpine meadow soils),characterized by humid spectrum of altitudinal belt in peripheral tropical andsubtropical zones (PENG, 1984; ZHENG Du et al., 1975,1981 a).

Sub-humid group of structure-type of altitudinal belt is commonly found insoutheastern part of the plateau. Because of higher elevation of valley bottom, it isusualIy composed of base-belt of montane broad-leaved and needle mixed forest(montane brown soils) belt and dominating belt of montane coniferous forest belt.At bottom of temperate and cool-dry valleys in the middle and northern sections ofthe Hengduan Mts., vegetation consists mainly of zero-mesophilous deciduousscrubs, with montane cinnamon soils and carbonate cinnamon soils as thecomponent in the formation of special base-belt and altitudinal belt (ZHENG Du etal., 1985a; ZHENG Du, 1992).

Corresponding with transitional tendency from the gorge area to the plateau,alpine meadow belt occurs above alpine shrubby and meadow belt. It stretches onplanation surface, being the base-belt of the high-cold sub-humid structure-typegroup with transitional features. With an increasing effect of continental frigiddesiccation, the structure-type group appears chiefly in mountains of the centraleastern part of the plateau from Nagqu to Aba. The spectrum-structure of altitudinalbelt is simply composed of alpine meadow belt, subnival belt and nival belt wheredeveloped frost-sod soils (alpine meadow soils) (ZHANG Rongzu et al., 1982)

By contrast, continental system of altitudinal belt, consisting chiefly of alpinesteppe belt, alpine desert belt, montane steppe belt and montane desert belt, appearsin interior and northwestern part of the plateau. It is characterized by intensephysical weathering, with alkaline soil reaction and coarse texture, xerophytic andsuper-xerophytic types of vegetation. According to regional differentiation ofmoisture regimes on the plateau, the continental system of altitudinal belt can besubdivided into six groups of structure-type: high-cold semiarid, high-cold arid,high-cold super-arid, super-arid, arid and semi-arid (ZHENG et al., 1994).

The high-cold semiarid group of structure type of altitudinal belt extensivelydistributes on the plateau proper, being the representative dominating group. Abovebase-belt of alpine steppe belt usually occurs alpine meadow with cushion plant belt

THREE DIMENSIONAL DIFFERENTIATION 49

at the upper part of mountains neighboring the high-cold sub-humid region. But inthe interior with dry climate, alpine steppe belt connects immediately with subnivalbelt (ZHENG Du et al., 1989b).

With base-belt of alpine desert, the high-cold arid group of structure-typemainly appears in northwestern part of the plateau, upwards the alpine desert-steppeand alpine steppe belt may be observed. However, in the interior of Middle KunlunMts., because of disappearance of alpine desert-steppe belt, sub-nival and nival beltoccurs above alpine desert belt, pertaining to high-cold super-arid group ofstructure-type of the altitudinal belt.

The semi-arid group of structure-type with montane shrubby steppe andmontane steppe as base belt may be found in eastern Qilian and Southern Tibet.Above base-belt, montane coniferous forests are locally met with at shady slopes,upwards exist alpine steppe belt, alpine shrub and meadow belt.

The arid group of structure-type dominates in the Kunlun Mts., and WestQilian Mts., as well as the Ngari Region of west Tibet with the following belts insuccession: montane desert belt, montane desert-steppe belt, montane steppe beltand forest-steppe belt, alpine meadow belt with cushion plants, sub-nival belt andnival belt. Based on the occurrence or disappearance of montane coniferous forestand various combinations of the altitudinal belt, it may be subdivided into mesoxerophillic and xerophillic patterns (ZHENG Du, 1988; ZHENG Du et aI., 1989b).

Characterized by disappearance of montane steppe belt, super-arid group ofstructure-type of the altitudinal belt is simply composed of montane desert belt,alpine desert belt, sub-nival belt with sparse plants and nival belt. This structuretype group may be chiefly observed in the Altun Mts. and interior of the KunlunMts. (ZHENG Du et al., 1989b, 1990a).

Distribution pattern of various groups of structure-type of the altitudinal belt inthe Plateau is shown in Figure 3-1. Different types of combination of spectrumstructure occur in different areas due to distinct differentiation of temperaturemoisture regimes. Two spectral systems of the altitudinal belt form a strikingcontrast: monsoonal system predominates in southeast, and continental systemprevails in northwest while a number of high-cold groups of structure-type widelyspread in the interior of the plateau.

From margin to interior of the plateau, in addition to the difference in base belt,there is a decrease in number of altitudinal belts and a simplification of spectrum ofthe altitudinal belt. For example, there are 7 to 8 belts with tropical rainforests atlower altitudes in Mt. Namjabarwa area (PENG, 1984), 5 to 6 belts with the basebelt of montane desert at northern flanks of the West Kunlun (ZHENG Du et al.,1988), and only 3 to 4 belts in the interior ofthe plateau.

Uupper forest limit is a significant boundary to distinguish alpine belt frommontane belt. Altitude of the upper forest limit depends not only on eco-biologicalcharacteristics of trees themselves, but also on environmental factors in situ,especially temperature-moisture regimes. Altitude of the upper forest limit on theplateau is usually lower in humid areas and higher in sub-humid areas. A decreasingtendency is seen in accordance with northwards of latitude. In eastern Tibet the

so ZHENGD.

upper forest limit of Picea balfouriana is at 4400 m asl on shady slope, and that ofSabina tibetica at 4600 m on sunny slope. These are the highest on earth. Inaddition to the location of subtropical zone (30-31 ON), its higher elevation may beresulted from the heating effect of vast mass of the plateau.

Highland uplift effect7000 - --==::)+ + C:=:===-

1000

Figure 3-1 Distribution model diagram of structure-type of altitudinal belt in Tibetan Plateau

I--Semiarid; II--Arid; III--Super-arid; IV--High-cold super-arid; V--High-cold arid;VI--High-cold semiarid; VII--High-cold subhumid VIII-Subhumid; IX--HumidI--nival belt; 2--subnival belt; 3--alpine desert; 4--alpine desert-steppe; S--alpine steppe;6--alpine meadow/cushion plants; 7--alpine meadow; g--alpine shrub/meadow; 9--montane desert1O--montane desert-steppe; II--montane steppe; 12--montane coniferous forest-steppe;13--montane scrub/meadow; 14--dry valley scrub; IS--montane coniferous forest;16--montane coniferous/broad-leaved mixed forest; 17--montane pine forest(subtropical);18--montane evergreen broad-leaved forest; 19--snowline; 20--upper forest limit;21--piedmont or valley bottom

Considered as the lower limit of nival belt, snowline is chiefly dependent upontemperature-moisture regimes. The elevation of snowline increases from the marginto the interior and from SE to NW. The snowline is at 4500 m asl in the periphery ofthe plateau, correlated respectively with humid regime in the southeast andpoleward latitude in the northern margin. Snowline reaches up to 6000-6200 m aslin the semiarid region at the northern side of Mt. Qomolangma and Mt. AnglongGangri in the interior of the plateau, which is the highest one in the northernhemisphere.


Lowering amplitude of ancient snowline in last glacial stage was very differentin different regions, merely 100-300 m in the interior of the plateau, while 500-800m in the southeastern part and the peripheral mountains. It is much smaller than thatin the Alps, where the lowering amplitude of ancient snowline was 800-1000 m, inrelation with dimension of glaciation and the intense uplift in late Pleistocene andHolocene times (SHI Yafeng et al., 1981; LI Jijun et al., 1986).

3.2 Some Unique Geo-Ecological Phenomena

With regard to regional differentiation of the Tibetan Plateau, moisturecorridor in the lower reaches of the Yarlung Zangbo, dry valleys in the HengduanMountains and other mountainous areas in the periphery of the plateau, high-coldscrub and meadow zones on the middle and eastern part of the plateau, and a highcold arid core area in the interior of the Kunlun Mts. are all of striking geoecological phenomena, forming a unique spatial pattern of physical geography onthe plateau. These phenomena have been paid special attentions in geo-ecologicalstudies of the Plateau (SUN and ZHENG, 1996, 1998). Figure 3-2 shows a sketchmap of geo-ecological phenomena of the plateau

~dryvalley

90

'/0'

~ zone of high-cold~ scrub and meadow

.,.

~ high-cold arid core area

30

Figure 3-2 Sketch map of geo-ecological phenomena of the Tibetan Plateau

52

3.2.1 MOISTURE CORRIDOR

ZHENGD.

Based on results of the integrated expedition to Mt. Namjabarwa area, YangYichou et al. (1987) investigated and demonstrated the formation, evolution of theMoisture Corridor and its impact on natural environments and human activities.With continuous uplifting of the plateau and the Himalayas during and after theMiddle Pleistocene, the river valley in the lower reaches of the Yarlung Zangbo hasplayed a significant role in carrying the moisture-laden air-mass from the IndianOcean to the plateau proper and determined the start of rainy season andprecipitation on the plateau.

Located at the "big bend "of the Yarlung Zangbo River gorge at the eastern endof the Himalayas, a tongue zone with abundant precipitation stretches northwards,forming a central shape of the existing glaciation. The alpine belt, with heavyprecipitation in summer and snowfall in winter and spring, is favorable for glacialdevelopment. By estimation, most part of the glaciated center with an ice coveredarea of about 8,000 km2 are concentrated in the southern flanks of theNyainqentanglha Mts. owing to the obvious barrier of the mountain ridges.

Being mostly the humid section of the Himalayas, the southern flanks of theEastern Himalayas are covered by various forests. Here tropical rainforest stretchesalong river valleys as far north as to 29°N, much beyond the northern boundary oftropical forests in other continents of the world (ZHENG Du et al., 1981 b). Theriver valleys that facilitate migratation and intermixing of the biota between bothsides of the mountains are one of the richest biota areas and an important center ofthe speciation and variation. For example, there are 3600 species of vascular plants,making up two-thirds of the total species in Tibet (YANG Yichou et al., 1987). Themoisture corridor exerts considerable impact on the altitudinal belt, glacier typesand dimensions of both flanks of the Himalayas (PENG, 1984). Various debrisflows of rainstorm type, landslides and rock fall occur frequently with greatintensity, especially in the valleys of the lower reaches of the Yarlung Zangbo River.In addition, the moisture channel has provided a favorable geo-ecologicalenvironment for living and reproducing of ancient and contemporary human race,playing a significant role in human contact and interchange between lowland andhighland.

3.2.2 DRY VALLEYS

Situated at periphery of the plateau, a number of dry valley landscapes occurextensively at the bottom of deep gorges in the Hengduan Mts. in the southeasternpart of the plateau, middle and west Himalayas in the south and the Karakorum Mtsto the west, being one of the striking, attractive geo-ecological phenomena inmountainous areas on earth. From a view of point of physical geography, dry valleyis a drier part of the valley bottom as compared with its surrounding humid or subhumid environments. It is inconsistent with humid or sub-humid landscapes in thestudied areas.


As a general term, dry valley is not identified by arid climate, because it is notcharacterized by zonal types of vegetation and soils of desert or semi-desert in aridregions (ZHANG Rongzu et al., 1990; ZHENG Du et al., 1985a; YANG Qinye etaI., 1989). Most of the dry valleys in middle and northern section of the HengduanMts, pertaining to the semiarid category with an aridity index of 1.5-3.9, arepredominated by meso-xeromorphic, microphyllous thorny scrubs with sparsecoverage. The montane drab soil in the valleys is characterized by aridisol withweak eluviation, residual calcium carbonate and alkaline reaction. According todifference of temperature regimes, dry valley may be classified into three majortypes, i.e., warm-dry, temperate-dry and cool-dry. While in Hunza valley, onsouthern side of the Karakorum Mts., some types of vegetation and soils of montanedesert exist.

Based on studies of palaeo-botany, the Hengduan Mts. region wascharacterized by subtropical arid climate with xerophytes growing in Early Tertiary,providing a natural historical background for the formation and development of dryvalleys. The occurrence and formation of dry valleys is related to the geographicalsituation, topographical pattern and atmospheric circulation, as well as interactionof topographic-climatic factors (such as mountain wind and valley wind systems).An expansion tendency of dry valleys 'is influenced by long-term human activitiesin historical periods (ZHENG Du et al., 1985a).

Dry valleys in Hengduan Mts and Hunza valley in Karakorkum Mts.,characterized by long-term cultivation, concentrated with cultivated land and densepopulation, are agriculturally developed and serve as bases for further economicdevelopment of these regions. Stability of ecosystems in dry valleys is liable to bedisturbed and deterioration of environment has become obvious. Countermeasuresfor rational utilization should be taken to raise productivity and preventenvironments from being deteriorated in the dry valleys.

3.2.3 ZONE OF HIGH-COLD SCRUB AND MEADOW

Located in middle-eastern part of Tibetan Plateau, the zone of high-cold scruband meadow, characterized by highland sub-polar humid / sub-humid climate, is atransitional region from deep gorges to inland of the plateau proper. The zone ofhigh-cold scrub and meadow stretches in direction of WSW to ENE, forming anatural zone on the plateau. The natural zone is unique in physical environmentsand ecosystems, and could not be found at the lowlands elsewhere on earth (SUN &ZHENG, 1996,1998; ZHENG Du, 1996b).

Most of wetlands on Tibetan Plateau are distributed in this natural zone, suchas swamp of Zoige plateau in the east, swamp and swampy meadow of theheadwaters of Tongtian He, Lancang Jiang and Nu Jiang in the west, wherethickness of permafrost is 20-100 m, with frozen period of 4 months for the surfacesoils of 1O-30cm (SUN Guangyou et al., 1995). Existing permafrost has asignificant effect on the percolation of surface water, promoting developments ofthe swamp.

54 ZHENGD.

Due to high cold climate and low temperature of the warmest month thevegetation of alpine scrubs and meadows distributes widespread on vast expanse ofthe natural zone.

Alpine meadow, predominated by frigid-resisting perennial mesophytes,consists chiefly of Kobresia plants of dense tussock, rhizome geophyte(cryptophyte), and other herbaceous plants of hemicryptophyte, belonging to one ofthe typical zonal vegetation on Tibetan Plateau. It is a major nutrition source andproductive base for animal husbandry on the plateau.

The main types of alpine meadow include Kobresia meadow, herbaceousmeadow and swampy meadow. Swampy meadow is normally distributed in broadvalleys and basins or rims of fans, due to gentle relief and impacts of permafrost.Alpine scrubs consist chiefly of Rhododendron, Salix, Potentilla, Caragana,Spiraea, Sibiraea and Cotoneaster, etc. Most of them occur on the shady slopes,reaching upwards on elevation of 4600-4800 m as!. In addition to some deciduousscrubs, scrubs of Sabina pingii var. wilsonii appear on sunny slope too.

As concerns physical environments, or natural ecosystem itself in the zone ofalpine scrub and meadow, does not exist a corresponding natural zone at lowlandselsewhere on earth. The zone of alpine scrub and meadow, being the alpine scruband meadow belt of altitudinal belt spectrum of sub-humid structure-type, stretcheson the plateau surface, characterized by a unique natural zone and in sense ofhorizontal zonality.

Concerning boundaries of the natural zone of high-cold scrub and meadow, theregional differentiation is obvious on both sides. Boundary of the natural zone atsoutheast side corresponds to the northwest limit of montane forests, depending onthe mean temperature of the warmest month and corresponding to the boundarybetween the plateau sub-polar belt and the plateau temperate belt. Therefore a fewof forest stands can be found only in patches at lower elevation in the natural zone.In contrast, the boundary of the natural zone in the northwest side is correlated withthe occurrence of high-cold steppe and high-cold meadow steppe, being in accordwith the limit of moisture regimes from sub-humid to semiarid (ZHENG, 1996b).

By comparison, the natural zone of high-cold scrub and meadow is usuallybetter in temperature conditions and moisture regimes than the sub-polar zone oftundra in the northern hemisphere. According to Budyko, the radiation index ofdryness (Ro/Lr) has a value less than 0.33 for tundra and less than 0.45 for foresttundra and high-cold scrub and meadow zone of the Tibetan Plateau (ZHENG Du,1996b).

With regard to human activities, the natural zone of high-cold scrub andmeadow on the Tibetan Plateau differs clearly from sub-polar zone of tundra innorthern hemisphere. By rough estimation, the total area of the natural zone of highcold scrub and meadow amounts to 269,000 km2 making up 10.7% of the total areaof the Tibetan Plateau. Population density in the natural zone is 3.0 persons / km2,

being lower than the average of the plateau, but much higher than that in zones ofhigh-cold steppe and high-cold meadow steppe, while the sub-polar zone of tundrabelongs to uninhabited area with negligible impact of human activities.

THREE DIMENSIONAL DIFFERENTIATION

3.2.4 A HIGH-COLD ARID CORE AREA

55

Concerning the spatial pattern of regional differentiation on the TibetanPlateau, Karakorum and Kunlun Mts. in northwestern and northern Plateau, belongto high-cold desert and semi-desert, connected by the montane desert and lowlanddesert in the Tarim Basin of Warm-Temperate Zone, presenting a striking contrast tomoisture the corridor in southeast Plateau (ZHENG Du, 1999).

The Expedition to the Karakorum and Kunlun Mts has explored and confirmedthe high-cold arid core area in the interior of Kunlun Mts. (ZHENG Du et a1.1989a;ZHENG, 1994b). Under the influence of moisture-bearing air mass coming fromthe west, the areas concerned are characterized by obvious regional differentiationwith an increasing tendency of desiccation from northwest to southeast. Thenorthern flanks of Western Kunlun and the southern flanks of Karakorum are to acertain extent sub-humid and are dotted by montane coniferous forests (ZHENG Du,1998).

Broad valleys, basins and plateau in between Karakorum and Kunlun Mts. andthe interior areas of Middle Kunlun Mts., such as the Lake Yanghu, White Gobi etc.with a vast area without any flowering plant, are far off both tracks of moisturetransportation. Therefore these areas, on elevations of 4700~5200m asl with gentlerelief (Figure 3-3), are climatically extremely cold and dry, with annualprecipitation of 20-50 mm and mean temperature of 3-6°C in the warmest monthand <-20°C in the coldest month, prevailed in arid denudation and periglaciation.The zonal type of vegetation is alpine desert, dominated by dwarf cushion suffruticewith sparse coverage and alpine gypsiferous desert soils.

Wissmann, H. v. (1960/1961) pointed out that the extremely arid area wassituated in between the Kunlun and Karaakorum Mts. with drought all the yearround. In comparison with the term of "Arid Core of High Asia" used by C. Troll(1972), the areas concerned may be called as "A High-Cold Arid Core Area".Because of this aridity, which occurs elsewhere mostly in the lowlands of thetropical, subtropical and temperate zones, we found alpine super-arid group ofstructure type of the altitudinal belt corresponds to the super-continental type ofglaciers in the study areas (ZHENG Du et al., 1989a, 1999).

Most of these areas are unsuitable even for temporary grazing due to severeclimatic conditions, low quality of pastures and lack of water supplies. A number ofwild animals and endemic species of the Tibetan Plateau, such as antelope(Pantholopd hodgsoni), Tibetan wild ass (Asinus Kiang) and wild yak (Poephagusmutus) graze mainly in the periphery outside of the area (ZHENG Du ed., 1999).Up to now the frigidization and desiccation tendency is still developing. The lakeshave been intensely contracted with higher mineralization, for example, the LakeYang Hu is 96.1g/l, which belongs to the chloride Na type. Degradation ofhydrophytic community of Potamogeton spp. at lake fringe in the area concerned isobserved owing to higher salinity.

56 ZHENGD.

Figure 3-3 Denudation plateau surface of northern Qiangtang Plateau

3.3 Physical Regional Differentiation

On account of combined effect of high altitude, vast extent of the plateau, itslatitudinal position, as well as the accompanying intense thermodynamic effect, theplateau is a unique physic-geographical region in the world. Natural conditions ofthe plateau are very complicated and the horizontal zonation is closely correlatedwith altitudinal belt. It differs from other high mountainous areas in the low- andmid-latitudes and is also distinct in landscapes of high mountains and plateau inhigh latitudes.

3.3.1 COMPARATIVE STUDIES ON PHYSIC-GEOGRAPHICAL PROFILES

Main mountain systems on the Tibetan Plateau follow a nearly west-eastdirection, the Kunlun Mts., the Qilian Mts. to the north, and the Great Himalayas tothe south. In between from north to south extend the Karakorum, the Tanggula andthe Kangdise-Nyainqentanglha Mts. with ridges of over 5,000 m asl and broadvalleys and basins of more than 4,000 m asl in elevation. Yet in southeastern part ofthe plateau it turns to be the north - south oriented Hengduan Mts. (literally,"Traverse Block Mountains" or "Gorge Country") with a series of high mountainridges sandwiched between deep gorges. While in northwestern part of the plateau,stretches the vast interior area--the Qiangtang Plateau with an average elevation of4,400~4,700 m asI. On the whole, the plateau region tips from northwest tosoutheast. During the winter half-year, the westerly belt prevails, while in summer,the southern warm and moist monsoons dominate, making up a strong contrast of


temperature-moisture conditions.A comparison of three physic-geographical profiles crossing the plateau shows

obvious regional differentiation of physical environments (ZHENG et ai., 1981 a;ZHANG et ai., 1982).

A cross section along 95°E shows that the annual precipitation decreases fromsouth to north. As a consequence, it results in a sequence of vegetation types;beginning with tropical evergreen and semi-evergreen rain forest at southern slopesof the East Himalayas, upwards occur montane evergreen broad-leaved forests andconiferous forest. Northwards in the Nyainqentanglha Mts., montane sc\erophyllousforests and montane coniferous forests dominate due to higher elevation with mildand sub-humid climate. Various kinds of coniferous forest distribute continuously orin patches. The Nagqu region, in middle-east of the plateau, is slightly dissected.Predominant types of vegetation are alpine scrub and alpine meadow whereMontane deserts prevail. In the headwater areas of Tongtian He River in southQinghai plateau, there appears the alpine steppe with alpine meadow on mountainslopes. In Qaidam Basin of the northern sides of the Kunlun Mts. and northwards,connecting with the temperate desert in the Hexi Corridor of the Central Asia.

Another cross section along 87°E, crossing the Central Himalayas nearby theMt Qomolangma shows precipitation decreasing from south to north. As a result,natural landscapes start with tropical forest at the southern slopes of the Himalayas,and then followed by altitudinal belts of montane evergreen broad-leaved forest,coniferous forests and alpine scrub-meadow. Southern Tibet lies under the rainshadow area at northern sides of the Himalayas, dominate alpine steppe andmontane shrubby steppe. The Qiangtang plateau prevail alpine steppe and endingwith alpine desert and montane desert in the Kunlun Mts. to the Tarim Basin.

An east-west cross section of the plateau along 32°N begins with theHengduan Mts. to the east, and ending at the West Himalayas to the west. Naturallandscapes of montane forests, alpine scrub and meadow, alpine steppe andmontane desert appear in succession from east to west. Subtropical evergreenbroad-leaved forests dominate in the Sichuan Basin, prevail montane coniferousforests in the Hengduan Mts., crossing high-cold scrub and meadow zone onslightly dissected plateau of Nagqu region, stretches the alpine steppe on theQiangtang plateau, westwards occur montane desert and desert-steppe in the Ngariregion, and ending with montane forest-steppe and shrubby steppe in Kashmir. Itreflects the impact of moisture regimes on regional differentiation.

3.3.2 IDEA OF THREE-DIMENSIONAL ZONALITY

There are various ideas on physic-regional differentiation of the TibetanPlateau. Some scientists insist that horizontal zonality does exist, which is partlycovered by vertical zonality; others suggest that zonality is distinguished by verticalone only; and still others highlight that azonality is apparent on the plateau, it isunnecessary to divide it into natural zones. The disagreements are derived frominsufficient scientific data, incomprate understanding of the plateau, as well as

58 ZHENGD.

different ideas about zonality (ZHANG Du et al., 1982).In fact, the regional differentiation results from interaction between zonal and

azonal factors. The zonal principle is to observe horizontal zonality of naturalphenomena and to search corresponding method of division based on reflection ofclimate on soils and vegetation. This kind of broad explanation of zonality is aboutthe same as the concept of three dimensional zonality explained by C. Troll, acomparative geographic idea indicating the three-dimensional spatial arrangementof geographic objects on earth surface and ecological type of landscapes (Troll C.,1959).

Based on the basic belt, spectrum structure, dominant belt as well as thermaland moisture conditions, altitudinal belts of the Tibetan Plateau can be divided intomonsoonal and continental systems. The monsoonal system mainly includesmontane forest and alpine meadow, with three structure-type groups of humid, subhumid and high cold sub-humid; while the continental system consists mainly ofsteppe and desert, with six structure-type groups of high cold semiarid, high-coldarid, high-cold super-arid, super-arid, arid and semiarid (ZHENG Du et al., 1994a).According to the idea of three-dimensional zonality, the altitudinal belt in the rim ofthe plateau is associated with its nearby horizontal belt. While the connection andexpansion of the basic belt or dominant belt of the altitudinal belt on the plateauindicate the horizontal differentiation of natural zones, and influencing thecharacteristics of altitudinal belt in turn. Therefore, the combination andinterlacement of horizontal zones and altitudinal belts of the plateau reflects theunique characteristics of physic-regional differentiation of the plateau, beingincomparable with plateau and montane areas in a small scale.

The Tibetan Plateau stretches more than 12° of latitude from south to north;hence, solar radiation as the main controlling factor of latitudinal zonality has itsimportant influence within the plateau, bringing about the dropping in temperatureand boundary elevation of altitudinal belts northerly. For example, Bamda (30° 14'N,4,115 m asl) has a mean temperature of 11.1 °c of the warmest month and a meantemperature of -8.4°C of the coldest month; while Mori (38° 15'N, 4,091 m asl) atalmost the same elevation, records 5.6°C and -16.9°C respectively. The upper limitof montane forest belt and the elevation of existing snowline of northern flanks ofthe middle Qilian Mts. are 600-1,000 m lower than those on southern flanks of theMiddle Himalayas. The latitudinal differences are larger if the impact of moistureregimes on temperature is considered. However, such latitudinal horizontaldifferences of radiation balance and temperature of the plateau are usuallyovershadowed by elevation and topographical factors. Isotherms of temperature inJuly show an enclosed pattern with northern Qiangtang plateau and Kunlun Mts., atelevation of over 4,700 m asl, as the center increasing outward, largely reflectingthe function of elevation and topographic feature, and obviously differing fromgeneral differentiation of latitudinal zones (ZHENG Du et al., 1979). Therefore,natural zones do not vary simply followed with latitude, but with combined effectsof latitude and altitude. It has evidently made a disconnection and deformation oflatitudinal zonal distributions in Eurasia (ZHENG Du et al., 1981 a).


Affected by atmospheric circulation and topographic configuration, differentregions have different combination of temperature-moisture conditions, whichchange from warm-humid in southeast to cold arid in northwest. Natural landscapesoccur in the following succession: montane forest--alpine meadow--alpine/montanesteppe--alpine/montane desert. Compared with corresponding natural zones intemperate belt, they have similar moisture regimes, with low temperature as theplateau's characteristics (ZHANG et al., 1982).

However, natural zones in the plateau differ substantially from correspondinghorizontal zones in low altitude regions. A comparison of temperature-moisturerelationship of natural regions in the plateau with those in temperate zone of Chinais shown in Figure 3-4.

351-------------~

30

_.. - .._..............

.= .... ; .. ' )AlpIne "!'P\'" .....:... /

AJ~e scrub and ntndow

I .I/ /

'/ ,// .........._..

15

10

Mean 5temperature

of thewarmest month

"C

25

20

00-0---;;~--""7:----r--.l0.5 1.0 1.5

Annual precipitation I annual evaporation

Figure 3-4 Comparison of the temperature-moisture regimes between the natural zones ofthe plateau and those of the temperate zone of China

60 ZHENGD.

The abscissa shows ratio of annual precipitation to annual potentialevaporation, i.e. reciprocal of aridity; the ordinate shows temperature of thewarmest month. It can be seen that natural regions of the plateau are near thebottom of the diagram, indicating heat deficiency, such as alpine scrub and meadow,alpine steppe and alpine desert. If a similar type of region exists both inside andoutside of the plateau, that one of the plateau is a variety of corresponding oneoutside the Plateau that has been raised up to much higher elevation (ZHENG Du etal., 1981; ZHANG et al., 1982).

3.4 Physic-Geographical Regional System

Study systematically on physic-geographical regions on the plateau, zonalityand azonality in high altitude areas serves as a basis for developing physicalgeography. Scientifically, such study will be able to provide an eco-geographicalframe for regional response to global change, application of GIS technology, layoutof experimental network and analysis of observational data. Practically, its purposeis to get better understanding of the basic characteristics of nature of the plateau'ssurface from the point of view of regions, advantages and disadvantages inproduction and construction, and probability of fully using and transforming thenature. The study can provide necessary and effective scientific basis for rationalutilization of renewable natural resources, increase of land potential productivity,introduction and popularization of advanced agricultural techniques, managementand protection of physical environment and the making and executing of theplanning for transforming of nature (HUANG, 1991).

3.4.1 PHYSICAL REGIONALIZATION

According to difference in geologic structure, mechanism of geotectonicstresses and the degree of dissection by river erosion, as well as general inclinationof the plateau surface from NW to SE, the Tibetan Plateau can be divided into threesub-regions. They are I) western region of high mountains and deep canyons; 2)interior plateau proper interwoven with mountains and basins; and 3) parallel rangesand valleys in the southeast.

In a study on climatic classification of the Tibetan Plateau (LIN Zhenyao et al.,1981) the temperature index, concerned with plant growth including the number ofdays with mean temperature ~10°C and mean temperature of the warmest month, istaken as main criterion for demarcating temperature zones on the plateau. Inaddition to subtropical montane region at the southern flanks of the Himalayas,three zones may be recognized on the plateau, i.e., the plateau polar, plateau subpolar and the plateau temperate. Aridity and annual precipitation are adopted as thesecondary index for delineating moisture regime regions. According to naturallandscapes, five climatic regions are recognized on the plateau, i.e. the humid, subhumid, semiarid, arid and extremely arid.

Based on a study of regional differentiation of spectra of floristic elements in


Tibet with help of a quantitative floristic method (ZHENG Du, 1983), it is obviousthat the Sino-Himalayan element prevails in eastern and southeastern Tibet,whereas the tropical element is confined at lower elevation on southern flanks of theHimalayas. On the contrary, the Tibetan Plateau element dominates on the plateauproper, while the Central Asiatic element plays a significant role in northwesternpart of the plateau.

As a whole, spatial differentiation of temperature-moisture regimes on theplateau, caused mainly by combined effect of topographic pattern and atmosphericcirculation, is mirrored in succession of montane forest, alpine meadow, alpinesteppe and alpine desert from SE to NW. It is similar to the longitudinal zonation ineastern part of Eurasia. H.S.Chang (1981) drew a conclusion that the plateau zonesare in part a combination of characteristics of ordinary horizontal and altitudinalzones (horizontally extensive belts, but at high elevations), in part distinctive to theplateau as a vast region with its own climates. The pattern may be described as"plateau zonation" of vegetation.

According to three-dimensional zonation of physical geography, difference oftopography, various combinations of temperature-moisture conditions, zonal typesof vegetation and soils, as well as structure-types of spectra of the altitudinal belt, atentative scheme for nine major physic-geographical regions has been proposed,except the southern slopes of the Himalayas (ZHENG Du et al., 1979, 1981a;,ZHANG Yongzu et al., 1982). _

Division of physic-regions in the Tibetan Plateau applies a principle andmethod suitable for understanding rule of physic-regional differentiation inlowlands. Natural regions of the plateau should be demarcated based on realdifference of surface nature (landforms structure and topographic configuration),various combinations of temperature-moisture condition and zonal vegetation andsoil types.

In a broad sense, zonality includes horizontal and altitudinal ones. Thehorizontal zonality mainly affected by planet-universe factors, is higher-level rule;while the altitudinal zonality mainly controlled by topography, is lower level rule.Correspondingly the division of higher-level units is based on bio-climatic principle,i.e. zonal principle, reflecting horizontal zonality rather than altitudinal one.Different horizontal zones have relative spectrum-type of altitudinal belts.Therefore, understanding the rule of altitudinal zonality should be based on therecognition of horizontal one. Otherwise, spectrum types of altitudinal belts becomemarks for identifying the horizontal zones. Higher-level division should be mainlybased on existence and advanced characteristics in nature, highlighting the naturalfactors stable; the lower-lever division is mainly based on remaining characteristics,laying stress on the natural factors sensible to change (HUANG, 1959).

The plateau itself not only has montane area with altitudinal-horizontalzonality types, but also has plateau's proper zonality, and montane areas withobvious altitudinal zonality existed in the rim and interior. In consequence,comparative studies of spectrum type of altitudinal belt in various mountains on theplateau, analysis of its structure type, determination of basic and dominant belts and

62 ZHENGD.

suitable classification are not only the need for systematically recognizing thecharacteristics of altitudinal belts, but also for studying of physic-regional systemon the plateau.

It is necessary to make comparative studies on various combinations ofgeomorphologic types and base elevation, to determine the typical base and itselevation range and eventually to make bio-climatic data comparable (ZHENG Du,1989). For example, the Qiangtang plateau represented by lacustrine plain andpiedmont plain is situated at elevations of 4,500-4,800 m asl; while South Tibet isfeatured by broad valley basins with elevation of 3,500-4,500 m. The mainsettlements of local resident and agricultural activities are also located in rivervalley basins. According to the elevation range of determined typical base region,we can compare combinations of temperature-moisture regimes and zonalvegetation and soils and then establish various natural zones or regions. In middlenorth sector of the Hengduan Mountains, elevation of typical base surface iscomprehensively considered according to spectrum type of altitudinal belts,elevation of dominant altitudinal belt and main river valley basins. Therefore, rivervalley basins on elevations of 2,500-3,500 (4,000) m asl are regarded as typicalbase surface.

The physic-geographical regionalization of Tibetan Plateau by using deducedway, top down from high to low levels can be divided into type and regionaldivisions. Temperature belt and zonal moisture regime have the characteristics oftype regionalization. The formed physic-geographical zones are transitionalregional units from type to regional division. In demarcation of temperature belt andregional type of moisture regimes, relative temperature and aridity index have beenworked out by taking account of relationship amongst climate, soils and vegetation,instead of climatic isopleths, as index or index complex proposed for demarcatingboundaries.

3.4.3 SELECTION OF INDEX FOR REGIONALIZATION

According to temperature condition, moisture regimes and features oflandforms the Tibetan Plateau can be divided into 2 temperature belts, 10 naturalzones and 28 physical districts (ZHENG, et aI., 1979; ZHENG, 1996a).

(1) Temperature conditionTemperature, being an important factor influencing growth and distribution of

plants, is hard to change on large scale or in a long period. Days with a mean dailytemperature above lOOC is regarded as the principal index, mean temperature of thewarmest month as the subsidiary criterion, thus, the plateau can be divided intoplateau sub-polar, plateau temperate and montane subtropical zones. Days with amean daily temperature above 10°C and mean temperature of the warmest monthare closely correlated with growth and distribution of certain zonal vegetation, aswell as related to crop cultivation. These two indexes can be compared with eachother and with that in low altitude regions (Table 3-1).

THREE DIMENSIONAL DIFFERENTIATION

Table 3-1 Division of temperature belts on the Tibetan Plateau

Days with mean Days with mean Mean temperatureIndex daily temperature daily temperature of warmest month Basic characteristics

above 10°C above 5°C (0C)

63

Plateausub-polarbelt

Plateautemperatebelt

Montanesubtropicalbelt

<50

50-180

>180

<120

120-250

>250

<10(12)

10(12)-18

>18

Hard for tree growth,without natural forest,highland barley can beplanted locallyMontane forest orafforestation, croppingsystem being one crop peryearSubtropical montane forest,cropping system being twoto three crops per year, riceand tea can be planted

(2) Moisture regimesUnder a certain temperature condition, moisture regime becomes limited factor

affecting plant growth and distribution. By taking account of annual aridity (ratio ofannual evapo-transpiration potential to annual precipitation) as the principal index,subordinated by annual precipitation, four moisture regional types can bedistinguished: humid, sub-humid, semiarid and arid (Table 3-2).(3) Landforms

Within any natural zones, differentiation of landforms gives rise to changes ofnatural conditions such as climate, moisture regime, soils and vegetation, andvariation of processes such as weathering, erosion, and accumulation, reflectingdifferences of factors such as rock composition and internal force. Landform is aleast changeable factor too. Same landform has different functions in differentnatural zones. Therefore, physical districts should be further divided based ondifferent landforms followed by regionalization of temperature belts and naturalzones.

Table 3-2 Division of regional types of moisture regime on the Tibetan Plateau

Index

Humid (A)

Subhumid (B)

Annual aridity Annual precipitation (mm) Basic characteristic

<1.0 >800 Forest, acid soil reaction

1.0-1.50 800-40 I Forest, mesophilous shrub meadow,acid-neutral soil reaction

Semiarid (C)

Arid (D)

1.51-6.0

>6.0

400-200

<200

Steppe, alkaline soil reaction, withcarbonate remains, and salinization

Desert, alkaline soil reaction, no cropcultivation without irrigation

64 ZHENGD.

Influenced by regional differentiation of the plateau, selection of index forlandforms classification is different. For example, lower limit of extreme alpine beltis at elevation of 5,000-5,500 m asl, which approaches to the lower limit of subnival belt between the end of existing continental glacier and snowline of theplateau. The lower limit of the plateau and the boundary between alpine and middlemountains are about 3,500 (4,000) m, near the upper limit of montane forest. Ingeneral, above the boundary of alpine belt, frost and mechanical weathering andsolifluction are well developed, and soil-forming process on coarse materials, isslow. Below the boundary, fluvial process is getting stronger under humidconditions. The boundary in middle and lower mountains is at an elevation of about1,000 m asl, and the part below the boundary belongs to periphery out of the plateau(Zhang et al., 1982).

3.4.4 HIERARCHIC UNITS AND REGIONAL SYSTEM

System of physic-geographical region in the plateau is worked out bygeographical correlative method, which lay stress on comparison of distributioncharacteristics of various physic-geographical elements, with emphasis onrelationship amongst climate, biome, soils and their significance to agriculturalproduction. The selected hierarchic units are of temperature belt, natural zone andphysical district.

(1) Temperature beltThe region, influenced by topographic configuration and latitudinal factors,

has common characteristics in temperature condition, and strongly affects landutilization. The plateau's topography dominates temperature status, resulted in theformation of regionalization in plateau sub-polar, plateau temperate and montanesubtropical belts. The last is located on southern sides of the Himalayas, whichbelongs to peripheral region of the plateau. The division of temperature belt is typeregionalization. The belts are the areas with common characteristics, which wasformed in physic-historical processes. The belts, based on the classification index,are strictly identified and are convenient for comparison.(2) Natural zone

Affected by topographic configuration and atmospheric circulation, naturalzone has common characteristics in combination of temperature and moistureconditions with zonal vegetation and soils in area, and has similar altitudinal beltsand combination of structure types. Features of land use and agricultural, forestryand pasture development are almost the same within a natural zone. This is aninitial regional unit in the system of physic-geographical region in the plateau.(3) Physical district

It has roughly the same combination of vegetation and soil types due todifferentiation of landform or geographical location. Structures of altitudinal beltsare similar within a physical district. It usually corresponds with certain regionaltopographical unit, having related combination of landforms-types.


(4) System of physic-geographical regionsAccording to principle, method and index for physical regionalization, the

Tibetan Plateau can be divided into 2 temperature belts (except southern side of theHimalayas, which belongs to montane subtropical belt), 10 natural zones (each ofthem has its own striking characteristics, with naming principle of regional nameplus dominant zonal vegetation types), 28 physical districts (with names of regionalname plus combination oflandforms) (Table 3-3, Figure 3-5).

Table 3-3 System of physic-geographical region in the Tibetan Plateau

Temperaturebelt

IPlateau'sSub-polar

belt

Natural zone

IB I Golog-Nagqu high-coldshrub-meadow zone

IC I Southern Qinghai highcold meadow steppe zone

IC2 Qiangtang high-coldsteppe zone

101 Kunlun high-colddesert zone

Physical district

IBla Zoige plateau with hillsIB Ib Golog-Yushu plateau with broad valleyIB Ic Damqu-Nagqu headwater with broad valleyICla Headwater of Yellow River with broad valley

and basinIC Ib Headwater of Tongtian River with broad valleyIC2a South Qiangtang plateau with large lakesIC2b North Qiangtang plateaulOla Plateau on south sides of Middle Kunlun Mts.10 Ib Plateau and high mountain on south sides of

W .Kunlun and north sides of Karakorum Mts.

lICIII

Plateau's IIC2Temperate

belt IIDI

IID2

1ID3

lIABI West Sichuan- East IIABla Minshan-Qionglai Mts.Tibet montane IIABlb Gorges of Middle Hengduan Mts.coniferous forest zone IIAB Ic North Hengduan Mts.Southern Tibet montane IIAB Id South sides of East Nyainqentanglha Rangeshrub-steppe zone IICla Plateau and lake basins on north sides ofEastern Qinghai- Qilian Central HimalayasMontane steppe zone IIC Ib Broad valley in middle reaches of YarlungNgari montane desert- Zangbosteppe and desert zone IIClc Broad valley in upper reaches of YarlungQaidam montane Zangbodesert zone IIC2a Mountains in upper reaches of Yellow RiverNorthern slopes of lIC2b Huangshui River Drainage basinKunlun montane IIC2c Qinghai Lake Basindesert zone IIC2d East Qilian Mts.

IIDla Langqin Zangbo Drainage basinIIDlb Gar-Bangong broad valley and basinIID2a Mountains in eastern rim of Qaidam BasinIID2b Qaidam BasinIID2c West Qilian Mts.IID2d Altun Mts.IID3a North slopes of Middle Kunlun Mts.IID3b West Kunlunb Mts.

o OAlMontane

subtropicalbelt

Southern slopes ofHimalayas montaneevergreen broad-leavedforest zone

OAla Mountains in Zayu River DrainageOAlb South slopes of East Himalayas Mts.

66 ZHENGD.

,3S"N_ '1I --;-.>-~....,b",""-~ T"l--__-"-7""~-!-T-- -~~~~d~~-='-~I HDI'\. ~

L.N- d-~--~~fT===;;;;:::=:::7"'fi-->t-\ 0 300 600 kin

! ' ,

80' E 85 'E

--Boundary ofnatural ;ones

Figure 3-5 System of physic-geographical regions in Tibetan Plateau

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55. ZHENG Yuanchang et al., 1984. Trial discussion on the vertical natural zone of themountains in West Sichuan. Mountain Research, 2 (4): 237-244 (in Chinese with Englishabstract).

56. ZHONG Xianghao, 1984. Physical Geography of the Mt. Gongga Region. SichuanGeography, No.6: 23-32 (in Chinese).

CHAPTER 4 THE POPULATION CHANGES AND URBANDEVELOPMENT

FU Xiaofeng

4.1 Evolution of Administative Regionalization

The Qinghai-Xizang (Tibet) Plateau has long history of human cultivation.Many ancient nationalities and tribes once lived here. They have migrated andmerged each other during the long historical time. Until the early 7th Century, theunified Tufan Dynasty was built and had close political and economic relation withthe Central China. The Tufan Dynasty collapsed at mid-9th Century. At mid-13thCentury, the plateau was confined to the unified administration of the Yuan Dynasty.It was divided into three parts followed as the northeast, southeast, and the westadministrated by three relevant Xuanwei Si, which actually is basis ofadministrative regionalization of the plateau nowadays. In the Ming Dynasty, theadministrative regionalization of the plateau generally adopted the old system of theYuan Dynasty. The present Deqin, Zhongdian Counties, etc belonged to the YunnanProvince, and the Xining Zhou located in the present eastern Qinghai Province waschanged to Xining Wei and confined to Shaanxi Province. In the Qing Dynasty, theXining Wei (later changed to Xining Fu), Hezhou was zoned to Gansu Province, theSongpan, Aba and the eastern Yalongjiang River zoned to Sichuan Province. In1726 AD, the Jinsha River was defined as the basic boundary between Xizang andSichuan and Yunnan Provinces. Since 1729 AD, the government began to sendchancelleries to administrate the Tibet. In 1731 AD, areas dominated bychancelleries distributed from the Qing Government to the Tibet and Qinghai wasdefined. In 1929, the Qinghai Province was set. Thereafter, related changesoccurred. The whole Plateau was liberated in 1951. According to social requirementand evolution of administrative regionalization historically, autonomous agencies ateach level were built. Now the plateau mainly includes the Tibetan AutonomousRegion, Qinghai Province, Gannan Tibetan Autonomous State of the GansuProvince, Ganzi Tibetan, Aba Tibetan and Qiang Autonomous State, and MuliTibetan Autonomous County of the Sichuan Province, and Diqing TibetanAutonomous State of the Yunnan Province (CHEN et ai., 1995).

4.2 Historical Population Change

The Tibetan Plateau is the birthplace of the Tibetan. Early in the late

71

ZHENG Du. ZHANG Qingsong and WU Shaohong (eds.), Mountain Geoecology and Sustainable Development oftheTibetan Plateau. 71-88.©2000 Kluwer Academic Publishers.

72 FUX.F.

Paleolithic Period there was human activities in Tibetan plateau. The historicalpopulation change was restricted by the political and economic development of theTibetan plateau. Historically there were little statistic documents and the early dataabout population scale is poorly reliable. A rough estimate about Tibet's populationwas 1,400,000 in 6th Century and 4,210,000 in 7th Century. In the middle of 13thCentury the first check on residents was hold in Wei and Zang region (comprisingthe middle reaches of the Yarlung zangbo River) and the result was 38,963households which regards about 234,000 people. And the total amount of Tibet'spopulation in that time was 1,080,000. In the middle of Qing Dynasty (1734-1736)a comparatively overall residents check was hold in Tibet and there were 128,100household's common people and 316,200 monks. According to the averagehousehold's people in that time plus some omission region, the total amount ofpopulation in Tibetan Plateau was about 2,150,000 in 18th Century. It is generallybelieved that the Tibetan population kept decreasing from early Qing Dynasty to thebeginning of 20th Century. Table 4-1 shows the historical population change ofTibetan Plateau. The main factor responsible for the population decrease from 18thCentury to 1933 was the serf system, low living level and poor medical care (MA,1996; ZHANG, 1989; LlU, 1988).

Table 4- I Historical population changes of the plateau ( 104 persons)

Tibet Autonomous Region Qinghai Province Total

The 6th Century 90 50 140




1933 80 13 1 211

1951 105 156 261

Source: reference (DUOJIEOUZHU et al., 1994; HU, 1990; ZHAI, 1989)

4.3 Population Growth since 1951

After peaceful liberation in 195 I, especially after democratic reform in 1959,Tibet's economic level have been developing and the living standard of the peoplehave been rising, the medical and health conditions get improved, therefore, thetotal amount of population in Tibetan plateau increases rapidly. The total amount ofpopulation had increased from 2.78 million in 1952 to 7.383 million in 1997. Theamount of population increased 4.603 million in 45 years, on average, thepopulation increased 100,000 people per year. The yearly population increase ratereached 21.9960, which is higher than that of the whole China that is 18.1 %0. Table4-2 shows the population growth of the main part of Tibetan plateau (the TibetAutonomous region and Qinghai Province).

POPULATION CHANGES AND URBAN DEVELOPMENT 73

Table 4-2 Total population growth of Tibet and Qinghai (104 persons)

Year Tibet Autonomous Region Qinghai Province Total1952 115.00 161.38 276.381959 122.80 260.Q1 382.811960 126.98 248.65 375.631961 129.87 211.42 341.291962 130.17 205.01 335.181963 132.38 209.74 342.121964 134.67 219.48 354.151965 137.12 230.45 367.571966 139.67 240.61 380.281967 142.41 250.45 392.861968 145.16 260.95 406.111969 148.05 271.93 419.981970 151.20 282.73 433.931971 155.38 295.65 451.031972 159.28 307.05 466.331973 162.92 318.15 481.071974 166.12 328.75 494.841975 169.11 337.49 506.601976 172.40 346.59 518.991977 175.62 356.75 532.371978 178.82 364.86 543.681979 182.69 372.02 554.711980 185.28 376.90 562.181981 185.96 381.60 567.561982 189.25 392.79 582.041983 193.14 392.57 585.711984 196.68 401.61 598.291985 199.48 407.38 606.861986 202.49 421.12 623.611987 207.95 427.90 635.851988 212.91 434.20 647.111989 215.91 440.20 656.111990 218.05 447.66 665.711991 221.78 454.43 676.211992 225.27 461.02 686.291993 228.88 466.70 695.581994 231.98 474.00 705.981995 235.55 481.20 716.751996 239.30 488.30 727.601997 242.74 495.60 738.34

Source: Extracted from Outlook of Tibet's Economy (1965-1985), Yearbook of Statistics in theTibet Autonomous Regio in 1998, Yearbook of Social and Economic Statistics in the QinghaiProvince in 1991, and Yearbook ofStatistics in the Qinghai Province in 1998.

In whole Tibetan Plateau, the total population increase rate is high than that ofaverage level of whole nation since 1952. The total amount of population in wholeTibetan plateau increases from 8,666,000 in 1985 to 9,466,000 in 1990. Till 1997,the total amount of population in whole Tibetan reached 10,365,000, which was

74 FUX.F.

higher than the population bearing capacity of the plateau (the population loadbearing capacity of Tibetan plateau is 10,000,000). And the pressure of futurepopulation increase upon resources environment will become greater and greaterunceasingly. Table 4-3 shows the changes of different part of whole plateau inrecent years.

Table 4-3 Recent population Growth in Tibetan Plateau (104 persons)

YearTibet Autonomous RegionQinghai ProvinceGanzi Prefecture, Sichun ProvinceAba Prefecture, Sichun ProvinceMu1i county, Sichun ProvinceGannan Prefecture, Gansu ProvinceTianzhu county, Gansu ProvinceDiqing Prefecture, Yunnan ProvinceTibetan Plateau

1985199.5407.478.671.910.551.419.328.0

866.6

1990218.1447.782.376.611.358.220.931.5946.6

1991221.8454.483.176.811.455.921.231.8956.4

1993228.9466.783.977.511.560.721.432.1

982.7

1997242.7495.686.580.512.064.321.933.0

1036.5

Source: According to the statistical materials of each province and region

4.4 Main Reasons of Rapid Population Growth

4.4.1 HIGH BIRTH RATE REDUCE HIGH POPULATION GROWTH RATE

Comparing Tibet Autonomous region and Qinghai province with wholecountry from four nationwide censuses, the birth rate of Tibet autonomous regionand Qinghai province was higher than that of the whole country. Although the deathrate in the plateau was also high higher than that of the whole nation, populationgrowth rate was quite clearly higher than that of the whole nation. Table 4-4 showsthe details.

Table 4-4 Comparison of population growth in the Tibet Autonomous Region, Qinghai Provinceand the whole country among the three national censuses

Birth rate(%o) Mortality (%0) Natural increase rate(%o)Year

China Tibet Qinghai China Tibet Qinghai China Tibet Qinghai1964 39.14 / 52.10 11.50 / 15.50 27.64 / 36.601982 21.09 24.47 26.65 6.60 7.66 7.48 14.49 16.81 19.171990 21.06 23.98 24.34 6.67 7.55 7.47 14.39 16.43 16.871991 19.68 23.53 23.37 6.70 7.40 8.35 12.98 16.13 15.021992 18.24 23.63 22.54 6.64 8.09 8.14 11.60 15.54 14.401993 18.09 26.68 20.50 6.64 7.60 8.26 11.45 19.08 12.241994 17.70 25.64 22.06 6.49 8.71 6.82 11.21 16.93 15.241995 17.12 24.90 22.10 6.57 8.80 6.89 10.55 16.10 16.10

Source: The four census data of China, and reference (WANG et al., 1996)


Figure 4-1 shows the changes of the population growth rate in TibetAutonomous region.

The general tendency was that the pattern of population increase had changedwithin a short period. At first, the death rate was lowered quickly and the naturalpopulation increasing speed was quickened, then, the death rate became lower, thebirth rate began to rise at a quick speed, this process ranges from the beginning of1952 to 1970. After 1970, the death rate and birth rate was generally stable, thelevel was relatively lower than before, the death rate slowed down more quicklythan the birth rate. The natural population increase rate rose extremely slowly,which forms the population development situation of steadily quick increase.

199319881983197819731968

(, " ~#

',,1' \\..•. ,-------- _ ... .6'''''\' __ ---_J-,.. ~ ....... -- ~ - _.... -/. '.,I!/' .

1963

35

30

25

20

15

10

5

o- 5

---j ncr ease_. _. - deat h rat e

- - - - bi r t h rat e. - ..... nat ur al i ncr ease rat e

Figure 4-1 Population Growth Rate Change in the Tibet Autonomous Region

The population development tendency of Tibet appears that the populationgrowth pattern had changed rapidly in a short time. First of all, the death ratedecreased in a short time and the natural growth rate increased. Secondly the deathrate further decreased and the birthrate increased rapidly. This process began in1952 and finished in 1970. After 1970 the birthrate and death rate decreased slightlyand the decreased speed of the death rate was a little faster than that of birthrate.Consequently, the natural growth rate increased slightly, which formed a fastgrowth state of the population development.

4.4.2 LARGE- SCALE POPULAnON IMMIGRAnON LEADS TO HIGHMAGNITUDE OF THE TOTAL POPULAnON OF THE PLATEAU

Before the liberation, the economy of the plateau was backward with adverseclimate, special cultural and religion atmosphere, and blocked transportation, andthere were few populations immigrating from the inland. Since 1951, large-scaleeconomic construction has been carried out and professional administrators andtechnicians are urgently needed for newly built industries, farms, schools andhospitals, etc.

76 FU X. F.

From the 1950s, professional technicians and technical workers have beenallotted to support the construction of the plateau. Large number of volunteerscoming from each corner of China joined and acted as diaphysis in the economicconstruction. Mechanical increase of population plays an important role in the totalpopulation of the plateau. Massive immigrants result in great fluctuation of the totalpopulation ofthe plateau (ZHAO et aI., 1994).

After the liberation, there are two obvious periods about population migrationof the plateau, which are 1950s - 1970s, and 1980s - present, respectively. Duringthe first period, population migration was characterized by immigration, namely,remarkable mechanical increase of population. The reason relied on newly builtindustries, immigrants for land reclamation, decommission of the military officials,and allocation of graduate students from senior high schools, colleges anduniversities. From the 1980s, population moving out of the plateau rises greatlywith high - speed developmeilt of the eastern China and changes of political andeconomical environment. The mechanical increase of population is negative.Moreover, most of the population moving out is technical population. Thepopulation migration of the plateau changed from the net immigration within1950s-1970s to net emigration since 1980s.

Taking the Qinghai Province as an example, within the period of 1950s 1990s, the immigrants are 126.23x104 persons, the emigrants are 74.85x 104 persons.So the net immigrants are 51.38x 104 persons. From 1950 through 1959, the netimmigrants were 80.4x 104 persons, and the mechanical increase of population wererapid. However, the mechanical increase slowed down in 1960s. The netimmigrants were 29.6 74.85x104 persons from 1964 through 1979. On the contrary,since 1980s, the population migration is characterized by net emigration andnegative mechanical increase of population. The net emigration were 6.6x 104

persons within 1983-1993.As for the Tibet Autonomous Region, the situation is similar to that of the

Qinghai Province. The mechanical increase of population were 18.94x 104 personswithin 1952 through 1992, which accounted for 21 % of the total of populationincrease. There were about lOx 104 Tibetan population moving out the Tibet within1964-1984. From the 1980s, the population migration of the Tibet presented netemigration of 7.9x 104 persons.

4.4.3 THE AGE STRUCTURE TENDS TO YOUNG TYPE

The age and sex structures are the basic factors, which directly influence thepopulation growth. With the rapid increase of population, the age structure of thepopulation of the plateau has changed remarkably. Due to high natural increase ratereduced by the rising of the birth rate and the lowing of the death rate within 1950s1960s, the age structure of Tibet autonomous region tend to young type (Table 4-5).It means that the base of the young population has been enlarged, which suggeststhat the amount of population will increase fast in the future.


Table 4-5 Age Structure of the Tibet Autonomous Region of 1982 Census and 1990 Census (%)

0-14 years old I the total 40+ 30-40 30'65 years old and older Ithe total 5 5-10 10+65 years old and older/0-14 years old IS- 15-30 30+Age median (years) 20' 20-30 30+

CatalogueInternational Standard

Young Adult AgedYear

198236.614.5912.5820.47

199035.584.6212.9821.08

Source: the census data of 1982 and 1990 of the Tibet Autonomous Region

Table 4-6 indicates that the population age structure of the Qinghai Provincetended to adult type within 1953-1964, young type within 1964-1982, and adulttype again since 1982. The change of population age structure that tended to adulttype within 1953-1964 was mainly influenced by massive migration. Within 19641982 the change of age structure was result of high birth rate and low mortality,which made the natural increase rate rise. From 1982 the age structure of adult typebenefits from the gradual carrying out of the policy of population controllingbeginning from the 1980s.

Table 4-6 Age Structure of the Qinghai Province of four population censuses (%)

Catalogue International StandardYong Adult Aged

0-14 years old Ithe total 40+ 30-40 30-65 years old and older/the total 5 5-10 10+65 years old and older/0-14 years old 15- 15-30 30+Age median (years) 20- 20-30 30+Data source: Reference (ZHAO et aI., 1994)

4.4.4 LOW SEX STRUCTURE OF POPULAnON

195340.032.837.0619.70

Year1964 198238.45 40.562.07 2.705.38 6.64

21.36 18.55

199030.753.079.9822.46

The sex structure of population in Tibet plateau, rather low since long time ago,becomes increasingly high since 1980's. In Tibet Autonomous region, before 1980sthe sex proportion was less than 96.0. In 1982 census the sex proportion marked97.76 and in 1990 census the sex proportion reached 100.16, however it was stillthe lowest one compared to other provinces or regions in china. The situation is dueto the low sex ratio of Tibetan infants and children caused by the low sex ratio ofnewly-born infants and the high death rate of male infants, which will slow downthe population increase in a limited way.In brief, the future population development tendency is that, the quick increasetendency characterized by young population will continue for quite a long time, andthe pressure of future population increase upon resources environment will becomegreater and greater unceasingly.

78 FUX.F.

4.5 Nationality Structure

About 50 nationalities inhabit in the plateau. Besides the Tibetan, they alsoinclude the Han, Hui, Tu, Qiang, Lisu, Sala, Mongolia, Naxi, Vi, Bai, Meiba, Miao,Dongxiang, and other nationalities. The minority population amounts to 597.25xl04

,

which accounts for 61.8% of the total population of the plateau. Among them, theminority population rate is even 94.9% in the Tibet Autonomous Region, and40.2% in the Qinghai Province, which reach the first and third location, respectively,among provinces and autonomous regions of the whole country. It is the highproportion of minority population and multi - nationality structure that determineobjectively the complexity of problem of regional economic development (SeeTable 4-7).

Table 4-7 Outline of the Han and minorities in the Tibetan Plateau

TibetPlateau

Tibet

Qinghai

GannanAbaGanzi

Diqing

Numberof

nationality

51

38

43

232425

25

the Han(104

persons)

369.81

12.00

285.49

28.1316.4622.43

5.30

minorities(104

persons)

597.25

224.00

190.55

33.1968.1655.89

27.50

Proportion ofminority (%)

61.76

94.92

40.20

54.1371.3680.55

83.84

Order of main nationalities(> 1000 persons)

The Tibetan, Han, Hui, Tu,Qiang, Lisu, Sala, Mongolia,Naxi, Vi, Bai, Meiba, Luoba,Miao, Dongxiang, PumiThe Tibetan, Han, Meiba, Hui,Luoba, NaxiThe Han. Tibetan, Hui, Tu, Sala,Mogolia, DongxiangThe Tibetan, Han, HuiThe Tibetan, Han, Qiang, HuiThe Tibetan, Han, Vi, Hui,QiangThe Tibetan, Lisu, Han, Naxi,Bai, Vi, Pumi, Hui, Miao

Data source: Calculated by the Statistical Yearbook o/Chinese Nationalities in 1995; Order ofmain nationalities is basing on the data of the fourth census of China

Among the nationality population, the Tibetan population is most with widestdistribution, and population of other minorities and the Han are relative few withconcentrated distribution (See Table 4-8). There are 38 nationalities in the TibetAutonomous Region, among which the Tibetan occupies 95.5% of the totalpopulation of the whole Region, and population of the Han, Meiba, Hui, Luoba,Naxi just accounts for 3.68%, 0.34%, 0.13%, 0.1 %, and 0.06%, respectively. As fordistribution, the Tibetan distributes all over the Region, the Han mainly in Lhasaand Qando Prefecture, the Hui in the Lhasa city, the Meiba and Luoba in Medog,Nyingchi, Mainling, Cona, Lhunze, Zayu Counties and other counties, the Naxi inthe Mangkam County, while other nationalities scatter here and there. Consideringthe most population and wide distribution of the Tibetan, the Tibetan economybecomes the core of economic development of the plateau. Therefore, it is vital forsocioeconomic development of the plateau to well handle the problem of economic


development of the Tibetan Nationality and its relation with that of othernationalities of the plateau. The multi-nationality structure and particular nationalityrelation confined by multi- nationalities will perpetually be one of important factorsduring the developing process of the plateau.

Table 4-8 Population of nationalities and its distribution of the plateau (1990)

Population Distribution areasNationality

Total populatinProportion accounting Proportion of regional population accounting(104 persons) for the total of the for the total for certain nationality in the

plateau (%) plateau (%)

7.74

0.16

0.31

1.791.451.010.840.78

37.10

2.84

1.44

16.3713.279.277.747.19

70.84

339.62

439.24 47.99 Tibet (47.73), Qinghai (20.76), Ganzi (14.27),Aba (8.55), Gannan (6.30), Diqing (2.39)Qinghai(75.98), Nannan (7.72), Aba (7.19),Ganzi (5.23), Tibet (2.38), Diqing (1.50)Qinghai(90.17), Nannan (5.63), Aba (3.35),Tibet (0.42), Ganzi (0.24), Diqing (0.19)Qinghai (99.51), Nannan (0.43), Tibet (0.06)Aba (98.64), Ganzi (1.28), Tibet (0.08)Diqing (99.89), Tibet (0. II)Qinghai (99.48), Nannan (0.52)Qinghai (99.44), Nannan (0.17), Tibet (0.14),Ganzi (0.13), Aba (0.12)Ganzi (66.20), Diqing (32.75), Tibet (0.43),Aba (0.38), Qinghai (0.24)Diqing (97.92), Qinghai (0.83), Tibet (0.67),Ganzi (0.35), Aba (0.23)

Meiba 0.74 0.08 Tibet (100.00)Luoba 0.22 0.02 Tibet (100.00)Miao 0.20 0.02 Diqing (65.00), Aba (15.00), Ganzi (10.00)Dongxiang 0.17 0.01 Qinghai (90.30), Nannan (9.70)Pumi 0.14 0.01 Diqing (99.86), Tibet (0.14)

Hui

Bai

Yi

Han

TuQiangLisuSalaMonglia

Tibetan

Note: Calculated by data of the fourth census of China.

4.6 The Restrict Resources and the Threat of Over-Population

4.6.1 THE HARSH NATURAL ENVIRONMENT AND THE HUMANACTIVITIES

Tibetan plateau is largely in dry and cold climate, where the heat and waterresources are hardly enough. The widespread disastrous climate in this high altitudeenvironment results in great difficulties for human activities. The high altitude alsohas a significant influence upon the development of human body.

4.6.2 THE FOOD SUPPORT AND THE POPULATION GROWTH

In spite of the extensive areas, the arable land resources are not abundant withsmall proportion of suitable cultivated lands. Since 1952, the cultivated lands of the

80 FUX.F.

plateau have expanded gradually. However, accompanying with the rapid increaseof the population, the area of cultivated land per capita declines. In 1952, the totalarea of cultivated lands reached 16.33x104 hm2 with 0.14 hm2 per capita in the Tibet,and 46.46xl04 hm2 with 0.29 hm2 per capita in Qinghai Province, which in 1995rose to 22.21xl04 hm2

, and 58.99xl04 hm2, respectively. However, the area of

cultivated land per capita in 1995 to 0.09 hm2 in Tibet and 0.12 hm2 in QinghaiProvince, which decreased by 35.7%, and 58.6%, respectively, than that of 1952(See Table 4-9). Presently, there are few barren lands suitable for agriculture in theplateau. In addition, there often exist many limited factors about utilization orcultivation for resources of arable lands. With further development of the totalpopulation of the plateau, it is unavoidable that the area of cultivated land per capitawill decrease continuously.

Grain is basis for survivals of population. The problem of grain has been oneof key factors that restrict the development of population and socioeconomy in theplateau. Since the liberation, the total and specific yields of grains have increaseddramatically, but the level per capita has increased slowly (See Table 4-9). Thefurther development of agriculture in the plateau will only depend on improvementof farming technology so as to increase specific yield. Therefore, large input offunds is needed, and certain scientific and technological knowledge andadministrative ability are required for mass peasants. The limited agriculturalresources could not feed the increasing population in the plateau (SHl, 1987).

Table 4- 9 Population growth and changes of cultivated land, and grain production in the plateau

Total population Area of cultivate Area of cultivated Total grain yield Grain yield per(104 persons) land (103 hm2

) land per capita (hm2) (104 tons) capita (kg)

1952 1995 1952 1995 1952 1995 1952 1995 1952 1995Tibet 115 240 163.3 222.1 0.14 0.09 15.5 70.0 135 292Qinghai 146 481 464.6 589.9 0.29 0.12 37.1 114.2 230 237Data source: reference (WANG, 1996)

Farming in Tibet plateau has a long history. Till 1952, the cultivated land ofTibet reached 163.3 thousand ha. And the per capita cultivated land was 0.135 her.Since 1952 the area of cultivated land increased year by year. Up to 1979, there was229.9 thousand her. of cultivated land in Tibet, which was the highest level in itshistory. After that time the area of cultivated land decreased slightly. However, thecultivated land per capita decreased continually from 1967's highest level of 0.152ha. (Table 4-10). Up to 1995, the area of Tibet's cultivated land was 222.5 thousandha. And the per capita cultivated land had decreased to the number of 0.093 ha. Andper hectare yield had only 3.8 ton. There are few barren lands appropriate forcultivation and exists many restricting factors for cultivation or utilization. With thefurther increase of Tibetan population, it is inevitable for the level of cultivated landper capita to drop continuously. So the store food supply cannot rely on the simpleextension of the cultivated area. The grain supply in Tibet will still be the mainproblem for its regional development with the increase of population. It is


impossible for the limited agricultural resources in Tibet to support a quicklyincreasing population.

Table 4-10 Changes of the cultivated land in Tibet autonomous region

Cultivated land Cultivated land per Cultivated land Cultivated land per~~ ~~(103 ha.) capita (ha.) (IOJ ha.) capita (ha.)1952 163.3 0.153 1977 227.6 -----0:1"29----···1959 167.6 0.137 1978 227.6 0.1271960 185.2 0.146 1979 229.9 0.1261961 188.7 0.145 1980 229.2 0.1231962 194.3 0.149 1981 225.1 0.1211963 194.5 0.147 1982 227.4 0.1201964 197.1 0.146 1983 229.1 0.1191965 202.8 0.148 1984 225.4 0.1151966 205.9 0.147 1985 223.6 0.1121967 217.7 0.153 1986 222.3 0.1101968 218.4 0.151 1987 22 \.4 0.1071969 218.3 0.145 1988 221.5 0.1041970 218.3 0.145 1989 222.4 0.1031971 222.7 0.143 1990 222.5 0.1011972 224.4 0.141 1991 222.9 0.0991973 222.1 0.137 1992 223.8 0.0981974 223.6 0.135 1993 222.6 0.0961975 225.7 0.133 1994 223.0 0.0951976 226.9 0.132 1995 222.5 0.093Source: Calculated by Statistic Yearbook ofSociety and Economy ofthe Tibet Autonomous Regionin 1989 and Statistical Yearbook ofthe Tibet Autonomous Region in 1996.

Grain, as the basis for the population in an area to survive, is always one of thekey factors that restrict the economic development of Tibetan plateau. Such as TibetAutonomous Region, since peaceful liberation, grain production developed rapidly.Total output of the grain had increased from 155.3 thousand ton in 1952 to 719.6thousand ton in 1995, the annual average increase rate reached 3.63%. At the sametime the per unit grain yield increased from 1,204.5 kg/ha. to 3,804 kglha., theannual average increase rate reached 2.71 %, and grain owned per capita increasedfrom 135.1 kg to 300 kg (Table 4-11). Nevertheless the grain production stillcouldn't satisfy the needs of Tibet. Grain support is still the key factors that restrictthe economic development of Tibet Autonomous Region.

In a word, in spite of wide regions and plenty of resources in the plateau, manyresources could not exploited within short period, which is confined by the level ofscience and technology, and economic strength. Moreover, it is difficult for theexploited resources to commercialize with high efficiency because of the influenceof the local economic system. To some degree, the survival space of the populationin the plateau is narrow. Hence, it is the vital strategy for the development of theTibetan Plateau to control the rapid growth of population.

Therefore, the population development direction of Tibet hereafter can only beto tighten quantity control and to popularize family plan knowledge among Tibetan

82 FUX.F.

people. It is a fundamental strategic policy for the social and economic developmenthereafter in Tibetan plateau that the family plan be developed progressively.

Table 4- 11 Changes of grain production in the Tibet Autonomous Region

Year Total output Per unit Grain output per Year Total output Per unit Grainof grain yield (kglha) capita (kg) of grain (ton) yield output per

(ton) (kglha.) capita (kg)1952 155,335 1,204.5 135.1 1977 500,116 2,625.0 284.81959 182,905 1,371.0 149.0 1978 513,449 2.505.0 287.11960 205,934 1,447.5 162.2 1979 423,245 2,047.5 231.71961 225,063 1,468.5 173.3 1980 504,970 2,542.5 272.51962 239,588 1,488.0 181.9 1981 483,749 2,505.0 260.11963 265,188 1,572.0 200.3 1982 447,854 2,272.5 236.71964 272,668 1,539.0 202.5 1983 368,834 1,920.0 191.01965 290,725 1,644.0 212.0 1984 494,489 2,580.0 251.41966 313,916 1,779.0 224.8 1985 530,669 2,737.5 266.01967 334,802 1,761.0 235.1 1986 454,448 2,389.5 224.41968 333,110 1,761.0 229.5 1987 467,043 2,457.0 224.61969 292,249 1,564.5 197.4 1988 508,670 2,707.5 238.91970 294,916 1,563.0 195.1 1989 549,932 2,901.0 254.71971 321,827 1,645.5 207.1 1990 608,280 3,169.5 274.71972 288,893 1,512.0 181.4 1991 644,186 3,357.0 286.31973 373,605 1,975.5 229.3 1992 657,121 3,417.0 287.51974 432,518 2,301.0 260.4 1993 672.185 3.490.5 289.51975 445,827 2,271.0 263.6 1994 664,480 3,547.5 281.41976 478,011 2,503.5 277.3 1995 719,605 3,804.0 300.0Source: Calculated by Statistic Yearbook ofSociety and Economy ofthe Tibet Autonomous Regionin 1989 and Statistical Yearbook ofthe Tibet Autonomous Region in /996.

4. 7 Population Quality and Education

4.7.1 THE PROCESS OF MODERN EDUCATION DEVELOPMENT INTIBETAN PLATEAU

Before peaceful liberation, religion education occupied the main type of theeducation in most part of Tibetan plateau, whose basic characteristics are the factthat the temples undertake the social education duty and the Buddhist scriptures wasthe main content. Although the temple education can carry forward the traditionalculture, it definitely could not promote the modern science and technologydevelopment. Most of the masses of the society except monks could not get thestudy opportunity. The temple education system in Tibetan plateau was obviouslyunsuitable for modern civilization.

In most part of Tibetan plateau, modern education began in 1952. Since 1959the modern school education had developed. Central and local governmentespecially after 1985 has supported the school education. The financial support hadincreased from 80 million yuan in 1985 to 297 million yuan RMB in 1995. Through40 years' effort, an integrated education system from primary school to institutions


of higher education had been established in Tibet. Till 1993, more than 200,000pupil and 100,000 middle school students, 21,000 polytechnic school students and12,000 college students had been trained and graduated under modern schooleducation system.

Before the liberation, the development of education was rather backward. Theinternal students just amounted to 2.8% of the total population in the end of 1949.There was even no modern education before the peaceful liberation of the Tibet,and the religious education with temples as main body had predominated theeducation of the Tibet. As the continuation of medieval religious education, eachaspect of the temple education showed obvious conservatism and limitation, whichwas un-adaptive to the modern civilization.

After the liberation, great development of education in the plateau has takenplace. Taking the Tibet as an example, the education of the Tibet has jumped fromthe medieval religious education to the modern school education. And now thewhole education system has been constructed ranging from primary schools tocolleges and universities. Until 1993, more than 200, 000 pupils, near 100,000students of high schools, 21, 000 polymetric students, and 12,000 undergraduates aswell had been trained, which changed the cultural structure of the population inTibet and pushed the development of the whole society forward from the slaverysystem to the modern society.

4.7.2 POPULATION CULTURAL QUALITY

The improvement of cultural quality and educational level plays an importantrole in the development of regional economy.

With the construction and development of the modern education within thewhole Plateau, the cultural quality of the population in the plateau rises greatly.Even so, the level is relative low. For example, compared to the level of the wholecountry, the educational level of the Tibet is still much lower, the proportion of theilliterate and semi - illiterate is as high as 2.88 times of that of the whole country,and the proportion of cultural population of each walks is lower.

As for the educational level of employees in the Tibet, in 1990 the populationwith the cultural level of college and university, senior high school, junior highschool, preliminary school, the illiterate and semi-illiterate accounts for 0.97%,3.25%,5.53%,3.35%, and 66.90% of all the employees, respectively, which showsthat the whole quality of the employees is rather low. The labors of agriculture,forestry, livestock husbandry, and fishery count for 79.1 % of the whole employees,among which the proportion of the illiterate and semi - illiterate reaches 79.4%.Undoubtedly, such low cultural quality of the employees is the biggest obstacle forthe sustainable development of the plateau.

The population's cultural quality rises rapidly with the rapid advancement inmodern education system in Tibet. Comparing with 1982 census and 1990 census, itappears that the education level of the Tibet's population had distinctly been raised(Table 4-12). However, compared with the whole nation, Tibet's education level isstill the backward area (Table 4-13).

84 FUX.F.

Table 4-12 Compare levels of education between censuses in 1982 and 1990 in Tibet

Level of 1982 1990 Growth rateEducation Population Ratio of population Population Ratio of population (%)

~6 years old (%) ~6 years old ( %)College 8,022 0.51 12,417 0.67 0.16Senior middle 22,925 1.44 46,564 2.50 1.06schoolJunior middle 68,232 4.30 84,524 4.54 0.24schoolPrimary school 308,436 19.43 407,939 21.90 2.47Illiteracy 872,835 54.98 980,883 52.60 -2.38Source: Census data of 1982 and 1990 in the Tibet Autonomous Region.

Table 4-13 Level of education of population in 1990 in Tibet and its contract to whole nation

University 0.46 0.24College 0.79 0.43Polytechnic school 2.43 1.30Senior middle school 2.23 1.20Junior middle school 8.45 4.54Primary school 40.79 21.90Illiteracy 98.09 52.65

Level ofEducation

Tibet autonomous regionPeople Ratio of population

(103 persons) ~6 years old %People

(103 persons)62.6296.87170.82726.30

2,631.444,209.941,822.46

ChinaRatio of population~6 years old %

0.630.971.727.3026.4442.3018.31

Source: Census data of 1990 of the Tibet Autonomous Region.

4.8 Religion and Monk Population

As a unique form of Buddhism, the religion of Tibet deeply influences the allpacts of the Tibet's politics, economy and culture. Tibetan Buddhism acts a veryimportant impact Tibet's population, society, economy and culture.

The prosperous state of Buddhism in Tibet caused the rapidly increasednumbers of the monk. According to the accounts, in 1,694 there were 1,807 templesand 97,538 monks in Tibet. Till 1,737 of Qing Dynasty, temple number reached3,477; monk's number was 316,231, which made up one-thirds of the Tibet'spopulation. This phenomenon produced a great impact for the social productiondevelopment and population growth of Tibet and Tibetan area.

Before 1958, there were 2,711 Buddhism temple in Tibet and monk's numberreached 114.1 thousand, which account for 9.51 percent of the total population ofTibet. In 1976 there only had 8 open temples and only 800 monks that made up 0.05percent of the total population of Tibet. Since 1978, many temples have beenopened anew, and the numbers of monk have been rising gradually. In 1986 therewere 234 open temples and 6,466 monks, which occupied 0.32% of the totalpopulation. Till the end of 1990, the open temples reached 1,353 and the monk's


number increased to 26,000, which occupied 1.24% of total population of TibetAutonomous Region. Furthermore, the number of monks has been increasingconstantly these days (see Table 4-8).

With the development of Buddhism, the temple force and the number ofmonks increased rapidly, which induced a large number of labor populationsreleased from production. The Tibetan area's economy came to a standstill in a longtime. After democracy reform, Tibet's traditional serf and temple system wereabolished, the religion privilege was given up and the religion force and influencewas greatly weaken. However, up till the present the religion population still hasimpacts on Tibet's society and economy. Especially after opening and reform, a lotof strong labor forces have become temple's monks. In addition a large number ofmonks live in their family and this number have been increasing year by year. In1994 the number of monks accounted for 1.8 percent of total population in TibetAutonomous Region. This phenomenon no doubt affects the social and economicdevelopment in Tibet in some way.

Table 4-14 Outlook of change of the monk's number in Tibet

7

Number of monks I totalpopulation (%)

7

Number of monks( I03 persons)

100

Total population( I03 persons)

Year

Middle of 13th Century(Yuan Dynasty)18th Century(Qing Dynasty) 93-100 31.62 33.7.

1958 120 11.41 9.511960 126.98 1.81 1.431976 172.40 0.08 0.051986 202.49 0.65 0.321990 218.05 2.60 1.24Source: The Population ofChina Towards the 21st Century: Tibet Autonomous Region.

Tibet's development must be based on the reform of existing religion and thepropagation of modern knowledge. Under the circumstance of huge contrastbetween the requirement of modern social and economic development and existingtraditional religion culture, more attention should be paid to the social publicwelfare such as medical and health work, infrastructure construction and providingdisaster relief etc. to promote Tibet's development. At the same time major effortsmust be devoted to developing modern education. And the process of urbanizationmust be push on. With unremitting efforts, Tibet can surely move to amodernization society.

4.9 Urbanization

4.9.1 PROCESS OF URBANIZATION IN THE PLATEAU

The history of towns in the plateau is long. However, the development of

86 FUX.F.

towns in the plateau was slow because of their location, weak base of regionalsocio-economy, low production level, and backward transportation. The level ofurbanization lagged behind that of the whole country. By the time of 1952, therewas 75,000 towns population, which accounted for 6.5% of total population in theTibet. Among them, there were only 30,000 populations in the Lhasa with narrowstreets, simple house, and little public infrastructure. As for the Qinghai Province,there was 83,800-town population, which just occupied 5.2% of total population.The development of towns of wide Tibetan regions in the plateau was confinedmainly by the development of Buddhism, and the construction of temples was theoriginal driving force of the development of towns (FU, 1994; ZHA et al., 1994).

After the peaceful liberation, the speed of urbanization in the plateauaccelerated obviously accompanying with resource exploitation, the natural increaseof population and immigration, process of industrialization, and development oftransportation. By 1997, there were five cities and 69 towns in Qinghai and theTibet. The town population amounted to 2.1356 million persons that accounted for28.9% of the total population. Among the town population, population living incities reached 1.4789 million persons that occupied 69.3% of the total townpopulation.

Generally speaking, the development of towns in the plateau is backward.Besides, its spatial difference is remarkable (See Table 4-15). The rate ofurbanization in the Qinghai Province attained to the national level in 1962.Thereafter, the urbanization developed slightly faster than that of the whole countrywith high rate of urbanization. While for the Tibet, its rate of urbanization was just10.3% in 1985, and was only half of that of the Qinghai Province in 1997.

Table 4- 15 Comparison of Urbanization between the Tibet, Qinghai and the whole China

China Tibet Autonomous Region Qinghai ProvinceYear Urban Rate of Urban Rate of Urban Rate of

population urbalization population urbalization population urbalization(104 persons) (%) (104 persons) (%) (104 persons) (%)

1952 7163 12.46 7.50 6.50 8.38 5.21957 9949 15.39 / / 30.04 14.71962 11659 17.33 / / 35.49 17.31965 13045 17.98 10.87 8.10 37.98 16.51970 14424 17.38 / / 48.68 17.21975 16030 17.34 / / 62.99 18.71978 17245 17.92 (25.92) (14.5) 67.84 18.61980 14424 17.38 18.30(26.15) 9.80(15.5) 74.71 (96.51) 20.1 (25.6)1985 25094 23.71 20.53 (25.74) 10.3 (12.9) 137.75116.14) 33.8 (28.5)1988 28661 28.51 27.84(31.1) 13.1 (14.6) 146.86(126.27) 33.8(29.1)1990 30191 26.41 35.68 (29.83) 16.4 (13.7) 153.22 (126.47) 34.2 (28.3)1995 35174 29.04 39.38(32.49) 16.7(13.8) 163.13(130.42) 33.9(27.1)1997 36989 29.92 41.72 (33.6) 17.2 (13.8) 171.94 (131.79) 34.7 (26.6)Note: Numbers within brackets are that of nonagricultural population and its proportion.


4.9.2 DRIVING FORCES OF THE URBANIZATION

The main dynamic mechanism of the rapid urbanization process beginningfrom the 1950's in the plateau is up-down. Since the reform and the open policy iscarried out, much attention has been paid to the construction of the plateau, and theurbanization process has been accelerated. Although its dynamic mechanism is stillthe up-down investment pulling by the government, many new investment typescome into being. The multiply driving forces of the urbanization mainly show asfollows.

(1) Investment to resource development by the governmentThe Plateau is characterized with broad land and sparse population, plenty of

resources, and insufficient funds and technological strength. Therefore, manyimportant projects have been constructed by the direct investment of the centralgovernment. Consequently, large numbers of resource - development immigrationhave appeared, which then speed up the process of urbanization.

(2) Integral removal of enterprises from the inland and coastal areasThe potential influence of the shift- in modem industries and the reservation of

funds, technology and market prepare for good base for the process of urbanizationin the plateau. Taking the Qinghai Province as an example, during the periods of"the third-five" (1966-1970) and "the fourth- five" (1971-1975), there were near50,000 works removed to Qinghai. If their relatives accompanying with themtogether were taken into account, the number would be 120,000 persons.

(3) Establishment and enlargement of administrative organizationsAccording to the lack of constructive personnel, specialized technicians and

technical workers have been allocated from each comer of China to support theconstruction of the plateau since 1950's. Meanwhile, lots of new administrativeorganizations have been built and the original ones enlarged continuously as well.Since the peaceful liberation of the Tibet Autonomous Region, a large number ofpersonnel of science and technology, education, administration have been importedannually to the Tibet.

(4) Transfer of agricultural surplus labors and afflux of quantities of individualbusinessmen

Since 1979, the surplus labors of agricultural and pasturing areas have beenencouraged and supported to work in the third industry in cities so as to speed upthe transfer from the natural economy to commercial economy in pasturing areas,which stimulates the remarkable growth of nonagricultural population. In the mid1980's, the individual and private economy played more and more important role inthe process of urbanization when the policy that peasants could trade or work incities was carried out. Within the period of 1984-1992, in Tibet the number ofindividual businessmen had increased by 18% from 15,341 to 18,127, and theemployees of individual businesses increased by 92% from 12,918 to 24,830.

References

1. CHEN Qingying and FENG Zhi, 1995. Administrative Division of Tibetan Areas, Beijing:

88 FU X. F.

China International Press.2. MA Rong, 1996. Tibet's Population and Society, Beijing, Tong Xing Press. 32 (In Chinese).3. ZHANG Tianlu, 1989. The change of Tibet's Population. Beijing: China Tibetology Press.

(In Chinese)4. Liu Rui, 1988. Chinese population: Tibet Autonomous Region. Beijing, China Finance and

Economy Press. (In Chinese)5. DUOJIEOUZHU, LI Yongshen and XI Jingsheng, 1994. The Population of China Towards

the 21st Century: Tibet Autonomous Region. Beijing: China Statistics Press, 460. (InChinese)

6. HU Congqing, 1990. Hu Huanyong's Selected Works of Population Geography, Beijing:China Finance and Economy Press, 56. (In Chinese)

7. CAl Songtian, 1989. Chinese population: Qinghai Province. Beijing: China Finance andEconomy Press, 36-70. (In Chinese)

8. WANG Tianjing, 1996. The Population and Environment of Qinghai-Tibet Plateau. Beijing:China Tibetology Press (In Chinese)

9. SI Kerning, 1987. Economic Geography of Qinghai Province. Beijing: Xinhua Press. (InChinese)

10. FU Conglan, 1994. The History of Lhasa. Beijing: China Social Sciences Press. 35. (InChinese)

11. ZHAO Henglun and SONG Xuiyuan, 1994. The Population of China Towards the 21 stCentury: Tibet Autonomous Region. Beijing: China Statistics Press. 10-53. (In Chinese)

CHAPTER 5 CLIMATE: PAST, PRESENT, AND FUTURE

LIN Zhenyao, ZHANG Xueqin, YIN Zhiyong

The Qinghai-Tibetan Plateau is characterized by its vast area and strong thermaland dynamic forcing, which make it one unique climatic unit distinguished fromother regions of the same latitude. It exerts strong influences on the atmosphericconditions in its surroundings, as well as regional and global climatic conditions. Theuplift of the plateau during the past several million years has greatly affected theenvironment of the plateau itself, the neighboring regions, and the globalenvironmental changes.

At present, climatic records over the plateau are incomplete, with short timeseries of instrumental observation, lack of proxy materials, and uneven spatialtemporal distribution. Therefore, it is necessary to calibrate as many multi-proxyrecords as possible, and to reconstruct representative and reliable climatic time-series.Since the mid-20th Century, the characteristics of climatic changes induced bymacro-scale uplift of the plateau were primarily clarified by comprehensive analysis,verification using historical literatures, modem meteorological observation records,and the limited proxy materials (e.g., ice core, tree ring, lake sediments, etc).

This chapter will emphasize on the following topics: (l) uplift of the Qinghai Tibetan Plateau and the monsoon system; (2) climatic changes during historicalperiods; (3) heat sources and sinks of the plateau; (4) moisture pathway and its geoecology effects; and (5) sensitive regions for climatic changes.

5.1 Uplift of the Tibetan Plateau and Monsoon System

As described in Chapter 2, the Qinghai - Tibetan Plateau had experienced threestages of tectonic uplifting and two stages of peneplanation. Before 3.4 Ma BP, theplanation surface that was estimated to be less than 1000 m asl extended broadly overthe plateau. Thereafter, the strongest tectonic uplift occurred during the late Tertiaryand the early Quaternary, and then the modem plateau began to come into being(SUN et al., 1998; SHI et aI., 1997, 1998, 1999; ZHONG et aI., 1996).

5.1.1 UPLIFT OF THE PLATEAU AND ITS MONSOON SYSTEM

The geomorphic evolution of the plateau in the past 40 Ma was correlated withatmosphere continuously, for which the evolution of the plateau monsoon system was

89

ZHENG Du. ZHANG Qingsang and WU Shaohong (eds.). Mountain Geoecology and Sustainable Development of theTibetan Plateau, 89-112.©2000 Kluwer Academic Publishers.

90 LIN Z. Y., ZHANG X. Q. and YIN Z. Y.

closely associated with the uplift process of the plateau. The GCM numericexperiment showed that the East Asia monsoon is rather sensitive to the uplift of theplateau, and that the impact of the uplift on the East Asia winter monsoon is greaterthan that on the East Asia summer monsoon. In addition, the monsoon regime did notexist in East Asia north of 300 N when the plateau was below half of its present height.On the other hand, there is a controversy about the impact of the uplift on the SouthAsian (Indian) monsoon. Several earlier studies have shown that the Plateautopography has caused significant changes in the surface circulation pattern in Southand Southeast Asia. However, a more recent study suggested that a monsoon regimecould have existed even without the Plateau topography, as the result of low-latitudeplanetary winds and meridional land-sea thermal contrast.

During the early Tertiary the plateau was mainly characterized by zonaldifferentiation as induced by the planetary wind system. In Pliocene age of the lateTertiary, the plateau surface might be at an elevation of 1000 m asl or so andmoisture coagulation level was attained, then the pressure system could maintainbecause of thermal forcing. Consequently the plateau monsoon began to form.However, such plateau monsoon was not stable, therefore, it could be called shallowplateau monsoon system when climate in the plateau was humid and warm (TANG etaI., 1997).

The strong uplifts of the Qinghai-Tibetan Plateau began since 3.6 Ma BP wasnamed by Qinghai-Tibet movement (LI et al., 1996, 1998), which was accompaniedby disintegration of the main planation surface, and formation oflarge faulting basins.At 2.5 Ma BP, the plateau reached a dynamic threshold height (about 2000 m asl)that could exert significant influence on the atmospheric circulation over andsurround the plateau. When the plateau surface attained 3000 m asl in late midPleistocene, both horizontal and vertical scale had exceeded the threshold scale forthe formation of plateau monsoon. And then, the plateau monsoon system was stablewith the decrease of temperature and obvious increase of precipitation. The planetarywind system changed from climbing atop the plateau to bifurcating around theplateau, and the shallow plateau monsoon system was replaced by deep plateaumonsoon. This event signaled the formation of the modern monsoon pattern.Coincidentally, loess began to accumulate in northern China from 2.5 Ma BP.

During 0.8 Ma-0.5 Ma BP, the plateau surface might be uplifted further to 3000m-3500 m, and mountain ranges were even over 4000 m. Temperature decreasecaused by uplift was coupled by the global orbital transition called as "the radicalchange of mid Pleistocene". Cryosphere and the macro-scale glaciers began to formin high mountainous regions of the plateau. The area of glaciers amounts to over50x 104 km2 (SHI et al., 1995). Persistent ice and snow cover over the plateauincreased the albedo and strengthened the clod high over the plateau, which furthercooled the plateau. Strong plateau monsoon blowing outward towards the ArabianSea caused the drop of the sea surface temperature (SST), which weakened thesummer monsoon. The climate changed abruptly over the plateau that wascharacterized by the marked strengthening of the plateau winter monsoon and theweakening of the plateau summer monsoon. Meanwhile, precipitation of the middleand eastern China was 2-3 times higher compared with nowadays, which was in

CLIMATE: PAST, PRESENT AND FUTURE 91

sharp contrast to the rather dryness of the western China. In addition, the plateau withice and snow cover became a strong heat sink resulting in expansion of the desertsand loess deposition of the northwestern China.

At 0.15 Ma BP, an abrupt and inhomogeneous tectonic uplift occurred, and themarginal mountains of the plateau became barriers for the intrusion of warm andhumid air masses. Thereafter, with the advent of the interglacial period, the melt ofice and snow, and the albedo of the land surface decreased. The plateau became aheat source relatively to the atmosphere, which endowed the plateau some of thecharacteristics of the modem plateau climate (SHI et al., 1998, 1999).

5.1.2 UPLIFT OF THE PLATEAU AND CHANGES OF TEMPERATUREPATTERN

Based on integrated analysis, before its strong uplift, the Qinghai-TibetanPlateau was dominated mainly by a weak high-pressure system (Lhasa high) inwinter, and the Siberian-Mongolian high north of the plateau didn't exist. The landsurface of the plateau and the troposphere were prevailed by northerly, and weakwesterly flows. In summer, the regions south of the plateau were dominated bysoutheasterly flows with a warm and humid subtropical sub-humid climate (LIN etaI., 1981).

o

........ 16....... ----8

Qandoo

6"---_16 ~---

6'-_-=--__ 6I (_8_....... \:

\ \ \ ' ....... "- 1 - - _ " " " ,," 14"'16 -_ " " ..... "-

- , '" -6..... " ........ ./..... _ ) \ 0---- e- - -,./ Geerllu Xining

\

Late Tertiary Late mid - Pleistocene

Figure 5-1 Temperature distribution for the Qinghai - Tibetan Plateau during the late Tertiary(solid line) and mid - Pleistocene (dash line)

92 LIN Z. Y, ZHANG X. Q. and YIN Z. Y.

With the uplift of the plateau, major mountain ranges (e.g., Himalayas andKunlun Mountains) rose to more than 4000 m asl, and temperature declinedsignificantly. At that time, the weak Lhasa high in winter strengthened, while itslocation moved northward and eventually formed the present Siberian-Mongolianhigh. Meanwhile, the East and South Asia monsoons enhanced, which caused theclimate of the plateau to change dramatically.

At the late Teritary, the plateau surface was only approximately 1000 m asl, andthe highest mountain, the Himalayas was just about 3000 m as!. Figure 5-1 suggesteda roughly zonal pattern of temperature spatial variation. The relative relief of the lowreaches of the Yarlung Zangbo River valley was low, and there were high mountainbarriers to both its north and south. Therefore, cold air was difficult to invade thelower valley area, making it relatively warm. Compared to present, one remarkablecharacter for temperature variation pattern over the plateau at that time was that thenorth-south temperature gradient was much smaller than that of nowadays.

At the late mid-Pleistocene, the plateau surface was about 3000 m asl withtemperature of 8-1 ooe or so. Compared with the modern condition, the former zonalpattern had changed to a pattern with a gradual decrease from the southeastern to thenortheastern. Moreover, regions with low temperature were found in the KunlunMountain area. In those days, the Qaidam Basin had begun to form, withtemperatures warmer than its surroundings. In addition, the north-south temperaturegradient became greater than that of the late Tertiary, but still smaller than that ofmodern times. The spatial pattern of temperature distribution of the late midPleistocene had a transitional nature, from the Iate-Tertiary to the moderntemperature regime. With a gradual decrease of temperature, an enhancement oftemperature gradient from the southeastern to the northwestern, and the influence oftopography, this pattern approached more like the modern once. The mid-Pleistoceneshould be an important milestone for climatic changes over the plateau during thegeologic age (Figure 5-1) (LIN et al., 1981; SUN, 1996).

5.1.3 CLIMATIC CHANGE SINCE THE LAST INTERGLACIAL AGE OVERTHE PLATEAU

Based on analysis of 8 180 in Guliya ice core, the climatic changes over theQinghai-Tibetan Plateau since the last interglacial age can be divided into five majorstages: the last interglacial (125-75 Ka BP), the early (75-85 Ka BP), middle (58-32Ka BP), and late stages of the last interglacial period (32-10 Ka BP), and theHolocene (10 Ka BP-present). The five stages corresponded well with the 5-1oxygen isotopic stages of the deep ocean records (YAO et aI., 1995, 1996). At theLast Glacial Maximum (LGM), the average temperature of the plateau decreased by7°C and the precipitation just 30%-70% of that of present times. The area of glaciersincreased to 35xl04 km2 (SHI et al., 1997). Additionally, studies on ice cores, lakesediments, and loess profiles indicated that climate changes over the plateau wereunique, with great climatic variability across the plateau, warmer interglacial periodsthan other regions, rapid transition to the glacial periods, and slow warming at theonset of interglacial periods.


Analysis of the records of 8180 and N03' concentration of the Guliya ice coresuggested that the temperature change over the plateau was intimately related withsolar radiation variations that has been regarded as a major driving mechanism ofclimatic changes over the plateau.

According to comparative studies on ice core records of the Antarctica, theArctic, and the plateau regions, the major cold or warm events were consistentglobally. While the amplitude of each event and the minor climatic events variedwith the region, the change magnitude over the plateau was larger than that in theAntarctica and the Arctic regions.

5.2 Climatic Change during the Historical Periods

5.2.1 DESCRIPTION ABOUT TIME SCALE AND MATERIALS

The focus of this section is on climate changes during the past 2,000 years. Thisis the period when human society has exerted the greatest influence on the Earth'senvironment. It is also a period where historical documents overlapped with naturalproxy records of climatic variations and changes, including the Medieval WarmPeriod, the following Little Ice Age, and the warming since the Industrial Revolution.The study on the historical climate and environmental changes over the past 2,000years is very important for understanding the processes of climatic changes atregional and even global scale.

Constrained by the social and historical conditions, available historicaldocuments about the Qinghai-Tibetan Plateau have been relatively sparse.Furthermore, the historical records are often discontinuous. From the late 1970s andthe early 1980s, the government of Tibetan Autonomous Region initialized the effortto organize and compile Tibetan official archives in the Budala (Potala) Palace,particularly the records on natural disasters. These archives not only includedmemorials to Dalai Lama, Ga Sha (former Tibet local government) and Yi Cang(Secretariat of Dalai Lama) by Tibetan local government officers, including Lamas,Zong Bi (county magistrate), local headmen and others, but also includedcorrespondences delivered by Da Lai and Ga Sha.

The Tibet Local Archives Series were formally published in Chinese since themid-1980s, including three volumes on snow hazards, floods, and disasters of hail,frost and insect, respectively (Chancery of Tibetan Autonomous Region et al., 1985,1990a, 1990b). Since these records were extracted from the Tibetan official files, thereliability should be high.

You Tai, a senior official dispatched to Tibet by the Emperor of Qing Dynasty,recorded his activities and observations in details during Feb. 9, 1904-April 17, 1907when he was in Lhasa. LIN Zhenyao et al. (1984) compiled the You Tai LhasaWeather Diaryl), an important document describing the climatic characteristics ofLhasa during the early 20th Century. In addition, modern meteorologicalobservational records and proxy records (especially tree rings an ice cores) were

I) You Tai Lhasa Weather Diary (the collator is LIN Zhenyao)


included in the analysis as well.Based on aforementioned data, the characteristics of historical climate changes

and climate disasters of Tibet were investigated (LIN et at., 1977, 1984, 1986; WUet at., 1981).

5.2.2 CLIMATIC CHARACTERISTICS DURING THE PAST 2 000 YEARS

TemperatureThe temperature index curve for the Qinghai-Tibetan Plateau over the past

2,000 years was obtained by combing data from tree rings, historical documents, andmeteorological observations (WU et at., 1981). The index values in Figure 5-2 are50-year moving average with a value of 3.0 representing normal temperature, andhigher or lower than 3.0 representing warmer and colder conditions, respectively.The corresponding X - axis is the terminal year of the moving period.

4 -

l\ ---I I ...-

I' ~'- -----~-_ ~:Ff:i::~ - --"~~ -fZi

3f=<;..~Q.

e 2 -~

500 1000 1500 2000 Year

Fig 5-2 Temperature grade of the Qinghai-Tibetan Plateau over the past 2 000 years

Figure 5-2 revealed that it was colder at beginning of the Christian era. Then itbecame approximately I°C warmer than today's condition during 100-200 AD.During 200-400 AD, the temperature was again probably I°C colder than today's.Between the 6th through 12th centuries, there was a relatively warm period that wasgenerally consistent with the records based on Guliya ice core (901-1100 AD, 12011405 AD) and Dulan tree ring (819-1086 AD) (YAO et at., 1996; KANG et at.,1997). Thereafter, the climate became colder again, particularly around the mid-17thCentury. Although there were short warm periods, a large amount of data andevidence indicated the existence of an unusually cold condition on the plateau. Themean annual air temperature was about I°C lower than normal. During this coldperiod, the majority of the mountain glaciers on the plateau advanced significantly.Since the mid-19th Century the climate has been warmer. However, according to thediary of You Tai (LIN et aI., 1984), it was colder at the beginning of the 20th Centurythan in recent years. For example, ponds froze over frequently in Lhasa at that time,and people could walk on them.


Precipitation andflood-droughtData from Guliya ice core indicated that the precipitation was low during 400

1400 AD, and then increased from 1500 to 1700 AD. It reduced in the 19th Centuryand then increased in the 20th Century. The highest precipitation reached 400 mm/a,while the minimum was only 150 mm/a during this period (YAO et al., 1996).

On the basis of historical documents and modem meteorological observationalrecords, an index of flood/drought condition from 1883 through 1984 wasconstructed in Figure 5-3. The moisture condition was classified into 5 levels: severeflood (1.0), moderate flood (2.0), normal condition (3.0), moderate drought (4.0), andsevere drought (5.0). There were three wet periods (1883-1906, 1916-1934, and1947-1962) and three dry periods (1907-1915, 1935-1946, and 1963-1980). The wetperiods seemed to become shorter over the time, while the dry periods became longer.The first dry period covered only 9 years, the second 12 years, and the third 21 years,probably indicating a drying trend of the plateau. Because of the drying climate, evenwhen the annual precipitation in agricultural regions in the southern Tibet doubledthe normal annual amount, e.g. in 1962, floods didn't occur. However, wheneverannual precipitation was 100 mm lower than the normal years, serious droughts wereexperienced in spite of improved water conservancy facilities (LIN et aI., 1986). Inaddition, other evidence demonstrated the drying trend. For example, the depth ofunderground water in the 1980s was much lower than that in the 1910s (GAO et al.,1984).

o

1924 1931 1949 1954

2

i>'l~'0 3c--.c: 4e'0

5

6

1913 1937 1956 1961 1915 1983

1883 18'33 1903 1913 1923 1933 1943 1953 1963 1913 1983~

-Flood/drought grade - 5a moving average value ~ Dry period

Figure 5-3 Flood and drought index of the Qinghai - Tibetan Plaleau from 1883 through 1984


5.2.3 SPATIO-TEMPORAL CHARACTERISTICS OF MODERN CLIMATECHANGES 1)

Climate over the Qinghai-Tibetan Plateau is sensitive to global climatic changes.Considering its geographic location and unique physical environment, it is veryimportant to analyze meteorological observation records of the plateau for a betterunderstanding of the plateau's climate and its connection with the global climaticchanges. Such analysis may also assist predicting the climatic and globalenvironmental changes. During the 1950s, the network of weather stations wasestablished and the monthly temperature and precipitation data were collected for 50stations with long and relatively complete records for this study. Data for otherstations were used as the supplement, especially in the process of filling missingvalues using spatial interpolation and auto-regression models.

Temperaturei) Mean annual and seasonal temperature

The inter-annual variability of temperature was greatest in winter for themajority of stations over the plateau, followed by that in autumn and spring, and wassmallest in summer. This indicated that the magnitude of fluctuation of wintertemperature was larger than that of summer. The variability of winter temperaturewas mainly caused by short-term annual or biannual oscillations. The seasonalchange of temperature over the plateau was evident, which is consistent with that ofmajority of China (ZHANG et aI., 1997).

Generally speaking, the mean annual temperature was better correlated withspring or autumn temperatures than that of summer or winter over the plateau.Therefore, spring and autumn temperature of the plateau could well reflect thevariation pattern of the mean annual temperature. In other words, mean annualtemperature was often the result of the fluctuation of spring and autumn temperature.In contrast, for Hetian, Qiemo, Ruoqiang stations located on northern slope of theKunlun Mountains in Xinjiang Uygur Autonomous Region, along the northwesternfringe of the plateau, the mean annual temperature is remarkably better correlatedwith summer or autumn temperature than that in spring or winter. On the other hand,both annual and seasonal temperatures displayed prominent spatial variability.ii) Trend of temperature variation

The mean annual temperature for most of the plateau's stations has been risingfrom the 1950s through the mid-I990s, as indicated by positive inclination of lineartrend lines, particularly for Mangya (0.0709oC/year), Golmud (0.0652oC/year), andDingri (0.0568oC/year). Among 11 stations that temperature dropped 4 of them(Ganzi, Kangding, Yaan and Maerkang) were located in western Sichuan Province. Itis interesting to note the cooling trends in winter and summer temperatures inwestern Sichuan Province during the past decades, which seemed to be in sharpcontrast with the rest of the plateau. SHAO et al. (1999) also pointed out that winter

1) Contents of this part are extracted from ZHANG Xueqin's dissertation (1999)-Analysis about thecharacteristics ofclimatic change over the Qinghai-Tibetan Plateau during the past 2, 000 years.


of the second half of the 20th Century was colder in western Sichuan, but thentemperature had been rising remarkably since the 1960s. Among more than 100stations participated in analysis, there were only 11 stations located in westernSichuan and the remaining 7 stations all displayed warming trends.

For the majority of the stations over the plateau, the trends in wintertemperature was well consistent with that of annual temperature, both increasedduring the past decades. The stations with cooling summer temperature were mainlyfound in the northeastern part of the plateau. The rate of warming for wintertemperature at approximately 3/4 of all stations was greater than that for summertemperature. Compared to winter temperature, summer temperature rose only slightlyor even declined. The stations with greater summer warming than winter warmingwere mostly located in the southern Tibet Autonomous Region.

'3 0

G 0.0185% G0 ~ -1'-' 8~ ~.. .. -2= =- -= 7 =.. .. -3401 401Cl. Cl.E 6 E -4~

1951 1959196719751983 1991~ 1955 1963 1971 1979 1987 199~

Lhasa8 4

G y = G~ 7 ~ 3

401 ~.. ..= =- -= 6 = 2.. ..401 ~Cl. Cl.E

5E

1~ ~1956 1964 1972 1980 1988 1996 1957 1964 1971 1978 1985 1992

Xigaze Lertghu8 ------~I

G G 5 y : 0.023&. + 2.5247 i~ ~i~ ~.. ..

= & =- -= = 3.. ..401 ~Cl. Cl.E E~ 4 ~ 1

1954 19&2 1970 1978 198& 1994 1951 1959 19&7 1975 1983 1991

Xining ¥ushu

Figure 5-4 Annual temperature curve of six representative stations of the plateauNote: Thin line, thick dot line, and thick line represent temperature change, linear trend of

temperature, and five- year moving average temperature, respectively.

iii) Abrupt change in temperatureAbrupt climatic changes are sudden transitions from one stable state to another.


They often manifest as consistent changes of climate from one statistic feature toanother. There are many different methods to analyze abrupt changes of climate (FUet al., 1992; FU, 1994). Judged from the consistency of algorithm output, thealgorithm of Mann-Kendall is considered the most ideal because it is non-sensitive tominor change so as not to identify too many abrupt changes. Since the purpose hereis not to find the actual years of the abrupt changes, the Mann-Kendall algorithm wasused only to identify the time ranges of abrupt changes and to specify thecharacteristics of temperature time-series.

The results showed that there was an obvious period of abrupt temperaturechanges over the plateau from the mid- and late-1970s to the early 1980s. Since the1980s, there had been one remarkable period of high temperature across the plateau.Furthermore, the higher the altitude, the greater the warming (LIN, 1993). It isimportant to point out that there was significant regional differentiation for the mostrecent warming period beginning since the 1980s. Not only was the beginning timedifferent from station to station, but also the sustaining length and the rate of increase.For example, positive temperature anomalies of Lhasa were found between 1984 and1996, suggesting that Lhasa entered the latest warm period in 1984, which sustaineduntil the late 1990s. However, for the same warm event, warming at Xining, Lenghu,and Hetian occurred later with smaller rate of temperature increase. Moreover,temperature at these three stations declined around the mid-1990s (Figure 5-4).

Comparison oftemperature changes between the plateau, world, and Chinai) The trend of global temperature changes

Recent research (Jones, 1999) indicated that: (1) annual global surfacetemperatures warmed by 0.6oC from 1861 to 1997; (2) the warmest years on recordall occurred in the 1990s; (3) most warming in the 20th Century occurred in twodistinct periods: 1925-1944 and 1978-1997 (Figure 5-5(b)). Mann et al. (1999) alsopointed out that the 1990s would be the warmest decade of the millennium, with1998 the warmest year so far. It was also found that the warming in the 20th Centurycountered a 1,OOO-year-iong cooling trend. Analysis of LIN el al. (1995) showed thatthe variations of the mean temperature over entire China were similar to that over theworld (Figure 5-5(a)).ii) Temperature comparison

There exist remarkable differences in temperature changes between the plateauand eastern China. Comparison of temperature anomalies was performed betweenLhasa, Beijing, Shanghai, and the North Hemisphere (NH in short) during 19511995.

Table 5-1 and Figure 5-6 suggest that mean annual temperature at Lhasa,Beijing, Shanghai, and NH tended to increase with positive anomalies and positivelinear inclination during 1951-1995. Taking Lhasa as an example, its meantemperature anomaly was 0.07oC, and its linear rate of change was +0.0176oC/year,which was only second to that of Beijing. In addition, the temperature standarddeviations of Beijing and Lhasa were high, indicating considerable inter-annualvariability.


1.5

~..E O. 50.. /..

~a)~ 0=fX- -0.5E~

-1

G 0.6"-->.

0.4'"E0.. 0.2..~= 0fX- lE -{).2

~-{).4

-{).6

Figure 5-5 Annual temperature anomaly of China and the worldNote: The thin and thick line represents annual temperature anomaly, and II-year moving averagevalue, respectively. (a) Entire China (1873-1990) with a 1951-1990 reference period mean (LIN etal., 1995); (b) World (1851-1997) with a 1961-1990 reference period mean (Jones, 1999)

Table 5-1 Statistic indexes oftemperature anomaly series of the Lhasa and related regions

Correlation coefficient Related statistic index

Average StandardLinear

Lhasa Beijing Shanghai NH Global Inclination(DC) error (DC/year)

Lhasa 1.000 .272 .366' .307' .378' 0.07 .5214 0.0176

Beijing .272 1.000 .629" .701" .661" 0.08 .7711 0.0273

Shanghai .366' .629" 1.000 .562" .498" 0.00 .4805 0.0131

NH .307' .701" .562" 1.000 .933" 0.06 .1791 0.0063

Global .378' .661" .498" .933" 1.000 0.04 .1555 0.0058

Note: * indicates significant correlation at the level of 0.05;** indicates significant correlation at the level of 0.01.


0.50

0.00

I. 50

lJ I. 00

t~''"! -I. 00

-I. 501951 1956 1961 1966 1971 1976 1981 1986 1991

Lhasa.

I. 00

0.00

0.50

19911986198119761971196619611956-I. 50

1951

2.00

lJ I. 50

t~! -0.50

~ -I. 00

1. 00

0.50

1. 50

lJ

te 0.00a

eR -0.50

~-1. 00

1951 1956 1961 1966 1971 1976 1981 1986 1991

Shanghai

-a'i

!

J

0.6

O. 3

o

-0. 3

-0.61951 1956 1961 1966 1971 1976 1981 1986 1991

NH

Figure 5-6 Mean annual temperature anomalyNote: The reference period is 1961-1990; the thin and thick lines are annual temperature anomaly,and 5-year moving average, respectively.


Table 5-2 indicates that all maximum temperature anomalies occurred in themid-1990s, while the minimum anomalies were found during the 1950s-1970s.Additionally, the warmest year appeared in 1994 and 1995 during the period of 19511995.

Table 5-2 Maximum and minimum values of temperature anomalyfor Lhasa, Beijing, Shanghai, and NH

Maximum temperature anomaly Minimum temperature anomaly

Value (OC) Occurred year Value (0C) Occurred year

Lhasa 1.3 1995 -1.3 1963

Beijing 1.9 1994 -1.3 1956

Shanghai 1.4 1994 -0.9 1957

NH 0.5 1995 -0.3 1976

Correlation coefficients among the temperature anomalies of Lhasa, Beijing,Shanghai, and NH were positive during 1951-1995, which indicates that their interannual temperature variability was synchronized (Table 5-1). Furthermore,temperature variation of Lhasa was better correlated to that of Shanghai and worldthan that of Beijing and NH. Except for Beijing, temperature of Lhasa was correlatedsignificantly with that of the rest at the 0.05 significance level. Temperature anomalyof Beijing was correlated significantly with that of Shanghai, NH, and world at the0.01 significance level. Temperature at Beijing was better synchronized with that ofNH and world than at Shanghai, which probably reflected the differentiation ofclimate changes in eastern China in terms of global warming. On the other hand,correlation coefficients of the temperature at Beijing and Shanghai with NH and theworld temperatures were higher than that of Lhasa, which seemed to suggestdifferent temperature sensitivity to global warming between plain stations and theplateau stations. The differences may have come from elevation and disturbances ofhuman activities. One of the two important new scientific discoveries of the IPCC1995 Report was the detection of climate change caused by human activities derivingfrom climate records (Houghton, 1996). Hence, attention should be paid to detect thecontribution of human activities to climate change by comparison of temperaturebetween eastern China and the plateau.

At Lhasa, it was warmer in the early 1950s, colder during 1959-1971, warmeragain during 1972-1976, and then colder during 1977-1983. Afterwards there was asignificant period with higher temperature. In 1995, the temperature anomaly reachedthe maximum of the study period (1.3°C). Compared to Lhasa and Beijing,temperature anomalies at Shanghai did not show prominent warm or cold periods.Nevertheless, temperature of Shanghai fluctuated greatly during 1982-1995. Forexample, mean annual temperature of 1992 dropped 1.3°C from that of 1990, buttemperature of 1994 rose 1.5°C from that of 1992. For NH, temperature anomaly waspositive during 1957-1964, negative during 1964-1976, and then positive during


1979-1995 (Figure 5-6). There was a warm period for the global temperature from1978 through 1997 (Figure 5-5 (b)).

Based on Figure 5-5 and Figure 5-6, the beginning of the recent warm periodvaried remarkably from station to station. For Beijing and Shanghai, the beginning ofthe warming period was similar to that of NH and the world temperature (Table 5-1).As mentioned early, the beginning of warming at Lhaha lagged behind that of Beijing,Shanghai, NH, and the world. On the contrary, study of LIN et al. (1998) consideredthe entire period since the early 1960s as a singular warming period. Therefore, theyclaimed that the beginning of the recent warm period of Lhasa was earlier than thatof the global temperature.

Precipitationi) Annual and seasonal precipitation

Mean annual precipitation displays strong spatial variability across the Plateau.It decreases from the southeast to the northwest and from the marginal area to theinterior of the Plateau. For the majority of the Plateau's stations, precipitationconcentrates in the summer, with summer precipitation accounting for more than50% of the annual amount, followed by the spring and autumn, and winter has thelowest precipitation. As a result, for nearly all of the Plateau's stations, annualprecipitation was strongly correlated with summer precipitation.ii) Trends in precipitation

The earliest meteorological observation record available can be traced back to1894 in the Chumbi station located in the Yadong County. The record lasted from1894 through 1954 with a few missing years. This record is very valuable toclimatological research of the plateau because of the lack of early observationalrecord. The mean annual precipitation of Chumbi was about 1000 mm with largefluctuation (Figure 5-7). There was plenty of precipitation during the late 19thCentury and the early 20th Century with an average annual precipitation ofapproximately 1300 mm and the highest precipitation of nearly 1600 mm in 1903.Afterwards, annual precipitation declined. Although it rose slightly during 19351951, it was still nearly 1/4 lower than the amount around the turn of the century. Theprecipitation variation at Chumbi reflected to some degree that the precipitation ofthe southern fringe of the plateau was high at the late 19th and the early 20thcenturies and afterwards it became lower for the first half of the 20th Century.

1600

e 1200!.c

8000.~

.s.

.~ 400Q.,

o1894 1902 1910 1918 1926 1934 1942 1950

Figure 5-7 Annual precipitation of Chumbi station located in the Yadong County


The precipitation trends at several representative stations of the plateau areshown in Figure 5-8. Stations with increasing precipitation accounted for 45% of allstations on the plateau during 1950-1995. These stations were mostly found in Nagquregion of northern Tibet, on the northern slope of the Himalayas, and along thereaches of the Yarlung Zangbo-Lhasa-Niyang River with high elevation.

y = 12.474x + 586.63

y = -1.2617x + 462.51

200 '----'-_~___"_~_.......:....___"_~...J

1952 1958 1964 1970 1976 19B2 19BB 1991

Lhasa

E 8005

650

:1 5000. I'\J-'_~, -\"~'""'_i~~f~'u :\50[:,

1971 1976 1981 1986 1991

Borne

800

600

400

200 '--------'--""-----"'----'---'----'

1961 1966

1200 .----------------,E5 1000

y = -0. 583x + 187.6

400

200 '----'---'--'----'-------'---'-'

1951 1957196319691975 1981 1987 199:1

Qando

§ 500

'3'5.

£ :100

1000 ,----------------,

900

BOO

700

600

500

400 '----'--~---'--'---'------'

1960 1965 1970 1975 19BO 19!15 1990 1995Nyingch

700 ,--------------,

E 6005

199219871977 1982

Nyalam1972

1000 ,---------------,

900

800

700

600

500400300 '----'----'----'-----'--..........

1967

800 .---------------,

E 700

5 600co 500

:~ 4000.£ 300

200 '---'--'----'----"'---'----"-................

195519601965197019751980198519901995Nagqu

Figure 5-8 Annual precipitation curves of6 representative stations of the PlateauNote: Thin line, thick dot line, and thick line represent precipitation change, linear trend ofprecipitation, and five-year moving average precipitation, respectively.

Combination oftemperature andprecipitation changeThe matching between temperature and precipitation is an important climate

characteristic of the region. From the mid-1950s to the mid-1990s, changes oftemperature and precipitation not only had consistent patterns, but also displayedregional difference, which determined the regional differentiation of the combinationoftemperature-precipitation changes. Generally speaking, there was a warming trendfor most of the plateau, while precipitation trends varied spatially. Therefore, thespatial difference of combination of temperature-precipitation can be well reflectedby the spatial distribution of precipitation. Since the mid-1950s, most of the plateauhad become warmer, with either wetter or drier condition in the interior and margin


of the plateau, while part of Sichuan Province located in the plateau had becomecooler and wetter. In the 1990s, it was evident that the precipitation during floodseason was lower. Summer and autumn droughts occurred in five out of eight yearsfrom 1990 through 1997.

Previous studies indicate that the combination of temperature-precipitation inthe plateau was related to the warm and humid moisture coming from the Bay ofBengal (LIN et aI., 1992).

5.3 Tibetan Plateau as Heat Source and Sink

5.3.1 HEAT TRANSPORTATION

Regions providing heat to the atmosphere are commonly known as heat sources.On the contrary, regions absorbing heat from the atmosphere are regarded as heatsinks. Except for areas covered by ice and snow perennially and a small part of thewestern Tibet, the Qinghai-Tibetan Plateau is a heat source providing heat to theatmosphere over the plateau on the annual basis. The mean annual heat transportedfrom the plateau to the atmosphere is about 344 calorie / cm2.d (Table 5-3). The areaof the plateau is about 250x 104 km2 with elevation over 3000 m asl. Therefore, thedaily heat transported to the atmosphere from the plateau is about 8.5x I018 calories,equivalent to the heat generated by the burning of 1.2 billion tons of coal.

Table 5-3 Total heat transported to the atmosphere from the surface of the plateau(calorie/cm2.d)

Month Jan. Feb. Mar. Feb. May June July Aug. Sept. Oct. Nov. Dec. Meanannual

Heat•••••••• h .......... _ •••••

212 260 350 443 495 481 418 385 355 296 232 196 344transport

It is a complex question whether the heat transported from the surface to theatmosphere is sufficient to compensate the cooling by long wave radiation to theexosphere, namely, whether the atmosphere over the Plateau is a heat source or a heatsink for its surroundings. According to observations and experiments over thePlateau, it has been concluded that the atmosphere over the Plateau is a heat sink inwinter and a stable, strong heat source in summer.

Because plenty of precipitation occurs in eastern and southeastern Plateau, thereis a large amount of latent heat flux. Taking the southeastern Tibet as example, theaverage daily precipitation is about 4-8 mm during the rainy season, which wouldtranslate into a latent heat flux of 240-280 calories/ calorie / cm2.d. Taking theseheating mechanisms into consideration, it can be determined that the center of thestrong heat source of the Plateau is located in the southeastern Plateau.

The vertical profile distribution of temperature anomaly of June along 32°N wascalculated, which exhibited that the atmosphere over the plateau would be hotter thanthat of its surroundings. The plateau can be vividly regarded as one heat engine with


its huge chimney in the southeastern Plateau transporting heat upwards endlessly,which make the plateau a huge heat island unparalleled in the world skyscraping theupper air.

5.3.2 THERMAL FORCING OF THE PLATEAU

In summers, the strong heating of the plateau to the atmosphere make the airabove the surface rather unstable. The heated air ascends continuously, forming thickcumulus and cumulonimbus clouds. In addition, the heating can cause the airtemperature of the lee-side to rise. When the plateau is dominated by the westerlyflow, the temperature of the upper air east of the plateau is I-2°C higher than that ofthe west. Similarly, when the plateau is dominated by the easterly flow, the upper airtemperature to the west of the plateau is approximately 1°C higher than that of theeast.

There exists a nearly static hot center in the troposphere over the plateau insummer. Therefore, a heating-induced circulation is maintained constantly, whichwill heat and mix convergent air masses from the surroundings and guide weathersystem in the regions. It also influences the general circulation of the upper air overthe plateau and its surroundings, and has strong impacts on weather and climate ofmost of China, the formation of floods and droughts in Japan, the Indian monsoon,and the general circulation of the whole North Hemisphere.

Sensitive studies on climatic effects of albedo change over the plateau (LIU etal., 1996) revealed that the increase in surface albedo of the main body of the plateauis an important controlling factors. It can cause noticeable weakening of the EastAsia monsoon and the plateau monsoon, producing a warm condition for thenorthern part of the monsoon areas in eastern China, a cool condition for the southernpart of the monsoon areas, and decreased monsoon precipitation generally.

5.4 Moisture Transportation Pathways and its Geo-EcoIogicaI Significance

The study on moisture of the Qinghai-Tibetan Plateau will be not onlybeneficial to a bettering understanding of the processes of precipitation, formation ofglaciers, and distribution of surface runoff, but also significant for allocation of waterresources, agriculture and animal husbandry, and water conservation engineering.

5.4.1 MOISTURE TRANSPORTATION PATHWAYS TO THE PLATEAU

Moisture could enter the plateau from all directions, but mainly from the westand the south. The amount of moisture transportation is fairly small if justconsidering the so-called internal cycle, namely, depending on the local andneighboring moisture sources. As far as the whole plateau is concerned, moisture ismainly carried from the Indian Ocean following three pathways, the east, middle, andwest, to the plateau (Figure 5-9), which determines the primary pattern of moisturedistribution ofthe plateau (LIN et aI., 1989, 1990, 1991, 1992).


60 70 80 90 100

10

100

T

90

BAY OF BENGAL

URUMQIO

'T' A1pi 11P. rlp.sp.rt.

,., lIontane desert * Alpine .eadoy

80

V Alpinp. stP.ppP.

---~--- ~~, lIontane coniferous forest

~ Montane broad-leaved evergreen forest

70

2°r-)f-t---+-_--=L~~'f4___1I 20

Figure 5-9 Moisture transportation pathways to the plateau and its geo-ecological significance

The eastern pathway originating from the Bay ofBengalBased on the analysis of satellite cloud images and surface observations,

originating from the Bay of Bengal, the warm and humid tropical air masses movealong the Yarlung Zongbo River northward to the interior of the plateau, then theyare transported to the northern periphery from the east to the west. It is very clear onsatellite images that in summer, warm and humid tropical air mass, with the help ofstrong southwesterly, moves along the Brahmaputra and Yarlung Zangbo Rivervalley and pours into the interior of the plateau from its southeastern part, shaped likea wet tongue. This provides plenty of water vapor to the formation of the maritimeglaciers over the Nyainqentanglha Mountains. After the jet stream cloud system ofthe Bay of Bengal enters the plateau from its southeast, it stretches westwards to theTarim Basin along the northern part of the plateau low vortex. Plenty of water vapor


and energy is brought by the intrusion of cloud masses from the Indian monsoon low,which will merge with the cold-front cloud system of vortex cloud systems from thenorthwest. These cloud systems will produce precipitation under suitable circulationcondition.

During the late autumn and the early winter, storms formed in the Bay of Bengaloften assault the plateau, which bring rich rain or snowfall to the plateau. It can beseen on the satellite images that there are cloud systems moving northward along theYarlung Zangbo River and Hengduan Mountains, then turning westward, andgenerally causing heavy rain or snowfall when they meet the cold-front cloud systemcoming from the northwest.

The western pathway from the Arabian SeaBy examining the distribution, movement, and evolution of cloud system, it is

found that the Arabian Sea moisture plays an important role to the precipitation ofthe western plateau. This is another moisture transportation pathway that varies withseason.

In summer, the thermal low system over the Indian subcontinent and theArabian Sea is rather active. Accompanied with strong southwesterly and southerlyflows in the front portion of a trough in mid-troposphere, a large amount ofconvective cloud masses move northward and reach the Karakorum-KunlunMountains of the western plateau.

In winter, when wide bands of clouds of the jet stream over the Arabian Seashifts from Pakistan to the Pamirs, the vortex system will transport the warm andhumid air mass from the Indian Ocean to the Karakorum-Kunlun Mountains and thenproduce precipitation. During its eastward movement, it can even affect the Ngariareas of the Tibet and bring heavy snowfall. Similar to those storms from the Bay ofBengal, there are also storms from the Arabian Sea, which usually move into thewestern plateau and cause precipitation covering large areas.

The warm and humid air mass from the Arabian Sea is helpful in the formationof rainstorm, snow, and glaciers over the Karakorum-Kunlun Mountains and Ngariareas of the western plateau.

The middle pathway from the Indian SubcontinentIn summer, when the thermal low system of the Indian Subcontinent is active, a

large quantity of cloud masses surpasses high mountains to the Ngari areasaccompanying strong southwesterly and southerly flows in the front portion of atrough. Besides, along the valley of the Himalayas, some of the warm and humid aircurrents will move northward to the southern Tibet bringing plentiful rainfall.

In winter, there is still moisture transportation from the Indian Subcontinent.When the moisture reaches the plateau, large-scale snowfall events occur. Moreover,the snowfall of the Ngari areas will occur slightly earlier than that along the southernfringe of the Tarim Basin. The satellite images indicate that there is no snowfall inother regions at the same time. This proves that the middle pathway of moisturetransportation, as the western pathway, can also have impacts on precipitation in theregion of Karakorum-Kunlun Mountains.


5.4.2 GEO-ECOLOGICAL SIGNIFICANCE OF MOISTURE TRANSPORTATION

Annual precipitation and its seasonal distribution along the pathways ofmoisture transport to and on the plateau are clearly different from those in theneighboring areas. In fact, their climates are also different. As a result, various typesof vegetation appear in accordance with different distances from the sources ofmoisture transportation pathway. With regard to the eastern moisture transportationpathway on the plateau, the variation in vegetation types corresponds well with thetendency of moisture-bearing air masses to dissipate from south to north and fromeast to west (Figure 5-9) (LIN et al., 1991, 1992). .

Characterized by a tropical and subtropical climate, the lower reaches of theYarlung Zangbo River are warm and humid, with a large daily range and smallannual range of temperature, and plenty of precipitation. A tropical montane forestecosystem stretches upward and northward along the Yarlung Zangbo River valley to29°N- the northernmost limit of the tropical montane forest in the NorthernHemisphere.

On the southern slopes of the eastern Himalayas, the most humid area on theperiphery of the plateau, an evergreen rainforest of D. macrocarpa, Mesua !errea,Artocarpus cheplasha, and Tetrameles nudiflora stretches northward as far as Siging(450 m asl), and a semi-evergreen rainforest dominated by Terminalia myriocarpa,Altingea excelsa, Negerstroemia minuticarp, and Homalium zeylanicum reaches tothe north of Medog (1000 m asl, 29°N), much further than the northern boundary ofthe tropical montane forests in other continents of the world. Many tropical flora andfauna elements reach their northernmost boundary and the highest limit in the easternHimalayas.

Northwards are the Nyainqentanglha Mountains, with a warm and subhumidhumid climate. Montane forests are found here, starting with a sclerophyllous broadleaved evergreen forest at the southern slopes of the mountains followed by montaneconiferous forest, and then an alpine scrub-meadow. The number of species decreasesgradually from south to north with evident changes in the dominant components. Themontane coniferous forest mainly consisting of Picea balfouriana is distributedcontinuously on the southern slopes of the mountains, but discontinuously or inpatches on the shady northern slopes.

In the valley of the Nujiang River, and on both flanks of the TanggulaMountains with higher elevation and cold climate, the montane forest disappears andthe major types of vegetation are alpine scrub-meadow and alpine meadow. Theformer consists chiefly of Salix, Rhododendron, and Sabina, while the latter isdominated by Kobresia and Polygonum.

Northwards, in the source region of the Yangtze River in southern QinghaiPlateau, alpine steppe vegetation is found due to the gradual decreases inprecipitation. Vegetation becomes alpine desert-steppe, with Stipa purpurea, S.Subsessiliflora, Carex moorcroftii, and Ceratoides compacta on the southern slopesof central Kunlun Mountains. On the northern slopes of the central KunlunMountains and in the Qaidam Basin, the climate is extremely arid and montanedesert vegetation is found here with Sympegma regelii, Salsola abrotanoides,


Ceratoides latens. and Kalidium schrenkianum as major species. In general, annualprecipitation and the moisture condition decreases from south to north on the plateau,resulting in a zonal succession of different vegetation types from montane forest,northwestward to alpine scrub and meadow, alpine steppe, alpine desert, steppe, andfinally montane desert.

As regards to the western moisture transportation pathway originating form theArabian Sea, the distribution pattern of vegetation also reflects variations in themoisture regime. On the southern slopes of the western Himalayas, the base belt issubtropical montane sclerophyllous forest, while in the southern part of the Nagriregion, montane desert-steppe and montane steppe vegetation appears correspondingto scant precipitation. Northwards to the Bangong Lake basin is montane desertvegetation. On the plateau between the Karakorum and Kunlun Mountains, there isalpine desert vegetation dominated by Ceratoides compacta. Affected by moisturebearing air masses from the Altai valley to the west, the northern slopes of thewestern Kunlun Mountains are discontinuously covered by montane coniferousforests.

The basins and plateaus in the interior and the southern sides of the centralKunlun Mountains, such as the Angekule, White Gobi, Yang Hu Lake, andHeshibeihu Lake, are far from the moisture source regions and transport pathways,and therefore, have cold and extremely arid climates. So ultra-xerophilous vegetation(alpine desert) is well established in the alpine gypsiferous desert soils. These areasmay be considered as a "High Cold Arid Core Area" in Eurasia.

5.5 Sensitive Regions for Climatic Changes

Since the 1970s, much attention has been paid in order to extract the earlystrong signals of climatic changes of the Qinghai-Tibetan Plateau. Investigationswere focused on various forcing mechanisms and the timing of the warming trends incomparison with the global patterns for the most recent warming period.

5.5.1 SOLAR RADIATION AND BOUNDARY LAYER OF THE PLATEAU

The plateau is the largest heat source in summer, which has strong impact on theclimate of the neighboring areas and the North Hemisphere as well. Features of theplateau boundary layer, particularly the macro-scale long-lasting cryosphere,influence the atmospheric processes of various scales. The plateau is covered by thelargest cryosphere in regions of the same latitudes in the world, with a total glacierarea of approximately 4.9xl04km2

, which effectively controls the albedo of theplateau surface. Additionally, the anomalies of the areas covered by snow and ice inwinter can significantly alter the effect of the plateau as a heat sink that will influencethe development of the South Asia high, the southwestern monsoon, as well as theEast Asia monsoon and the seasonal variation of rainy belt in China in the followingsummer (SUN, 1996).

The stratification stability that near the boundary layers over the plateau isgreater than that over the plain areas (WU et al., 1981). Moreover, the plateau


responses to warming dramatically because of lower mass of air molecules, whichmay be reflected in the climatic sensitivity. The subtropical location and the heatingof the plateau make the structure of the cryosphere fairly unstable and sensitive totemperature changes. Therefore, the climate and environment of the plateau areconstantly under a fragile equilibrium condition that can change dramatically withexternal and internal disturbances.

5.5.2 SENSITIVITY OF CLIMATE CHANGES OF THE PLATEAU

The sensitivity of climate changes of the plateau has attracted attention ofresearchers at home and abroad (WU et al., 198 I; LIN, 1984; Kuhle, 1987; TANG etal., 1989, 1997; FENG et al., 1998). For example, Kuhle (1987) and FENG et al.(1998) pointed out that the Qinghai-Tibetan Plateau could have triggered the globalclimatic changes in the past.

Analyses in previous sections indicate that the temperature variation of theplateau has been consistent with that of the eastern China, the North Hemisphere, andthe world during 1951-1995. The latest warming trend was obvious in the plateau,but the beginning of the warming varied from station to station and from region toregion (Figure 5-6 and Table 5-1). The southeastern Tibet was the first region thatentered the warming period since the early 1960s. Yarlung Zangbo River valley andits vicinities began the warming since the early 1980s. And the last were Shiquanheand Gerze where temperature rose largely at the late 1980s and the early 1990s andkept rising afterwards. The beginning of the latest warming period tended to leapnorthward and eastward (LIN et al., 1996).

Analysis of the global temperature record since the 1970s indicates that thecentral Asian continent including the northern part of the Xinjiang UygurAutonomous Region was one of the three sources of the global climatic abnormality,while the climatic abnormality of the plateau occurred five years earlier than that ofthe central Asia (FU et al., 1982). Compared to the Arctic region, the cold period ofLhasa appeared about five years earlier, so did the warm period with large amplitudeof temperature change, which can be regarded as one kind of earlier signal of globalwarming.

During the past 2,000 years, the warming trend is not only notable but alsoslightly earlier than its surrounding areas. One hundred-year-scale climate changesfirst appeared in the main portion of the plateau, then the Qilian Mountains, and thenplains of East China later (FENG et al., 1998). Moreover, temperature of the northernTibetan Plateau changed more than that of the southern plateau. Similarly,temperature of the arid western plateau changed more than that of the humid easternplateau. Besides, the higher the elevation, the greater the amplitude of temperaturechanges over the plateau (SUN, 1996, 1998).

In summary, the Qinghai-Tibetan Plateau is a sensitive region to climaticchanges. Its complex landforms with high elevation, powerful and far-reachingmonsoon circulation patterns, and solar radiation forcing makes it response stronglyto temperature changes, indicated by its large amplitude of its temperature variation.Compared to other regions, the climatic changes of the plateau may have occurred

CLIMATE: PAST, PRESENT AND FUTURE

earlier, the plateau is, therefore, regarded as a sensitive region to global change.

References

III

I. Chancery of Tibetan Autonomous Region et aI., 1985. Disaster Records: disasters caused byheavy snow. Lhasa: Tibet People's Press.

2. Chancery of Tibetan Autonomous Region et aI., 1990. Disaster Records: disasters caused byhailstone, frost, and insects. Beijing: Chinese Tibetan Press.

3. Chancery of Tibetan Autonomous Region et aI., 1990. Disaster Records: disasters caused byfloods. Beijing: Chinese Tibetan Press.

4. FENG Song, TANG Maocang, WANG Dongmei, 1998. The new evidence about the QinghaiTibetan Plateau is triggering region of climate change in China. Chinese Science Bulletin,Vol.43 (11): 633-636 (in Chinese).

5. FU Congbin, 1994. Studies on the observed abrupt climatic change. Scientia AtmosphericaSinica, VoI.18(3): 373-384 (in Chinese).

6. FU Congbin, et al., 1982. The preliminary study on the global surface air temperature in the1970s. Scientia Atmospherica Sinica, Vol. 6(4): 405-412 (in Chinese).

7. FU Congbin, WANG Qiang, 1992. The definition and detection of the abrupt climatic change.Scientia Atmospherica Sinica, Vol. 16(4): 482-493(in Chinese).

8. GAO Youxi, JIANG Shikui, ZHANG Yiguang, et al., 1984. Tibet Climate. Beijing: SciencePress (in Chinese).

9. Houghton, J.T., 1996. IPCC: Climate Change 1995. Cambridge: Cambridge University Press.10. Jones, P.D, 1999. Surface air temperature and its changes over the past 150 years. Reviews of

Geophysics.11. KANG Xingcheng, L. J. Graumlich, P. Sheppard, 1997. The last 1835 years climate changes

inferred from three ring records in Dulan region, Qinghai, China. Quarternary Sciences, I:70-75(in Chinese).

12. Kuhle, M, 1987. Subtropical mountain and highland glaciation as ice age triggers and thewanning of the glacial periods in the Pleistocene. Geo journal, Vol. 13(16): 1-29.

13. Ll Jijun, FANG Xiaomin, 1998. Study on the uplift of the Qinghai - Xizang Plateau and itsenvironmental changes. Science Bulletin. Vol. 43 (15): 1569-1574 (in Chinese).

14. Ll Jijun, FANG Xiaomin, MAa Haizhou, et al., 1996. Geomorphological and environmentalevolution in the upper reaches of the Yellow River during the late Cenozoic. Science in China(Series D), Vol. 39(4): 380-390 (in Chinese).

15. LIN Xuechun, YU Shuqiu, TANG Guoli, 1995. Series of average air temperature over Chinafor the last 100-year period. Scientia Atmospherica Sinica, Vol. 19(5): 525-534 (in Chinese).

16. LIN Zhenyao, 1993. Abnormal cliamte in Tibet and its impact in the 1980s. In: Climaticchange and its impacts (ZHANG Yi, et aI., eds). Beijing: Meteorological Press, 43-49 (inChinese).

17. LIN Zhenyao, WU Xiangding, 1981. Climates of the Qinghai - Xizang Plateau before andafter the uplift. In: Problems of the epoch. amplitude. and forms about the uplift of theQinghai - Xizang (Tibetan) Plateau. Beijing: Science Press, 59-165 (in Chinese).

18. LIN Zhenyao, WU Xiangding, 1984. The climate of Lhasa in the early 20th Century. PlateauMeteorology, Vol.3 (4): 14-20 (in Chinese).

19. LIN Zhenyao, WU Xiangding, 1986. A preliminary analysis on the regularity in flood,drought and snowstorm in Tibetan Plateau during historical times. Acta Meteorologica Sinica,Vol. 44(3): 257-264 (in Chinese).

20. LIN Zhenyao, WU Xiangding, 1989. Evolution of the desert climate on the Tibetan Plateau.Chinese Journal ofArid Land Research. Vol.2 (4): 369-373 (in Chinese).

21. LIN Zhenyao, WU Xiangding, 1990. A preliminary analysis about the tracks of moisturetransportation on the Qinghai-Xizang Plateau. Geographical Research, Vol.9 (3): 33-40 (inChinese).


22. LIN Zhenyao, WU Xiangding. 1977. A preliminary analysis ofthe climatic change during thehistorical time in Xizang. Proceedings of the symposium on climatic change and climaticprediction. Beijing: Science Press (in Chinese).

23. LIN Zhenyao, ZHAO Xinyi, 1996. Spatial characteristics of changes in temperature andprecipitation of the Qinghai-Tibetan Plateau. Science in China (Series D), Vol. 39(4): 442448.

24. LIN Zhenyao, ZHENG Du, 1991. Moisture transportation pathways to the Qinghai-TibetanPlateau and their geoecological significance. Chinese Journal ofArid Land Research. VolA(I): 41-47 (in Chinese).

25. LIN Zhenyao, ZHENG Du, 1992. The tracks of moisture transportation and its vaporgeoecological characteristics on the Qinghai-Xizang Plateau. Arid Zone Research, Vol.9 (2):1-7 (in Chinese).

26. LIU Xiaodong, MA Zhuguo, 1996. An important cause leading to short-term climaticvariation in China-the change in the surface albedo in Tibetan Plateau. Journal of TropicalMeteorology, Vol. 12(3): 240-245 (in Chinese).

27. Mann, M.E., R. Bradley, M. Hughes, 1999. Northern Hemisphere temperatures during thepast millennium: influences, uncertainties, and limitations. Geophysical Research Letters, Vol.26(6): 759.

28. SHAO Xuemei, FAN Jinmei, 1999. Past climate on west Sichuan Plateau as reconstructedfrom ring-widths of dragon spruce. Quaternary Sciences, No.1: 81-89 (in Chinese).

29. SHI Yafeng, LI Jijun and LI Bingyuan, et al., 1999. Uplift of the Qinghai-Xizang (Tibetan)Plataeu and east Asia environmental changes during late Cenozoic. Acta Geograpgica Sinica,54 (1): 20-28 (in Chinese with English summary).

30. SHI Yafeng, ZHENG Benxing, YAO Tandong, 1997. Glaciers and environments during theLast Glacial Maximum (LGM) on the Tibetan Plateau. Journal of Glaciology andGeocryology, Vol. 19(2): 97-113 (in Chinese).

31. SHI Yangfeng, LI Jijun and LI Bingyuan (Chief Eds.), 1998. Uplift and EnvironmentalChanges of Qinghai-Xizang (Tibetan) Plateau in Late Cenozoic. Guangdong: Science andTechnology Publishing House, 459pp ( in Chinese).

32. SUN Honglie (eds.), 1996. Formation and evolution of Qinghai- Xizang Plateau. Shanghai:Shanghai Science and Technology Press, 160-190(in Chinese).

33. SUN Honglie and ZHENG Du (Eds.), 1998. Formation,Evolution and Development ofQinghai-Xizang (Tibetan)Plateau. Guangzhou: Guangdong Science and Technology Press (inChinese).

34. TANG Maocang, 1989. Some annual variation characteristics for the northern hemisphericmonthly mean precipitation fields. Adv in Atmo. Sciences, 186-201.

35. TANG Maocang, DONG Wenjie, 1997. Influences of seven Tibetan Plateau raising processeson climate and environment. Plateau Meteorology, Vol.l6 (1): 23-29 (in Chinese).

36. WU Xiangding, LIN Zhenyao, 1981. Some characteristics of the climate changes during thehistorical time of Qinghai-Xizang Plateau. Acta Meteorologica Sinica. Vol.39 (I): 90-97 (inChinese).

37. YAO Tandong, JlAO Keqin, HUANG Cuilan, et al., 1995. Environmental records in ice coresand their spatial coupling features. Quaternary Sciences, No.1: 23-29 (in Chinese).

38. YAO Tandong, L.G. Thompson, QIN Dahe, et al., 1996. Variation in temperature andprecipitation in the past 2 000 a on the Xizang (Tibet) Plateau - Guliya ice core record.Science in China (Series D), Vol. 39(4): 425-433.

39. ZHANG Shunli, HUANG Xiaoqing, 1997. The climatic characteristics of temperaturevariation more than forty years in Lhasa. Plateau Meteorology, Vol.l6 (3): 312-318 (inChinese).

40. ZHONG Dalai, DING Lin, 1996. Rising process of the Qinghai-Tibetan Plateau and itsmechanism. Science in China (Series D), Vol. 39(4): 369-379.

CHAPTER 6 PERMAFROST: STATUS, VARIATION ANDIMPACTS

ZHAO Lin, CHEN Guichen, CHENG Guodong and LI Shuxun

6.1 Distribution and Characteristics of Permafrost

Permafrost is defined as a thickness of soil or other superficial deposit, or evenof bedrock, at a variable depths beneath the surface of the earth in which atemperature below O°C has existed continually more than 2 years (Washburn, 1979).Permafrost on the Tibetan Plateau has unique developing history and characteristicsdue to the unique geological and climatic fluctuation history. It is the result of massand heat exchanges between lithosphere and atmosphere influenced by lithologic,climatic, geographic, hydrologic, and pedologic conditions and vegetation, snowcover etc. under the background of the uplifting of the plateau.

The high elevation (more than 4000 m asl in average) and severely coldclimate on the plateau made the permafrost widespread, which occupies about1,401,000 km2 in the plateau (LI et at., 1996) (Figure 6-1; Table 6-1). Permafrost ofthe Tibetan Plateau is the highest in elevation and largest in area in the middle-lowlatitude in the world, and about 69.2% of the total permafrost area in the plateau(Table 6-1). It discontinuously distributes from the Qilian Mts. in the north toHimalaya Mountains in the south, and from west Hengduan Mts., northeast ofAnyemaqen Mts. and Bayan Har Mts. in the east to Gangdise Mts. in the west.Climate is the main factor, which is controlled mainly by altitude, then latitude and

Table 6-1 The area of permafrost in the plateau

Region

High mountainsin West China

Tibetan Plateau

Former USSR

AfghanistanIndiaPakistanNepal

Total

261

1401

22022

93.210.417.2

2024.8

113

Percentage (%) References

12.9 ZHOU and GUO, 1982

69.2 LI et al., 1996

10.9 A. P. Gorbunov, 1986

1.14.60.5

0.8

100

ZHENG Du, ZHANG Qingsongand WU Shaohong (eds.), Mountain Geoecology and Sustainable Development oftheTIbetan Plateau. 113-137.©2000 Kluwer Academic Publishers.

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PERMAFROST: STATUS, VARIATION AND IMPACTS 115

longitude, to affect the distribution of permafrost. Mean annual air temperatures(MAAT) tend to become cooler northeastwards and higher in elevation. So, thelower limits of permafrost (LLP) tend to lower northeastwards (Figure 6-2).

Based on the differences in distributional characteristics, the permafrost on theTibetan Plateau was divided into 5 zones (Figure 6-1; Table 6-2).

Table 6-2 Distribution of permafrost on the Tibetan Plateau (after LI et al., 1996)

Permafrost zone LLP Area Percentage ThicknessMAGT COC)(m, asl) (lOlkm2) of its area (m)

Alpine permafrost in Altun West: 4000 85.3 45 Several to 0~-2.5

and Qilian Mts. area East: 3450 139

Lowest: 3300

Karakorum and 4200-4600 135.9 67 4~120 -O.I~ -3.2West Kunlun

Permafrost Mts.

on the Kunlun Mts. 4000-4200 75.7 63 4-100 0--3.2mainplateau Qiangtang 4500 406.8 97 Several- -1.7~-3.2

Plateau 100

Mountains in the 3840-4300 181.9 63 Several-70 -0.5-3.2South-east ofQinghai Province

Gangdise and Nyainqen- 4700-4800 265.6 51 5~100

Tanglha Mts.

Alpine permafrost in 4600-4800 97.2 23 <20 0-1.0Hengduan Mts.

Alpine permafrost in 5000-5100 152.1 40 <20 0- -0.5Himalayas

Total area in Tibetan Plateau Permafrost area 140I 54.3 4~120

(2578x I03km2)

Note: LLP--Lower limit of permafrost

6.1.1 ALTUN AND QILIAN MOUNTAINS

The alpine permafrost in this region ranges from 36° to 400 N and from 86° to103°E, which occupies about 85,300 km2

, about 45% of its territory (188,100 km2)

and 6.1% of the total permafrost area on the plateau. LLP is from 3700 to 3950 masl on south slopes, coincides with the -2°C isotherm; and from 3500 to 3740 m aslon north slopes and coincides with -2.5°C (GUO and CHENG, 1983). It lowers at arate of 120-150 m per degree of latitude northwards and 60-80 m per degree oflongitude eastwards (YI et al., 1992) accompanied with the lowering airtemperature northwards and eastwards (QIU et aI., 1996). Generally, the permafrostthickness ranges from several meters to 140 m (GUO, 1983), which is controlled

116 ZHAO L., CHEN G. C., CHENG G. D. and LI S. X.

mainly by elevation, and also influenced by slope characters, lithologic, andhydrological conditions etc. The higher the elevation rises about 100 meters, thethicker the permafrost would be about 10 to 30 m (Table 6-3). There are three typesof taliks within the permafrost zone, which are taliks under lake and river waterbodies, taliks induced by warm spring and high geothermal flow, and taliks in someareas with very coarse soils, where surface water together with heat infiltratesdownwards rapidly.

...5N

Qilian Mountains Kunlun Mountains Qiangtang Plateau Himalaya Mountains3000

4000

Altitude

Figure 6-2 Permafrost distribution elevations of different mountains on Tibetan PlateauNote: SFG-Seasonally frozen ground

Table 6-3 Permafrost in typical regions in Qilian Mts (after Guo, 1983)

Region Elevation (m asl) Thickness (m) Active layer thickness (m)

North slope of Daban Mt. 3,500 25 1.5-2.0

North slope of Zoulangnan Mts 3,529 33 1.8

3486 8 2.3

Reshui 3696 30 1.I

3862 >60 2.4

Jiangchang 3970 50 I

3887 87 I

3992 60 I

Muli 4016 76 23984 95 I

3839 46 2

The Source Area of Heihe River 3829 79 1.7

4032 139 1.7

The south slope of Tulai Mt. 3950 78 1.6

Danghenan Mt. 3741 12

PERMAFROST: STATUS, VARIAnON AND IMPACTS 117

6.1.2 GANGDISE AND NYAINQEN-TANGLHA MTS.

Almost no investigation on permafrost was conducted in this region till now.Based on the MAATs for permafrost distribution and altitudinal gradient of MAAT,LI et al. (1996) mapped the permafrost in this region. The alpine permafrost is about256,600 km2 in area, 51 % of its territory, and 10.3% of the total permafrost area onthe Tibetan Plateau. LLP is from 4800 to 5000 m asl The MAGTs at the tops ofmountains are lower than -8.0°C, so the permafrost thickness is estimated to bemore than 270 m there.

6.1.3 HENGDUAN MOUNTAINS

Permafrost in Hengduan Mountains is about 972xl04 km2, 23% of its territory,

and 6.9% of the total permafrost area on the Tibetan Plateau. LLP is from4200-4600 m asl in its northern part, about 600 to 1000 m lower than modern snowline, to 4800-5000 m asl in its southern part, similar altitude with modern snow line(LI and YAO, 1996). It is mainly influenced by climatic conditions, which belong tomaritime climate in the southern part and continental climate in the northern part.Permafrost tables are 1 to 4 m deep in Quaternary sediments and 6-10 m in barebedrock. Table 6-4 shows the distribution of permafrost in different areas fromsouth to north in this region.

Table 6-4 Permafrost distributions in Hengduan Mts.

Regions

North slope ofYulong Mt.

North slope of Baimang Mt.

North slope of Meili Mt.

Dongdala

Gongga Mt. North slopeWest slope

East slopeNorth slope of Sulong Mt.

QuerMt.

North slope ofXuebaoding

Serxu County

Zuige

Latitude (N)

27°10'

28°20'

28°30'

29°03'

29°30'

31°38'

32°00'

32°29'

32°59'

33°34'

Altitude of LLP (m asl)

4800

4700

4700-4800

4540

46004200

49004600

4900

4600

4300

3300-3500

MAATCC)

-4.0

-4.2

-3.0 to -3.7

-3.2

-2.2-4.9

<-2.6

-4.0

-3.6

-2.2

-0.6 to-1.1

Due to the effect of snow cover, seasonally thawing processes of active layer npermafrost regions in this zone differ greatly from other zones, especially in itssouthern part. Snow cover occupies most of the permafrost areas for more than 6months. It greatly delays the spring thawing process due to its insulation effect(ZHAO et al., 2000). The other unique characteristics of permafrost in this zone are

118 ZHAO L., CHEN G. C., CHENG G. D. and Ll S. X.

of buried glacier ice and snow ice (LI and YAO, 1996). For example, the terminalof glaciers on the northwest slopes of Gongga Mts. is at 3800 m as!. Buried glacierice was found in the moraines, which does not advance now.

6.1.4 THE HIMALAYAS

Permafrost in this region is about 152,100 km2, 40% of its territory, and 5.9%

of the total permafrost area on the Tibetan Plateau. The LLP varies somewhat fromthe northwest to southeast of this region because of the differences in climaticconditions. Generally, it is from 4900 to 5000 m asl (Table 6-5). In the Mt.Qomolangma area, it is from 5100 to 5300 m asl on north slopes, and 4900 to5000m asl on south slopes (ZHOU and GUO, 1982). According to Trush'sestimation (Table 6-6), the MAGT of permafrost is from 0 to -27°C and itsthickness is several meters in the lower boundary to more than 1000 m on thehighest peat of the Himalayas, the Mt. Qomolangma.

Table 6-5 LLP in three areas in the Himalayas (Fujii. 1980)

Regions LLP (m asl) Latitude (N) Longitude (E)

Gongbu Himalayas 4900 to 5000 27°55' 86°50'

Mukut Himalayas 4900 to 5000 28°45' 83°30'

Rongbu Temple, Himalayas 4900 28° 10' 86°50'

Table 6-6 Calculated MAGTS and thickness of alpine permafroston the Tibetan Plateau(Trush, 1986)

Kunlun and Karakorum Mountains (36°N) Tibet (32°N)Himalayan Range

Altitude (m) (28°N)

°C M °C m °C m

4200 0 <30

4400 -0.7 354600 -2.0 1054700 -3.3 1754800 -4.0 210 0 <30

5000 -4.6 245 -0.7 35 0 <30

6000 -5.9 315 -1.9 105 -6.9 3507000 - 12.8 665 -8.8 455 -13.8 7007400 -19.7 1015 -15.7 805 -16.5 840

7800 -22.4 1155 -18.4 943 -19.2 9808000 -25.3 1295 -21.1 1085 -21.7 1050

8600 -26.6 1435 -25.9 1260

8800 -30.7 1645 -27.2 1330


6.1.5 QIANGTANG PLATEAU (MAIN PLATEAU)

The permafrost in this region is the best developed on the Tibetan Plateau andcontinuously distributed excluding some talik regions due to the influences of highgeothermal flux and surface water bodies. It occupies about 406,800 km2 in area,89% of its territory (456,700 km2

), and about 29% of the total permafrost area onthe Tibetan Plateau (Figure 6-4 and Table 6-2). MAGTs are from -1.7 to -4.0°C,which are relatively low due to the high elevation (generally higher than 4500 masl). The depths of zero annual amplitude of ground temperatures are between 10 to16 m. Generally, they are deeper in islands permafrost zone and taliks, andshallower in continuous permafrost zone. Different types of ground ice are welldeveloped in permafrost within 20 m indepth, and form different types ofcryostructures. Segregated ice layers are developed widespread in lacustrine, slopewash and solifluction sediments with the thickness from several tens centimeters tomore than ten meters which was formed under the repeated segregation process(CHENG, 1983). The differences of permafrost distribution are great between the

Figure 6-3 Map of permafrost along Xin-Zang Highway (after LI et al., 1998)Note: SFG-Seasonally frozen ground

120 ZHAO L., CHEN G. c., CHENG G. D. and Ll S. X.

western, middle and eastern part of this region due to the climate tends to becomecolder and drier westwards (LIN and WU, 1981). LLP in the northern slopes of thisregion is 4200 to 4500 m asl in the west, 4250 to 4400 m asl in the middle and 3800to 3900 m asl in the east; and that in the southern slopes is 4430 m asl in the west,4780 m asl in the middle and 4200 m asl in the east (Ll et at., 1998), which lowersby about 27.3 m eastwards per degree of longitude. The characteristics ofpermafrost were discussed along the three best studied transects as:

The Qinghai-Tibet Highway (QTH) goes through the middle of this regionfrom north to south (Figure 6-1). The elevation is between 4400 to 5300 m aslwithin permafrost zone. The characteristics of permafrost along this section wereshown in Table 6-7. The LLP is between 4250 and 4350 m asl in the Xidatan Valleyin the north, and is about 4780 m asl near Ando in the south slope of Tanggula Mts.It rises about 100 to 130 m as the latitude rises I degree southwards. MAGTs lowerby about 0.5 to 0.6°C and the thickness of permafrost increases about 20 m as thealtitude rises 100 m. MAATs at the LLP are -2 to -3°C, and about -3.5 to -4°C atthe boundary between discontinuous and continuous permafrost zones (CHENG,1979). The thickness of permafrost is from several to more than 100 m in differentparts along the highway. It is mainly controlled by elevation and affected by theheat effects of surface water bodies and geothermal flows. Ground ice was welldeveloped within a certain depth beneath the permafrost table along this transect(Research Group of Qinghai-Xizang Highway, 1983). For example, a ground icelayer about 7.4 m thick from 1.6 (permafrost table) to 9 m in depth was revealed infive boreholes in 1998 in Fenghuoshan region. Ice-poor permafrost occupies onlyabout 15.2% of the total length of QTH within permafrost regions, ice-richpermafrost is about 65.8%, and taliks are about 19%. Ground ice development wascontrolled by many factors, for example, ground temperatures, lithologiccomposition, geomorphologic features and hydrologic conditions. Generally, it wasbetter developed in fine-grained materials with good water supplies on the plateau.

Table 6-7 Characteristics of permafrost along QTH (after TONG and L1, 1983)

Region Latitude Altitude (m) MAAT(°C) MAGT (0C) Thickness ofpermafrost (In)

Xidatan 35°44' 4250-4500 -2.0-3.5 0-1.0 Several-50Kunlun Mountains 35°40' 4800-5000 < -3.5 -2.0-3.5 75-120Chumarhe 35°20' 4480-4500 -6.2 -1.2 40Wudaoliang 35°15' 4610 -6.5 -1.4 36-60Beiluhe 34°27' 4620 -6.6 0-0.5 10-30Fenghuoshan 34°20' 4700-5100 -6.6 -2.0-4.0 60-120Tuotuohe 33°50' 4500-4700 -4.4 0-1.0 Several-50Kaixinling 33°40' 4800-5000 25-75Tongtianhe 33°30' 4500-4600 -4.4 -1.0-3.0 25Ganggula Mountains 32°57' 4900-5300 -6.4 10-120South slope of

32°40' 5000 128Tanggu1a Mountains


The Xinjiang-Tibet Highway (XTH) goes through the western part of thisregion from northwest to southeast. It belongs to the extreme continental climatewith an annual precipitation about 26 to 36 mm. The LLPs in the north were foundat about 4450 m asl near Dahongliutan, and that in the south at 4630 m asl near Jibu(Figure 6-5) (LI et al., 1998). Permafrost along this transect is about 330 km inlength, and distributed continuously. In the area from Tianshuihai to Guliya Pass,about 250 km in length along XTH and more than 4800 m asl in elevation, thepermafrost is more than 60 m in thickness which is developed mainly in the fluvial,lacustrine and glacial-fluvial deposited sediments. The ground ice, including icelayer near the permafrost table and thick ground ice layers, develops very well. Forexample, six layers of pure ice, thicker than 20 cm, are found within 15 m in depthin a borehole profile near Tianshuihai (35°16'N, 79°33'E), in which a layer ofground ice is more than 1.3 m thick. Ice wedges, ice vein and buried glacier icewere also found in this area (Ll et aI., 1998).

Highway No. 214 goes from Xining to Yushu southwestwards in the easternparts of this region (Figure 6-1). LLP has close relationship with latitude andlongitude. It lowers about 130 meters as latitude moves I° northward (Figure 6-4),and lowers eastwards accompanied with the increasing continentality (WANG et al.,1991). For example, it is at 3840 m asl in Hekananshan region in the east and about4150 m asl in the valley of Xiugou in the west. Generally, the permafrost is lessthan 50 m in thickness along the highway. The continuity of permafrost decreaseseastwards due to the lowering in elevation. Buried lake ice layer was found in aborehole at the northern bank of Ngoring Lake in the source of Yellow River(WANG and LI, 1993). The ice layer is 4.45 m thick in the depth of 19.81 to 24.26m and formed during the period from 35,030 to 45,209 yr. BP.

6.2 Periglacial Processes and Landforms

The frost action is defined as the mechanical processes caused by alternate orrepeated cycles of freezing and thawing of water in pores, cracks and otheropenings of soils (Gary et al., 1972). In permafrost regions, frost action happensmainly in the active layer, and is influenced by many factors, such as temperature,moisture, mineralogy, grain size etc (Washburn, 1980). Cycling freeze and thaw ofwater and ice segregation in active layer result in heave and settlement of soils,which result in the movement of soil particles within active layers and the upperparts of permafrost, and then forms a variety of landforms near ground surface,periglacial features. Thus, the landform formation processes in permafrost regions,i.e., periglacial processes, have unique characteristics due to the participation offrost action.

Almost all of periglacial processes play their roles on the Tibetan Plateau dueto the extensive and intensive frost action. The periglacial processes include frost,weathering, nivation, solifluction, frost sorting, frost heaving, frost cracking andthermokarst etc. GUO Dongxin and CHENG Guodong (1996) classified thealtitudinal spectra of periglacial processes into three zones and 7 subzones based on

122 ZHAO L., CHEN G. c., CHENG G. D. and LI S. X.

geological structure, petrologic composition, geographic zonation andgeomorphologic characters after Cui Zhijiu's classification based on climaticconditions (CUI, 1981). The combination of periglacial features is different in eachzone even in each subzone (Table 6-8).

Different periglacial processes result in different periglacial features on theTibetan Plateau. They are summarized as follows:

a) Frost weathering: It produces rock sea, debris slope, rock stream andperiglacial tors etc, which are mainly distributed in the upper parts of maintains,especially bedrock areas of relative steep slopes of mountainous regions, such asKunlun Mountains, Qilian Mts., Himalayas, Tanggula Mts., Gangdise andNyainqen-Tanggula Mts. etc.

b) Solifluction: It produces solifluction lobes, terraces and fans etc, whichare distributed mainly on the gentle slopes composed by fine-grained sediments.Permafrost table is not deep (generally less than 1.5 m) and with high moisturecontent during the thawing season of active layer. The solifluction landforms almostcan be found in all fine-grained gentle slopes in permafrost regions of the TibetanPlateau.

c) Frost cracking: It is caused by different thermal contraction andexpansion of materials at sub-freezing temperatures, and produces frost cracks andunsorted polygons even more hummocks and ice wedges in bog wetlands etc. Thesefeatures mainly develop on flat lands, such as terraces, bottom valleys, flood plainsetc, with fine or very fine-grained sediments. Ice wedges were found in TianshuihaiLake region along XZH (LI et al., 1998). It was buried about 100 cm deep beneaththe ground surface. The wedge is about 80 cm wide on top, 10 to 20 cm at bottom,and 150 cm long. There are very few reports about modern ice wedges in China(TONG, 1993). Generally, ice wedges are formed in very cold climate with MAATbelow -6.0°C (Washburn, 1979). The MAAT here is -4.4°C now. It is said that thewedge should be formed in the past with a climate lower about 1.6°C or more thanpresent.

d) Frost sorting: Sorted polygons, frost scars and stone stripes are developedunder this process. They are mainly developed on very gentle slopes and plains withmixed sediments of fine and course materials. The coarse materials are distributedin the fringes of polygons and the fine are in the middle. Frost sorting always movescoarse materials upwards and then to relatively loose places on ground surface, forexample, cracks. So, it made the ground surface scar like.

e) Frost heaving: It is resulted from moisture migration and ice segregationduring freezing processes and volume expansion when liquid water changes into ice.The main features include pingos, icing, upheaving stones and hummocks. They aredeveloped mainly on wetlands and riverbed etc with very good water conditions.The most well known feature of frost heaving on the Tibetan Plateau is the pingo(frost mound) near Kunlun Pass along QTH (Figure 6-5). This pingo is about 140 mlong, 45 m wide and 18m high. Pure ground ice nuclear was found in the center ofthis pingo. Borehole profile in the top of the pingo revealed that the ice layer isfrom 1.30 to 14.59 m in depth and about 13.2 m thick (WANG, 1983).

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124 ZHAO L., CHEN G. c., CHENG G. D. and LI S. X.

f) Nivation: Nivation is a periglacial process induced by snow. Thus, wherethere are snow covers, especially during the thawing seasons, there are nivation.Nivation hollows and plains are its typical features, which are developed on leewardslopes and passes of the mountains. In Hengduan, Himalayas, Gangdise andNyainqen-Tanglha Mountains, nivation landforms are well developed because ofmore snowfall there.

g) Thermokarst: Melting of ground ice even of permafrost would result inthermokarst landforms, which include thermokarst depressions and lakes etc.Surface erosion, artificial activities and climate warming would result in melt ofpermafrost, and then form thermokarst landforms. Thermokarst landforms are welldeveloped along QTH because the construction of roads disturbed the energybalance of permafrost.

Figure 6-5 Pingo near Kunlun Pass along QTH

6.3 Permafrost and Geo-Ecological Effects

6.3.1 ECOSYSTEMS IN PERMAFROST REGIONS

The research on flora of spermatophyte in permafrost regions on the TibetanPlateau (WU et aI., 1995) indicated that the flora is abundant although the weatheris atrocious and the ecological environment is fragile. About 67 families, 339genera and 1816 species of spermatophyte were found. The flora in permafrostregion has the traces of that in temperate zones and seems to have close relationshipwith the flora in the region of Himalayas. It can be concluded that the flora inpermafrost zones should be evolved from the flora in temperate zones gradually toacclimate the cold and arid climatic condition accompanied with the uplifting of theTibetan Plateau (The Comprehensive Scientific Expedition to the Hoh Xii Region,


1996). Most of the plants have unique morphologic and ecologic characteristics toacclimate the permafrost environment. For example, the plants in permafrost zoneare generally dwarf and with external tomentum, well developed root systems,cushion or rosette-form morphologic character, etc. (WANG, 1985). Thevegetations developed in the permafrost regions on the Tibetan Plateau include highcold meadow, steppe, desert, bog meadow, cushion vegetation and alpine periglacialsparse vegetation.

High cold meadow: It is the plant community mainly composed of coldtolerant, mesophytic, perennial herbs (CHEN and WANG, 1999) (Figure 6-6). Itsdominant species are Kobresia pygmaea and K. humilis which are cold-tolerant,perennial and dense geophyte with short rhizome grown in alpine meadow soils.The ground surface was cracked under intense freezing processes due to thedevelopment of permafrost. As a result, the plant community becomes mosaiclike on ground surface. The community structure is simple with coverage from 45%to 85%. Generally, the accompanying plants are Poa indattenuata, Thalictrumalpinum, Leontonpodium pusillum, Aster j/accidus, Gentiana squarrosa, G.leucomelaena, Draba oreades, Astragalus polycladus, Potentilla saundersiana,Deyeuxia tibetica var. przewalskyi, Reoneria nutans, Androsace yargongensis,Saussurea subulata, Taraxacum brevirostre, Festuca brachyphylla, Astragalusporphyrocalyx, Ptilagrostis dichotoma var. roshevitsiana, Saxifraga tibetica andArenaria saginoides.

Figure 6-6 High cold bog meadow (gentle slope below the hill foot) and high cold meadow (slopeabove the hill foot) vegetation near Liangdaohe (31 °49'N, 91 °44'£ and 4800 m asl)


High cold steppe: It is the plant community mainly composed of cold and aridtolerant, perennial, bunch grass, rhizome carex and small subshrub (CHEN andWANG, 1999) and is the typical cold-tolerant plant community on the TibetanPlateau from 4100 to 5200 m as!. Its dominant species are Stipa purpurea, S.subsessiliflora, S. purpurea var. arenosa, Littledalea racemosa and Carexmoorcroftii etc with simple and sparse community structure (Figure 6-7). Itscoverage is from 35% to 75%. Accompanying plants are Kobresia robusta,Regneria thoroldiana, Carex ivanovae, Saussurea arenaria. S. eopygmaea, Ajaniakhartensis, Leontonpodium pusillum. Heteropappus bowerii, Androsace tapete, Irispotaninii, Arenaria qinghaiensis, Heracleum millefolium, Poa litwinowiana,Neotorularia humilis, Astragalus hendersonii, Oxytropis stracheyana, Potentillacuneata, P bifurca. Pedicularis cheilanthifolia and Lagotis brachystachya etc.

••• fo .. '. . .~.

Figure 6-7 Photo of high cold steppe vegetation near the Eco-station along QTH(35°25'57"N, 93°35'54"E and 4510 m asl) the dominant species is Stipa Purpurea

High cold desert: It is the community mainly composed of cold and aridtolerant small subshrub from 4500 to 5500 m asl in Kunlun and KarakorumMountain regions. Its dominant species are Ceratoides compacta accompanied withStipa purpurea and Carex moorcroftii etc.

High cold cushion vegetation: Cushion plants are evolved gradually toacclimate the frigid, arid, strong windy climate (The Comprehensive ScientificExpedition to the Hoh Xii Region, 1996a). In the permafrost region on the TibetanPlateau, the cushion plants are abundant in species. There are about 50 species inthe permafrost region in Hoh Xii, and accounting for about half of the total numberof species of all cushion plants on the Tibetan Plateau (HUANG, 1994). Figure 6-8


shows one kind of the cushion plant widespread on the plateau. Cushion plantsgrow widespread in the community of high cold meadow, cold steppe, cold desertand alpine periglacial vegetation. Cold cushion vegetation is mainly composed ofcushion plants with coverage from 5% to 30%. Its dominant species includeThylacospermum caespitosum, Androsace tapete, A. tanggulashanensis, Arenariakansuensis and A. bryophylia etc. The accompanying species are Leontonpodiumpusilium, Saussurea arenaria, Astragalus hendersonii, Potentilia cuneata,Oxytropis stracheyana, 0. densa and Carex moorcroftii etc.

4Figure 6-8 Cushion plants (Saussurea soleulata) distributed near Fenghuoshan

(34°43'43.7''N, 92°53'36"E and 4767 m asl)

Alpine periglacial sparse vegetation: It is the highest types of vegetationdeveloped in the regions between alpine ice-snow zone and alpine vegetation zone,and mainly composed of cold-tolerant, perennial axiform TUderal plants (WU, 1980).Bare rocks could be found everywhere on ground surface. Compositae, Cruciferae,Caryophylaceae and cushion plants are dominant plants, which include Rhodiolaalgida var. tangutica, Thylacospermum caespitosum, Saussurea gnaphalodes,Saxifraga tibetica, Soroseris glomerata, Dilophia fontana, Christoleahimalayaensis and Oxygraphis glacialis etc with coverage below 10%.

High cold vegetation in permafrost regions of the Tibetan Plateau has obviousaltitudinal zonality (ZHANG, 1978). High cold meadow is mainly developed in thesoutheastern part of the permafrost region on the Tibetan Plateau, especially inTanggula Mountain area and the source area of the Yangtze and Yellow Rivers


(ZHOU et aI., 1991). High cold steppe is the largest in area on the Tibetan Plateau.It is mainly distributed in a wide range of permafrost regions in the west of QTHand most of the area in Qiangtang Plateau (ZHOU et aI., 1987; ZHOU et aI., 1991).High cold desert grows in extreme cold and arid regions on the south slopes ofKunlun Mountains (IPR and CIG, 1988). High cold cushion vegetation is mainlydistributed in the permafrost areas of Hoh Xil Region and the Qiangtang Plateau. Inconclusion, high cold vegetation alters from high cold meadow (including high coldbog meadow) to high cold steppe, desert steppe to cold desert accompanied with thedrier of climate from southeast to northwest.

6.3.2 GEOECOLOGICAL EFFECTS OF PERMAFROST

Permafrost plays a significant role in the territory portion of the hydrologicalcycle because it restricts moisture exchanges between surface water and deepground water (Prowse, 1990). The occurrence of permafrost is, therefore, animportant factor controlling drainage and the temporal and spatial distribution ofwetlands (Rouse et al., 1997). Furthermore, it influences characters of the soils inwhich vegetation developed. The distribution of wetlands or bog soils has veryclose relationship with the development of permafrost on the Tibetan Plateau (Sun,2000). The thinner the active layer, the wetter the soils, and the more preferentialfor cold meadow even to bog meadow plants growing (Table 6-9). In other words,the desert plants grow in the area where the active layer is thicker, then cold steppe,cold meadow and the last cold bog meadow plants grow in accompany with thethinner of active layer.

Table 6-9 Active layer thickness and vegetation types along QTH (August, 1999)

Location

Xidatan

Ecostation

Fenghuoshan

Wuli

Liangdaohe

Thickness of

active layer (m)

>3.0

2.0 to 2.7

1.3 to 1.6

>2.7

<1.0

Soil type

High cold desert steppe soil

Steppe soil

Meadow soil

Steppe soil

Bog soil

Vegetation

High cold desert steppe

High cold steppe

High cold meadow

High cold Steppe

High cold bog meadow

The source of Yangtze and Yellow Rivers are located in the permafrost regionsof Qiangtang Plateau. MAATs have risen about 0.8°C in the source of YangtzeRiver and 0.7 to 1.2°C in the source of Yellow River. Permafrost has decreasedabout 3 to 5 meters in thickness in high plains and wide valley regions (CHENG etal., 1998). As a result, the moisture content decreased greatly accompanied with thelowering of permafrost table, and the vegetation is degenerating gradually. At themean time, thermokarst features, such as thaw slumping, appeared. Patches of sodsslumps down slopes and the vegetation was destroyed. Furthermore, it will promotethe thawing process of permafrost there (Table 6-10).


Table 6-10 Comparison of permafrost characteristics in different ecosystems in the source ofYangtze River (after CHENG et aI., 1998)

VegetationMaximum thawing WMC MJGST

depth (m) (%) CC)Ground surface

condition

Bare land 1.8 to 1.9 15 21 Sparse plants 0.4 to 1.5

Steppe withcoverage of80%

1.2 37

Stable sand cover with16 steppe (0.2 m deep of

sand layer beneathground surface)

-0.1 to 0.7

Note: WMC-Weight moisture content; MJGST-Mean July ground surface temperature; MAGSTMean annual ground surface temperature

As discussed previously, extensive and intense seasonally freezing processes inpermafrost regions result in cracking in active layer, movement of coarse materialsupwards. Soils, therefore, would degrade gradually. Furthermore, it would result inthe degradation of vegetation. In the mean time, physical weathering during thefreezing processes result in the accumulation of silt (Konischev, 1988). This isprofitable to vegetation growth. Different periglacial processes have different geoecological effects. Frost weathering would crack the coarse materials into finegrains. Nivation would flatten the lands. Thus they are profitable for thedevelopment of ecosystems. Solifluction, frost sorting, frost heaving, frost crackingand thermokarst have negative effects to soils and vegetations.

6.4 Permafrost and Global Change

6.4.1 CLIMATE WARMING AND PERMAFROST DEGRADATION

Many extensive and persisting permafrost shifts occurred during the Quaternary dueto the rapid uplifting of the Tibetan Plateau and changing climates (WANG, 1989).Permafrost degradation was distinct in the past 1000 years. The periglacialevolution, which indicates the permafrost environment, in the terrace near Nachitaiwas formed during the Neoglaciation. The LLP of modern permafrost is in Xidatanvalley. It has moved 15 to 20 km southward in horizontal distance and 800 to 900 mupward in elevation after the Neoglaciation (FAN and YAO, 1982). The increasingtemperature about 0.5°C on the Tibetan Plateau after the 1970s (Kang, 1996),especially in winter, has resulted in permafrost degradation (WANG et at., 1996;ZHU et at., 1996). The evidences include increase of ground temperature and activelayer thickness, shrinkage of permafrost area, disconnected permafrost and thawednuclei within permafrost and rising in elevation of LLPs etc. (WANG et aI., 1996).Tables 6-11 and 6-12 show the changes of MAGTs along QTH and rises of LLPs inselected areas on the Tibetan Plateau. The MAGTs have risen about 0.3 to 0.5°C inthe past 15 to 20 years in the regions of seasonally frozen ground, taliks and island


permafrost where ground ice content is low, and about 0.1 to 0.2°C in continuouspermafrost regions with high ice content even to thick ice layers (WANG andZHAOI, 1999). The risen ranges of LLPs are from 40 to 80 m in elevation in someselected regions although the amplitudes of changes differ each other because of theinfluences of local climate, lithology, geomorphology and hydrologic conditions.The thickness of active layer under natural conditions changed a lot after the 1980s,and great differences existed here and there (Table 6-13). The amplitudes of theincrease in active layers under natural condition are greater in the vicinities of thenorthern and southern lower limits than those in the interior, such as in theFenghuoshan and Tanggula Mountains. Owing to the investigated sites being not sofar away from QTH, the influences of its construction to nearby permafrost mustexist. So the changes of the thickness active layer are not only induced by globalwarming, but also by thermal effect of the highway.

Table 6-11 Changes ofMAGTs along QTH (in 0c) (Modified based on WANG et at., 1996)

Borehole CK123-4 CK-7 Jing- CK-114 CK123-7 CK124-4 K2956 No.1xiangu

Latitude (N) 31°55' 33°52' 36°17' 32°21 ' 31°55' 31°48' 35°39' 34°20'

Longitude (E) 91°08' 90°19' 94°01' 91°42' 91°08' 91°46' 98°48' 97°54'

Type of frozen Seasonally frozenDiscontinuous permafrost

Continuousground ground permafrost

Present MAGT 0.8 0.8 0.3 0.8 -1.0 0.8 -0.9 -2.8

Increase from 70s0.3 0.4 0.5 0.3 0.2 0.3 0.1 0.2

to 90s

Table 6-12 Rises ofLLPs (from the 1960s to 1994) (after ZHU et aI., 1996)

Mountains Kunlun S. Amdo Rubber Laji S. Heka Buqing Naboeze Qilian

Location Xidatan Amdo W of Qinghai N T NH214 MadoN. Jing-

Lake . awan Ximencuo yangling

70s (m asl) 4300 4640 3700 3700 3840 4220 4070 3420

Present4350 4680 3780 3760 3900 4270 4140 3500

(m asl)

Rise (m) 50 40 80 60 60 50 70 80


Table 6-13 Changes of active layer thickness along QTH (after WU and TONG, 1995)

Natural surface Asphalt road surfaceLocation Permafrost type

1980s 1990s 1980s I990s

Kunlun Pass 1.0-2.8 1.8-2.8 3.0 4.2 Soil contained ice layer

Cumar River 1.0-3.5 2.0-3.5 3.6 4.0 Icy and ice-rich permafrost

Wudaoliang 1.0-3.0 2.0-3.5 3.8 4.8 Soil contained ice layer

HohXil 1.\-2.5 1.8-8.5 2.9 3.6 Soil contained ice layer

Fenghuoshan 1.\ -2.2 1.3-2.5 2.8 3.4 Soil contained ice layer

Tanggula 1.\ -3.2 1.5-2.5 2.2 3.0 Ice-contained and -rich permafrost

Taoerjiu 1.0-2.0 1.3-2.5 2.7 3.8 Ice-rich permafrost

Amdo 2.0-3.0 2.2-4.0 2.5 5.5 Ice contained permafrost

According to IPCC reports, the mean global air temperature will rise at a rateof O.3°C per 10 years in the next century, and the climatic warming in high latitudeand high altitude regions will be much more sensitive than elsewhere (lPCC, 1996).The changes of permafrost on the Tibetan Plateau were modelled under differentscenarios of climate change (LI, 1997). The results showed that:

a) Assumed that MAAT rises 0.5°C in the next 20 years and MAGT rises atthe seem amplitude, unstable permafrost less than 10m in thickness would degrade,and the total area of permafrost on the Tibetan Plateau would decrease 3% to 5%;

b) Assumed that MAAT rises 0.5°C in the next 50 years and MAGT rises atthe same amplitude, the permafrost less than 30 m in thickness would be affected,and the total area of permafrost on the Tibetan Plateau would decrease 12% to 16%;

c) If MAAT rises 1°C in the next 20 years, disconnection of permafrostwould appear in the permafrost regions less than 15 m in thickness, and the totalarea would decrease 10% to 14%;

d) MAAT rises 1°C in the next 50 years. Then the thickness of sub-stableand transitional permafrost would decrease 10% to 20%.

As previously discussed, a large amount of ground ice existed in permafrostzones on the Tibetan Plateau (see Figure 6-1). Actually, the degradation ofpermafrost is the process of ice melting. Thus, under the warming climate, a largeamount of energy would be consumed by ground ice melting, and the groundtemperature would be not warm greatly, especially in the warm permafrost regions(LI, 1996). The impacts of permafrost temperature on warming climate tend tobecome smaller as it is changed to more close to the freezing point of soil water.Furthermore, permafrost has the ability to adjust the soil-atmosphere heat balancedue to exist of large amount of ground ice.


6.4.2 VEGETATION DEGRADATION IN PERMAFROST REGIONS

As stated previously, permafrost on the Tibetan Plateau was degrading after the1970s. The thickness of active layer became thinner. As a result, ground water tablemoved gradually downwards. The water content of soils decreased gradually. Theecotype, thereafter, altered from hygrocolous to mesogenous. Kobresia tibeticaseceded gradually from cold meadow, and perennial' mesogenous gramineousspecies, such as Festuca ovina, F rubra and Elymus nutans etc., intruded in greatnumbers (ZHOU et al., 1998). Measurements on vegetation characters wereconducted in the island permafrost zone near Liangdaohe in August of 1999. Themean area of hummocks changes from 1. 15m2 in the middle of high cold bogmeadow zone to 0.26m2 in its fringe regions where permafrost was well developedin the 1960s, and the mean height of hummocks changes from 29.4 cm to 14.3 cmrespectively. The hummocks disappeared at all in the seasonally frozen ground zonewhere permafrost existed very well in the 1960s. It infers that the vegetation isdegenerating after 1960s accompanying with the degradation of permafrost resultedby climate warming. The investigation also indicated that the thermal depressions inhigh cold bog meadow zones, and the plants community is altering from thatdominated by Potamogeton pectinatus and Hippuris vulgariS to that dominated byKobresia tibetica and Carex enervis, and the hummocks of bog meadow dominatedby Kobresia tibetica are shrinking. The bog meadow has the tendency to changeinto Kobresia pygmaea cold meadow. Table 6-14 shows the ecological dominancesand species diversities of the community in the permafrost and the seasonallyfrozen ground area (after YAN et aI., 1996). It indicates that both ecologicaldominances and species diversities of the community increased after permafrostdisappeared (YUAN et al., 1997). Climate changes and permafrost degradationhave influenced the growth of plants. The height of cold meadow shortened by 30%to 50% and the biomass decreased more than 50% (ZHANG et al, 1999). Otherresearches indicated that the degradation of permafrost on the Tibetan Plateau haspromoted desertification progress (HUANG et al, 1993), and alteration ofvegetation, such as the decrease in species and coverage (YAN et al, 1996).

Table 6-14 Ecological dominances and species diversities of the communityin the permafrost and the SFG area near Liangdaohe (after YAN et at., 1996)

Types of frozen ground Vegetation type Ecological dominance Species diversity

Permafrost zoneKobresia tibetica

0.149 2.73cold bog meadow

Seasonally frozen Kobresia pygmaea0.166 3.05ground zone cold meadow

6.4.3 IMPACTS OF PERMAFROST DEGRADATION

Permafrost degradation directly affects the stability of engineeringconstructions and facilities on the Tibetan Plateau, and some human activities have


accelerated the permafrost degradation. While the roads and other facilities on theTibetan Plateau constructed, they are undergoing dramatic changes under thewarming climate. Various countermeasures have been and are being takencontinuously to adapt to the changing environment; however, the socio-economicdamages are substantial (JIN et at., 1997). The most remarkable effects ofpermafrost degradation after the construction of road are thickening of seasonallythawing depths under the warming climate (Table 6-13). It is mainly due to thealteration of surface albedo and evaporation. According to Zhang et at. (1994), theannual evaporation in the valley bottom of Dongkemadi River (33°02'N, 900 02'E,5170m) is about 340 mm, and consumes a large amount of heat. The highway cutoff the way for evaporation. This amount of the energy would be consumed in thethawing of permafrost, and resulted in settlement of ground surface. Consequently,the roads were damaged seriously (Table 6-15).

Table 6-15 Destructive state of the Qinghai-Tibetan highway in 1990

RangeofQTHLength

Damaged Length (km)Percentage

(km) (%)

Golmud-Lhasa (Whole Length) 1137 346 30.4

Highway within permafrost regions 543 289 53.2

IDamaged by settlement 289 83.5

QTH IDamaged by frost heaving and boiling 57 16.5

Permafrost degradation also has impacts on hydrology and environments.Permafrost hydrology is largely influenced by the heat-moisture dynamics of activelayer during seasonally freezing-thawing cycles. In many permafrost regions, themost striking effect of permafrost degradation is the shrinkage of talik lakes andlowering of lake water levels, as well as shrinkage and disappearance of wetlandsand bogs. The effects of permafrost degradation to river hydrology is extensive, andmuch more complicated. Intensive research is needed for the cold and arid regionson the Tibetan Plateau in which the two most important rivers, Yangtze and Yellowriver are feed.

6.5 Summary and Conclusion

Permafrost occupies about 56% of the total area of the Tibetan Plateau. Itsdistribution characteristics are different in different zones due to the differences inclimate, geology, hydrology and geomorphology etc. Ground ice was welldeveloped in fine-grained sediments on gentle slopes and plains.

Periglacial features could be found in all areas of permafrost induced by theextensive and intensive periglacial processes. Different periglacial processes inducedifferent periglacial landforms. Three periglacial zones and 7 subzones wereclassified based on geological structure, petrologic composition, geographiczonation geomorphologic characters and climatic conditions. The combination of


periglacial features is different in each zone and even in each subzone.The ecosystems in permafrost region have close relationship with the

development of permafrost. Permafrost confined the downward movement of waterand thus is profitable to growth of plants. But most of the periglacial processes tendto destroy permafrost soils and then have negative effects to vegetation cover.Warming climate and artificial activities has resulted in permafrost degradation, andthen significant changes of environment, engineering and ecosystems. The temporaland spatial differences of permafrost degradation were also observed which couldbe attribute to combined influences of climate, artificial activities and geology andother factors. Permafrost degradation has affected the constructions along highways.Further studies on the permafrost and its effects in this region are urgently neededbecause it not only influence local economy, but also have close relationship withthe global climate.

Acknowledgements

This work was supported by Chinese National Key Project (G 1998040803) and CAS KeyProjects (K.Z951-AI-204 and KZ952-S1-215). Some data were collected during in the summer of1999 under the support of Sino-US cooperation Project on the Ecological System of PermafrostSoils on the Tibetan Plateau. The authors would like to express our gratitude to Professor WANGShaoling who gave us many helps and valuable suggestions for this paper, Mr. WANG Yinxuewho drew the Figure 6-1 in this paper, and Miss L1U Jingren, Prof. GUO Dongxin and all thepeople helped us.

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CHAPTER 7 BIODIVERSITY: BIOTA AND BIOCOENOSE

WANG Jinting

Botanists and zoologists both in China and foreign countries have beeninterested in biota of the Tibetan Plateau very much. Since the 1950s, a largenumber of plant and animal specimens as well as scientific materials concerningflora and fauna of the plateau have been collected and investigated. A lot of relevantmonographs, books and papers, which laid a solid foundation for analyzing thebiota of the plateau, have been published (WU Zhengyi et al., 1983-1987; WANGWencai et al., 1993; ZHENG Zuoxin et al., 1983; FENG Zuojian et al., 1986; NlZhicheng et al., 1992). This charpter was written based on these documents.

7.1 Composition and Characteristics of the Biota in the Tibetan Plateau

Biodiversity of the Tibetan Plateau is characterized by unique composition ofvarious elements, abundant in endemics, distinct regional differentiation ofbiocoenose and specific adaptation of alpine species due to unique physicalenvironments caused by intensive uplift of the plateau in late Cenozoic Era.

7.1.1 COMPOSITION OF THE BIOTA

Flora and fauna of the Tibetan Plateau is very rich and complicated. Accordingto the estimation (WU Sugong, 1996; FENG Zuojian, 1996a, FENG and Ll 1998;LI Bosheng 1994a), there are more than 13,000 species of cormophyte and some1,100 species of terrestrial vertebrates on the plateau, which account respectivelyfor about 45% of total species in China. In addition, there are 152 species of fishesand numerous insects, invertebrates and lower level plants on the plateau.

Flora of vascular plants of the plateau consist of about 800 species belongingto 124 genera and 43 families of Pteridophyta, 88 species belonging to 18 generaand 7 families of Gymnospermae and more than 12,000 sp~cies belonging to 1,494genera and 169 families of Angiospermae. The above-mentioned species make uprespectively 40%, 44% and 44.4% of the relevant total species in China. The faunaof terrestrial vertebrates of the plateau is composed of 206 species of mammals, 678species of birds, 83 species of reptiles and 80 species of amphibians, accounting for41.3%, 57.2%, 22.1 % and 28.7% of the total species of China (FENG, 1996a)respectively. General picture of biota composition of the plateau is shown in Table7-1, which indicates that biodiversity of the plateau is abundant in species and plays

139

ZHENG Du. ZHANG Qingsong and WU Shaohong (eds.), Mountain Geoecology and Sustainable Development oftheTibetan Plateau, 139-157.©2000 Kluwer Academic Publishers.

140 WANGJ. T.

an important role in China.Analysis of geographical elements is an important field of floristic

composition of the biota. It is known to all, geographical elements of the plateau'sbiota are very complicated, extending across two bio-geographical regions, i.e. theHolarctic Kingdom and the Paleotrophic Kingdom in flora and the PalaearcticRegion and the Oriental Region in fauna, and are affected by geological evolutionof the plateau in Cenozoic Era. As regards the flora, among 124 genera and about800 species of Pteridophyta on the plateau, 76 gerera and some 200 species, orabout 61.2% and 25% of the respective total fern's genera and species of the plateau,are distributed in the tropical and subtropical regions, i.e. the southern flanks of theHimalayas and the south Hengduan Mts. While 40 genera of fern belonging totemperate type distribution make up 32.2% of the total. They consist of about 600species that account for 75% of the total. WU Sugong (1996) pointed out that thefern flora of the Tibetan Plateau is characterized by the nature of temperate zone inessence.

Table 7-1 Number of species of cormophyte and vertebrates·

Biota China Tibetan Plateau Tibetan Plateau/China

Bryophyta 2200 7541) -Cormophyte Pteridophyta 2000 800 40.0

Gymnospermae 200 88 44.0

Angiospermae 27000 12000 44.4

Mammal 499 206 41.3

Terrestrial Bird 1186 678 57.2

Vertebrate vertebrateReptile 376 83 22.1

Amphibian 279 80 28.7

Fish 2804 152 5.4.. ..

• Accordmg to WU Sugong, 1996; FENG ZuoJlan, 1996a; FENG ZuoJlan and LI Bosheng,1998.

1) Only the number of moss species of Tibet.

Based on 15 distribution patterns of flora in China by WU Zhengyi (1987), theareal types of spermatophyte of the Tibetan Plateau identified are shown in Table 72. The areal types of temperate pattern consist of 743 genera including most of thetotal species, which make up 49.1 % of the total 1513 genera of the plateau.Although the genera of all tropical distribution patterns are rather abundant with595 genera in total, which only amount to 39.3% of all the genera of the plateau.They are composed of a few of species and appear strictly in areas with loweraltitude in southeastern part of the plateau. As a whole, the flora of the TibetanPlateau is characterized with the temperate character (Wu Zhenyi, 1987, WuSugong, 1996).

BIODIVERSITY: BIOTA AND BIOCOENOSE 141

Table 7-2 The areal-types of genera of spermatophyte in Tibetan Plateau*

Areal-types Number of generaNumber of genera!Total genera %

I.Cosmopolitan 88 88 5.8 5.82.Pantropic and its subtypes 213 595 14.1 39.33.Trop.Asia & trop. America disjuncted 27 1.84.01d world tropics 83 5.55.Trop.Asia &trop. Australia 52 3.46.Trop.Asia to trop Africa 55 3.67.Trop.SE Asia (Informal.) 165 10.98.North Temperate 256 743 16.9 49.19.E.Asia & N.America disjuncted 71 4.7

10.Old world temperate 99 6.5II.Temperate Asia 29 1.912.Mediterranean, W. Asia to C. Asia 53 3.513.Central Asia 39 2.614.East Asia 196 13.015.Endemic to China or/and Tibetan Plateau 87 87 5.8 5.8Total 1513 100.0* Accordmg to Wu Sugong, 1996, to be slmphfied and supplemented.

As regards the fauna, taken terrestrial vertebrates as example, the geographicalelements are divided into 4 types and 9 subtypes as shown in Table 7-3 (FENGZuojian, 1996a).

Table 7-3 Geographical elements ofterretrial vertebrates of the Tibetan Plateau*

* Accordmg to Feng ZUO]lan, 1996a, to be slmphfied.I) Birds excepting resident birds, summer migrant and breed birds, as well as two species of

amphibian are excluded.

Geographical elementsNumber of species Number of species/total

Types Subtypes

Cosmopolitan III 12.3

Oriental Indo-Malaysian 259 331 36.7

East Asian 72

Palaeoarctic North continental of Euro-Asia 87 180 19.9

Northern Asia 93

Endemic Endemic of the Plateau 71 281 31.1

Endemic of Hengduan Mts. 59

Endemic of the Himalayas 56

Hengduan-Himalayan endemic 95

Total 903 1) 100.0..

142 WANG J. T.

From Table 7-3 one can see that the oriental type with 331 species prevailsamong 4 types, being similar to species of tropical areal type of spermatophyte.They occur mainly in low altitude areas of the south Hengduan Mts. and thesouthern flanks of the Himalayas. While the vast area of the plateau are dwelt bythe endemics and the palaeoarctic species of fauna.

7.1.2 ABUNDANT IN ENDEMICS

Unique geological history and complicated environments of the plateau havenot only brought about sheltets for many relicts, but also being favorable tospecializing new species. Southeast part of the plateau is one of the most activeareas for differentiation of species in China, and a very markable region inendemism. Based on statistics (WU Sugong, 1996), there are one endemic genus,Sorolepidium, and 348 endemic species, which make up 43.8% of the total speciesamong the Pteridophyta of the Plateau. As concerns Gymnospermae on the plateau,there are 17 species (and varieties) of Abies with 11 endemic species, 5 endemicspecies among the total 16 species (and varieties) of Picea, 6 species (and variety)of Larix with 3 endemic species. In addition, there are endemic relicts such asCupressus gigantea etc, on the plateau. As regards Angiospermae, there are 55endemic genera on the plateau, such as genera Przewalskia, Acanthochlamys,Anemoclema, Notopterygiam, Ajaniopsis Sinoleontopodium, Tibetia, Xizangia, etc.Most of them are endemic to the southeastern part of the plateau. As for theendemic species of the plateau the total statistics have not done so far, but there are955 endemics of spermatophyte only in Tebit Autonomous Region and which makeup 18.03% ofthe total (WU Zhengyi, 1987). It is estimated that there are a little lessthan 2000 endemics of vascular plants on the whole Tibetan Plateau (LI Bosheng,1994a). Some important representative endemics and their distribution areas areshown in Table 7-4.

According to statistics by FENG Zuojian (l996a), there are 281 species ofendemics in the 1047 species of terrestrial vertebrates on the Tibetan Plateau, ormore than 80% of the total endemics in China. In which, there are 59 endemicspecies of mammals, 141 endemics of birds, 32 endemics of reptiles and 49endemics of amphibians. Some representative endemic species of the plateau are asfollows: Asinus kiang, Pantholops hodgsoni. Lepus oiostolus. Ochotona spp.Marmota himalayana, Moschus chrysogaster, Mfuscus. Budorcas taxicolor,Dremomys lokriah, Rattus eha etc. of the mammals; Tetraogallus tibetanus, Perdixdauuricae, Grus nigricollis. Syrrhaptes tibetanus, Pseudopodoces humilis,Garrulax maximus, Aleippe striaticauis, Tragopan melanocephalus, Lophophorusimpejanus, Psittacula derbinana, Aethopyga ignicauda, etc. of the birds;Phrynocephalus vlangalii, Japalura j/aviceps. Theremophis baileyi, etc. of thereptiles; and Batrachuperus tibetanus. Bufa tibetanus. Altirana parheri, etc. of theamphibians. Besides, there are some endemics of fishes, aquatic vertebrate, in therivers and the lakes of the Plateau, for example, Gymnocypris waddelli,schizothorax oconnori, Trilophysa tanggulaensi, etc.


Table 7-4 Representative endemic plants and their distribution regions on the Tibetan Plateau

Classes Endemic plants Geographical distribution

Bryophyta Grimmia himalayana Mt. Qomolangma region

Pteridophyta Sorolepidium glaciale West Sichuan, northwest Yunnan andsoutheast Tibet

Gymnospermae Abies squamata West Sichuan, East Tibet and south Qinghai

Picea likiangensis var.linzhiensis Southeast Tibet, southwest Sichuan andnorthwest Yunnan

Lasix potaninii var.macrocarpa Southwest Sichuan, northwest Yunnan andsoutheast Tibet

Cupressus gigantea Nyingchi and Nang Xian region of Tibet

Pinus densata Southeast Tibet, southwest Sichuan, southQinghai and Northwest Yunnan

Angiospermae Acanthochlamys bracteata West Sichuan, East Tibet

Ajaniopsis penicilli/ormis Central Tibet

Eolocephalus saussureoides Southeast Tibet

Chamaesium paradoxum Yunnan, Sichuan, east Tibet

Sinolimprichtia alpina Sichuan, Yunnan, southeast Tibet andQinghai

Przewalskia tangutica Tibet, Qinghai, Sichuan and Gansu

Platycraspedum tibeticum Sichuan, Tibet

Metaeritrichium microuloides North Tibet and south Qinghai

Lomatogoniopsis alpina East Tipet and Qinghai

Sinadoxa corydalifolia Qinghai

Spenceria ramalana Yunnan, Sichuan and southeast Tibet

Sinoleontopodium lingianum Southeast Tibet

Xizangia serrata Southeast Tibet

Primula kongboensis Southeast Tibet

Tibetia tongolensis East Tibet, west Sichuan and northwestYunnan

Salweenia wardii East Tibet and west Sichuan

Parapteropyrum tibeticum Nang Xian region of Tibet

7.1.3 DISTRIBUTIONAL CHARACTERISTICS OF THE BIOTA

Species of the plateau's biota are mainly presented by remarkable distinction invarious regions and of the different belts on the Tibetan Plateau due to markeddifference in geo-ecological conditions and great disparities in altitude of variousregions in the plateau, as well as geographic isolation for spreading and removingof the species.

144 WANG 1. T.

As above, there are about 13,000 species of vascular plants and 1047 speciesof terrestrial vertebrates on the Tibetan Plateau, but species numbers of them are noteven-distributed. Most of the majority of the total species is found in warm-humidareas with low altitudes in the southeastern part of the plateau and the southernflanks of the Himalayas. As concerns vascular plants, including 369 species ofPteridophyta, 35 species of Gymnospermae and 3364 species of Angiospermae, aredistributed in a small region of Mt. Namjabarwa, situated at the eastern end of EastHimalayas, showing abundant in plant species (NI Zhicheng et al., 1992). But thereare some 200 species of spermatophyte only in Hoh Xii region of Qinghai with alarger area in central part of the plateau (GUO Ke, 1993), and the flora of theKarakorum-Kunlun Mts. with an area of 400,000km2 consists of 827 species ofplants, including 5 species of ferns (GUO et al., 1999). Thus it is shown that thespecies richness of the latter two regions is quite poor. Distribution of animalspecies of the plateau is characterized by obvious regional differentiation similar tothat of vascular plants. For instance, there are 160 species of birds belonging only tothe Oriental in the southern part of the Hengduan Mts. (FENG Zuojian, 1996a), butall of 71 species of birds belonging to different geographical elements occur in theKarakorum-Kunlun Mts. (GUO Ke et aI., 1999), while only 30 species of birdsappear in the Hoh XiI region (Wen Jingchun et a\., 1994). These show that thenumber of species in various regions of the plateau is not extremely evendistributed.

In addition, regional characteristics in distribution of different geographicalelements are also remarkable. Genera and species of various tropical areal-types ofplants and the Oriental elements of animals are mostly found in the southern flanksofthe Himalayan Range and the southern part of the Hengduan Mts, while the biotaof the interior and the northern part of the plateau are dominated by the temperateareal-types of plants and the Palaeoarctic species of animals with a plenty ofendemic species (WU Sugong, 1996; GUO Ke et aI., 1999; FENG Zuojian 1996a).Besides, an approach to the characteristics of the floristic phytogeographicaldifferentiation of Tibet are made with aid of quantitative floristic method and thespectra of floristic areal-type. The following conclusions are drawn: the tropicalgeo-elements are confined to lower elevation of the southern flanks of theHimalayas, the Sino-Himalayan geo-elements prevail in eastern and southeasternTibet, on the plateau proper the Tibetan Plateau geo-elements dominate and theCentral Asiatic geo-elements playa significant role in the northwestern part of Tibet(ZHENG Du, 1985).

The number of species and the kinds of the biota vary greatly with increasingaltitude. This feature is remarkably shown in the high mountains of the southeastern,in particular, and the southeastern marginal parts of the plateau. In general, speciesnumber and the species richness decrease gradually and the geo-elements of thebiota have been successively changed with the increase of the altitude. In thealtitudinal belt below 2500 (3000) m asl, the number of species is abundant withplants of the tropical and subtropical zones and the Oriental animals. The biota ischaracterized with floristic elements of broad-leaved evergreen forests and needle-


leaved and broad-leaved mixed forests, as well as corresponding animals of foresttype. In the belt from 3000 (2500) m to near 4200 m asl, the Palaeoarctic andendemic species dominate the coniferous trees and other plants belonging to thetemperate areal-types are commonly met with decreasing number of species, andthe fauna (FENG Zuojian, 1996a). In the belt above 4200 m asl, the number ofspecies is further decreased with cold-resistant shrubs and herbs belonging totemperate areal-types and the highland types among Palaeoarctic and endemicanimals. By contrast, in high mountains of the interior and northern part of theplateau, the altitude difference in biota is relatively simple. In Kunlun Mts. themiddle montane belt with semi-humid/semiarid conditions is !icher in species thanin the low ones with arid climate (GUO Ke et al., 1999). And it is shown that thestructural type of altitudinal belt differs essentially from those in southeastern partof the plateau.

The obvious vicarious phenomenon in distribution of geographical species isone important characteristics of biota on the Tibetan Plateau. For instance, the 3species of Picea /ikiangenses, P /ikiangensis var. balfouriana and P/ikiangensis var.Linzhiensis are interrelated, the former is found in the southern part of the middlesouthern section of the Hengduan Mts., the second occurs in the middle-northernpart of the Mts., and the latter is mainly distributed in areas of Borne and Nyingchito the west of Boshulaling Range. The above three distributed areas are neighboringbut isolated respectively, each species has its own distributional area forminggeographical vicariousness. Similar phenomenon appears in some other genera,such as among Pinus yunnanensis, P densta and Ptabulaeformis of the Pinus,Cupressus giganten, C. terulosa, C. duc/ouxi and C. chengiana of the Cupressus aswell as between Sophora viciijo/ia and S. moorcroftiana of the Sophora, Quercusaquijo/ioides and Q. semecarpijo/ia of the Quercus and so on. The reason forvicarious phenomenon on the Tibetan Plateau is quite obvious because themigration of species were separated by high mountains caused by plateau uplifting,and the species stimulated and activated by changed various environmentsspecializing a lot of new species.

7.1.4 SPECIFIC ADAPTATION OF ALPINE SPECIES

As regards the biota of the Tibetan Plateau, specific features of adaptation,differing from those of species in lowlands, have been selected and developed in theevolution process due to high elevation, thin air, intensive radiation, lowtemperature and strong wind, etc on the plateau. One of the specific life forms iscushion plant. There are more than 40 species of cushion plants of such genera asArenaria, Androsace, Thylacospermum, Astragalus, Chionocharis, Sibbaldia,Oxytropis, etc on the plateau. The number of species with life form of cushionplants is much more than those of other mountainous areas in China. These plantsuse their cushion-like body to adapt to low temperature and windstorm on theplateau. In addition, many alpine plants, such as Saussurea medusa, Leontopodiumspp. Eriophyton wa//ichii, etc., with the aid of dwarf body and foliages covered by

146 WANG J. T.

dense gray villose, can adapt to extremely cold, intensive radiation and strong wind.In addition, structural changes for adaptation have taken place within bodies ofalpine plants. For example, there are much developing aerenchyma and the lacunaewithin parenchyma of the stems and leaves of Rheum punmila, OxygraphisgraciaUs, Soroseris hookeriana, and Polygonum macrophyllum, etc. and thesupporting structures such as collenchyma and sc1erenchyma etc. have been welldeveloped within the body of many herbs. All of these changes are undoubtedly thecharacteristics in evolution for adapting continuously to physical environments ofthe plateau (WANG Weiyi, 1985).

As concerns animals, unique characteristics for adaptation are also veryapparent (FENG Zuojian, 1996b). For adapting to low temperature, for example,some animals, such as Lepus orostolus, Babax lanceolatus, etc. are covered withdarker hair or feather in favor of heat absorption; others such as Poephagus mutus,Pantholops hodgsoni, Panthera uncia, etc. are covered with thickened hair in favorof heat preservation. All of them are characterized by adaptation to prevent harmfrom severe cold. In addition, some animals adapting to low temperature with aid ofchanged ecological behavior, for instance, Montifringilla spp., PseudopodoceshumiUs, etc. on the proper of the plateau, usually dwell in the rock crevices andburrows to build nests and breed nestlings. Thermophis baileyi is only found ingravels and ground holes of limited warm place around hot springs on the plateau.Some fish such as Schizothorax sp. usually swim downstreams to river section withlow altitude in winter and so on. All of those changed ecological behavior are toavoid severe cold. In addition, the variation of some organs, such as the developingnasal cavity of Pantholops hodgsoni and Lepus oiostulus, the protruding craniumcerebrate of Ochotona curzoniae and Oladacensis as well as the round-egg smallhole on frontal bones of Ogloveri and Oroylei, may be significant in adapting toless oxygen (02) on the plateau. Many wingless insects and ground insects arecommonly met with on the plateau, obviously relevant to strong winds of theirhabitats.

7.2 Main Types and Characteristics ofthe Biocoenose

The biocoenose is extreme diverse and abundant in types on the TibetanPlateau. Biocoenose types of various environments from northern margin of thetropics to severe cold of subpolar on the proper of the plateau, from wet toextremely arid climate, and from piedmont plains, basins in low altitude to thesubnival belt of high mountains are distributed on the plateau. Among them, mostof the unique types are a series of alpine biocoenoses with widespread distributionand extensive areas.

7.2.1 FOREST BIOCOENOSE

Forest is one of the main biocoenoses on the Tibetan Plateau. Forestbiocoenoses, controlled chiefly by moisture and temperature factors, occur mainly


in humid and semi-humid regions of southeastern part of the plateau and thesouthern flanks of the Himalayan Range (coordinated group of Vegetation ofSichuan, 1980; editorial committee of Vegetation of Yunnan, 1987; ZHANGJingwei et al., 1988; LI Wenhua et al., 1985). A few of forests appear scattered onshady slopes of East Qilian and West Kunlun Mts. (ZHOU Xinmin et al., 1987;Guo Ke et aI., 1999). They contain a number of community-types, such as tropicalevergreen and semi-evergreen rainforest, montane tropical broad-leaved evergreenforest, montane needle-leaved and broad-leaved mixed forest, montane broadleaved deciduous forest, montane broad-leaved evergreen sclerophyllus forest,montane pine forest, subalpine coniferous forests, etc. Coniferous forests,dominated by species of genera Picea, Abies, Sabina and Larix are widelydistributed, forming the landscape biocoenose of the region. The main types offorests are briefly disccussed as follows:

Tropical evergreen and semi-evergreen rainforestTropical evergreen and semi-evergreen rainforests are distributed in piedmonts

and valleys of southern flanks of East Himalayas (CHEN Weilie, 1988). The formerusually occur in lower montane belt at elevation below 600 m asl, characterized byhot and wet climate with heavy fog and annual rainfall of about 4,000 mm. Themain soil types are yellow latosol and yellow lateritic red earths, dominant plantsare Dipterocarpus turbinatus, D. macrocarpa, D. Pilosus, Shorea assamica, etc.The latter is found between 600 and 1,100 m asl, with annual mean temperature ofabout 18-20°C, annual rainfall of more than 2,000 mm. Main soil type is yellowlatosol, with dominant plants of Dysoxylum gobara, Ckukrasia tabularis, Terminalismyriocarpa, Lagerstroemia minuticarpa, etc. The tropical forests northwards alongthe Yarlung Zangbo valley up to near 29°N is the northernmost limit of tropicalrainforests on earth. The communities are very abundant in floristic compositionwith complicated structure. The first tree layer with tall and straight trucks is30-40m in height and very rich in vines, epiphytes, ferns and mosses. In rainforestsspecies of animals mostly belong to Oriental elements, with representative speciesof Pteropus geganteus, Sphaerias blanfordi, Macaca assamensis, viverricula indica,Neofelis nebulosa, Psittacula alexandri, Pericrocotus j/ammeus, Leiothrixargentauris, Xenochrophis piscator and Rhacophorus bimaculatus, etc (FENGZuojian, 1996a).

Subtropical broad-leaVED evergreen forestSubtropical broad-leaved evergreen forest is one of the main forest

communities of the marginal mountains in eastern and southern parts of the TibetanPlateau, characterized by warm and humid climate with annual mean temperature ofabout 15°C, annual rainfall of 1,000-2,000 mm. Soils under forest are chieflyyellow earths and yellow-brown earths. Community types of broad-leavedevergreen forest exist mainly at altitudes below 2,000-2,400m as!. The maindominant trees include Cyclobalanopsis glauca, C. glaucoides, C.oxyodon,Castanopsis platyacantha, C.delavayi, Schima sinensis, Lithocarpus cleistocarpus,

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1.variolosus, Cinnamomum longepaniculatum, Phoebe chinensis, etc. Regards eastmargin, mountains of the plateau (LIU Zhaoguang, 1985). The upper limit of broadleaved evergreen forest with dominant trees of Castanopsis delavayi,Cyclobalanopsis glauca, Lithocarpus variolosus, 1. hance, Schima argentea, etc. isat elevation of 2,500m in mountains of NW Yunnan of southeastern part of theplateau (Editorial Committee of Vegetation of Yunnan, 1987). Montane broadleaved evergreen forests with dominant trees of Castanopsis hystrix,Cyclobalanopsis oxyodon, C. lamellosa, C.annulata, Quercus kiukiangensis andMachi/us yunnanensis var. tibetana etc. occur at altitudes of 1, I00-2,500 m asl insouthern flanks of the middle-east Himalayan Range and the george region of theYarlung Zangbo in southestern part of Tibet (CHEN Weilie, 1988). Floristiccompositions of subtropical broad-leaved evergreen forest are quite rich, containinga large number of trees, shrubs and herbs as well as the abundant ferns and mosses.Most of the animals dominated by Oriental species live in the forests, withrepresentative species of Callosciurus erythraeus, Muntiacus muntjak, Macacamulatta, Presbytis entellus, Ai/urus fulgens, Felis temmincki, Lophura leucomelana,Pericrocotus ethologus, Aethopyga nipalensis, Heterophasia capistrata, Garrulaxspp., Naja naja, Bufo himalayanus, Japalura kumaonensis, Rhacophorus spp. andRana maculosa, etc. (FENG Zuojian, 1996a, ZHANG RongzlI et af., 1982).

Montane needle-leaved and broad-leaved mixedforestThe montane needle-leaved and broad-leaved mixed forest is an important

community belonging to the vertical belt type on the mountains of the east and thesouth margins of the plateau, and can be found nearly between 2400 and 3200 m inelevation. The climate is warm-temperature and humid with heavy fogs, the soiltypes under forest are the acid burozems or montane yellow-brown earths. Twomain communities are usually seen, one of them is the mixed forest dominated byTsuga chinensis and Acer spp, which is chiefly found on the mountains of theeastern part of the plateau; the other mixed forest is dominated by Tsuga dumoraand Quercus semecarpifolia, which occurs on the mountains of the south flanks ofthe Himalayan Range. In addition, the needle-leaved forest dominated by Tsuga spp.is also found the more humid mountains of this belt. The mixed forests contain aplenty of trees. The floristic composition and community structure are complicated;a great number of Sinarundinaria spp. grows under trees, the ground layer ofmosses is quite developed. The mixed forest is praised as "multicolored forest"because of the mosaic mixture of the needle-leaved and broad-leaved trees withcanopies of various colors along changes with seasons. The animals living in themixed forest are also very rich. The representatives frequently seen are Budorcastaxicolor, Neamorhedus goral, Presbytis entellus, Ochotona cansus, Tragopan,blythi, Lophophorus impejanus, Aethopyga ignicauda, Psittacula derbiana, Elaphemandarina and Rana yadongensis etc. (FENG Zuojian 1996a; ZHANG Rongzu etaf., 1982; LI Bosheng, 1994b).

Subalpine coniferous forest


Subalpine coniferous forests are most important communities of forests in theTibetan Plateau and are chiefly distributed in southeastern parts of plateau andmiddle-east Himalayas, only a few amount of them appear separately in eastern partof the Qinghai Province, East Qilian and West Kunlun Mts. (Coordinated Group ofVegetation of Sichuan, 1980; CHEN Weilie, 1988; ZHOU Xinmin et al., 1987;GUO Ke et al., 1999). They occur approximately between 3000 and 4200m asl withtemperate and humid-semi-humid climate and bleached gray soils (podzolic soils).Coniferous forests contain a lot of community-types, dominated by species of Piceasuch as Plikiangensis, P spinulosa, P smithiana, Ppurpurea, P wilsonii, Pcrassi/olia, P schrenkiana var. tianshanica and of Abies such as A, squamata, A.forrestii, A. ernestii, A. fobri, A. faxoniana. A. georgei, A. delavayi var. motuoensis,A. Densa, A. spectabilis and so on. Most of them are endemic species of theHengduan Mts. and the Himalayas, with a lot of geographical vicarious species(GUAN Zhongtian, 1982; CHEN Weilie, 1988). Abies forests are generally foundon southern part of coniferous forest region due to adaptation of Abies species tocold and humid conditions, while Picea forests are extended to the interiorboundaries of coniferous forest region of the plateau owing to adapation of Piceaspecies to cold and semi-humid conditions.

Subalpine coniferous forests usually grow well with tall and straight treetrunks and high productivity. Community structure of forests contains tree-, shrub-,herb- and moss layers, and abundant in accompanying plants. Trees of Larix spp.Betula platyphylla, Sorbus spp., shrubs of Rhododendron spp., Lonicera spp.,Sinarundinaria spp. and herbs of Carex spp., Poa spp., Smilacina spp., Cacalia spp.,as well as ferns of Athyrium, Dryoptesis, Polystichum Cystopteris, etc. arecommonly met with in the coniferous forests.

Coniferous forests are abundant in animal species, including a great number ofpalaeoarctic and endemic species, and a few oriental species, with representatives ofCervus elaphus, C.albirostris, Moschus berezovskii, M Chrysogarter, Ochotonatibetana, Petaurista xanthoUs, Tetrastes sewerzowi, Ithaginis cruentus, Crossoptiloncrossoptilon, Phylloscopus affinis, Accipiter nisum, Tetraophasis obscurus andRana temporaria (FENG Zuojian, 1996a; ZHANG Rongzu, et al., 1982; LIBosheng, 1994b).

7.2.2 ALPINE SCRUB

Scrubs are widely distributed on the Tibetan Plateau, especially in semihumid-humid areas of southeastern parts of the plateau. Community types includemontane scrub, subalpine scrub, alpine scrub dry-valley scrub etc. (CoordinatedGroup of Vegetation of Sichuan, 1980; ZHANG Jingwei et al., 1988; ZHOUXinmin et al., 1987). The first two types are basically secondary communities,developed after trees felled and in low altitude, containing a lot of communitiesdominated respectively by Cotinus coggygria, Vitex negundo, Coriaria sinica,Rhododendron racemosum, Rubus omabilis, Rosa omeiensis, Caragaufranchetiana,Cotoneaster, etc. Dry-valley scrub makes up a type of particular natural landscapes

150 WANGJ. T.

in the Hengduan Mts. and southern Tibet, with arid or semiarid climate. The maindominants of scrubs are mainly Pistacia weinmannifola, Sophora viciifolia,Caryopteris forrestii, Sargeretia pycnophylla and Sophora moorcroftiana etc.

Alpine scrubs with distinct features are chiefly found in southeastern part ofthe Tibetan Plateau. They occur commonly in the lower alpine belt neighboringsubalpine coniferous forest belt and in transitional regions from montane forests tohigh-cold meadow and to high-cold steppe of the plateau. Alpine scrubs usuallyexist at altitudes of 4000 (3800)-4800 (5000) m asl, but higher in the interior thanthe marginal regions of the plateau. It may be divided into 3 subtypes, namelyevergreen sclerophyllous broad-leaved scrubs, evergreen needle-leaved scrubs, andbroad-leaved deciduous scrubs.

Evergreen sclerophyllous broad-leaved scrubs, being the most representativecommunity of alpine scrubs, occur chiefly in southeastern part of the plateau andconsist of species of Rhododendron, such as Rhododendron litangensis, Rh.fastigiatum, Rh. jlavidum, Rh. Cephalanthum, Rh. traillianum in the Hengduan Mts.,Rh.nivale, Rh. Trichostomum and Rh. setosum and Rh. repens in southeastern Tibetand the Himalayas, Rh. thymifolium, Rh. capitatum and Rh. przewalskii in easternQinghai. Rhododendron scrubs, characterized by abundant in floristic composition,large coverage and a lot of accompanying shrubs, herbs as well as the developingmossess layer, are principally found on shady slopes. Alpine evergreen needleleaved scrubs with sparse coverage and poorly developed or lack of moss layers,exist widely on sunny slopes of alpine belt in southeast plateau and the south Tibet.The most widely distributed Sabina pingii var. wi/sonii community is the prevailingone of alpine evergreen needle-leaved scrubs. In addition, there are Sabinasquamata and S. wallichiana communities in alpine belt of the middleeastHimalayas. Evergreen sclerophyllous broad-leaved scrubs and evergreen needleleaved scrubs constitute all the complex distribution patterns with differentappearances in southeastern parts of the plateau.

Broad-leaved deciduous scrubs, containing various communities, aredominated by Potentilla fucticosa, P parvifolia, Salix sclerophylla, S. oritrepha,Spiraea alpina, Caragana jubata, C. Versicolor, etc. Except Caragana vesicolorcommunity that is chiefly encountered in semiarid areas of the plateau due to itsdrought endurance, the others occur chiefly on shady slopes in semi-humid areas ofthe eastern and southeastern parts of the plateau.

Animals lived with alpine scrubs are dominated by plateau's endemics andpalaeoarctic species, such as Cervus albirostris, Moschus sifanicus, Ochotonatibetana, Myospalax baileyi, Martes fOina, Vulpes vulpes, V ferri/ata, Felis manul,Perdix hodgsoniae, Phasianus colchicus, Anthus hodgsoni, A.roseatus, Turdusruficollis, Phylloscopus affinis, Carpodocus pulcherrimus, Crossopti/oncrossopti/on, Scutiger boulengeri and Nanarana pleskei (FENG Zuojian et al., 1988;ZHANG Rongzu et al., 1982).

7.2.3 ALPINE MEADOW


Meadow, one of the main biocoenoses on the Tibetan Plateau, contains mainly2 subtypes, namely subalpine and alpine meadows. Subalpine meadow, dominatedby Elymus nutans, Roegneria nutans, Anemone spp., Iris bulleyana, etc., occursprincipally on the plateau with relatively low elevation in the Hengduan Mts. Butalpine meadow is the chief representative community.

Alpine meadow exists widely in the high-cold zone of scrub and meadow withsemi-humid climate in West Sichuan, East Tibet and South Qinghai, and in shadyslopes of alpine belt of the Himalayas, the Gangdise and East Qilian Mts. Inaddition, it is occasionally encountered in local shady slopes of alpine belt of Ngari,the Qiangtang plateau, Hoh Xii, Karakorum and the Kunlun Mts. in the semiaridand the arid regions of the plateau (ZHANG Jingwei et al., 1988; ZHOU Xinmin etaI., 1987; GUO Ke et al., 1999). Alpine meadows appear roughly between 4000and 5200 (5400) m asl that is presented higher in the western part than the eastern,and mostly below 4000m asl in northern marginal mountains of the plateau. Theclimate is characterized by cold and semi-humid with annual mean temperature of0-3°C and annual precipitation of 350-550mm. The dominant soil is felty soils(alpine meadow soils) with a surface stratum consisted of herb roots 10cm or so inthickness. Kobresia meadow occurs extensively with a vast area on central-eastplateau, forming a landscape community of the high-cold meadow zone. Kobresiapygmaea community is a predominant one on the plateau, Other dominant speciesare commonly met with such as K. humilis, K. capillifolia, K. setchwanensis K.prainii, K. tunicata, K. stiebritziana, K. stenocarpa, and K. littledalei, K. tibetica, K.Deasyi, etc. Kobresia meadows are characterized by abundant in floristiccomposition, large coverage, low herb layer, and physiognomy of dull greenish.Forb meadows, dominated by Polygomum macrophyllum, P viviparum, Anaphalisflavescens, Leontopodium longifolium, Spenceria Ramalana, Anemone rivalaris, A.trullifolia var. Linearis, A.obtusi/oba, and Potentilla stenophylla, are chiefly foundin more humid and fertile sections of alpine belt in southeast plateau and eastHimalayas. The outstanding features of these communities are characterized bydeveloped forb synusia, taller layer of herb, color physiognomy, abundant seasonalaspects.

Genera Ochotona, representative animal living in high-cold meadows, ischaracterized by numerical superiority, high density and wide distribution. Thereare more than 10 species in total, such as 0. curzoniae, 0. himalayana, 0. thibetana,0. roylei, 0. forresti, etc. Others such as Myospalax baileyi, Marmota himalayana,Procapra picticaudata, Asinus kiang, Calandrella rufescens, Melanocoryphamaxima, Eremophi/a alpestris and Montifringilla taczanowkii are commonly metwith the Carnivores of Canis lupus, Vulpes ferri/ata, Mustela eversmanni, Aqui/achsysactos, Falco tinnunculus, Buteo hemi/asius, as well as omnivorous Ursusarctos, etc. in the high-cold meadow zone. Insects within meadow communities aredominated by subterranean and under-rock herbivores ones, the representatives areHepialus sp. and Gynaephora qinghaiensis, Chorthippus brunneus, etc. In addition,a great number of livestock, especially yak, Tibetan sheep, and Tibetan horse, isgrazed on the high-cold meadow zone (FENG Zuojian et al., 1998; ZHANG

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Rongzu et aI., 1982; LI Bosheng, 1994b).

7.2.4 MONTANE STEPPE AND ALPINE STEPPE

Steppe, characterized by continuous zonal distribution in semiarid areas ofcentral-northern part of the plateau and formed a wide belt on mountains ofnorthern margins of the plateau, is of the widest distributed biocoenose on theTibetan Plateau (ZHANG Jingwei et al., 1988; ZHOU Xinming et al., 1987;Comprehensive Expedition Team to Xinjiang, CAS, et al., 1978).

Montane steppe occurs chiefly in areas at relatively low elevation with cooltemperate and semiarid climate, such as some valleys, basins in east Qinghai andmiddle montane belt of northern marginal mountains of the plateau, as well asvalleys and low mountains in south Tibet and Ngari regions. The dominants areStipa bungeana, S glareosa, S breviflora, Achnatherum splendens, Orinuskokonorica, Tripogon hookeriana, Artemisia gmelinii, etc.

Alpine steppe, growing low in height, sparely with small coverage, isextensively found on the Qiangtang plateau and its contiguous regions, such as themiddle west of southern Qinghai plateau and Hoh Xii platform, and interior of theplateau and basins of Kunlun Mts. It appears also in alpine belt situated in semiaridand arid areas of the plateau (WANG Jinting et al., 1982; ZHANG Liyuan et al.,1986; GUO Ke, 1993). Alpine steppe, characterized by cold and semiarid climatewith, annual mean temperature of about 0--5°C and annual precipitation of some100-300mm, exists mainly at elevations between 4200 and 5300 (5400) m asl, butabout 3500-4000 (4500) m asl on the northern marginal mountains of the plateau.Alpine steppe may be divided into 3 subtypes, namely alpine bunchgrass steppe,alpine rhizome sedge steppe and alpine dwarf semi-frutex steppe. Alpinebunchgrass steppe is the main subtype with typical representative of Stipa purpureacommunity, other communities of the alpine bunchgrass steppe, dominatedrespectively by Sroborowskyi, Ssubsessiliflora, S basiplumosa, Littledalearacemosa and Leucopoa olgae, are commonly met with in the plateau. Alpinerhizome sedge steppe, consisting of a few communities with principalrepresentative community of Carex moorcroftii, occurs mainly on middle-northernpart of the Qiangtang plateau and in upper alpine steppe belts of high mountainssituated in its contiguous regions. Alpine desert-steppe community is dominated byCarex moorcroftii and Ceratoides compacta. Dwarf semi-frutex steppe, consistingof dominant Artemisia wellbyi, A. younghusbandii and A. stracheyi adapted tocoldness and drought, is mostly found in some regions with a little low elevationand gravel soil in south Tibet, southern part of the Qiangtang plateau and the middlenorthern part ofNgari region.

Regards animals living in high-cold steppes, as far as livestock structure isconcerned, big domestic animals, such as yak, Tibetan sheep and/or Tibetan goatmostly dominate horses, decreasing in number, while small ones increasing.Concerning wild animals, dominated by plateau endemics, typical andrepresentative species are some big- or medium-body herbivorous mammals, such


as Asinus kiang, Pantholops hodgsoni, Procapra picticaudata, and Poephagusmutus, and others, for instance, Lepus oiostolus, Ochotona curzoniae, 0. macrotis,Marmota himalayana, Pitymus leucurus, Cricetulus kamensis, Alticola stoliczkanus,etc. In addition, carnivorous Vulpes ferri/ata, V.vulpes, Canis lupus, Lynx lynx,Panthera uncia and omnivorous Ursus arctos are occasionally encountered. Birdsfrequently met in communities are Calandrella acutirostris, Eremophila alpestris,Pseudopodoces humilis, Pyrrhocorax pyrrhocorax, Montifringilla ruficaullis, Mblanfordii, M taczanowskii, Syrrhaptes tibetanus, Tetraogallus tibetanus andcarnivorous bird of prey as Aquila chrysaetos, Falco cherrugmilvipes, Buteohemi/asius, etc. A few of reptiles and amphibians are occasionally encountered, forexample Phrynocephalus vlangallii. P Theobaldi, etc. (FENG Zuojian et al., 1998;ZHANG Rongzu et al., 1982; GUO Ke et al., 1999; WEN Jingchun et al., 1994)1)2).

7.2.5 MONTANE DESERT AND ALPINE DESERT

Desert biocoenoce, found mainly in northwestern part of the Tibetan Plateau aswell as lower belts and basins of northern marginal mountainous regions of theplateau, may be divided into 2 subtypes, namely montane desert and alpine desert.Montane deserts occur in low montane belts and lower sections of middle montanebelt of the Kunlun-Altun-west Qilian ranges situated in northern marginal plateauand the Qaidam Basin as well as the Banggong Co Basin of West Tibet, at altitudeof relatively low with climate of cool-temperate and arid, soils of brown-browndesert soil and montane brown desert soil. Based on comparative analysis ofcommunity characteristics, floristic composition and dominant species the montanedesert ought to be a component part of the temperate desert of China. As concernsdistribution areas, there are a lot of desert communities in the Qaidam Basin, bothdwarf arboreous desert dominated by Haloxylon ammodendron and shrub desertsdominated separately by Ephedra przewalskii, Calligonum mongolicum, Tamarixhohenackeri, Nitraria roborowskii, and the dwarf semi-frutex deserts dominated bySalsola arbuscula, Reaumuria soongorica, Ceratoides latens, Sympegma regelii,etc., as well as the succulent holophytic dwarf semi-frutex deserts dominated byTamarix hispida, Nitraria sibirica, Kalidium cuspidatum, K. Foliatum, etc.(ZHOUXinmin et al., 1987; DU Qing et al., 1990). Dwarf semi-frutex deserts, dominatedseparately by Sympegma regelii. Ceratoides latens and Reaumuria soongorica,occur in low mountains of the northern margin of the plateau. In addition, montanedeserts dominated by Salsola abrotanoides, etc. is locally found in Middle KunlunMts. (Xinjiang Comprehensive Expedition Team of CAS, et al., 1978; GUO Ke etal., 1999). Montane desert communities, consisting of dominants Ceratoides laten,Ajania jruticulosa and Artemisia sp. appear in Banggong Co basin and lowerreaches of the Langqen Zangbo (ZHANG Jingwei et al., 1988). Representativeanimals living in montane deserts are Vulpes vulpes, Mustela altaica, Gazellasubgutturosa, Lepus oiostolus, Dipus sagitta, Euchoreutes naso, Meriones

I) Gu Jinghe et al., 19852) Gao Xingyi, 1985;

154 WANGJ. T.

meridianus, Lagurus luteus, Syrrhaptes paradoxus, Calandrella eineria, Podoeeshendersoni, Phoenieurus oehruros, Oenanthe deserti and Phrynoeephalus vlangalii(FENG Zuojian et al., 1999).

Alpine deserts occur mainly at elevations of 4,700-5,OOOm asl in northwesternareas of the Tibetan Plateau, namely northern parts of the Qiangtang plateau,extensive interior mountainous plateau between the Karakorum and the Kunlun Mts.(ZHANG Jingwei et al., 1988; WANG JinTing, 1988; GUO Ke et al., 1999).Climate of the areas is severely cold and arid, with mean temperature of <4-6°C inthe warmest month, annual precipitation of 20-50mm only, and frigid desert soils.Alpine desert communities are characterized with poor floristic composition, sparsecoverage, low herb layer in height and appearance of dull color. Ceratoidescompacta community is the main typical one of alpine desert, found widely in vastareas of the plateau. In addition, communities of Ajania tibetiea and Artemisiarhodantha are occasionally met in local areas. Fauna and population of animalsliving in the high-cold desert is much less and poorer than in the contiguous highcold steppe, and also less than in montane deserts. Main species, such as Oehotonaladaeensis, 0. kozlowi, 0. macrotis, Phodopus roborovskii, Syrrhaptes tibetanus,Oenanthe deserti, Phoenieurus erythrogaster, Prunella eollaris, Emberiza cia,Eremophila alpestris elwesi, Capra ibex, Ovis ammon, Pantholops hodgsoni,Asinus kiang and Ursus aretos, are commonly met with in the high-cold desert zone(FENG Zuojiang et al., 1983; GU Jinghe et al., 1985; GAO Xingyi, 1985).

7.2.6 ALPINE CUSHION VEGETATION

Alpine cushion vegetation, at elevations of about 4300-5400m asl with lowerlimit of 3800m asl or so in northern marginal mountains of the plateau, occurmainly on the plateau proper, especially in alpine belt of northern slopes of thecentral-Himalayas. Climate is cold and semi-humid to semi-arid. The main soil isfrozen soil (alpine frozen soil). Distribution of alpine cushion vegetation usuallyrelates to local landforms, gravel substance and excessive grazing. So alpinecushion vegetation is separately presented in patches or fragments in alpinemeadow belt, or upper alpine steppe belt, and lower alpine sparse vegetation belt.An independent belt, dominated by alpine cushion vegetation, usually could not befound on the Tibetan Plateau (WANG Jingting, 1988). Plants of the communitygrow densely or sparsely. The ranging of the coverage is great. The herb layer islower. Alpine cushion vegetation, with dense or sparse coverage and poor infloristic composition, contains a lot of communities. Dominant species of alpinecushion vegetation are Arenaria bryophylla, A. pulvinata, Androsaee tapete, A.tangkulashanensis. A. squarossula. Chionoeharis hookeri, Sibbaldia tetrandra.Thylaeospermum eaespitosum. Artragalus montieolus, A. arnoldii, etc. Wildanimals frequently met in alpine cushion vegetation are mostly similar to thosespecies of alpine meadow or alpine steppe, such as Oehotona spp., Marmotahimalayana, Lepus oiostolus and Pseudopodoees humihi. In addition, alpinecushion vegetation is also grazed with yaks, Tibetan sheep, etc.

BIODIVERSITY: BIOTA AND BIOCOENOSE

7.2.7 ALPINE SPARSE VEGETATION

155

Subnival belt characterized by extremely cold climate, is widely found in highmountains of the Tibetan Plateau, such as the Himalayas, GangdiseNyainqentanglha, Karakorum, Kunlun Mts. There is a large number of scree, rockswith more or less soils in subnival belt. Alpine sparse vegetation consists of a fewflowering plants, some kinds of mosses and lichenes, poor in species of animals andinsects. Unique alpine sparse vegetation biocoenose is extensively formed in alpinesubnival belt, with different component species of the community from southeast tonorthwest of the plateau due to decreasing precipitation. Alpine sparse vegetationof eastern and southern marginal mountains mainly consists of various kinds ofmosses, forbs and sedges because of very moist eco-conditions. With decreasingin mosses composition, flowering plants such as Sussurea medusa, S. obvallata andsome species belonging to genera Cremanthodium, Rhodiola, Kobresia, Poa, etc.are frequently met with in communities of alpine sparse vegetation in semi-humidcentral-east parts of the plateau. Main animals living in communities are onlyPseudois nayaus, Ochotona himalayana, Alticola stracheyi, and Panthera uncia.Because of semiarid and arid climate, Saussurea tridactyla, S. wellbyi, Phyllophytoncomplanaturn, Thylacospermum caespitosum, Waldheimia glabra, etc. arecommonly seen in alpine sparse vegetation in central and northwestern parts of theplateau. Pseudois nayaur, Panthera unica, Ovis ammon and Capra ibex are metwith in alpine sparse vegetation. But Tetraogallus tibetanus usually lives in alpinespace vegetation of semi-humid and semiarid regions. Besides, biotic component isquite different in communities from upper, middle and lower sections of thesubnival belt in the same region (ZHANG Jingwei et al., 1988).

7.2.8 WETLAND SWAMP BIOCOENOSE

Alpine herb swamp biocoenoses covering vast areas exist separately in centraleastern part of the plateau, such as the Zoige region of west Sichuan, the XingxiuHai ofthe central-south Qinghai and Nagqu region of Tibet. In general, swamp andswampy meadow with peaty stratum developed under ground usually present amosaic distribution pattern. Swamp is poor in community-types with dominantplants of Carex muliensis, C. doniana, Kobresia tibetica, K. littledalei, Hippurisvulgaris and some species of genera Blysmus, Eleocharis, Juncus, Scirpus andCaltha Trollius. Animals of swamp are characterized by waterfowls, includingmany kinds of water birds with a great number of population, such as Grusnigricollis, Anser indicus, Tadorna jerruginea, Mergus merganser, Larusbrunnicephalus and Charadrius mongolus, etc. In addition, Ochotona spp. appearsoften in raised land within swamp and in swampy marginal zone, big livestock suchas yak and Tibetan horse are often grazed on swampy wetlands.

156

References

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I. CHEN Weilie, 1988. Forests, In: Vegetation ofXizang (Tibet). Beijing: Science Press, 98147 (in Chinese).

2. Editorial Committee of Vegetation ofYunnan, 1987. Vegetation of Yunnan. Beijing: SciencePress (in Chinese).

3. Coordinated Group of Vegetation of Sichuan, 1980. Vegetation of Sichuan. CHENgdu:Sichuan People's Press (in Chinese).

4. Du Qing et al., 1990. Vegetation and Utilization ofQaidam Region. Beijing: Science Press(in Chinese).

5. FENG Zuojian et al., 1986. Mammalia ofXizang. Beijing: Science Press (in Chinese).6. FENG Zuoj iang, 1996a.The fauna characteristics and formation, evolution of terrestrial

vertebrates. In: Formation and Evolution of Qinghai-Xizang Plateau. Shanghai: ShanghaiScience & Technology Press, 209-222 (in Chinese).

7. FENG Zuojian, 1996b. The adaptation of the plateau animals to peculiar environment. In:Formation and Evolution of Qinghai-Xizang Plateau. Shanghai: Shanghai Science &Technology Press, 222-236 (in Chinese).

8. FENG Zuojian and Li Bosheng, 1988.The bio-diversity of the high-cold region of theQinghai-

9. Xizang Plateau. In: Research Report on National Conditions of the Chinese Biodiversity.Beijing: China Environmental Science Press, 82-89 (in Chinese).

10. Guan Zhongtian, 1982. Phytogeography on the Pines and the Firs of Sichuan. Chengdu:Sichuan People Press (in Chinese).

II. Guo Ke, 1993. Vegetation of Qinghai Hoh Xii region. Acta Phytoecologica et GeobotanicaSinica, 17(2): 120-132 (in Chinese).

12. Guo Ke, et al., 1999. Biota. In: Physical geography of the Karakorum-Kunlun Mountains.Beijing: Science Press. 85-115 (in Chinese).

13. Li Bosheng, 1994a. The characteristics and conservation of biodiversity of the QinghaiTibetan Plateau. In: East Asia Covered with Green Color. Beijing: China EnvironmentalScience Press, 635-661 (in Chinese).

14. Li Bosheng, 1994b. On the ecosystems of the Qomolangma nature conservation. In: EastAsia Covered with Green Color, Beijing: China Environmental Science Press, 670-687 (inChinese).

15. Li Wenhua et al., 1985. Forests ofXizangt. Beijing: Science Press (in Chinese).16. Liu Zhaoguang et al., 1985. Vegetation ofGongs Mountains. Chengdu: Sichuan Science &

Technology Press (in Chinese).17. Ni Zhicheng et al., 1992. The Flora of Vascular Plants in Mt. Namjagbarwa Region ofTibet

(Tibet). Beijing: Beijing Science & Technology Press (in Chinese).18. The Comprehensive Expedition Team to Xinjiang and Institute of Botany, Chinese

Academy of Sciences, 1978. Vegetation and Utilization ofXinjiang. Beijing: Science Press(in Chinese).

19. WANG Jinting et al., 1982. Main types and characteristics of high-cold steppe in theQiangtang Plateau of Xizang. Acta Phytoecologica et Geobotanica Sinica, 6( I): 1-13 (inChinese).

20. WANG Jinting, 1988a. A preliminary study on alpine vegetation of the Qinghai-Xizang(Tibet) Plateau. Acta Phytoecologica et Geobotanica Sinica, 12 (2): 81-90(in Chinese).

21. WANG Jinting, 1988b. The steppes and deserts of the Xizang Plateau (Tibet). Vegetation,75: 135-142.

22. WANG Jinting, 1996. The biodiversity of the Plateau, In: An Introduction to Developmentand Environment of the Qinghai-Xizang Plateau, Beijing: China Science Press, 65-84 (inChinese).

23. WANG Weiyi, 1985. An investigation on specific structural characteristics of alpine plants


on Qinghai-Xizang Plateau. Acta Biologica Plateau Sinica, 4:19-34, (in Chinese).24. WANG Wencai et al., 1993. Vascular Plants of the Hengduan Mountains Region. Beijing:

Science Press (in Chinese).25. Wen Jingchun et al., 1994. The nature conservation in planned construction of Qinghai Hoh

XiI Region. In: East Asia Covered with Green Color. Beijing: China Environmental SciencePress, 312-316 (in Chinese).

26. Wu Zhengyi, 1979. The regionalization of Chinese flora. Acta Botanica Yunnan, 1(1): 1-22(in Chinese).

27. Wu Zhengyi et al., 1983-1987, Flora Xiangica.Vols.I-5. Beijing: Science Press (inChinese).

28. Wu Sugong, 1996. The characteristics, formation, and evolution of the flora. In: Formationand Evolution of Qinghai-Xizang Plateau, , Shanghai: Shanghai Science & Technology.Press, 194-209 (in Chinese).

29. ZHANG Jingwei et al., 1988. Vegetation of Xizang (Tibet). Beijing: Science Press (inChinese).

30. ZHANG Rongzu et al., 1982. Physical Geography ofXizang (Tibet). Beijing: Science Press(in Chinese).

31. Zheng Du, 1985. Study on the floristic phytogeographical differentiation of Xizang (Tibet).Acta Botanica Sinica, 27(1): 84-93 (in Chinese).

32. Zheng Zuoxin et al., 1983. Aves ofXizang. Beijing: Science Press (in Chinese).33. ZHOU Xinmin et al., 1987, Vegetation of Qinghai. Xining: Qinghai People Press (in

Chinese).

CHAPTER 8 HUMAN HEALTH ASPECT IN GEOECOLOGY

TAN Jian'An, ZHU Wenyu, LI Ribang and WANG Wuyi

From the viewpoint of geographical ecology, the geoecosystem, with humans asits core, differs according to characteristics of geographical environment.Geoecosystem is the sum of man and its environmental factors as a whole body,besides man proper, including rocks, soils, water, air, plants, and animals (TANJian'an 1990).

As to the question of human health in geoecology, it means that some humanhealth issues are closely associated with physical, chemical, biological and evensocio-cultural factors of local environment. As well known, Tibetan Plateau is calledthird pole and roof of the world. So there exist some particular environmentalconditions/stresses, such as, cold, low humidity, windy weather, hypoxia and highlevel of solar and cosmic radiation arising from its high altitude, also strong erosion,thin soils, and chemical element abnormality owing to its rugged relief andgeological structure, finally forming its special biological community and landscapes,which all could influence human health. Of them the altitude, life element deficiencyor excess in geoecosystem, and landscape bio-factors are of important for theirimpacts on human health, which will be put on the focus of discussion in this chapter.

8.1 Influence of high Altitude on Health

As mentioned above, high altitude will lead to forming a series of particularenvironmental features. Among them the hypoxia is a very important stress thatimpacts most systems within the human body. As well known, oxygen in air will bedeclined with the altitude elevation. The people who live permanently or entertemporarily in the high altitude areas have to experience the stress of hypoxia owingto reduced oxygen pressure.

8.1.1 INHALATION, TRANSFERENCE AND UTILIZATION

Oxygen enter into lung by respiration, then trapped by alveoli and transferred toblood in pulmonary capillaries, and finally the oxygen bound to hemoglobin wastransported to tissues through blood circulation and where utilized to a variety ofbiochemical processes by cells and subcellular components. It should be noted themyoglobin, which is found in heart and skeletal muscles, have a greater oxygenaffinity, compared with hemoglobin, and an elevated trend in high altitude.

159

ZHENG Du, ZHANG Qingsong and WU Shaohong (eds.), Mountain Geoecology and Sustainable Development oftheTibetan Plateau, 159·180.©2000 Kluwer Academic Publishers.

160 TAN J. A., ZHU W. Y., Ll R. B. and WANG W. Y.

8.1.2 HYPOXIA AND HEALTH

Like in other high mountainous districts in America and Europe, hypoxia in theTibetan Plateau arises from its high altitude, but its height is much higher than othersare. Most of the plateau is over 3000m above sea level. Oxygen pressure inatmosphere decreases with increase of altitude, the altitude higher the oxygenpressure lower, at sea level the pressure is 21.3 kPa, up to the elevation of 3000m, itdeclines to 14.7 kPa. As result of lower oxygen pressure in high altitude, whereoxygen content in air is decreased compared with that at sea level. At altitude of3000m atmospheric oxygen content is 72 per cent of that at sea level, however at5000m, only equal to 57 per cent of content at sea level.

Under lower oxygen environment in high altitude, physiological load of humanbody increases, its main manifestations are that heart rate and energy metabolismelevate, whereas degree of oxygen saturation in blood declines. The studied data ofheart rate and oxygen-saturated degree are in Table 1 (Ll Jianguo, 1993). It showedus that heart rate was elevated with altitude increase, their percents of increase at2260m, 3000m and 41 OOm were separately 16.6%, 21.3%, and 33.8% compared withplain area; however blood saturation level with oxygen declined with altitudeelevation. Owing to lower oxygen saturation of hemoglobin in high altitude, workcapacity will be declined. It have been proved that in Qinghai Province the workcapacity at altitude of 2000m, 3000m and 4000m are declined separately 10.1 %,29.2% and 39.7% compared with plain area, it means that per 1000m increase inaltitude, the work capacity reduces 10% (WANG Yongzhen et aI., 1996).

Table 8-1 Heart rate and oxygen saturated level in different altitude of Tibetan

Height 450m 2260m 3000m 3450m 4100m

Average heart rate 63.7/min 74.3/ min 77.3/ min 79.6/ min 85.2/ min

Saturated level· 97.9±O.78 94.1±1.I 92.00±O.5 90.40±l.6 86.4±2.5

*Takmg under resting state

Usually for the lower sea-level people who firstly enter in high altitude areaabove 2500m or 3000m, some systems such as shortness of breath, rapid pulse rate,headache, nausea, fatigue, sleeplessness, mental disorientation and general malaiseare of frequent occurrence. However, in high altitude it can lead to impairment ofadequate transport of oxygen, in some conditions, then affect normal respiratory andcardiovascular function in new comers from lower altitude areas, and finally carry ahigh risk of mountain sickness. Mountain sickness including a group of illness,which could be divided into forms, acute and chronic. A epidemiological study onhigh altitude health in Tibetan Plateau, had been conducted for 8 years (1978-1985)(WU Tianyi et al., 1996), the investigated subjects consist of children of 15251 andadults 25618 both from migrants and natives, including three kinds of altitudes:2261m-2808m, 3050m-3797m, 4068m-5226m. The main results are as follows.

Acute mountain sickness Also there are three forms, acute high altitude(plateau) response, high altitude (plateau) pulmonary edema and high altitude

HUMAN HEALTH ASPECT IN GEOECOLOGY 161

(plateau) encephaledema.High altitude response As people enter in the plateau, the hypoxia

symptoms such as headache and nausea etc. appear. Averagely the incidence rate is39.8%, however, at the altitude of 4000m, up to 86.4 %.

High altitude pulmonary edema The main manifestations are pulmonaryartery hypertension and pulmonary edema. The incidence rate is 0.47%. In anotherstudy, three towns at altitudes of 3301 m, 3407m and 4200m ware investigated, theirincidences are 2811000000, 41/1000000 and 7811000000 respectively.

High altitude encephaledema It occurs usually in acute, severe and highrisk, with a series of neural and psychic symptoms and high case fatality. Itsincidence rate is 0.28%.

Chronic mountain sickness It also have three forms: high altitudeasthenia (decay), high altitude (plateau) heart disease and High altitude (plateau)polycythemia.

High altitude asthenia People who reside long in high altitude, are likelyto occur a series asthenia both physically and psychically. Prevalence rate in migrantsis 2.8%, and at the altitude over 4000m, up to 6.63 %.

High altitude heart disease The patients are with hypoxia inducedpulmonary artery hypertension, right ventricle hypertrophy and finally appearringcongestive, cardiac failure, with incidence rate 0.96 % for children and 0.32 % foradults, however less for natives.

High altitude polycythemia It arises from chronic hypoxia and lead toelevation of red cell density and greater blood viscosity, finally result in impairmentto the functions of heart, lung, brain and micro circulation. Incidence rate is 3.85 %for migrants and 1.07 % for natives.

8.1.3 ADAPTATION TO HYPOXIA OF HIGH ALTITUDE

Hypoxia is one of the most severe stresses arisen from high altitude. Peoplewhether who are natives or permanent residents or temporary comer have to adaptthis special kinds of environmental conditions or stresses. Biologically peopleusually have themselves approaches/abilities of adaptation to hypoxia of high altitude,mainly morphological, and physiological and biochemical aspects. In China, througha long period study on adaptation to high altitude, it was identified that Tibetannatives in Tibetan Plateau have obtained the advantage, compared with new residentsfrom lowland, even better than another high altitude ethnical group Indians living inAndes of South America (WU Tianyi, 1996). The main points are:

Morphological adaptation Usually the typical one of morphologicaladaptation is that the chest size and lung capacity of natives in high altitude isrelatively greater than the residents living at low sea level. The study mentionedabove identified that chest shape and lung volume of Tibetans have gooddevelopment, so that their lung capacity and vital capacity are greater compared withother people groups living in lower altitude areas.

Physiological adaptation Compared with Han people, Tibetan is: 1. Withhigher ventilation under rest state, increased density of capillary vessels; 2. For

162 TAN J. A., ZHU W. Y., LI R. B. and WANG W. Y.

Tibetan natives, heart rate (HR) and stoke volume (SV) at 3417m-4520m increasedgradually with exercise load increase, then cardiac output also elevated, whereas SVof migrant decreased under moderate load, HR also declined under heavy load; 3.Keeping the red cell and hemoglobin at normal level (even at 37 19m-4280m altitude,still retain optimum hematocrit 48%--52%); 4. Pulmonary arterial oxygen pressureand saturation of arterial oxygen are stable relative to non-natives. 5. Their maximaloxygen uptake and Maximal work capacity value are larger.

All results mentioned above could be regarded that Tibetan natives havedeveloped complete system for oxygen transmission within human body and betweenbody and environment. The uptake, transmission and utilization oxygen are allefficient under high altitude hypoxia condition.Another study on geographical changes of hematocrit, blood vicosity and erythrocytesedimentation rate has been conducted (GE Miao et al., 1996, 1997, 1999). The mainresults list in Table 8-2. Table 8-2 showed that geographical change of blood indicesalso reflected human body adaptation to disadvantage environments.

Table 8-2. Geographical changes of hematocrit, blood vicosity and erythrocyte sedimentation rate

Location Altitude (m) Hematocrit (%) Vicosity (230.1) ESR mm/h

Male Female Male Female Male Female

Lhasa 3658.0 56.0±4.2 50.5±4.8 7.3±1.3 6.15±0.9 4.2±3.2* 5.5±3.5*

Guiyang 107 \.2 47.6±4.0 42.1±3.4 5.1±1.5 4.3±0.7 9.33±4.8 17.3±8.8

Beijing 45.3 45.8±4.0 40.1±3.0 4.2±1.5 4.I±O.7 1O.2±5.0 18.4±8.4

* Calculated values.

8.2 Effects of Life Elements in Geo-Ecosystem on Health

As well known, the composition of chemical elements in surficial earth isuneven. So geographical distribution of elements in ecosystem are different, whichresults in certain element deficiency in some areas or excess in others, and finallyaffects human health to various degrees. Among numerous elements in geoecosystem,the essential elements to life process, which have been known 26 up to now, are veryimportant in relationship between health and life elements in geoecosystem. Ofcourse, besides them, which may be possibly harmful to life or have antagonistic andsynergistic relations with life elements within biological body also should beinvolved. All of them are called life related elements (TAN Jian'an, 1990). InTibetan Plateau three life elements i.e. iodine, Fluoride and Selenium are importantin environmental health problem owing to their abnormal distribution geographically.This section will focus on influences ofthese elements on health.

8.2.1 IODINE IN THE ENVIRONMENT AND ITS HEALTH EFFECT

Since last century, it has been considered that there are some relations between


iodine deficiency in the environment and the endemic goiter (called "Big-neck" inChina) and endemic cretinism. Iodine deficiency makes children becoming idiot,deaf, dwarf, mute as the main characters of endemic cretinism, which mostly occursin extremely iodine-deficient area. In recent 20 years, it has been found that besidesthese two diseases resulted from iodine deficiency, iodine deficient disorders (100)also include stillbirths, miscarriages, premature births, teratogenesis, and healthdamage as low intelligence, slow development, which all arise from iodinedeficiency in environment.

Biologicalfunction ofiodineHuman life needs iodine to synthesize thyroxine for maintaining physiological

activity, therefore iodine metabolism closely relates with the function of thyroidgland. 15-20 mg of iodine exists in human body and most iodine stores as the form ofgoiter globulin in the thyroid gland in which 70-80 % of total amount of iodine inhuman body concentrates, others distributes in plasma, muscle, adrenal gland, skin,central nervous system, ovary and thoracic gland.

The major physiological function of iodine is as followed: (1) Tissuemetabolism. Thyroid hormone/ thyroxine can promote synthesis of protein,absorption of carbohydrate, decomposition of fat, synthesis metabolism of calciumand phosphorous in skeleton. It can also increase the activity of enzyme, regulatemetabolism of water and electrolyte, and accelerate synthesis of cholesterol, at thesame time transform it into cholic acid. (2) Growth and development. Thyroidhormone/thyroxine can promote skeleton development and synthesis of protein. Italso can maintain the structure of central nervous system. Hypothyroidism couldresult in infant slow development, dwarf and low intelligence (KONG Xianghe et aI.,1989). When insufficient intake of iodine for human body, synthesis of thyroxine wi IIbe limited. Due to the low level of thyroxine in blood, pituitary gland will secretemore thyroid-stimulating hormone (TSH), leading to gland proliferation caused fromof compensation, and then goiters are resulted consequently.

Iodine in the environmentIodine is an active element of halogen family and a typical rare dispersive trace

element in the earth crust. With the impacts of geological leaching and biologicalaccumulation iodine was strongly migrated in earth surface. Especially at the end ofglacial period the mature humic soil enriched in iodine was removed, iodine lostfrom earth into ocean and the new soil of iodine deficiency left on the surface. This isthe geological causation of iodine deficiency disorders. Biological accumulation canenrich iodine on earth surface. Therefore concentration of iodine in the seawater (5060 J..lgIL) is much higher than that in surface water; marine plants such as helpcontaining iodine of 1000-4000 mg/kg.

Iodine in the soil The distribution of iodine is uneven in the soils. Theaverage content of iodine in world soil is 5 mg/kg (0.1-25 mg/kg). There areapproximately same values in Chinese nature soils. Laterite soil contains 18.49mg/kgiodine as the highest and the second highest level of iodine is 7.26 mg/kg in red earth(LI Ribang et al., 1985). The regions with higher concentration of iodine in soil


locate in the south parts of Yangtze River basin (CNEMC, 1994). Tibetan Plateau isone of the regions where soil contains lowest iodine under 2.2 mg/kg as the most.The region with lowest level of iodine in Tibetan can be divided into two parts: oneis the tens counties around Yarlung zangbu River basin as the center of Lhasa ranged0.7-1.2 mg/kg; the another is the north of Tibetan Plateau ranged 0.8-1.2 mg/kg. Thehigher content of iodine in soils of Tibetan Plateau can be found in the borderbetween eastern Qinghai Province and Gansu province (2.2 mg/kg-3.9 mg/kg, Figure8-1).

Iodine in drinking water The source of iodine in drinking water comesfrom rock and soil. The iodine in cereal food is most from soil and water. Iodine inmeat comes from domestic animal by intake iodine of water and plant. Therefore thelack of iodine in the environment especially its deficiency in soil and water is mainreason for human iodine deficiency.

"

A'unl un Ml $.

8l

90

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Dun~ff.tt~d

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100'

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Fig 8-1 Iodine in soils in Tibetan PlateauData from "The Atlas of Soil Environmental Background Value in the People's Republic of China"

According to the law of transfer leaching-movement-accumulation of iodine inthe environment, its vertical differentiation in mountain area should be shown thatthe concentration of iodine increased with the decreasing of altitude. The horizontaldifferentiation of iodine means that its content in the inland is lower than coastal area.Tibetan Plateau is in both high altitude area and far inland area. Consequently, it isthe severe, iodine deficient area. Because of iodine deficiency in water, soil and foodgrain, this can result in deficient nutrition status of iodine in human body. Wateriodine is the common indicator for the level of environment. Figure 8-2 showed thatiodine in most drinking water of Tibetan Plateau is less than 5 ~g/L, and 70.1 % of


total below 3 Ilg/L.Iodine is essential element to human. People obtain it from drinking water, food

and air. The distribution of iodine is uneven in the environment. When people couldnot intake enough iodine to maintain body physiological demand, iodine deficiencydisorders could appear.

According to iodine metabolism, the minimum demand of iodine is 75 Ilg/dayper capita. There are different demands of iodine in different age; the physiologicaldemand is 100-150 Ilg per day for adults, 200 Ilg for adolescents, 75 Ilg for childrenand 30 Ilg for infants respectively. Pregnant women and breast-feeding women needas much as 400 Ilg. 80-90% of iodine in human body is from food, 10-20% fromdrinking water and approximately 5% from the air. Therefore, food is the mainsource of iodine for human body. On the other hand, excretion of iodine from thebody per day equals to the amount of intake, 85.36% of the total excretion by urineand 9.76% through feces, others in sweat and hair. This showed that iodine could notretain in the body, as a result people need to supplement iodine every day.

_35

\"'~ 'f~'

r Content ( JJ gIL)

~ 5·10 ~ >10 DI~hulilblt';'au

Fig 8-2 Iodine in drinking water in Tibetan Plateau

Environmental iodine and healthExcept Iceland, iodine deficiency disorders are prevalent in different areas and

in different degree in every country. The famous prevalent regions include the Alps,the Andes, the Himalayas, Rocky Mts.. and Big Lake area, Congo River basin, NewZealand and Papua New Guinea. China is one of the countries where iodinedeficiency disorders have been severely prevalent. According to 1997 statistics, atotal of 2345 counties in 30 provinces, autonomous regions and municipalities inChina have IDD related problems (only Shanghai has no IDD). Among these

166 TAN J. A., ZHU W. Y, LI R. B. and WANG W. Y

counties, it was prevalent in 175 counties in 6 provinces of Tibetan Plateaus (Figure8-3). 24 counties have these problems in the eastern of Qinghai Lake in QinghaiProvince; total 73 counties in Tibet are all disease-affected area; 26 counties inGansu province; 9 counties in Xinjiang; 39 counties in Sichuan, 3 counties in Yunnan(Figure 8-3).

In Tibetan Plateau, IDD affected-areas mainly locate in Himalayas,Nyainqentanglha Mts.., Hengduan Mts.. , Kunlun Mts.., Qilian Mts.., where are theglacial effected area, mountain erosion alluvial fan, severe erosion area in the upperreaches ofYellow River and Yangtze River.

As concerns morbidity of IDD in Tibetan Plateau, the most severe area locatesin Tibet, 39 counties have above 10% of morbidity, 17 counties in more than 20%.Nanxian, Nedong, Lhozhag, Zadoi, Qamdo and Qiongjie are the most severelyprevalent areas with over 50% of morbidity. Sangri, Gyaca, Mailing, Lhasa,Nyingchi and Maizhokunggar have the morbidity between 30-50%.

Compared with men, the IDD morbidity of women is higher in Tibetan Plateau.The 20-50 years old people are in the highest morbidity group.

The population the who live in the iodine-deficient area in the world is up to onebillion, 425 million Chinese people at risk of IDD accounts for 40%of world'spopulation at risk of IDD. The total patients of the world account more than 200million. Chinese government has promised to eliminate IDD by the year 2000. Toachieve this objective, which requires much hard work. Effort has been made tostrengthen financial and material support and outstanding progress has been had,such as about 362 counties nearly under control.

;"""~~30()~1;;;;:'50 600 750 km I··rC~ !I I

1I11 l'~

Prevalence rater')

"!.1111

\

\

\,.,

~ <3 ~ 3·10 m :>10 0 Jrfoavulable<Jala(1997) c=JthlllfffOCTel1

Fig 8-3 Distribution ofIDD in Tibetan Plateau

HUMAN HEALTH ASPECT IN GEOECOLOGY

8.2.2 FLUORIDE IN ENVIRONMENT AND ITS EFFECTS ON HEALTH

167

Biologicalfunction offluorideFluorine is one of the essential trace life elements. The fluoride in organism

concentrates in teeth and skeleton. It indicates that the teeth and skeleton are themain physiological action position. Fluoride has important action to teethdevelopment and protecting its normally function. The hydroxyapatite in the toothenamel would become the fluorapatite after fluoride being absorbed, and then, theteeth become harder, its resistance to acid can be furthered and the osmosis of teethsurface reduces. Besides that when fluorine ion combines with bacteria body protein,it can restrains the active of lactate dehydrogenase in oral cavity and reduce theability of producing acid, and it can also restrain various enzymes such as enolase,which produce acid. These physiological functions of fluoride can preventoccurrence of dental caries. Fluoride is helpful to growth and development ofskeleton, and advances the process of calcium and phosphorus forming bone-salt.Fluoride can keep the enzymes, which are related to the calcium and phosphorusmetabolism being active, and ensure these metabolism process can go not normally.Fluoride can advance for the forming kernal during bone-salt deposition, and quickenskeleton growth, and form stable fluorapatite to make skeleton harder and solid.

On the other hand, fluoride is harmful to organism. The excessive fluoride ispoison to protoplasm. Fluoride has a strong ability to pass through cell membrane ofvarious tissues. When Fluoride enters into cell, it will combine with cytoplasm thus itdestroys structure and function of cytoplasm, and influences the physiologicalfunction of organism. Fluoride can also restrain the activity of bone phophorglase,and influences the absorption and accumulation of calcium salt in skeleton and thebone-salt formation, then results in decalcification of skeleton. The excessivefluoride has poison to hard tissues such as skeleton and teeth; it can produce poisonto osteoblasts, osteoclasts and dentines, and destroys their physiological function,finally leads to degeneration and even necrosis of these cells. Its clinicalmanifestation is dental fluorosis and skeletal fluorosis.

Fluoride in environmentFluoride in soil The fluoride contents in soil in most regions of Tibetan

Plateau are 336-721 mg/kg, it is in the middle level of China. There are three placescontaining high fluoride in the soil in Tibetan Plateau, they are Gaer area, and thenorth of Lhasa in Tibet, the region between Dagaidam and Delingha in QinghaiProvince, their soil fluoride is from 850 to 1500mg/kg. There are also five areas withlow fluoride in soil: (I) The area near Siquanhe; (2) The area around Naggu andNyainrong County; (3) The area around Ayakekum Lake in Xinjiang and nearby thewest of Golmud in Qinghai; (4) The part of Guoluo prefecture in Qinghai. The areaof Aba and Garze in Sichuan, Huangnan in Qinghai, Gannan and Linxia in Gansu.The fluoride contents in soil are 191-336mg/L there (Figure 8-4) (CNEMC, 1994).The average soil fluoride content in Tibet is 506mg/kg, it is higher than that inthroughout country (400mg/kg). The general distribution law of the fluoride in soil isthat fluoride is declined from southeast gradually to Northwest. For example, the


fluoride in yellow-brown earth and dark brown earth in Zayti county in the southeastof Tibet is high as 500-700mg/kg, the highest is up to 1085mg/kg; but the fluoride inalpine meadow earth and alpine desert soil in Qiangtang plateau in the northeastTibet is lower, it is 200-400mg/kg (ZHANG Xiaoping, 1998).

300 450 600 750 km. F- __ • :".-;,;"

I)ill

F Content (mglkg)

,III

l-."

'1(> '<

---;(1

~<338 I\;;~~l 336

Fig. 8-4 Fluoride content in soil of Tibetan PlateauData from "The Atlas Soil Environmental Background Value in the People's Republic of China

It is also very obvious for the vertical difference of soil fluoride in TibetanPlateau. The distributive law is that soil fluoride declines gradually from the highland to the low place. For example, in Motuo prefecture at low altitude, south side ofthe Himalayas, the fluoride of red earth is up to about 700mg/kg, and in sub-alpinemeadow soil at high altitude it is low, about 500mg/kg (CNEMC 1994). This relatesto the state of fluoride in soil mostly as the soluble salt. The fluoride in soil becomesthe major source of the fluoride in ground water.

Fluoride in Water It is windy, little rain and strong evaporation in TibetanPlateau. Therefore the fluoride contents in shallow groundwater are high and will behigher than the health standard of drinking water (I.Omg/L). For example, thefluoride in shallow groundwater is 1.70mglL in Huzhu county, 2.lOmglL in Leducounty, 3.40mgIL in suburbs of Xining city, Qinghai Province; 3.70mglL in Weiyuancounty, 3.20mgIL in Lintao county, 2.40mglL in Lintan county, Gansu province;1.90mgIL in Minfeng county, 2.61mglL in Yecheng county, 2.49mglL in Taxkorgancounty in Xinjiang Uygur Autonomous Region. The fluoride in deep groundwater isalso high in some areas. For example, the fluoride is high as 3.4mglL in Guide


county, 1.20mgIL in Gonghe county, Qinghai Province; 2.60mg/L in Tewo county,Gansu province. The fluoride is higher in the action area of ground hot water, thereare 120 samples with 3.10-10.0mg/L fluoride among 252 samples of ground hotwater in Tibet, accounting for 47.6% of the total; there are 20 samples with fluorideover 10.0mgIL, it is 7.9%. Among them, the fluoride in ground hot water is high as14.2mgIL in Yangbajain terrestrial heat area, and the highest fluoride content inground hot water is 25.0mglL in Ngamring county, Tibet (The ComprehensiveScientific Expedition to the Tibetan Plateau, CAS, 1981). In Tibet, the action areas ofground hot water distribute in 7 prefectures and over 50 counties. The ground hotwater with high fluoride distributes in Shannan, Xigaze, Ngari and Nyingchiprefecture. Their average fluoride in ground hot water is over 4.0mglL (Table 8-3).The counties whose ground hot water contain fluoride very high are Nagqu, Burang,Gar, Darnxung, Maizhokunggar, Tingri, Nyemo and Sangri. Their average fluoride isover 8.0 mglL (Figure 8-5).

Table 8-3. The Fluoride content in Hot Ground Water in Tibetan Plateau (TONG Wei et at., 1981)

Place Aver. N Range Place Aver. N Range

2.25-3.00

0.85-25.00

0.16-7.003.50-9.00

3.75-7.801.40-7.003.00-6.900.64-6.500.30-4.403.67-9.000.12-3.502.83-11.003.00-16.001.00-3.005.00-9.50

12 3.80-4.502 4.45-11.002 0.87-3.252 1.35-7.9013 1.75-8.802 4.15-4.404 7.00-17.401

21

131

131334466545I83

3.504.157.732.064.635.684.2810.415.752.634.907.707.903.255.683.624.533.251.386.020.968.548.911.706.772.502.615.43

QusumConaLhozhagNyalemLhazeXaitongmoinGyangzeTingriRinbungYadongGyirongAngrenSagyaDinggyeSagaNamlingGambaKangmarRutogGegyaZandaBurangGarGerzeZaytiMainlingBomiGougbogyamda

201

3 5.45-15.005 4.90-16.609 2.65-17.802 2.75-3.1010 0.32-5.0013 0.40-4.008 1.20-8.007 0.11-4.805 2.06-11.607 1.18-6.102 3.00-6.503 0.28-3.508 1.03-6.505 0.30-13.29 1.16-16.605 0.12-1.726 1.20-8.076 3.34-15.602 0.63-1.388 0.08-1.007 0.20-8.681

5 0.80-6.701

17 2.60-15.403 0.75-4.80

7.292.2510.2511.389.662.931.921.803.072.918.093.554.751.993.633.703.670.693.626.681.000.452.220.843.0012.000.717.562.35

Lhasa CityDoihmgdegenMozhugongkaNyemuDamxungLhtinzhubNyainrongBaqenBaingoinXainzaNagquAnduoSogxianLhariBiroNyimaMarkemRiwoqeZaytiBaxoiJomdaDenggenQamdoLhorongZogangSangriMagarzeComaiLhiinze


F Content ( mg/.t)

1-:-:·:-:1 < '.00 I~\~~~J 2.00 £>;/')4.00 § 6.00 ~ )8.00 0 NO Oata

Figue 8-5 Fluoride in hot ground water in Tibetan Plateau

Environmentalfluoride and healthThe unbalance distribution of environmental fluoride in Tibetan Plateau,

especially the excessive fluoride in drinking water would result in obvious effect onhealth of human being, that is, the local residents come to endemic fluorosis. Itsclinical manifestations are: teeth turn to yellow (dental fluorosis), and spinal columnturns to wingding (skeletal fluorosis). The endemic fluorosis in Tibetan Plateau couldbe divided into four types according to its fluoride source as follows (Figure 8-6).Three of them belong to types of drinking water high fluoride: Shallow ground waterwith high fluoride, such as, Hoton of Xinjiang, Haidong and Hainan of Qinghai,Linxia and Gannan of Gansu, and Qamdo of Tibet; deep ground water with highfluoride, which appears in Guide, Gonghe of Qinghai Province and Tewo of Gansuprovince; and hot spring with high fluoride such as in Xaitongmoin County of Tibet,137 residents suffered from dental Fluorosis among 203 residents drunk directly hotspring with high fluoride, with incidence rate 67.50% (The Health Prevention Stationin Xigaze prefecture, Tibet, 1988). The fourth is type of brick tea, which is used byherdsmen in daily live, this kind of tea is made of old tealeaves and tea-stalks, itsfluoride contents are usually higher than that in common tea. Therefore, someherdsmen suffer from endemic fluorosis arisen from drinking milk tea. In the pastoralarea of Aksay county, Gansu province, there live some Kazak and Han herdsmen, thefluoride in brick tea water drunk by Kazak herdsmen is high up to 3.69mglL, higherthan that (2.07mg/L) drunk by Han herdsmen, although the fluoride in drinking waterof both nations is not high, only 0.32mg/L and O.39mg/L respectively. Therefore, theincidence of dental fluorosis in children is high up to 84.42% for kazak nation,


25.0% for Han nation; and in adult 93.33% for Kazak, 38.39% for Han (CAO Jin etaI., 1996). There are also patients of endemic fluorosis in Uygur residents who drinkmilk tea made of brick tea in Qiemo, Ruoqiang and Hotan county, Xijiang UygurAutonomous Region (WANG Lianfang et aI., 1993; WANG Jianping et aI., 1997).The similar situation occurs in Aba and Gatze of Sichuan province, the incidence ofdental fluorosis is 72.64% in peasants and herdsmen of Zang Nationality in Rangtangcounty, 76.47% in herdsman, and 84.56% for the residents of seimi-agricultural andsemi-pastoral areas (BAI Xuexin et ai, 1986). Endemic fluorosis would result fromdrinking directly hot spring containing high fluoride.

Fluorosis Type

I·:·:·:· :1 ~:~e~Y~~ t~f h1~~1~~~o~~~~nd

~ Bric}( tea type

t~~~~ \:~~e;Y~~t~fh~~~Pf~~~~~~e

~ '~~~ht~~~ho~l~~~i~:ring

c;] unAffectl'l11 area 0'" no d3t;'l

Figue 8-6 Distribution of Endemic Fluorosis in Tibetan Plateau

8.2.3 SELENIUM IN ENVIRONMENT AND ITS EFFECTS ON HEALTH

Selenium is an essential element belonging to group VI of the periodic table. Itschemical property, forms in nature and geo-chemical behavior are similar to sulfur.Se exists naturally in several oxidation states such as -2, 0, +4 and +6, and also insmall quantity but ubiquity. Its uneven distribution in environmental factors leads toapparent health effects on some people, who live in Selenium abnormal distributionareas, deficient or excessive.

Biologicalfunction ofseleniumSelenium absorption sites are gastrointestinal tract, the respiratory tract and the

172 TAN J. A., ZHU W. Y, Ll R. B. and WANG W. Y.

skin. Se amount in adult human body range from 3 to 14.6mg (WHO 1987), Usuallykidney and liver have larger concentration than other organs or tissues have. KlausSchwarz and his colleagues found the first evidence of a positive metabolic functionof selenium in studies of liver necroses in rats in 1957 (Schwarz and Foltz 1957).After then, in 1971, Rotruck et al. demonstrated Selenium as a componentincorporating into glutathione peroxides (GSHPx), a selenoenzime. Its major actionis related to maintaining the integrity of cell membranes and preventing oxidativedamage. Since then a lot of progress in this area have been made. For example, othernew selenoenzyme and selenoproreins have been identified. As to selenoenzymes,phospholipid hytroperoxide glutathione peroxidase (PHGPx), and Type Iiodothyronine 5-deiodinase etc. are new findings of selenoenzymes which all arewith important, biological activity. For the selenoprotein, low-molecular-weightselenoprotein (10,000MW) from normal lamb (Whanger et al., 1973), smallerselenoprotein (17,000-20,000 daltons) from rat sperm (Calvin, 1978), selenoprotein Pfrom plasma of rat and rhesus monkey (Motsenbocker et al 1984) have been foundsuccessively; however, these still await further precise characterization. Anotherfunction of selenium is its role in some processes of detoxification. The studies haveproved that selenium have a property to protect against toxicity of cadmium, lead,mercury, silver and thallium. Selenium is also involved in decreasing some cancers,cardiovascular diseases, and elevating immunization, etc.Selenium, owing to its important role in anti-oxidation, detoxification, anti-cancer etc.in biological processes, is widely associated with health and diseases in human andanimals. However, in this section only problem on environmental Se deficiency andhealth in Tibetan Plateau will been discussed.

Selenium in environmentSelenium in soil Selenium in soil is the basically source for human to

get it through food pathway; so soil selenium level is important for local people'shealth. According to our studies of soil selenium throughout the country (Table 8-4),the average value of soil Se in the country is 0.173mgl kg; so soil Se in TibetanPlateau is located in the low level (Figure 8-7). Figure 8-7 shows that for most ofthe plateau Se in soils is below the average value of China. Only in smaller area insouth Tibet and North part of Qinghai Province there exists higher Se in soil thanaverage level of the country. Low Se in soil has influenced on Se content of cereals,then on human health.

Table 8-4 Threshold Values for Se Dividing Ecological Landscape (mg/kg) (TAN Jian'an, 1989)

Se content Total ingrading topsoil

Water-soluble F d .. t'l 00 gramsm opsOJ

Hair ofchildren

Effect

Deficient < 0.125

Marginal 0.125-0.175Moderate 0.175-0.400High 0.400 +Excessive ~3.0

< 0.003

0.003-0.0060.006-0.0080.008 +~0.02

< 0.025

0.025-0.0400.040-0.0700.070 +~1.0

< 0.200

0.200-0.2500.250-0.500

0.500 +~3.0

Se-responsive diseasePotential Se deficiency

Se poisoning


Se Content (mg/kg)

g.. ; <0.08 1~~~~~1 0.08 .0.t2 m ~O.'8 EJ Glacier

Figure 8-7 Selenium in soils in TibetW1 PlateauData from "The Atlas of Soil Environmental Background Value in the People's Republic of China

Selenium in Cereals Owing to low Se in soil, Se in crops of Tibetan Plateauis also lower Compared with national standard of dividing selenium eco-Iandscape(Table 8-4, 8-5), Se in cereals in plateau, like its soil Se, is also situated in the lowerlevel even for food grains in the non-affected area.

Table 8-5 Se in cereals (mg/ kg) (WANG Wuyi et at., 1985)

KSD* area KB* area Non-affected

Wheat O.009±O.003(13) O.009±O.003(17)

HighlW1d barley O.009±O.004(12) O.008±O.004(16)

PeW1 O.008±O.008(11) O.006±O.OlO(17)

*KSD stW1ds for KeshW1 disease, KBD stW1ds for Kashin-Beck disease

O.026±O.032( 12)

O.020±O.023(13)

O.027±O.091(8)

Selenium in geoecosystem and endemic diseasesKeshan disease (KSD) is an endemic cardiomyopathy in man. In the winter of

1935 in Keshan County, Heilongjiang province, a disease, known subsequently asKeshan disease, became prevalent and was later recognized in the North, Northwestand Southwest China including some areas in Tibetan Plateau successively. KashinBeck disease is an endemic, chronic, high incidence and degenerativeosteoarthropathy. Records of a disease similar to Kashin-Beck disease were reported


in the "Geography of Anze County, Shanxi Province "in 1664. Furthermore aRussian, I. M. Urenski, reported many dwarfs in Transbaikalia region of Siberia in1849, after then, H. 1. Kashin and E. V. Beck investigated the disease between 18551902 and concluded that the osteoarthropathy, which occurred in Urov Drainge Basinof Transbaikalia, was a separate disease and named Urov disease. Usually calledKashin-Beck disease. However, in China by means of image it is commonly called as"enlarged bone joint disease "Causes of both KSD and KB were not known for longtime, many hypotheses of pathogenesis proposed for both the diseases. A lot ofresearch works from different viewpoint of pathogenesis conducted by differentdepartments, universities, scientific institutes and anti-epidemic institutions.However, since 1960s, among these studies selenium deficiency is widely noted dueto three findings: 1. The low selenium eco-landscape belt coincides with thedistribution of Keshan disease, the two diseases are always occurs in the area withlow Se environment (EGAS, 1986; TAN Jian'an et al., 1987, 1990a-c and 1994); 2.Selenium supplementation is acknowledged as an effective approach to control KSD(KSD Research Group of CAM, 1979; KSDIT, 1987) and KB (LI Chongsheng, 1979;KBIT, 1984); 3. It has been proved that amelioration of living standard and elevationof Se intake is very effective and feasible way to improve human Se nutrition in lowSe regions (TAN Jian'an et at., 1995 and 1999). All of these make clear thatselenium in geoecosystem is an important factor to control occurrence of the twodiseases.

Similarly Keshan disease and Kashin-Beck disease in Tibetan Plateau are alsodistributed in the areas with selenium environmental features. However, owing to theinfluence of customs or life style on selenium intake, the diseases occur only infarming villages in low Se areas, usually herdsmen living in pasture are not affected.Kashin-Beck disease have been found in 37 counties within the plateau, among them3 in Qinghai Province, 14 in Sichuan Province, 20 in Xizang (Tibet) AutonomousRegion (Figure 8-8). The affected counties of KB are listed in Table 8-6 and KSDdetected, rate in some counties of the plateau being put in Table 8-7. However, insome severe villages the incidence rate reached to 70%-80% or more. As to Keshandisease within the plateau it has not been found in Qinghai Province. Table 8-6 and8-7 showed the prevalent rate of the diseases in some Couties of the plateau before1980s, however, since then whether KSD or KB incidences have commonly declined.As our study (WANG Wuyi et at., 1985) the two diseases are closely associated withselenium level in geo-ecosystem, in disease affected area, selenium concentrations infood grains and in hair expressed significantly lower than that in non-disease affectedarea, as Tables 8-5 and 8-8 showed us. However, even in disease unaffected area,

Table 8-6 County detectable rate of Keshan disease (Data from TAN Jian'an, 1989)

Counties Population Population in No. Examined Detectable number Detectable rateaffected area

Doilungdegen 30737 1257 1140 27 2.37

Nyemo 21294 797 667 30 4.49

No data counties Lhasa, QOxO, Xigaze, etc.


township Jinxin ofNyingchi County, the Se concentration in hair is still low, not highenough for human health. Since 1980's in Tibetan Plateau, like other places of thecountry, owing to rapid elevation of living standard, selenium intake in low seleniumregions also increased, and diseases incidence declined correspondingly. Of course,the relationship between selenium in geo-ecosystem and KSDIKB should becontinued to further study in this special region.

Table 8-7 County detectable rate of Kashin-Beck disease in Tibet

Counties

Dagze

Gongbogyamda

Nyingchi

Nyemo

Lhasa

Doilungdegen

Maizhokunggar

LhUnzh

Buomi

Number examined

15429141438173

193002887

2230120259

Detectable number

36194781

2622172415150861

Detectable rate

0.231.37

9.5513.585.951.86

1.74

I Content (mg/kg)

m 3.9-2.2 ~ 2.2-1.2 ~,:-~~~~11 ,2-0.8 ~<O.8~

Figure 8-8 Distribution of Keshan disease and Kashin-Beck disease in Tibetan Plateau


Table 8-8 Comparison of hair Se between disease area and unaffected area

Regional type

UnaffectedKB

KSDKB+KSD

County and township

Nyingchi, JinxinBomi, TayaQilxil,Deji

Nyemo, Angang

Mean±SD mg/kg

O.13 I±O.038O.022±O.O12O.086±O.027O.027±O.008

No. of samples

12II

23II

8.3 Impacts of Landscape Bio-Factors on Health

Plague, a natural focus-based disease, is one of the deadly infectious diseasesmost harmful to human beings. Because of its focus-based nature, it is closely relatedto the geographic environment or landscape. The pathogens, epidemiology, preventionand control of the disease are all highly related to physical and human factors. Plaguehas long been epidemic in China and it has posed a serious threat and caused muchharm to the Chinese people.

Three pandemics of worldwide plague occurred in human history. The firstpandemic, recorded in the 6th century (520-565 A.D.), was regarded as originatingfrom natural plague foci in the Middle East, with the Middle East and Near East alongthe Mediterranean coast as the center. The second pandemic started in the 14th centurythrough to the 17th century (1346-1665), reaching Europe, Asia and northern part ofAfrica with Europe the most seriously affected region. It was known as the BlackDeath in medical history. The third pandemic occurred at the end of the 19th century(1894). It lasted till the mid 20th century and reached a peak in the 1930s. The infectedarea was the largest in scope, involving over 60 countries and regions on the fourcontinents of Asia, Europe, America, and Africa. Up to now, plague foci have beenidentified in over 60 countries and regions. In China plague foci are distributed in 274counties of 18 provinces.

In Tibetan Plateau, owing to its unique natural environment, there exist a series ofspecial eco-Iandscapes, and correspondingly form different biocenoses. Among these,alpine/subalpine meadow, alpine/subalpine steppe, and mountain steppe/forest steppeare important natural resources for animal husbandry. However, in these ecolandscapes unique natural plague foci developed, which have distinctive reservoirs,vectors, and bio-ecotypes of Yersinia pestis. The Plateau's plague foci are characterizedas follows.

The Marmota Himalayas plague foci in the Tibetan (Tibetan) Plateau were foundin 1954. It lies between 79°-103°E and 29°-400 N, the vast extent faces GandiseMountains and Nyainqentanglha Mountains at the southern margin, bounds Altun andQilian mountains to the north, starts from Gannan (southern Gansu) highlands in theeast, and reaches the eastern bank of Yurungkax River of the Kunlun Mountains inXinjiang in the west. It covers an area of containing 73 plague counties in Qinghai,Gansu, Xizang (Tibet), Xinjiang and Sichuan and constitutes one of the natural fociwith vigorous epizootics.

Fifty one species of rodents were registered and 16 animal species were foundinfected in the natural foci. Of these, 5 species are Rodentiae: Marmota Himalayas,


Allactaga sibirica, Mus musculus, Cricetulus migratorius and Microtus oeconomus;one species is Lagomorphae: Ochotona curzoniae; 8 species are Carnivorae: Mustelaeversmanni, Canis familiaris, Vulpes corsac, Vulpes ferrilata, Vulpes vulpes, Melesmeles, Felis sp., and Lynx lynx; and 2 species are Artiodactylae: Ovis aries andProcapra picticaudata. The main reservoir of plague is Marmota Himalayas.

Marmota Himalayas extensively inhabit various types of meadow-steppe withelevations between 2 700m to 5 450 m on the Tibetan Plateau. The density is normallymore than one individual per hectare in a relatively favorable habitat. The plague focusis mostly found in high-frigid shrubs and meadow-steppe. The Marmota arehibernating animals. They go into hibernation in September to October and come outof hibernation from late March to mid April the next year.

In the natural foci, more than 150 species of fleas were found and six species werefound infected, Among them, Callopsylla dolabris and Oropsylla silantiewi are theprincipal vectors, Rhadinopsylla Ii ventricosa is the second vector, and Pulex irritans,Neopsylla hongyangensis and Frontopsylla wangeri can be infected in nature.

The highest blood-sucking rate of the principal vector fleas is from April to May,and then drops gradually. The second blood sucking peak, occurring in July forCallopsylla dolabris and August to September for Oropsylla silantiewi, lasts untilhibernation. This might be of great significance to Yersinia pestis overwintering.Rhadinopsylla Ii ventricosa belongs to nest flea, its body index is quite low, but theblocking rate can be 2 to 4 times higher than that in Oropsylla silantiewi. Concerningthe amount of infected fleas, Callopsylla dolabris occupies the first place (60.4%),Oropsylla silantiewi comes second (33.8%), and Rhadinopsylla Ii ventricosa makes up5.2%.

According to Yersinia pestis strains, there are three ecotypes of plague foci inTibetan Plateau: ecotype of the Qinliang Mountains ecotype of the Tibetan Plateau andecotype of the Gangdise Mts.. Their biochemical features are listed in Table 8-9, theirdistribution shown in Figure 8-9.

Table 8-9 Biochemical features of Yersinia pestis in Tibetan Plateau

I a Qilian Mountains +II a Tibetan +III a GandiseIV b Kunlun Mts. +

type AV d Kunlun Mts. + +

type B

Ecotypes Ecotypegroup

EcotypesFermentation

Arabinose Melibiose MaltoseNutritive type

62.5 Phe+ Phe-

Phe-+ lie, Glu-

+ lie, Glu-

Note: I. + Glycolytic or sensitive; • Non glycolytic;2. Phe -- Phenylalanine; lie -- Isoleucine; Glu -- Glutamic acid;3. Comer sign"-"denotes amino acid dependent;

Comer sign"+"denotes amino acid low nutrition4. Ecotype Group a: glycerol+ rhamnose- denitrification+

Ecotype Group b: glycerol+ rhamnose-denitrificationEcotype Group d: glycerol+ rhamnose+ denitrification+


Ecotypes

bd Qilien mountain type

~ Kunlun lIlounta1.n type A ~ Kunlun mountain type 8

Figure 8-9 Distribution of Ecotypes of Yersinia pestis in Tibetan Plateau

For the plague foci have been put under rigorous monitoring by the plaguesurveillance net, the plague incidence in man was basically controlled.

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26. TAN Jian'an, ZHU Wenyu, LI Ribang, WANG Wuyi, and HOU Shaofan, 1995. Effects ofrural development on the decline of endemic disease incidence in Se-deficient areas in China.In The Health of Nations, edited by B. Folasade Iyun et al., Avebury, Aldershot, BrookfieldUSA, Hong Kong, Singapore, Sydney, 41-52.

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CHAPTER 9 LAND-USE AND AGRICULTURALDEVELOPMENT

WU Shaohong and YANG Qinye

9.1 Introduction

Due to the unique environment and social-economic development situation,the Tibetan Plateau has its characteristics in land-use. In Tibetan Plateau,agricultural land occupies about 138,285 thousand hectares, of which farmland is1,562 thousand hectares, orchard is 21 thousand hectares, forestry land is 26,067thousand hectares, and grazing land is 110,636 thousand hectares. Non-agriculturalland occupies 419 thousand hectares, of which residential and industrial land takes292 thousand hectares, and communication land 127 thousand hectares. Watersurface occupies 8,422 thousand hectares and undeveloped land occupies 75,881thousand hectares. Agricultural land is 62% of the total and undeveloped land is34%. On the other hand, output value of agriculture is not as much as the secondaryand the tertiary industries but proportion of agricultural output value is higher thanthe national average. Taking 1993 for example, output value of agriculture is30.21 % of the total output value of the plateau, while the national average is 21.2%.The proportion of agricultural output value is 9% higher than that of nationalaverage (Table 9-1). Therefore agricultural land plays a very important role andactivities of agricultural production are the principal part of land-use in the plateau.

Table 9-1 Output value comparison betweenthe plateau and the national average (106 RMB, %)

Industry Primary Secondary Tertiary TotalTibet 1827 551 1350 3728Qinghai 2163 4839 5574 10574Garze 533 442 375 1332Aba 505 612 387 1504Gannan 281 199 171 651Deqen 175 93 101 369Muri 55 116 28 199Tianzhu 52 39 51 142Total 5590 6873 6037 18499P1ateau% 30.21 37.15 32.64National% 21.20 51.80 27.00

181

ZHENG Du, ZHANG Qingsong and WU Shaohong (eds.), Mountain Geoecology ond Sustainable Development oftheTIbetan Plateau, 181·202.©2000 Kluwer Academic Publishers.

182 WU S. H. and YANG Q. Y.

Farming and livestock husbandry are the main part of agriculture in the plateau.Forestry and orchard production are much smaller and fishery is almost zero.Agriculture in the plateau can be traced back to the Neolithic Age 4000 years ago.However, up to the 1950s, farming and livestock husbandry were undeveloped withsimple tools and primitive cultivated manner. Wood plough and wood hoe werecommonly used in farming activities. Some parts of the plateau even kept slashand-bum cultivation. Food yield had been only 3-5 times of the seeds. Livestockhusbandry maintained primitive nomadic manner. Herdsmen settled according towater and grass conditions. They had very low capabilities against natural disaster.With such livestock husbandry manner, survival rate of livestock was very low.According to the statistic data of the beginning of the 1950s, in some parts of theplateau, pregnant rate of cow was 40% and survival rate 50%. Pregnant rate ofsheep was 70% and survival rate only 30%.

After the 1950s, especially since the implementation of the "open-door" policyin China, agricultural production has been enormously changed in the plateau. InTibetan Autonomous Region, food production increased from 155.3 thousand tonsin the 1950s to 773 thousand tons in 1997 (the State Statistics Bureau, 1998),almost an increase of 5 times. In the corresponding period, food production ofQinghai Province increased from 371.3 thousand tons to 1 276 thousand tons, anincrease of 3.44 times. Per unit area yield offood rose from 1240.5 kg/ha to 3915.3kg/ha, an increase of 3.16 times and 1.7 times in Qinghai Province and 3 times inthe eastern part of the plateau. For livestock husbandry, in Tibet the total amount oflivestock available was 9742.4 thousand heads in 1952 and 23104 thousand headsin 1997, an increase of2.37 times. In the same period, in Qinghai Province, the totalamount of livestock available was from 9335.2 thousand heads to 21913 thousandheads, an increase of 2.34 times. East part of the plateau has more than doubled. Inthe same period, conditions and infrastructure of agricultural production have beenenormously improved. In Qinghai Province, more than 1500 irrigating ditches, 113reservoirs, 918 power irrigation stations, 192 hydraulic power stations, and an1800-km-long path between fields have been built. More than 200 thousandhectares of eroded soil have been controlled as a result of reforestation and grassplanting. In 1993, the total agricultural machine power in the province was 1547thousand kW. Area ploughed by tractors reached 230 thousand hectares. About onethird farmland was effectively irrigated. In Tibet Autonomous Region, more than7000 irrigating ditches and 8100 water-stored ponds were built in the mid 1980s, bywhich two thirds of the farmland was effectively irrigated. By the end of the 1980s,the central government of China has invested large amount of capital in improvingagricultural infrastructure for the plateau. The Yarlung Zangbo River, NyangquRiver, and Lhasa River Basins were taken as key developing areas. Suchconstruction ensures sustainable agricultural development in the plateau.

9.2 Characteristics of Land-use

LAND-USE AND AGRICULTURAL DEVELOPMENT 183

9.2.1 FACTORS INFLUENCING LAND-USE

Land-use in the plateau is influenced mainly in the following aspects:Landform First of all, the plateau has an average altitude of 4000 m asl.

There are many peaks of 6000-7000 meter above sea level, which are higher thansnowline. By 5000 meters higher than the surrounding areas, the plateau stands upto the middle part of the troposphere. Due to its high altitude, the plateau stops thecold airflow emission from Siberia and the Arctic to the south during winter seasons.Therefore, temperate desert of Asia is maintained and even enlarged and steppezone extends toward southeast. During summer seasons, monsoons from southwestand southeast are partially obstructed by the plateau, changing northward way intoeastward way, which makes the inland of the plateau extremely dry. Moreover, theplateau influences the east-wind and rapids that bring rain for the southern part ofChina's subtropical. It also influences on Pacific tropical cyclone (Typhoon) andIndian Ocean tropical cyclone (Bangladesh storm).

Climate Climatic characteristics on the plateau are of strong solarradiation, low temperature, and high daily temperature amplitude. With clearatmosphere, the plateau receives solar radiation as much as 540-800 kj/cm2.a that is50%-100% higher than that in lowland areas of the same latitude. However, highaltitude of the plateau causes low temperature. Average temperature of the coldestmonth is -10 to -15°C, similar to that in temperate areas of China. In warm season,the plateau is the coolest area of China. Average temperature of July is IS-20°Clower than the other areas of China with the same latitude. Comparing to thelowland areas of the same latitude, daily temperature amplitude in the plateau ismore than doubled with general characteristics of mountain climate. Because ofcontinental climate, annual temperature amplitude of the plateau is high, which isalmost as much as that in the lowland areas.

Snow, glacier and cold weathering High altitude of the plateau results inlow temperature as the main climate character, which is advantageous to thedevelopment of glacier and permafrost, and to production of special periglacial andcold weathering activities. The plateau is the biggest glacial development center innorth mid-latitude of the world. Modern glaciers are well developed on the plateauwith an area of 49162 km2• Total ice storage is 4105 km3, which occupies four fifthsof the total glacial ice in China. Proglacial traces of Quaternary distribute in thesurroundings of high mountains. Permafrost in thickness between 10m to120m iswell-developed and widely distributed in middle and northern parts of the plateau.

Flora andfauna Cold and drought are enhanced due to uplift of theplateau. Therefore special flora and fauna are formed, such as Ceratoides compacta,Ceratoides compacta, Stipa purpurea, Kobresia pygmaea and Tibetan antelope andyak. Flora of alpine shrub meadow, alpine steppe, alpine desert, alpine "pad" plants,and fauna of high land forest steppe, meadow steppe, and alpine desert are widelydistributed. The flora and fauna with ancient human activities determined thedevelopment of agriculture, forestry, crops, herbage and poultry in the plateau.

Vertical and horizon zones In the plateau, high mountains with high


relief not only surround the edge but also stand on the inland. Therefore, verticalnatural zones develop while horizontal natural zones change from warm-humid insoutheast to cold dry in northwest. That is from forest, meadow, and steppe to desert.Combination of vertical and horizontal natural zones forms the special landscapesof the plateau and determines the land-use pattern of the plateau.

Human activities Constrained by natural conditions, population densityis very low. There are less than 4 people per square kilometer, which is one twentyfifth of the national average level. Impact of human activities on the plateau notonly is much weaker than that on eastern China but also even weaker than that onwestern China. Parts of the plateau still remain primitive situation, especially, in thehinterland and northwestern part of the plateau, where human activities are rare. Sodifferences of geographical regions can be definitely reflected by natural vegetation.Development level of the plateau is very low. Usage of natural resources is at thebeginning stage. Livestock husbandry is the primary and farming and forestry arethe secondary.

9.2.2 COMPOSITION OF LAND-USE

According to land-use classification in China, the first class is divided intoeight types. They are cultivated land, orchard land, forestry land, grassland,residential land, transportation and communication land, water surface, and undeveloped land. Composition of land-use in the plateau is that cultivated landoccupies 0.7%, orchard land 0.01%, forestland 11.7%, grassland (grazing land)49.6%, residential and industrial land 0.13%, communication land 0.06%, watersurface 3.77%, and un-development land 34.0%, which is showing in detailed inTable 9-2.

Table 9-2 Land-use composition of the plateau (thousand hectares)

Land Tibet Qinghai Aba Garze Muri Deqen Garman TianzhuThe

plateau

Agricultural 77543.97 33207.92 7669.07 12498.28 1225.62 1972.97 3523.98 643.3Q 138285.21

Farming 360.6/ 688.39 111.22 141.7 I 20.54 69.69 116.16 53.07 1561.51Orchard 0 7.17 10.71 1.48 0.53 0.7 0.75 0 21.34

Forest 12659.51 1928.94 3074.55 4935.51 842.35 1525.83 940.1 159.97 26066.75Grassl

64523.80 30583.41 4472.59 7419.51 362.2 376.75 2466.97 430.35 110635.6grazing

Non-60.11 272.49 22.24 26.58 2.25 10.45 18.61 6.44 419.19

agricultural

Residential 36.07 207.95 10.71 11.81 1.46 6.9 12.29 4.54 291.79Communi-

24.05 64.54 11.53 14.7'" 0.79 3.49 6.33 1.9 127.39cationWater

5614.43 2495.43 60.9 181.65 6.49 23.6Q 30.16 9.2Q 8422.11surface

Un-37016.73 35739.21 486.06 2063.11 91.05 316.13 150.05 18.71 75881.04

developed


Grazing lands take more than 50% of agricultural lands in the plateau exceptDeqen and Muri where forest areas predominate, while in Qinghai, it takes as muchas 92% (seeing Table 9-3).

Table 9-3 Agricultural land-use structure of the plateau (thousand hectares, %)

Land Tibet Qinghai Aba Garze Muri Deqen Gannan TianzhuThe

plateau

Agricultural 77543.9 33207.92 7669.07 12498.28 1225.62 1972.97 3523.98 643.39138285.2

IFarming 360.6/ 688.39 111.22 141.77 20.54 69.69 116.16 53.07 1561.51Percentage'" 0.47 2.07 1.45 1.13 1.68 3.53 3.3 8.25 1.13Orchard 0 7.17 10.71 1.48 0.53 0.7 0.75 0 21.34Percentage'" 0 0.02 0.14 0.01 0.04 0.04 0.02 0 0.02Forest 12659.51 1928.94 3074.55 4935.51 842.35 1525.83 940.1 159.97 26066.75Percentage'" 16.33 5.81 40.09 39.49 68.73 77.34 26.68 24.86 18.85Grass/grazing 64523.8 30583.41 4472.59 7419.51 362.2 376.75 2466.97 430.35 110635.6Percentage'" 83.21 92.1 58.32 59.36 29.55 19.1 70.01 66.89 80.01"'Percentage of agnculturalland

Table 9-3 shows that grazing land takes high rate in agricultural land-usestructure of the plateau, about 80%. Cultivated land takes 1.13%, forestland 18.85%,orchard land only 0.02%. Grazing land distributes mainly in the northern andwestern parts of the plateau and joins into vast area. On the other hand, mostTibetans gather in farmland regions. Farmers there also raise livestock. There is nopure farming region. Of the total population of 9847 thousand, agriculturalpopulation is 7300 thousand, about 75% of the total population. In TibetAutonomous Region and eastern part of the plateau (including Aba, Garze, Muri,Deqen, Gannan, and Tianzhu), agricultural population makes up 86.3% and 85%.90% of the 4590 thousand Tibetans in the plateau are agricultural population. Theyare farmers and herdsmen. This shows that farming based on cultivated land andgrazing based on natural grassland consist of agriculture of the plateau. Of thisagriculture, grazing or livestock husbandry takes the lead. Therefore, developingfarming and livestock, raising productivity and economic benefit of farming andlivestock, maintaining ecosystem for farming and livestock and keeping productiveforces are the key ways to provide enough food to farmers and herdsmen and makethem richer.

9.2.3 INTENSITY OF LAND-USE

Intensity of land-use in the plateau has two characters. One is that parts of landare inadequately used for large area of land becomes fallow. The other is that partsof land are over-used. These two characters happen in large areas of farmland,grassland and forestland. General situation is that farmland is inadequately usedwhile grassland and forestland is over-used. The most serious case is that the steppe


ecosystem is very weak, grass production is low and grazing capacity is low. Table9-4 shows comparison of grazing capacity of grassland in Tibet and Qinghai withthat in areas at home and abroad.

Table 9-4 Comparison of grazing capacity of grassland

Region/country

Grassland/sheep-unit

Tibet Qinghai Inner Mongolia USA Former USSR New Zealand

2.13 0.70 0.75 0.41 0.57 0.12

Of useable grassland in the plateau three fifths are the third class(LUORONGZHANDUI, 1996). Grassland area in the plateau is about one third ofthe total grassland in China. But grass production is only 16% of the total of China.That is large area of grassland without any advantage. Moreover, because of lowproduction, cropping cannot provide much fodder for livestock husbandry. In otherwords, farming cannot give livestock much help. General state is that useablegrassland of the plateau loads one third more than the national average. Grassland isseriously overgrazed. Contradiction between grass and livestock is obvious.Consequently, meat and wool per unit area yield of livestock are obviouslydecreasing. Comparing with the 1950s, single body of a yak in Tibet AutonomousRegion is much smaller and produces 5 kg less butter of sheep's wool produced is0.5 kg less. In Qinghai Province, the weight of single body of a yak or sheep is onefifth lighter than in the 1950s. For forestry, large amount of wood is used. Butwoodland is irrationally developed. Trees in places with convenientcommunications are completely removed while those in places with inconvenientcommunication are over matured. Farmland is not fully used. That is showed inplanting index. Due to constraint of water and temperature crop planting index inthe plateau does not reach 100%. The highest crop plant index in east QinghaiProvince is 89%.

9.3 Farm land and Crop Production

Farmland of the plateau is distributed mainly in river valleys, piedmont slopes,alluvial fans, and lake plains. Most parts of farmland evolutes from meadow soils,sub-alpine steppe soils, and sub-alpine meadow soils. Soil organic matter offarmland is low. Some parts offarmland have relative high humus. But crops cannoteffectively absorb humus because of low temperature, slow microorganismbreeding and decomposition. Low fertile and imperfect texture results in partsfarmland becoming fallow. With climatic limitation, one crop per year is practicedin most of the farmland. Cold, insufficient oxygen and short frost-free period arebig obstructs for agricultural development. Special cultivation conditions determinethe special cropping structure of the plateau. Main crops in the plateau are coldresistant species such as wheat, highland barley, pea, buckwheat and rape. Smallareas of rice, sorghum and soybean grow in lowland of southeastern part of theplateau.


9.3.1 DISTRIBUTION OF FARMLAND

Special environment of the plateau determines small area of arable farmland.However, production value of cropping occupies a very important place in the totalproduction value. Farmland in the plateau is only 1.13% of the agricultural land.But in Tibet Autonomous Region, net increasing value from cropping is 191.6million US$ in 1997. That is a slight more than that from livestock husbandry,187.7 million US$. In Qinghai Province, net increasing value from cropping is242.6 million US$ in 1997. That is only a slight less than that from livestockhusbandry, 256.0 million US$. Geographical distribution of farmland in the plateauis very limited. In Tibet Autonomous Region farmland is mainly distributed inYarlung Zangbo River, Nyang Qu River and Lhasa River basins and southeasternareas. Very little farmland with low quality is distributed in Nagqu, Ngari andNyingchi. In Qinghai Province, farmland is mainly distributed in the eastern parts,of which Huangshuihe river valley (Haidong) takes 52%. Farmland in Huangshuiheriver valley together with Xining, Haibei, and Hainan is about 90% of the total.Table 9-5 gives the detail.

Table 9-5 Farmland distribution of the plateau (thousand hectares)

Agricultural land Farmland % of agricultural land % of the provincialTibet 77543.97 360.67 0.47

Of Tibet:Lhasa 2274.93 55.49 2.44 15.39Qamdo 8670.18 71.73 0.83 19.89

Shannan 6373.58 64.56 1.01 17.90Xigaze 12941.71 135.67 1.05 37.62Nagqu 20782.47 7.85 0.04 2.18Ngari 18354.44 2.97 0.02 0.82

Nyingchi 8154.71 26.36 0.32 7.31Qinghai 33207.92 688.39 2.07Of Qinghai:Xining 276.62 73.23 26.47 10.64

Haidong 1419.83 360.01 25.36 52.30Haibei 2523.70 68.13 2.70 9.90

Huangnan 1658.09 18.91 1.14 2.75Hainan 3632.87 99.60 2.74 14.47Go1og 6562.10 1.53 0.02 0.22Yushu 10049.80 17.68 0.18 2.57Haixi 7039.28 48.89 0.69 7.10

Aba 7669.07 111.22 1.45Garze 12498.28 141.77 1.13Muri 1225.62 20.54 1.68Deqen 1972.97 69.69 3.53Gannan 3523.98 116.16 3.30Tianzhu 643.39 53.07 8.25The plateau 138285.21 1561.51 1.13


9.3.2 MAIN CROPS AND PRODUCTIVITY

Crop production has a long history in the plateau. But with limitation ofnatural conditions, one crop per year is practiced in most part of the plateau. Andlow scientific and technologic level results in simple crops. Main crops are springwheat, winter wheat, highland barley, pea, buckwheat, rape rice, sorghum, maizeand soybean. Wheat is the major cereal and highland barley comes second inQinghai Province, while highland barley is major cereal and wheat secondly inTibet Autonomous Region. In Zayu and Metog higher temperature satisfies rice,maize and sorghum's growth. Cultivated system there is two crops per year or threecrops per two years. Total crop seeding area for the plateau is 74.1 % of the totalagricultural land, of which more than 50% is in Qinghai Province. Of the cropseeding area, 78.3% is food crops (see Table 9-6).

Table 9-6 Crop seeding area for the plateau (thousand hectares)*

Total Food Cerea ~f whicWheat Maize

HighlandBeans Potata

OilSeeding are~ Crop Cro~ Rice barley crops

Tibet 228.ti 197. 183.4 1.1 53.9 3.1 125.3 13.9 17.3

Qinghai 568.C ~94. 298.6 213.5 85.2 58.8 37.3 137.8

The east 389.C ~35.The plateau 118H ~27.*from State Almanac of Rural Statistics, 1998

In 1997, total food production of the plateau was 2862.5 thousand tons, ofwhich cereal crop took 61 % and wheat took 61 % of the cereals. Looking into theregional differences, Qinghai Province constituted 45%, Tibet 27% and the easternplateau 28% (see Table 9-7)

Crop planting differs greatly in the plateau. Crop distribution is much wider inTibet Autonomous Region, from 1800 meters above sea level at piedmont ofHimalaya and Kangrigarbo to the highest limit of 4700 meters above sea level inmid Gyangze, Yarlung Zangbo. In Himalayan and Kangrigarbo regions, twoharvests of rice and wheat can grow while in mid Gyangze, Yarlung Zangbo onlywheat and highland barley can grow (see Table 9-8).

Because of progress of the society, improvement of science and technology,reformation of relevant policies and helps from all over the country, per unit areayield of food crops in the plateau has been greatly increased. In early 1950s, perunit area yield of food crops in Tibet Autonomous Region was 1204.5 kg/ha, whilein 1997 raised up to 3915.3 kglha. General natural environment is a disadvantagefor crop growth, but sometimes it is an advantage. For example, large dailytemperature amplitude is good for wheat growth. In experimental field in QaidamBasin, Qinghai Province, the national highest record of wheat production wascreated there, as high as 15195.75 kglha. Per unit area yield of food crops in TibetAutonomous Region and Qinghai Province is given in Table 9-9.


Table 9-7 Food production of the plateau 1997 (thousand tons)

Items Tibet Qinghai Eastern plateau The plateau

Total food production 773 1276 813.5 2862.5

Total cereal production 758 1003 1761

Total rice production 5 5

Total wheat production 283 783 1066

Total maize production 14 14

Total highland barley production 456 220 676

Total bean production 15 132 147

Total potato production 140 140

Total oil crop production 33.7 183.6 20.3 237.6

Table 9-8 Crops distribution in Tibet Autonomous Region

Type Main distributing areas Up limit Crop composition

Up Lhaze, YarlungZangbo; 4700 Highland barley

Spring crop Langqen, Sengge Zangbo; 4700 Spring wheat

One crop Plateau lakes in the south; 4600 Pea

North of three rivers in the east 4200 Rape

Lhaze-Sanru; 4050Spring/winter crop

Langqen, Mabja Zangbo; 4100Highland barley

One crop Winter wheatMid of three rivers in the east 3700

Spring/winter cropDown Gyaca, YarlungZangbo;

3400 Winter wheat

One cropSouth piedmont of Himalaya and

3400 Highland barleyKangrigarbo

South of three rivers in the east; 3200 Winter wheatDry land cropping

South piedmont of Himalaya; 2700 MaizeTwo crops

Parlung Zangbo 2450 Buckwheat/round root

Rice/wheat South piedmont of eastern Himalaya Rice, winter wheat,1800

Two crops and Kangrigarbo maize

Table 9-9 Per unit area yield of food crops in Tibet and Qinghai in 1997 (kg/ha.)

Food crops Rice Wheat Maize Others Beans Potato Oil crops

Tibet 3915.3 4545.5 5249.5 4354.8 3936.3 1077.6 1964.5

Qinghai 3231.4 3604.4 2587.5 2244.1 4367.5 1322.4


9.3.3 STRATEGY FOR FARMLAND DEVELOPMENT

The plateau takes 1.84% of the total national farmland, produces 0.56% oftotal national food, and feeds 0.83% the total national population. It is definitelyunbalanced amongst food, farmland and population. Food productivity is 48%lower than that of the national average. In 1993, average unit food yield in theplateau was 2194.5 kg/ha, which was 45% lower than that of the national average.Even if the highest in the plateau, 3240 kglha in Muri is still 1560 kg/ha lower thanthe national average 4800 kg/ha. However, per unit food yield in GannanAutonomous Prefecture was only one sixth of the national average. Thus it can beseen that cultivation on farmland of the plateau was undeveloped. Self-reliance onfood has not been realized in the plateau. Tibet Autonomous Region has to import38.9 thousand tons food of each year, which is 21 % of the total import goods andmaterials. In other words, one out of five trucks getting in the Region was fortransporting food. That not only increases food consumption cost for the localresidents but also increases pressure for the already weak traffic. Qinghai Provincealso needs large amount food import. In 1970s, Qinghai Province imported 250thousand tons of food each year. As population growing and social economicdeveloping, food requ'irement by the end of the 1980s rose up to 350 thousand tonsannually. In the beginning of the 1990s, food requirement for the eastern plateauwas 200 thousand tons annually. Low food production of the plateau makesproblems on feeding cannot be solved completely. Challenge on developingcropping on farmland and raise food self-reliaJ.lce level cannot be neglected by theregion's government.

Food development for the plateau may follow the following ways. Land-useefficiency must be increased, especially farmland cultivation level must be raisedfor the plateau. Measurements include introducing water resources, inputting moreorganic fertilizers and alternatively planting wheat and beans. Under theimprovement of water resources, fertilizers, labor, livestock power, use fallow at acertain degree. Parts of fallows can be used to plant alfalfa. So that it can improvesoil fertility and also supply fodders.

Multiple crop indexes must be raised. Multiple crop indexes in the plateau isvery low. But areas with conditions satisfying two crops must fully use farmland.For example, frost-free period in Nyingchi is 204-212 days, which can satisfy twocrops of highland barley. Planting one crop of highland barley plus one crop ofbuckwheat will be more security. In the plateau, when frost-free period reachesmore than 183 to 189 days, it can satisfy the temperature requirement of two crops.

Properly open wasteland into farmland. There are more than 100 thousandhectares land in the valleys of the middle reaches of Lhasa River and YarlungZangbo River, which is suitable for farming. 90% of land suitable for farming inXigaze is distributed in alpine areas where landform is flat, thus easy to becultivated by tractors. An agricultural base can be constructed closed to Jangdam.Integrated development based on livestock husbandry may be realized in Namlingand Emagang to accelerate the integration of farming and livestock husbandry. All


of these can be demonstrated for farmland development in Tibet AutonomousRegion. In Qinghai Province, there are 8.92 thousand hectares of land suiTable forfarming in Gonghe-Tongde areas, and 68 thousand hectares in Qaidam Basin.

Other measurements include: cropping and arrangement according to differentlands, raising per unit area yield, increasing seeding area and seedling density,promoting rational use of solar radiation, improving conditions of waterconservancy and rational irrigation, reforming cultivation management,transforming low-and-medium yield land and spreading high yield techniques.

9.4 Grazing Land

9.4.1 DISTRIBUTION OF GRAZING LAND

Main types of grassland in the plateau include alpine meadow grassland, alpinewide valley steppe grassland, mountain shrub grassland, salt lake and riverbankssteppe grassland, alpine desert steppe grassland, swamp grassland, and forestgrassland. Main forage grasses are Koknesiu pygmaea, K. humilis, K. capillcfolia,Carex scabrirostris, Sitpa purpurea etc.

Livestock farming in Tibet Autonomous Region has two major patterns. One isgrazing in alpine areas. The other is semi-livestock farming mixed with semi-cropfarming. The alpine areas are pure livestock farming areas because climate there iscold and dry, and grass growth period is short. In the mixing areas, herdsmen settledown permanently or seasonally. During summer and autumn seasons, mostherdsmen go farther field for livestock farming. They return to areas nearby theirsettlement sites during winter and spring seasons. Part of the labor undergoes cropfarming. Grazing system in the Region can be recognized as two-season grazing,that is warm (summer and autumn) season and cold season (winter and spring), triseasons grazing and four-season grazing. Most grazing fields take the two-seasonsystem. Grazing land distribution in the Region is as follow.

Pure livestock farming areas include: 1) cold and semi-arid areas in north ofthe Region, where is middle and southern part of lake areas of the northern Regionand wide valleys of sources of Nujiang River, Lhasa River and Damqog Zangbo.Administrative areas include: Nagqu, Nyainrong, Baqen, Amdo, Biru, Lhari,Baingoin, Xainza, Woinbo ofNagqu Prefecture; Damxung of Lhasa City; Ngamring,Chumba, Saga of west Xigaze Prefecture; and part of Ngari Prefecture, 2) wide,cold and dry valleys of the western Region, including southern piedmont ofKarakorum Mountains. Administrative areas include: Gar, Rutog, Zanda, Burang ofNgari Prefecture. Mixing areas include: 1) warm and humid area of the easternRegion, from Dangla mountain range to Jinshajiang River, north facing QinghaiProvince, south neighboring Yunnan Province. Administrative areas include:Qamdo, Zhag'yab, Zogang, Markam, Baxoi, Lhorong, Banbar, Riwoqe, Dengqen,Gyamda, Gonjo of Qamdo Prefecture; Gyaca, Sangru of Shannan Prefecture; andparts of areas of Lhari, Sog, Baqen, Biru of Nagqu Prefecture, 2) warm semi-aridvalleys of the southern Region, where north limit is Gangdise Mountains, east limit


Nyainqentanglha Mountains, south limit Himalayan Mountains and west limitSangru-Saga-Gonjo.

Grass in Qinghai Province is mainly Gramineae. These grasses have wellgrown roots forming 10 cm of grass-root layer, which is strong enough for animaltrample resisting, good forage and suiTable for grazing. Natural grassland inQinghai Province can be divided into six main types according to family dominancespecies. 1) Meadow grassland mainly distributes in southeastern part of theprovince and eastern part of Qilian Mountain, where grow Koknesiu spp, Stipa spp,Elymus nutans, koeleria crisatata, Poa sp with good quality and high coverage of75-90%. But grass production is low. Average production is 1015-3600 kg/ha. 2)Steppe grassland mainly distributes northwest parts of the southern province,western part of Qilian Mountain, and bench land, sunny slope in the easternprovince. Family dominance species is Stipa bungeana, S. purponea, Orinusthoroldii, Achnatherum splendens, Blysmus hookeri which have long growth periodand good quality. But grass coverage has only 20-50%. 3) Shrub meadow grasslanddistributes separately in shadow slope at a height of 3600-4500 meters and meadowgrassland of local bench land in the eastern and southeastern plateau. On thegrassland there are Salix oritrepha, Caragana sp, Rhododendron spp, Potentillafruticosa of 60-120 cm which are not very good as forage. Main grasses areKoknesiu spp, Poa sp, Helictotrichon tibetica, Polygonum viviparum etc. Yaks,goats, and horses can graze there. 4) Desert grassland mainly distributes in QaidamBasin and partly in Hainan Prefecture. Main grasses are xerophilous and halophyticwith low coverage of 5-8%, which is not worth for using as grazing land. In eastpart of Qaidam Basin grow Tamarix spp., Kalidium. Nitraria, Salsoa arbuscula, andAchnatherum splendens. But quality of the grassland is low. There may only use asgrazing land for camels and sheep. 5) Forest grassland distributes mainly in the eastand southeast parts of the province. Below the trees there is a layer of shrubs ofSalix spp. Spriraea spp. Lonieera spp. etc. and another layer of grass of Poacrymophila, Carexs cabrirostris, etc. The grass production is 2250-3375 kg/ha.There is used as additional grazing land. In the high part of this grassland, grass isharvested as fodder for livestock in winter and spring. 6) Marsh grasslanddistributes in the west part of Yushu, areas of Datonghe River of the Qilian Mts.,and locally where shallow groundwater is not well drained. Grasses are mainlyKobresia, dense, thick and good quality, which is suiTable for livestock such ashouses and yaks. Salt marsh grows Phragmites communis, Cares melanantha, butthe quality is low.

Composition of grassland in the plateau is showed in Table 9-10(LUORONGZHANDUI, 1996).

Table 9-10 Composition of grassland in the plateau (%)

Type of grasslandsTibetQinghaiThe eastern part

Meadow40.649.0464.4

Steppe45.627.54

Desert4.64.07

Marsh

12.637.3

Shrub and forest9.26.7228.2


Tibet, Qinghai and the eastern part have different grassland structures. Grassquality in these three parts is much more different. Grassland production ofdifferent types of grasslands in Qinghai Province is one time more than that in TibetAutonomous Region. The eastern part is similar to Qinghai. Areas of grazing landare different between warm and cold seasons. Rate of areas of warm and coldseasons in Tibet is 120:89. Because temperature and water conditions are good forgrasses growth in cold season, the total grass production between warm and coldseasons is 1:0.95. Grazing periods between warm and cold seasons are 2:3 (4-5months: 7-8 months). Therefore, the integrated grazing capacity of warm and coldseasons is 1:0.69. During winter season grazing pressure on grassland is very heavy.Death rate of livestock may sometime reach 10% (LUORONGZHANDUI, 1996).

9.4.2 LIVESTOCK PRODUCTIVITY

The plateau is a livestock husbandry base in China. Three of the five largestgrazing areas are located in the plateau. One is in the northwest Sichuan Province,the second is in the south Qinghai Province and the last is in the northwest TibetAutonomous Region. 50% of total area of the plateau is grazing land. Livestockhusbandry has a long history in the plateau. Except grazing in natural grassland,family grazing is also very important in farming areas. Main species of livestock inthe plateau is yak, sheep, goat, cattle, house, donkey, and mule. Some families inlower altitude farmland feed pigs also. Yak is a unique livestock species of China. Ithas high birth rate, high milk and beef production, tender beef and wide-used wool.One head of yak may be sold 400-600 US$ in international markets. Tibetan sheephave big bodies, high butter production, brightly and elastic wool. "Xining Wool" iswell known inside and outside of China. Tibetan goats have fine and soft wool thatis good for cashmere sweaters. Yaks, sheep and goats can adapt low temperature,low oxygen and humid environment. They can be grazed as usual at very highelevation even up to 5000 meters.

The plateau has 16% livestock of the total of China with one third of thenational usable grassland. Grassland per capita in the plateau is 40 times that of thenational average and 17.8 times of the world average (0.61 hectare). Livestockproduction of Tibet Autonomous Region and Qinghai Province in1997 is showed inTable 9-11.

Table 9-11 Livestock production in Tibet and Qinghai, 1997

Slaughter number (1000 heads) Production (1000 tons)

Pig Cattle Sheep Poultry Total Pork Beef Button Milk

Tibet 132 666 4033 122 7 67 48

Qinghai 983 916 4071 1763 198 64 69 63 191


9.4.3 STRATEGY FOR LIVESTOCK HUSBANDRY DEVELOPMENT

Compared with domestic and foreign situation, production of livestockhusbandry in the plateau is low, especially in Tibet Autonomous Region. In theplateau, there is a large difference in livestock husbandry production. Grassland inTibet Autonomous Region is more than two times that of Qinghai but the totallivestock has only 5% more. Grazing capacity of grassland in Tibet AutonomousRegion is low. Fodder grasses for cattle and sheep are seriously shortage. Livestockquality is not high and its disaster-resisted capability is weak. Livestockproductivity is low. General situation is that slaughter rate and commercial rate oflivestock in the plateau are no more than 20% and 15% that are 10% lower thanthose of the national average. Different slaughter rate and commercial rate oflivestock are in different regions of the plateau. Qinghai takes the highest slaughterrate and commercial rate that are 2.31 % and 10.41 % higher than those of Tibet and4.66% and 6.46% higher than those of the east plateau (LUORONGZHANDUI,1996, Table 9-12).

Table 9-12 Livestock slaughter rate and commercial rate of the plateau (%)

Large livestock Sheep Itt d . d Integrated indexRegion Slaughter Commercial Slaughter Commercial negra e In ex of commercial

of slaughter rate trate rate rate rate ra e

Tibet 8.89

Qinghai 2.25

The east

19.84

4.05

13.04

9.11

22.41

16.00

17.53

19.84

15.18

3.70

14.11

7.65

Lower livestock slaughter rate and commercial rate of the plateau has not onlydirectly affected development of livestock husbandry but also increased pressure onthe fragile environment of the plateau. Reasons for lower livestock slaughter rateand commercial rate of the plateau are in natural and geographical aspects as wellas in social and historical aspects. During the last several decades, the state appliedlenient population policies for the Tibetan in the plateau. Population growth in thelivestock farming areas was too fast. It doubled in the last 40 years, maintaining anannual increasing rate of 15-20%. Original livestock farming areas applied simplenomadic economy. Herdsmen satisfied food requirement for population increasingby feeding more livestock. Specially, herdsmen had custom of unwilling toslaughter livestock and quantity of livestock was the most important criterion tojudge rich level of a family. Slaughter rate of large livestock was 10% less than thatof small livestock. Comparison of livestock quantity between families and tribesenhanced the viewpoint of keeping livestock. Consequently such livestockhusbandry manner enhanced degradation of grassland for winter and spring seasonsand enlarge contradictions between livestock and grass. Today these contradictionsstill remained.

On the other hand, it must be clarified that there are advantages for


development of livestock husbandry in the plateau. Livestock products that comefrom this environment of pollution-free area meet people's requirement. Suchproducts have priority of competition in markets. The priority of competition is notonly good for the traditional industry of the plateau going into modern markets butalso good for mitigating tension between livestock and grass. Moreover, it is alsogood for technological progress and scientific management in livestock husbandry,strengthening grassland protection, and construction of better ecological circle.Strategies of livestock development of the plateau will be construction ofinfrastructure, improvement of production conditions, casting off the passive stateof livestock development relying on weather. Tasks at present are: to improvenatural grassland and construction of artificial pastures, setting up pens for livestock,improvement of water conservancy conditions for grassland, increasing irrigatingareas of natural grassland, adhering the principles of feeding livestock according tograsses, adjustment of structure of livestock husbandry to promote coordinatedgrowth inside livestock husbandry, giving full play to local priorities to constructbases of livestock husbandry with various characteristics in light of local conditions,promoting service system and increasing members of sciences and technologies,organizing union of Iivestock-industry-and-commerce gradually to develop towardproduction-supplying-selling as a whole, energetically creating conditions to raiselevel of scientific management of livestock husbandry.

9.5 Forest and Horticulture Land

Tibetan Plateau has rich forest resources, which is the second largest forestregion in China and also the main wood cutting base in Southeast and NorthwestChina. Forest area in the plateau is about 26066.75 thousand hectares. Forest areaand timber accumulation are one forth of the total of China.

9.5.1 DISTRIBUTION OF FORESTRY LAND

Forest distribution is uneven in the plateau. One-third of the land in easternplateau is covered by forest. But less than 1% of land in Qinghai Province isforestland. Even in the same area, forest is also unevenly distributed (Table 9-13).The northwest Tibet Autonomous Region has almost no tree there. In the east TibetAutonomous Region, forest distributes geographically on eastern slopes alongrivers. Noticeable Yangtze River and Yellow River come from Qinghai and passthrough areas of densely forest of the east and forest-free Qinghai Plateau.Definitely, forest in the east plateau plays an important role on protecting waterquality of gold waterway of the Yangtze River. Forest of the plateau distributesmainly in transitional areas of the plateau and plain. Ecological values of the forestare much more than economic values.

9.5.2 WOOD AND ORCHARD PRODUCTIVITY


Forest coverage rate in the plateau is 11.7%. Coverage in the east plateau is37%. Tibet Autonomous Region and Qinghai Plateau has only 5.8% and 0.3%.Forest coverage and timber accumulation are shown in Table 9-14.

Table 9-13 Distribution of forest in the plateau (1000 hectares, %)

Land Agricultural Forest % of agricultural Wood % of forest

Tibet Auto. Region 77543.97 12659.51 16.33 8103.05 64.01

In the region:Lhasa 2274.93 101.25 4.45 4.43 4.37Qamdu 8670.18 2975.55 34.32 1323.67 44.48

Shannan 6373.58 3089.95 48.48 2176.60 70.44

Xigaze 12941.71 218.89 1.69 97.69 44.63

Nagqu 20782.47 1.93 0.01 0.00 0.00Ngari 18354.44 0.00 0.00 0.00 0.00

Nyingchi 8154.71 6077.07 74.52 4437.19 73.02

Qinghai Province 33207.92 1928.94 5.!"lI 279.63 1450

In the province:Xining 276.62 67.34 24.34 9.65 14.34

Haidong 1419.83 340.27 23.97 94.60 27.80Haibei 2523.70 210.39 8.34 43.75 20.79

Huangnan 1658.09 159.95 9.65 39.13 24.47

Hainan 3632.87 147.35 4.06 28.65 19.45Guoluo 6562.10 368.47 5.62 20.64 5.60

Yushu 10049.80 351.63 3.50 39.29 11.17Haixi 7039.28 286.79 4.07 6.52 2.27

Aba 7669.07 3074.55 40.09 1717.69 55.87

Garze 12498.28 4935.51 39.49 2430.83 49.25

Muri 1225.62 842.35 68.73 479.35 56.91

Deqen 1972.97 1525.83 77.34 1280.78 83.94

Gannan 3523.98 940.10 26.68 562.94 59.88

Tianzhu 643.39 159.97 24.86 62.16 38.86

The plateau 138285.21 26066.75 18.85 14855.57 56.99

Table 9-14 Forest coverage and wood accumulation of the plateau

Area Forest coverage% Wood 108m) % of the total

Tibet 5.84 14.4 56.2Qinghai 0.3 0.13 0.5

Garze 26.07 3.5 13.7

Aba 35.31 4.1 16.0

Deqen 55.65 1.57 6.1

Gannan 22.13 0.88 3.4

Muri 56.8 1.04 4.1

Total 25.62 100.0


Because the plateau is located in a remotely area with poor transport facilities,forest has kept its natural state for a long period. Since the 1950's, especial1y afterthe implementation of open policies in China, because of construction of highwaysand other infrastructures, wood has been developed as one kind of main naturalresources. For example, at present there are 14 forest farms (lumbering centers)with 3500 workers in Tibet Autonomous Region, where 300 thousand cubic metersof log were cut and 110 thousand cubic meters of timber were produced annually.The largest forest farm is Hongwei Forest Farm in Mainling County, where cuts20.5 thousand cubic meters of log annually. Other forest farms of annual loglumbering more than 10 thousand cubic meters are Lunang Forest Farm andGengzhang Forest Farm in Nyingchi County, Qamdu Forest Farm, and Xoka ForestFarm in Gongbo'gyamda County. Zhamo Forest Farm, Yadong Forest Farm, andlumbering farms in Shannan Prefecture (Nang County) and Nagqu Prefecture (SogCounty) lumber log 7000-8000 cubic meters annually. Wood resources developmentpushes the local economic development. Because forest resources is the mostimportant or even the only usable natural resources in some local areas, andreforestation is the most important measurement both for environmental andwoodland recovering. Therefore reforestation is paid much more attention in theplateau. For instance, reforestation area in 1997 in Tibet Autonomous Region was13 thousand hectares and Qinghai Province 35.6 thousand hectares (see Table 9-15).

Table 9-15 Reforestation in Tibet and Qinghai, 1997 (1000 hectares)

Type of reforestation Total

Tibet 13

Qinghai 35.6

Timber

7.1

4.9

Economic Shelter

4.1 1.4

1.9 18

Fuel

10.6

Special

0.1

In the last two decades, forestry economy of the plateau has been largelydeveloped. Horticulture area is increasing gradually (showed in Table 9-16).Production of fruit is increasing as well.

Table 9-16 Economic forest production in Tibet and Qinghai

1989 1990 1997Items Unit

Tibet Qinghai Tibet Qinghai Tibet Qinghai

Horticulture 1000 ha. 0.87 0.94 1.4 5.7

Total fruit Ton 4294.0 5444.8 7742.0 271790.0

Of fruit: apple Ton 3588.0 3695.7 4873.0 18884.0

Pear Ton 5891.0

Grape Ton 189.0

Tea yield Ton 77.0 65.9 89.0

Walnut yield Ton 793.0 1653.0 135


9.5.3 STRATEGY FOR FOREST AND HORTICULTURE DEVELOPMENT

Forest resources of the plateau have made great contributions to China'sforestry development. The eastern part of the plateau is still a forest base for Chinaat present. However, because of geographical limitation and insufficient recognitionon ecological role of woodland, there are still many problems in forestrydevelopment. The problems mainly are:

(1) Paying more attention to lumbering than to reforestation. Annualconsumption of wood in the east plateau is 1124.8 thousand cubic meters, which is1.4 times of total growth of wood in the area. Total wood in Garze and AbaPrefectures has been consumed 186.75 million cubic meters, that is 4900 thousandcubic meters each year, which is 60% more than wood growth. Even in the forestresources shortage province of Qinghai, 3020 thousand cubic meters wood wasconsumed in 1982, which is 10% of the total wood accumulation in the province.Lumbering area in that year was 12.7 thousand hectares but reforestation area wasless than 12 thousand hectares. However, wood consumption and lumbering areasmentioned above do not include those unplanned.

(2) Over mature and over lumbering of forest exist at the same time.Lumbering is not treated at point-separated but area removing manner. Forest crisiscauses a latent crisis for the ecology. Within 250 million cubic meters living wood,at lest 100 million cubic meters are over mature. Such forests located in remotemountain areas, which can only emerge itself and perish itself because of poortransportation hindrance and lacking capabilities to lumber in inland of thewoodland. For example, in the south Tibet Autonomous Region, there are 500million cubic meters of wood over matured, remained undeveloped. On the otherhand, woodland along highways and rivers were plundered lumbered. In some areas,woods were completely removed, which enhanced crisis for the forest and ecology.

(3) Daily energy was seriously shortage in pastoral areas. Fuel for people thererelies partly on wood. Especially in the areas close to woodland, wood is the mainresource of fuel. Fuel shortage resulted in disorder lumbering and destroyingwoodland in different levels.

In view of problems in woodland development, problems to be solved atpresent are the aspects of lumbering manners, construction of highways and otherinfrastructure and satisfaction of fuel for the local people. Highway constructioncan help to change lumbering manners. But satisfaction of fuel for the local peopleis an arduous task: firstly seeking alternative energy, secondly investment forchange new energy, and third degree of accepted by local people. For example,popularization of the solar energy stove requires high investment but receives lowacceptation by local people. Even so, the problems must be solved by well plannedby local governments and gradual development. Before alternative energyconfirmed, fuel wood lumbering must be well planned by the local governments.Disorder should be strictly controlled.


9.6 Other Lands

Other lands in the plateau include non-agricultural land, water surface andundeveloped land. Non-agricultural land consists of residential areas, industrialareas and traffic-used land. Non-agricultural land takes 0.18% of total land of theplateau, water surface 3.8% and undeveloped land 38%. Detailed distribution ofthese lands is showed in Table 9-17.

Table 9-17 Distribution of the other lands in the plateau (1000 ha.)

Area Irotal other land Non-agricultura Residential Traffic Water surface Undeveloped

Tibet 42691.28 60.11 36.07 24.05 5614.43 37016.73

Qinghai 38507.13 272.49 207.95 64.54 2495.43 35739.21

The east 3523.93 86.58 47.7~ 38.81 312.25 3125.10

Of the east:

Aba 569.27 22.24 10.71 11.53 60.97 486.06

Garzf 2271.34 26.58 11.81 14.7 I 181.65 2063.11

Moli 99.79 2.25 1.4~ 0.79 6.49 91.05

Deqen 350.28 10.45 6.97 3.4CJ 23.69 316.13

Ganan 198.83 18.61 12.2<; 6.33 30.16 150.05

Tianzhu 34.44 6.44 4.54 1.90 9.2CJ 18.71

The plateau 84722.33 419.ICJ 291.7<; 127.3CJ 8422.11 75881.04

9.7 Spatial Distribution of Agricultural Land-Use

9.7.1 AGRICULTURAL LAND-USE REGIONALlZATlON

With integration of landform, climate, crop, livestock and forestry production,the plateau may be divided into three regions for sustainable agriculturaldevelopment. They are the south and southeast region for cropping, forestry andlivestock husbandry, the northeast region for cropping and livestock husbandry, and.The regions were further divided into 13 sub-regions (Figure 9-1):

1. the south and southeast region for farming, forestry and livestock husbandry11 south Hengduan Mountain sub-region for farming and forestry12 northwest of Sichuan and south Gansu sub-region for farming and orestry13 southeast Tibet sub-region for farming and forestry14 north Hengduan Mountain sub-region for farming and forestry15 south Tibet plateau lake basin sub-region for farming/livestock husbandry16 the middle reaches ofYalung Zangbo River sub-region for

farming/livestock husbandryII. the northeast region for farming and livestock husbandry


III east Qinghai river valley sub-region for farming112 Qilian Mountains sub- region for and livestock husbandry113 mountains of middle Qinghai sub-region for farming and livestock

husbandry114 Qaidam Basin sub-region for farming and livestock husbandry

III. the middle and west region for livestock husbandry1111 hilly plateau of Qinghai, Tibet and Sichuan sub-region for livestock

husbandry1112 lake basin of Qiangtang Plateau sub-region for livestock husbandry1113 Ngari mountains sub-region for livestock husbandry

Figure 9-1 Map of agricultural land-use regionalization (after CHENG Hong and NI Zubin)

9.7.2 BRIEF DESCRIPTION OF THE REGIONS

The south and southeast region for farming, forestry and livestock husbandryincludes Hengduan Mountains, Garze, Aba, south Gansu Province and northwestYunnan Province, south Tibet Autonomous Region and the middle reaches ofYalung Zangbo River. Landform of the region is deep dissected mountains in thenorth and moderate dissected mountains and plateau in the south. Climate there isrelative warm and humid. Average temperature of the warmest month is 16-18°C inthe south and 16°C in the north. Annual precipitation is 500-800 mm and locallymore than 1000 mm. Main crops there are maize, paddy rice, tea, wheat, potato,buckwheat and highland barley. Main species of livestock there are cattle, buffalo,


goat, pig, yak and sheep.The northeast region for farming and livestock husbandry covers river valley

areas of east Qinghai, Qilian Mountains and mountains surrounding Qinghai Lake.Landform there is moderate dissected mountains, wide valleys and lake basins.Average temperature ofthe warmest month is 1O-16°C. Annual precipitation is 300500 mm and locally less than 200 mm. Main crops there are highland barley, wheat,rape, pea and broad bean. Main species of livestock there are yak, cattle, sheep, goat,camel and pig.

The middle and west region for livestock husbandry includes mountain plateauof Bayan Har Shan Mountain and Dangla Mountain in south Qinghai, vastQiangtang Plateau in the west plateau, Kunlun Mountains and Ngari at the west endof the plateau. Landform in the region is shallow dissected plateau, high mountainsand lake basins. Climate there is cold and dry. Average temperature of the warmestmonth is less than 10-12°C. Annual precipitation of the most area is less than 200mm and locally less than 50 mm. Almost no crop can grow there, except small areasof highland barley grows locally in Ngari. Main species of livestock there are yak,sheep and goat.

References

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3. LI Wenhua and ZHOU Xingmin (chief editors), 1994. Ecosystem and rational use models ofTibetan Plateau, Guangzhou, Guangdong Science and Technology Press.

4. Losang Lingzedojie (chief editor), 1995. Introduction of environment and development ofTibetan Plateau, Beijing, China's Tibet Study Press.

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7. SHEN Yuancu4xcn, REN Honglin and WU Shaohong, 1986. Agricultural conditions anddevelopment prospective in Qaidam Basin. Natural Resources, (4), 60-67.

8. SHEN Yuancun, REN Honglin and WU Shaohong, 1988. Land priority and land resourcesuse in Qinghai Province. Natural Resources, (2), 8-16.

9. SHEN Yuancun, REN Honglin and WU Shaohong, 1989. Regional differentiation of landtype and integrated natural Zonation of Qinghai Province. Geography Collection (21), 90-99.

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11. SUN Shangzhi (chief editor) 1994. Economic geography of Xizang Autonomous Region.Beijing, Xinhua Press.

12. WU Shaohong, 1987. Preliminary study on interpretation of land type from satellite image ofQaidm Basin. Arid Land Reserch, 4(3), 37-46.

13. YANG Qinye, 1983. Complex natural regionalization of the Hengduan Mountain region, astudy on Plateau Qinghai-Xizang. 1, Kunming, Yunnan People Press.

14. YANG Qinye and ZHENG Du, 1990. On a1titudinfal land use zonation of the HengduanMountain region in Southwestern China. GeoJournal, 20(4), 369-374.

15. ZHANG Rongzu, ZHENG Du and YANG Qinye, 1982. Physical geography of Xizang.


Science Press.16. ZHAO Songqiao et al., 1959. Agricultural and stock-raising geographical survey of the

interlock area between agriculture and animal husbandry in Sichuan and Yunnan Provinces.Beijing, Science Press.

17. ZHAO Songqiao, SHEN Yuancun, REN Honglin and WU Shaohong, 1985. Land types andagricultural potential in Qaidam Basin, Arid Land Geography, 8(4), 1-13.

18. ZHENG Du and YANG Qinye, 1985. Some problems on the altitudinal belts in SoutheasternQinghai-Xizang Plateau. Acta Geographica Sinica, 40(1),60-69.

19. ZHENG Du, YANG Qinye and LIU Yanhua, 1985. Tibetan Plateau of China, Science Press.

CHAPTER 10 NATURAL HAZARDS AND ENVIRONMENTALISSUES

ZHU Liping and LI Bingyuan

Have been being intensively uplifted since 3.4 Ma BP, the Tibetan Plateau, withthe elevation of 4000-5000 m asl, is the youngest and highest plateau on the earth.Extremely high elevation makes the plateau as the largest high-cold area in middlelatitude zone. The cold climate causes permafrost to be widely distributed in mostpart of the Plateau while modern glaciers are developed on the high mountains above5000-6000 m asl. Violent uplifting also causes intensive cutting which results in theformation of high mountains and deep valleys, steep slopes and higher relative reliefon peripheries of the Plateau. However, it is relatively warmer and drier in dryvalleys of southeastern part of the Plateau. Due to the influence of monsoon andlandforms, precipitation is gradually decreased from southeast to northwest andvegetation appears succession from forest to desert. Under the background ofintensive tectonic movement, multiple climatic types and active landform processes,many kinds of natural hazards frequently occur in certain areas. With increasing ofhuman activities, they also bring a series of issues to the fragile environment.

10.1 Natural Hazards

The Tibetan Plateau is the most intensively neotectonic uplifting area. Theyoungest and the most active tectonic movement zones are widely distributed in itsperiphery areas, in which earthquakes frequently occur because of large scale ofhorizontal and vertical movement and complex tectonic deformation. Landslideswidely appear in deeply cut valleys due to big relief and active landform processes.Complicated climatic conditions also result in a series of weather hazards such assnow hazard, frost, dryness, flood, etc. which endanger the production and lives oflocal people.

10.1.1 EARTHQUAKE

Although there is no recordation of earthquake in early history in the Tibetanareas, the fact that earthquakes are actually active may be inferred from a series ofactive fault zones distributed in its periphery areas. On the one hand, the Plateau isenclosed by the north fault of west Kunlun, Altun fault zone and north fault ofQianlian in its northern skirt, the Himalayan Main Boundary Thrust (MBT) in itssouthern border, the Longmenshan fault and Lijiang-Anshunchang fault in its eastern

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ZHENG Du. ZHANG Qingsong and WU Shaohong (eds.). Mountain Geoecology and Sustainable Development of theTibetan Plateau. 203-222.©2000 Kluwer Academic Publishers.

204 ZHU L. P. and LI B. Y.

boundary. On the other hand, there are many active fault zones in large scale in EW and NW-SE direction in its interior areas such as south fault of east Kunlun,Xianshuihe fault, Nujiang-Langcangjiang fault, Honghe-Jinshajiang-Hoh Xii faultand some nearly S-N direction faults which transect the Himalayas and the Gandise.These faults are formed in Paleozoic, Mesozoic or Cenozoic respectively, but stillactive until present (REN Jishun et al., 1980). According to instrumental records ofbig earthquakes since 1990, many earthquakes occurred on and were closely relatedto these fault zones. Among the earthquake zones surrounding the Tibetan Plateau,those in the Hengduan Mountains are most active while the others are relativelyweak except for the intensive ones in individual sites (GU Gongxu et al., 1983; 1984)(Figure 10-1).

• Great than Richter scale 8 earthquake o Less than Richter scale 8 earthquake

Figure 10-1 Earthquake distributive map on the Tibetan Plateau

The Hengduan Mountains earthquake zoneThe Hengduan Mountains, situated in the east of the Tibetan Plateau, is a very

active earthquake area with high frequency and big intensity. The epicenters ofearthquake zones are overlapped with faulted valleys whi Ie the hypocenters are notdeep but ground surface is greatly damaged. Earthquakes in this area are related todeep and big faults and form a series of earthquake zones such as Xianshuiheearthquake zone, Songpan earthquake zone and Jinshajiang-Yuanjiang earthquakezone. In addition, the Longmenshan earthquake zone and Anninghe-Zemuheearthquake zone in the outskirt area also have influence to this area.

Stretching along northwest direction, Xianshuihe earthquake zone with thelength of 360 km is coincided with Xianshuihe fault zone, on which manyearthquakes occurred. For examples, the earthquakes of Richter scale (R) 7.6, 6.9,

Figure 10-2 Blocked lake in Minjiang River causedby Diexi earthquake

NATURAL HAZARDS AND ENVIRONMENTAL ISSUES 205

7.5, 7.7 occurred on February 6, 1973 at Luhuo, on January 24, 1981 at Dufu, onApril 14, 1955 at Zheduotang of Kangding, and on June 1, 1978 at Kangding andLuding respectively. This earthquake zone is characterized with high frequency,big intensity and heavy damage. From 1700-1992, there were 50 earthquakes overR5.0, among which 9 were over R7.0 while 17 reached R6.0-6.9. It ranked the firstposition in the Hengduan Mountains for the high frequency of earthquake happeningand big damages to economy and lives.

Songpan earthquake zone is roughly extended along S-N direction. Since 638AD, there are 30 earthquakes over R5.0, among which 4 are over R7.0, 8 are betweenR6.0-6.9 and 18 range R5.0-5.9. An earthquake of R7.5 that occurred in Diexi ofMao County on August 2, 1938 had caused a group of landslides. The landslidesblocked the branch and main channel of Minjiang and formed tens of pools (Figure10-2). In this disaster, 5180 rooms collapsed, 6865 persons died and a town was

destroyed. In 1979, the earthquakeof R7.2 that occurred in Songpanand Pingwu destroyed 30 bridges,5000 rooms and made 38 personsdied.

Longmenshan earthquakezone, extended along S-Ndirection, is situated on easternperiphery of Hengduan Mountainsand partly overlapped with thesouthward extension of Songpanearthquake zone. On April 1621, 1657, an earthquake of R6.25occurred in Wenchuan, whichbroke the city walls and causedmany persons died.

Litang earthquake zone isdistributed on the Litang-Dewufault zone with the strike alongN40°W. There are 11 earthquakesover R5.0 in this zone, amongwhich the intensive one occurredon May 25, 1948 at Litang.

Himalayas earthquake zonesHimalayas earthquake zone is the eastern section of the Med-Himalayas

earthquake zone, in which the intensive earthquakes mainly occur on the southernflank of the Himalaya Mountains. Earthquakes over R8.0 were those on June 11,1806 at Lungmar, on March 26, 1823 at Gyirong, on August 15, 1950 at Zayue andMedog. Especially, Zayue-Medog earthquake reached R8.6 and about 80aftershocks occurred subsequently, in which 7 were over R6.0. In Zayue, these


earthquakes destroyed most of stone buildings, roads and resulted in many landslideswhile in Medog, the old buildings were generally broken down and the number ofdied and harmed persons was different to be calculated due to the rural area andinconvenient traffic condition. Many surface fissures had been produced in theseearthquakes. With about one meter wide and tens to hundreds meters long, thesefissures were generally distributed along the Yarlung Zangbo River and caused manylandslides. For an example, Yedong village of Modog County had fallen into theriver due to mountain collapse derived from surface fissure. This earthquake alsocaused the damages in Mainling, Ze La, Taizhao, Nyingchi, Zhaxize, Baimagang,Kongbu, Cona and Borne. In this disaster, 580 lamas of Demuqiacheng Temple andQiana Temple of Kongbu died and collapsed houses in Nyingchi covered nearly 200persons. The earthquakes occurred in the northern flank of Himalaya Mountains weremainly concentrated in the east and west ends. Since 1938, 10 earthquakes haveoccurred in NE direction faults of the eastern section, among which the mostintensive one was that ofR7.7 at Nang Xian in 1947. In Langqen Zangbo-YanglungZangbo fault zone of the west section, the earthquakes of R6.0-7.0 occurred in 1752,1911,1913,1966 and 1975 respectively.

Northern periphery earthquake zones ofthe Tibetan PlateauMany earthquakes occurred in the west Kunlun Mountains, of which most are

concentrated in the interconnection areas between Kunlun and Tien shan Mountains.It is only in Aketao and its westward extension areas that 7 earthquakes of R6.0-7.0have ever occurred in the piedmont of the Kunlun Mountains. The similarlyintensive earthquakes also occurred in the west and middle section of the westKunlun Mountains. For examples, the earthquakes of R7.2, R6.2, R6.7 occurred onJuly 3 and 12, 1924 in Minfeng, on February 13, 1948 in Hetian and in October of1920 in Yutian, in 1933 in Ruoqiang respectively. Fewer earthquakes occurred inthe middle Kunlun Mountains except for the earthquakes of R6.0 in records ofOctober of 1966 and November of 1959 in Muztagata. However, the intensiveearthquakes occurred in the east Kunlun Mountains such as the earthquakes of R7.2and R7.0 in January of 1937 and in April of 1963 in Mardo County, the east end ofBuhanbuda Mountains.

In Qilian Mountain areas, the northeastern periphery of the Tibetan Plateau,earthquakes are mainly concentrated in the fault zones that are distributed in thenorthern flanks of the mountains. For examples, an earthquake ofR8.0 on May 30,1927 in Gulang had made 40000 persons died. An earthquake of R7.6 onDecember 25, 1932 in Changma of Yumen had caused the piedmont deformationfracture zone extend as long as 116 km. This earthquake made total damaged areaas 500 km long and 155 km wide while 270 persons died and 300 persons wereharmed in Baoxiang of Changma. An earthquake of R7.2, which occurred on July12, 1609 in Hongyabao, the southeast of Jiuquan, had produced a great number oflandslides and had blocked the Taolai River for several days. 840 persons died inthis disaster. However, there are relatively fewer earthquakes occurred in theinterior of the Qilian Mountains and Qaidam Basin except for 8 earthquakes of R6.06.8.


The earthquake zones in the interior ofthe Tibetan PlateauEarthquakes in interior of the Tibetan Plateau are sparsely distributed except

those were concentrated in middle part of the Tibet Autonomous Region and HohXil-Tongtianhe areas. 23 earthquakes over R6.0 had occurred in northern flank ofKandese Mountains and west section of Nyainqentanglha Mountai'ns from 1924 to1980, of which most were related to S-N direction faults. 50 percent of them andnearly all of intensive ones were concentrated in periphery of the NyemoYangbajing-Damxung Basin of Nyainqentanglha Mountains, such as the earthquakesofR8.0 and R7.5 on November 18,1951 and on August 18, 1952 in Damxung.

In the Hoh Xil-Tongtianhe areas, 16 earthquakes over R6.0 occurred, in whichonly 3 reached R 7.2 and the others were R6.0-R6.5. Satang fault zone, as part ofthe Jinshajiang fault zone, is very active one in the southeastern section of the HohXil-Tongtianhe area for 9 earthquakes over R5.0 having occurred since 1870. Themost intensive earthquake recently occurred at Batang was that of R6.7 on April 16,1989. It appeared as group earthquakes and affected over 10 counties of Sichuanand Yunnan provinces as well as Tibet Autonomous Region. The earthquakesinduced severe landslides that blocked the roads for many times. In Satang County,52,608 rooms collapsed, 8 persons died, 34 and 87 persons were heavily and lightlyharmed respectively, 2008 livestock were killed. The direct economic loss reached0.3 billion RMB yuan.

Earthquakes of the Tibetan Plateau have the laws on their spatial distribution.Generally, dominated by and distributed along tectonic zones, these earthquakes, nomatter intensive or weak, are always derived from certain position of the relatedactive faults. Temporal cycles of the earthquakes, with alternation of concentrationand sparsity or intensive and weak, are also obvious according to historic data ofearthquakes. For examples, there were 2 active periods of 1922-1933 and 19541977 in Hexi corridor of northern flank of Qilian Mountains. The earthquakes havebeen active from 1910-1938 and since 1971 in north Tibet while there were 3 activeperiod of 1897-1916,1934-1952 and since 1975 in south Tibet (ZHU Haizhi, 1993).Although the cycles of earthquakes on the Tibetan Plateau are possibly not true dueto short historic records, this work is very valuable to long time forecasting ofearthquake occurrence.

Because of short historic earthquake record, wide area, and sparse populationand less in site investigation data, the materials of earthquakes on the Tibetan Plateauare quite incomplete. From the view of disaster degree, it is severe in periphery oroutskirt areas such as Gulang earthquake in 1927 and Changma earthquake in 1932.To interior of the Plateau, the disaster degree is relatively severe in Xianshuihe valleyand Minjiang Valley of Hengduan Mountains and in lower reaches of YarlungZangbo River. In the north Tibetan Plateau, though the earthquakes inducedintensive deformation of ground surface, the actual economic loss was less due tosparse population and fewer stone-brick buildings. For an example, the earthquakesoccurred in Damxung in 1951 and in 1952 reached R8.0 and R7.5 respectively, butthere were fewer records of economic loss caused by those disasters.


10.1.2 DEBRIS FLOWS AND LANDSLIDES

Debris flows and landslides are endemic natural hazards in mountain areas, ofwhich the formation is not only dominated by landform, but also related to geologicaltectonic, crustal activities, strata lithology and climatic conditions. Generallyspeaking, they occur in areas with steep slopes, active tectonic movement andfragmentized strata. Water content and earthquake are not only important inducingconditions to landslides, but also produce and provide a large quantity of materialsfor debris flows.

Three types of debris flows may be distinguished as glacier debris flow, stormdebris flow and that induced by burst of blocked lake (Blocked lake bursting debrisflow). Glacier debris flows are mainly caused by melting of glaciers, and generallydistributed in mountains with deep-cutting valleys and modern glaciers. Most ofthem occurred in the great gorge of Yarlung Zangbo River and its branches such asParlung Zangbo and Yi/ong Zangbo, the oceanic glacier distributive valleys thattransect the Himalaya Mountains and east section of the Nyainqentanglha Mountains.For an example, a super-big glacier debris flow occurred on September 29, 1953 atthe Kagangnongba of Guxiang valley. Situated at the north bank of Parlung Zangbo,the drainage basin of this valley is 2724 m asl in average elevation and 36.9° inaverage slope degree while 8.1 km2 of area is covered by modern ice and snow. Thedebris flow firstly blocked the mouth of glacier valley by 200 m high of accumulatedmaterials, and then rushed out of the valley and formed a "stone field" with 1.5-3.5km wide, 2 km long and about 4.2 km2 in area. It was estimated that peak fluxreached 28600 m3/s and alluvial solid materials was over 11 million tons, in which agranite-gneiss block was 20 m long, 12 m wide, 8 m high and 1500 m3 in volume.A great number of materials fell into the Parlung Zangbo and blocked river channel.The water level rose 40 m and a 70 km long Guxiang Lake was formed. Thisdisaster also damaged a large quantity of forests, farmlands and houses (SHI Yafenget a/., 1964). Debris flows kept being burst since then and there were as more as600 times of debris flows which rushed out of the mouth of valley according toincomplete statistic during 1953-1973. The total solid materials reached 150million tons. The road was damaged nearly every year from 1953-1991 (LUO Defuet al., 1995).

Another site for frequent occurrence of glacier debris flows was Zhamognongbavalley. Situated at left bank of lower reaches of Yi'ong Zangbo, this valley iscovered by accumulation snow in 2.2 km2 of the drainage basin. In summer of 1902,after 15 days stop of running water, a debris flow burst and rushed out of the valleyto arrive opposite slope of river valley. The houses and livestock of 50 familieswere covered near the mouth of valley and a lake--Yi'ong Lake was formed due tothe blocking of debris flow. Though debris flows occurred here year after year, theintensity was gradually decreased (LU Ruren et aI., 1999). However, a super-bigdebris flow burst out again in this valley on April 9, 2000 according to news report ofRenmin Daily of April 22, 2000. It broke off the Yi'ong Zangbo and formed anaccumulational platform with 2.5 km long, 2.5 km wide and 60 m high.

Glacier debris flows are also developed in the Konger Mountain, the Gez River


valley and its branches of the Kungai Mountains, in which they were very active inAierkuran valley and burst out in each summer. On August 18, 1984, the debrisflow rushed out of the mouth of valley and crossed the 30 m wide Gez River. Thisdisaster made communication lines and roads to be damaged.

Storm debris flows are distributed much widely than glacier debris flows.Influenced by geological conditions, slope degree and precipitation (especially thatbetween 700 and 1200 mm), many storm debris flows occurred below 3800 m asl inthe Hengduan Mountains and below 4300 m asl in the upper reaches of the NianchuRiver in the south Tibet. However, storm debris flows are smaller in scale, lower infrequency and less active on the gentle Plateau surface. There is nearly no stormdebris flow developed in interior of the north Tibetan Plateau. With decreasing ofelevation, the increased slope degree and precipitation induce many debris flows inriver valley areas, in which human activities are mainly concentrated due to the limitof landform and climatic conditions. The overlapped space between them madestorm debris flows produce much more damages to buildings, farmlands and humanlives. For examples, 25 persons died and the economic loss reached 1.5 millionRMB yuan in a debris flow which occurred on July 18, 1984 in Miaogou of NanpingCounty while 7 persons died and the roads were destroyed by those occurred inDerong County on August 11 in the same year. Storm debris flows also blocked theroads and endangered the factories and mines. According to statistics, there were400 debris flows occurred along the Sichuan-Tibet highway in precincts of SichuanProvince since the completing of the highway, and the blocking period resulting fromdebris flows reached more than one month per year (TANG Bangxing et al., 1995).In the precincts of Tibet Autonomous Region, there were 143 sites of valley debrisflow and 329 sites of slope debris flow along southern branch of the Sichuan-Tibethighway. The damage was quite severe from Baxoi to Yelashan due to frequentheavy rain and densely distributed slope debris flows. The destroyed roads weredifficult to be repaired because of narrow landform and incompact road base (LUODefu et al., 1995).

Debris flows induced by burst of blocked lakes are less distributed due to thelimit of their formation conditions, but they have large influencing ranges andintensively destructive ability because of huge wallop and water quantity in shortertime. Debris flows induced by burst of glacier lake are caused by the collapse oflake dam. One reason for collapse was the huge impact of shock wave that wascaused by ice blocks falling into lake. With the changing of temperature, frequentadvance and retreat of glaciers made huge ice blocks easily lose their stability andfall into lake. The second reason was pipe-gush occurred in the dam due to interiorice melting. This kind of debris flow is mainly occurred from Bu'gyai Kangri, Jiali,Gongbo'gyamda, Comai, Loca along main ranges of the Himalaya Mountains toGyirong and Zhongba while the farest sites may reach the Bangong Lake area. Inaddition, it also occurred in the Gongrigabu Mountains of the east Himalaya and thesource of Yarkant River in the Karakorum Mountains. According to statistics, therewere 15 times of burst in 13 glacier lakes in the Tibet Autonomous Region duringperiod from 1930s to 1995. The flood and debris flows induced by burst of glacierlakes have brought many hazards (Table 10-1).


Table 10-1 Some disasters caused by the debris flow induced by the burst of glacier lakes

Time Site Disaster

August 28, 1935 Taar Co, Nyalam Hundreds hectares of farmland were covered

July 10, 1940 Qionbixia Co, Yadong Yadong city, which was 43.9 km far to the burst site, wasdestroyed. Rinqengang, which was 10 km to Yadongcity, was attacked by the flood.

July 16, 1954 Sangwang Co, source 240 million m3 of water quantities flooded; 20,000ofNyangQu people in the disaster and 400 died; 5733 ha farmland

was flooded and 866.7 ha was destroyed; Gyangzi andXigeze city were attacked by the flood.

August 25, 1964 Longda Co, Gyirong The road was destroyed as long as 5-7 km and had to bechanged on its course.

September, 21, Jilai Co, Dinggye The road of20 km long was destroyed in the Sa'gya-1964 Zhentang highway and 12 trucks were engulfed in the

debris flow.

September, 26, Damenlakela, Nyang Qu was blocked as long as 10 hours; the section1964 Gongbo'gyamda of2.2 km long in the Sichuan-Tibet highway was

covered and had to be changed on the course; houses,farmlands rangelands and forests were covered ordestroyed.

August, 1968- Arya Co, Tingri Part of the rangelands was destroyed in the Tingri basin;1970 the No.1 bridge at Desar in the Sino-Nepal highway was

swept out as far as 2 km.

July 23, 1972 Poge Co, Sog Xian A bridge on the road was destroyed.

June 24, 1981 Zhari Co, Loca Bridges, small hydraulic power stations, water channels,farmlands and were destroyed.

July 11, 1981 Cirenma Co, source of The road of 50 km long and the Friendship Bridge whichZhangzangpu valley, was on the boundary between China and Nepal wereZham destroyed; Xunkexi electricity station of Nepal was

damaged and 200 persons in Nepal died.

August 27, 1982 Jin Co, Dinggye 8 villages and 18.7 ha of farmlands were destroyed while1600 livestock were swept.

July 15, 1988 Guangxie Co, Midoi Huge loss occurred in the Midoi and Mime villages; 42valley, Borne km of Sichuan-Tibet highway was destroyed; Borne

town, which was 97 km far to the debris flow site, wasflooded.

Data from LV Ruren et al., 1999

Burst of the slumping and landslide blocked lakes also produce huge damages.For examples, the slumping induced by Diexi earthquake in August of 1933 hadblocked the Minjiang River in 3 sites. The collapse of dams in subsequence onOctober 9 in the same year produced the flood as high as 60 m, which swept thevillages of lower reaches. According to investigation, 1600 persons died in GuanCounty while the Dujiangyan was severely damaged. In 1967, after 9 daysblocking at Tanggudong Mountain in the Yalungjiang River, the collapse even made

NATURAL HAZARDS AND ENVIRONMENTAL ISSUES 21 I

water level rise 14.5 m at Sanduizi of Jinshajiang River which was 600 km far tocollapse site. The flood had swept away roads, bridges and farmlands on its way(TANG Bangxing et al., 1995).

Landslides or slumping is necessary step for formation of debris flow as itprovides the loose materials. The large scale of landslides and slumpings aremainly distributed in the southern, southeastern part of the plateau, which are theareas with intensive tectonic movement and huge relief. For examples, manylandslides had occurred from September of 1987 to 1991 at the bank of DongjiuRiver, the branch of Parlung Zangbo in the great gorge area of Yarlung Zangbo(Figure 10-3). Among them, the three big ones made moveable materials reach 15SOx 103 m3 that produced torrential current and resulted in roads destroyed in manysites. In Maqimei valley, another branch of Parlung Zangbo, a large scale oftractive landslide group had occurred on old landslides and its eluvium. Theymoved materials as much as 1.2x 106 m3 and destroyed 0.5 km long of road.

Figure 10-3 Landslides along Sichuang-Tibet Highway

In southern flank of the Himalaya Mountains, southern and eastern parts of theHengduan Mountains and southern flank of the west Karakorum Mountains, debrisflows and landslides are characterized with large scale, high intensity and frequentcycles due to the existence of many rivers, steep slopes, fragmentized strata andplenty of precipitation or thawy water of ice and snow. These areas are the mostsevere ones attacked by the disaster of debris flows and landslides. Though thelandform is suitable for development of these geomorphologic phenomena in certainareas such as the Kunlun Mountains and Qilian Mountains, the less precipitationmade them weakly developed. In the valleys of south Tibet and north Hengduan


Mountains, debris flows and landslides are moderately developed due to relativelybig relief and medium precipitation while they hardly occur in explanate interior ofthe Tibetan Plateau. To sum up, debris flows and landslides are gradually weakwith decreasing of relief and slope degree from periphery area to interior of thePlateau (LI Bingyuan et al., 1996).

10.1.3 WEATHER HAZARDS

Weather hazards on the Tibetan Plateau include drought, flood, frost, hail, snowand strong wind. Due to difference of temperature and precipitation from southeastto northwest and from periphery to interior, land use manner is accordingly changedwhile weather hazards also have apparently difference. Planting is mainlydistributed in valleys that are lower than 4000 m asl in the south of the KandeseMountains, Nyainqentanglha Mountains, Tanggula Mountains and BayanharMountains and in basins or valleys that are lower than 3800 m asl in the north of eastKunlun Mountains. These areas are called farming belts for their main products offood and oil plants, in which weather hazards are drought, flood, frost, hail andstrong wind. Grazing is another land use manner for agriculture and distributedmore widely on the Tibetan Plateau, in which snowstorm has constructed, the mainweather hazard.

Drought, directly influenced by changes of precipitation, is the most severeweather hazard in farming belts on the Tibetan Plateau. Climatically, severedrought that causes farming products to be decreased may occur when precipitationis lower than 100 mm. It is analyzed that there are 3 drought periods of 1907-1915,1935-1946 and 1963-1980 in recent 100 years. One kind of drought is produced byirrational use of water. In south Tibet, the enlargement of effectively irrigative areasand irrational ratio of planting species have more influence to oCCurrence of drought(LIN Zhenyao et al., 1986). Thus, the frequency and intensity of drought may begradually weakened with improvement of irrigative condition in wide valleys ofsouth Tibet. Another kind of drought is caused by imbalance of precipitation. InHengduan Mountains, dryness in winter and drought in spring generally occurbecause precipitation in winter is only 10-20% in that of total year. For an example,the continuous drought had ever lasted from February to May in south-middle sectionof Jinshajiang due to the precipitation of less than 0.1 mm. The precipitation is richin summer, but it may be insufficient when plant needs water and over much whenplant does not. This kind of drought that appears in rain season is severelydangerous to farming production. According to statistics of occurrence, differentkinds of drought had almost occurred in the joint area of Yidun, Xiangcheng, Derongof Ganzi Prefecture and Deqin, Weixi in west Yunnan Province, but in the other areasdrought is only occurred seasonally (HE Sudi, 1989).

Although there were 3 rich water periods of 1883-1906, 1916-1934 and 19471962 in southern Tibet in recent 100 years, the increasing of precipitation had notobvious influence to farming belts. With construction of irrigation works sincemid-1960s, the frequency of water hazards has been reduced rapidly. For anexample, no flood or waterlogging occurred in 1962 despite of two times


precipitation than that of normal year. Actually, the flood in the Tibetan Plateau isusually related to the burst of blocked lakes and less influenced by precipitation.

If ending time postpones or beginning time advances to frost period, frost maybring hurt to plants with normal growing period. In the Tibetan areas, frost hazardis mainly distributed in high elevation areas that are near to upper limit for plantsgrowing. Though the Tibetan Plateau is the area where hails occur most in totalChina, the small hail grain and varied landforms made them form less hazards. Foran example, there was ever 36 days for occurrence of hails in Nagqu, but economicloss was less because it is a grazing area and light hit comes from small hail grains.

Figure 10-4 Pasture land covered by heavy snow in north Tibet

Snow hazard is a main weather hazard in grazing area on the Tibetan Plateau(Figure 10-4). According to analyses of historic records, it was mainly distribute.din Nagqu, Amdo, Pangkog, Xainza, Nyainrong, Baqen, Sog Xian of the TibetAutonomous Region and Zaduo, Yushu of Qinghai Province. These areas areroughly situated in the north of Nyainqentanglha Mountains and west of BayanharMountains and belong to semi-humid areas on the Plateau. If severe snow hazardstandard was taken as over 3 mm, more than 30 days and great than 2 counties inarea for snowfall, the severe snow hazards, according statistics of mid-1980s, shouldhave occurred in 1956-1957, 1961-1962, 1967-1968 and 1979-1980 in north Tibet.This also accorded with actual hazard degrees. These 4 snow hazards, plus those in1828-1829,1830, 1842, 1865-1866, 1887-1888, 1890, 1901, 1905, 1925-1926, 19271928 and 1948 in historic records, showed that there were 15 severe snow hazards onthe north Tibetan Plateau (LIN Zhenyao et al., 1986). The most severe one was in1828- I829 while most of livestock died in Nagqu, Damxung, Pangkog, Sog Xian,


Ngari. According to an investigation in 183 families of herders, 5614 standardcows l were lost and only 4339 were left in that snow hazard. In some area, the diedlivestock occupied 2/3 of total numbers. In recent snow hazards occurred in 19891990 in north Tibet and south Qinghai, accumulated snow reached 40-60 cm whilehazard area reached 200,000 km2 in Baqen, Biru, Sog Xian, Nagqu, Nyainrong,Pangkog. A great number of livestock died and nearly 60,000 persons wereimperiled in the snow hazard (LIN Zhenyao, 1992). In Qinghai Province, therewere 30 snowfall days from middle of February to April of 1989 and 1.3x 104 ha ofrangelands were covered by thick snow in 5 prefectures of Huangnan, Hainan, Hanxi,Guoluo and Haibei. 80 millions of livestock were in dangerous situation due to thestarvation caused by shortage of forage. According to incomplete statistics, over 70adult livestock and 960000 young ones died respectively in that hazard. The directeconomic loss reached 170 million RMB yuan.

10.2 Environmental Issues

Although the Tibetan Plateau is characterized by extremely high elevation andpeculiar environment, the climatic types are complex and multiple while naturalresources are rich and colorful under the conditions of monsoon and variedlandforms. However, these resources have been being exploited, developed andutilized to satisfy the needs of living and development for 9 million persons who areliving in this area. With increasing of population and enhancement of humanactivities, this peculiar and fragile environment is also facing huge pressure, which isinducing a series of environmental issues.

10.2.1 DEGRADATION OF GRASSLANDS

Climatically, the Tibetan Plateau is characterized with coldness but richinsolation, under the condition of which, a series of high-cold grassland types such ashigh-cold bushes, high-cold meadows, high-cold steppes and high-cold deserts wereformed. Among them, as important bases for grassland pasturage, high-cold bushesand high-cold meadows occupy roughly 46xl03 ha, nearly half of the total area ofnatural grasslands (ZHOU Xingmin et al., 1995). Limited by rigorous ecologicalenvironment, plant communities, the cores of grassland ecosystem, are characterizedby less species, simple structures, short trunks and low productions. Once disturbedor damaged, they are difficult to be restored. For long period, it is not fullyunderstood by people to the relationship between these basic features and pasturageproduction, the lack of scientific management has brought over grazing, overincreasing of pika and zokor and enhancement of other irrational human activitiesthat induce grasslands to be degraded (Figure 10-5).

Over grazing is one of the main causes for degradation of grassland. One formis that it has changed the structure of plant communities. Under the condition of

1) Standard cow is an unit for livestock statistic used by Tibetan People. One standard cow is equalto 1/4 horse or 10 sheep or 13 goats.


over grazing, the height, density and coverage of dominant species and otheraccompanied ones in degraded grasslands are obviously decreased while somespecies which are dietetically disliked by livestock may fully grow by use of light,heat and water resources. According to investigation, this kind of degradationoccurred 1/3 of the total area of natural grasslands and caused forage grassproduction reduced 20-50% (ZHOU Xingmin, 1989). Another form is that thecovers of grasslands are destroyed by trample of livestock. The thin soil layers areeasily to be stripped off by strong wind and grasslands are damaged patchedly(ZHENG Yuanchang and TANG Zhongshi, 1995).

Figure 10-5 Degraded grasslands induced by Pika znad Zokor

Over increasing of pika and zokor is another main cause for degradation ofgrassland. The main species of pika to destroy grasslands on the Tibetan Plateauare Ochotoma curzoniae, 0. Dahuricaamage, Myospalax baileyi, etc. Investigationshowed that there were roughly 600 million ochotomas and 100 million myospalaxesin the Plateau areas. They annually consumed 15 billion kilograms of fresh grassesthat were equal to the food quantities of 10 million sheep and destroyed 200 millionha of grassland areas (ZHOU Xingmin et al., 1995). The damage of pika and zokoris closely related to over grazing. Firstly over grazing has changed structure ofplant communities. With grasses and sedges were replaced by other weeds, animalcommunities dominated by Microtus oeconomus and 0. cansa were also supersededby that of Ochotoma curzoniae and Myospalax baileyi. The quick increasing ofOchotoma curzoniae and Myospalax bailey; not only restrained growth of grassesand sedges and contested against livestock for food, but also destroyed plant coverand formed micro landforms which induced loss of water and soil and essentially


spoiled the grassland ecological environment (FAN Naichang, 1992).Other causes for grassland degradation include grassland reclamation, human

digging, etc. In 1950s, about 600,000 ha of grassland in Qinghai had beenreclaimed in pursuit of food yield, but except for small part, most of them had beenwasted and difficult to be restored at present. With economic development, humandigging which aimed at mineral exploiting and road construction had been beinggradually destroyed the grassland.

10.2.2 LOSS OF WATER AND SOIL

The main causes for loss of water and soil on the Tibetan Plateau arereclamation and lumbering. Irrational reclamation and lumbering had badlydestroyed surface vegetation, caused decreasing of water-soil conservation abilityand enhanced land sandification and desertification. For examples, sanded plantshad been nearly cut out in the 7200 km2 area that was centered as Golmud in QaidamBasin. It had not only weakened the adjusting run-offs ability of vegetation, butalso enhanced the degradation of grasslands surround the Qinghai Lake and theenvironmental aridity (CHEN Guichen et al., 1995). In southeastern part of theTibetan Plateau where was distributed by dense population, forest area was sharplyreduced due to the policy of forest industry 'putting much to cutting and less toplanting' . In the same time, reclamation in some steep slope areas leaded slopesoils easily to be destroyed. These human activities had extremely increaseddisaster's frequency of debris flows, landslides, drought and waterlogging.According to statistics, in Lixian, Songpan, Moshui, Wenchuan and Maowen whichwere situated in upper reaches of Minjiang River, forest cover rate had decreasedfrom 30% in the beginning of 1950s to 18.9% in the end of 1970s (Uu Suqing et ai.,1986). In middle reaches of Yarlung Zangbo, Lhasa River and Nianchu River areaswhich were in the southern Tibet, the annually destroyed bushes had reached 40007000 ha. In addition, loss of water and soil had caused solid materials in riversrapidly increased. The annual sand transportation had reached 2480x 104 t in thesection from Longyangxia to Xunhua along the Yellow River (YUAN Shengxin,1993). The sandy content in water of Dadu River was 1.16 kg/m3 in 1981, twotimes of that before 50 years. The mud and sand which annually entered theYarlung Zangbo had already reached 5000x 104 t. At present, the area in which lossof water and soil occurred had occupied nearly 1/10 of total land area on the TibetanPlateau (ZHANG Mingtao et al., 1996).

10.2.3 DEGRADATION OF PERMAFROST

As one of the results of climatic warming, degradation of permafrost on theTibetan Plateau had been documented by the investigation data. Island permafrostbegan to disappear in south and north margin while ground temperature graduallyrose in the center of permanent permafrost area on the Tibetan Plateau (WANGShaoling, 1989). They had made underground ice melted near upper limit ofpermafrost layer and increased the unstability of slope surface layers.


The direct effect of degradation of permafrost was that it increased theunstabiIity of constructions on permafrost layers. By increasing the thickness ofseasonal active layers of permanent permafrost, degradation of permafrost hasenhanced amplitude of melting and freezing to the bases of constructions and thencaused asymmetrical subsiding. According to in site investigation in 1990, thedamage of Qinghai-Tibet Highway that had been produced by melting and subsidingof road base had occupied 83% of total damaged road surface (WANG Shaoling andMI Haizhen, 1993).

Degradation of permafrost has also important influence to landscape successionand land use. In permanent permafrost area, obstructed by underground waterprooflayer (permanent permafrost layer), the water in the seasonal active layer providesnecessary water source for surface vegetation. Actually, the fact that permanentpermafrost area has been overlapped with main part of the pasture area on theTibetan Plateau is more or less related to existence of permafrost. When lower limitof seasonal active layers descend, the water can not be restricted in the near surfacelayers. The reducing of usable water content for surface vegetation may acceleratedesertification tendency of grassland. In addition, the thickness increasing ofseasonal active layers may also lead to enhancement of slope unstability, and thenintensify development of freezing-thaw mud-flows and hot karst which will bringdestructive damage to development of vegetation in short period. It is worthy beingnoted that the enlargement of surface land sandification is positively related todevelopment of permafrost degradation (HUANG Yizhi et al., 1993). Both of themare mutually cause and result under the background of climatic warming.

10.2.4 SANDIFICATION

Influenced by continental cold climate of the Tibetan Plateau, intensivemechanic weathering has produced a great number of weathered clastic and finematerials as source for the action of wind and sand. Aeolian sand-gravel lands arewidely distributed on plateau surface while many kinds of wind-formed landformsappear in valleys and lake basins. The land sandification is very rigorous in theTibetan Plateau areas (ZHU Zhenda et al., 1994).

Under the actions of both climate and landforms, the most severe area for landsandification on the Tibetan Plateau are Qaidam Basin, Qinghai Lake Basin, GongheBasin, wide valleys in middle reaches of Yarlung Zangbo and river valleys in westTibet. Start from 30 km west to Mangai, the west end of Qaidam Basin toHuangshatou of Gonghe Basin; the desert zone ranges about 1000 km in length alongE-W direction and 300 km in width along S-N direction. The main types of thiswind accumulative desert include active dunes, fixed and semi-fixed dunes, of whichthe appearance is closely related to recent human activities. Population increasing,land reclamation; over grazing and forest cutting are main causes for landsandification that is derived from human activities. For examples, in Mugetan ofsouthern Guide Basin, the area of wind erosive land has increased 133.05 km2 due toland reclamation from 1977 to 1986 while fixed and semi-fixed dunes have beenbeing active as the rate of 1.48 km2/yr. It is also increased as the rate of 6 km2/yr to


the area of sandified lands in beach of Qinghai Lake (LI Chengzun et at., 1990).Land sandification is relatively severe in wide valleys of middle reaches of YarlungZangbo. During low water period, rich sand materials that are distributed onexposed riverbed are quite in favor of development of wind accumulative landforms.In flood season, the sand brought by river water may be deposited in wide valleyareas due to current slowing and provides new materials for wind accumulation ofnext time (Figure 10-6). Because human activities of this area are most intensive intotal Tibet Autonomous Region, the dangerous degree of sandification is also themost severe compared with the other areas (LI Bingyuan, 1998). It has alreadybrought much influence to agricultural production, road construction and irrigationestablishment. In Sengge Zangbo, Langqen Zangbo and their branches of westTibet, strong wind, dryness and coldness produce intensive mechanic weathering andmake many sand-gravels lands distributed. Though the sand dunes formed by windare small, the other actions of wind and sand are quite intensive such as soil winderoded soil, wind-formed sand current, and sandy accumulation and sand-dust devil.However, their destroy is only limited within covering of grassland and attacking toresident sites due to sparse population (JIN Jiong et aI., 1991).

Figure 10-6 Sandification of land in Yanglung Zangbo river valley

10.3 Discussion and Conclusion

As the Tibetan Plateau is characterized with complex geological andgeographical conditions, different climatic types as well as fragile and harsh basis ofecological environment, different natural hazards unceasingly occur on the Plateauand its periphery areas (ZHENG Du et al., 1996). Due to backward social economyand sparse population, the damage degree of natural hazards is far lower than that in


economically developed regions. However, with gradual economic development,human activities are keeping increased in this fragile environment, which not onlycause a series of natural hazards frequently occur, but also induce manyenvironmental issues (Figure 10-7). In certain degree, the loss and disastrous effectare difficult to retrieve.

@ Debris flows and landslides

=Permafrost area

~ Snow hazards ,;;:. Damage by Pika and Zokor

~ Sandification area

Figure 10-7 Sketch map for distribution of main environmental hazards and relative issueson the Tibetan Plateau

Based upon geological and physic-geographical features and developing degreeof social-economy in different areas of the Plateau, some main natural hazards needto be considered and understood according to their distribution features and damagedegree.

a. Earthquake Hazards frequently occur in on the Plateau surface and itsperiphery areas. This is because the neotectonic movement is very activeaccompanied by uplifting of the Tibet Plateau. However, earthquakes with highfrequency and large area on the Plateau result in lower economic losses than that indeveloped area due to its low population and backward economic situation (LIBingyuan et al., 1996). At present, the study of earthquakes and their activitieshave more contribution to geological theories while it provides a well basis for futuredevelopment and construction on the Plateau.

b. Landslide and debris flow Hazards mainly occur in the southern slope of theHimalaya and the Hengduan Mountains. These areas are situated in periphery ofthe Plateau where a great number of valleys have been deeply cut by rivers. Thesteep slopes and rapid currents are very favorable conditions to the formation and


development of landslides and debris flows. As they are main forest areas of theTibet Plateau and have much more water energy resources, these areas have hugeeconomic development prospect (CHEN Zisheng et al., 1992). Debris-flows havebeen studied both in theories and in large areas' fieldwork. Though the frequencyand scale of landslides and debris-flows in some key areas have been effectivelycontrolled by soil-water preservation, forbidding unorganizingly wood cutting andincreasing some engineering method. However, landslides and debris flows stillseriously imperil road and other engineering constructions, which limit the economicdevelopment.

c. Snow hazards mainly occur on broad plateau surface which is main naturalgrazing grounds. Heavy snow may destroy grazing ground in winter and lead tomany livestock's die due to shortage of natural herbage, and directly destroyproductive and living conditions to local people (LIN Zhenyao, 1992). Thus, theaccurate prediction of snowstorm is very important for resisting snow hazard. Bythis time, the scope of snow hazards, by using remote sensing and GIS method, hasalready been able to be forecast except depth of snowcover.

There are many other environmental issues occurred on the Plateau withincreasing of human activities. Degradation of grassland induced by Pika andZokor are 17 million ha in 120 million ha usable natural grazing ground on thePlateau. This is mainly because over grazing on grassland that leads to quantitativeimbalance among different species of rodents (FAN Naichang, 1992). Damagesinduced by Pika and Zokor are difficult to be controlled as they occur in so largeareas and have been influenced by policies of local governments. By this time, thisproblem has been only controlled in some demonstration areas based upon thestrategy of "appreciate pasture" and some chemical methods. Accompanied withdegradation of permafrost, the increasing of freeze-thaw amplitude keeps destroyingthe road in permafrost areas on the Plateau. In the past, some 10 million RMB (1.2million US dollars) per year are spent in repairing of the Qinghai-Tibet Highway.With study of freeze-thaw mechanism and progresses of engineering experiments,this destruction is being managed by using engineering methods (ZHANGXiangsong and CHEN Xiaobai, 1992). In addition, loss of water and soil, landsandification and desertification are also kept developing in certain areas on theTibetan Plateau. They have already been constructed or will be the threat toagricultural production and economic development.

References

1. CHEN Guichen, PENG Min, ZHOU Lihua, et al., 1995. Influence of the human activity onthe eco-environment of Qinghai Lake Basin and protection countermeasures. In China'sSociety on the Tibetan Plateau (ed.): Proceedings of symposium for the Qinghai-TibetanPlateau and Global Variations, Beijing: China Meteorological Press, 127-134. (in Chinese)

2. CHEN Zisheng, WANG Chenghua and KONG Jingming, 1992. Landslide disasters andmacro-prevention methods in China. In: Shi Yafeng, Huang Dingcheng and Chen Banqin(eds.), Disasters Conditions Analyses and Hazards Reduction Countermeasures for theNatural Hazards in China, Wuhan: Hubei Science & Technology Press, 307-313. (in Chinese)

3. FAN Najchang, 1992. The tendency of major population of injurious mouse and their controlin Qinghai-Tibet Plateau. In: Shi Yafeng, Huang Dingcheng and Chen Banqin (eds.),


Disasters Conditions Analyses and Hazards Reduction Countermeasures for the NaturalHazards in China, Wuhan: Hubei Science & Technology Press, 416-420. (in Chinese)

4. GU Gongxu, LIN Tinghuang, SHI Zhenliang, et ai., 1983. The earthquake list of China (1831BC-1966 AD). Beijing: Science Press, 1-894. (in Chinese)

5. GU Gongxu, LIN Tinghuang, SHI Zhenliang, et al., 1984. The earthquake list of China(1970-1979 AD). Beijing: Science Press, 1-334. (in Chinese)

6. HE Sudi, 1989. Weather hazards of Hengduan Mountains. In: Gao Shenghuai (ed.),Monograph of the studies of Hengduan Mountains. Chengdu: Sichuan Science andTechnilogy Press, 133-139. (in Chinese)

7. JIN Jiong, DONG Guangrong, SHAO Liye, et ai., 1991. Dangers of desertification and itsmanagement of Shiquanhe Town, Arli. Journal ofDesert Research (Zhongguo Shamo), 11 (3):20-26. (in Chinese)

8. LI Bingyuan, 1998. Some problems of desertification on Qinghai-Xizang Plateau. Journal ofDesert Research (Zhongguo Shamo), 18(supp.I): 13-18. (in Chinese)

9. LI Bingyuan, LI Juzhang and WANG Jianjun, 1996. Areal Association of Natural Hazard inChina. Acta Geographica Sinica, 51(1): 1-11. (in Chinese with English abstract)

10. LI Chengzun, SUN Bo, LU Jinhua, 1990. Present status and tendency of the formation anddevelopment of the desert in Qinghai. Journal ofDesert Research (Zhongguo Shamo), 10(4):40. (in Chinese)

11. LIN Zhenyao and WU Xiangding, 1986. Study on the flood, drought and snow hazards ofTibet in the historic period (1765-1980 AD)

12. LIN Zhenyao, 1992. Climatological Analysis of the Snowstorm Damage in Xizang. In: ChinaSociety for Qinghai-Tibet Plateau (ed.), Proceedings of the First Symposium on the QinghaiXizang Plateau, Beijing: China Science Press, 228-234. (in Chinese)

13. LlU Suqing, TANG Bangxing and TAN Wanpei, 1986. Man-made debris flows in thenortheast Hengduan Mountains. In Integrated Scientific Survey Team on the Qinghai-Xizang(Tibet) Plateau, CAS (ed.): Special issue of Hengduan Mountains scientific expedition,Beijing: Beijing Science and Technology Press, 315-318. (in Chinese)

14. LU Ruren, TANG Bangxing, ZHU Pingyi et 01., 1999. Debris flow and environment in Tibet,Chengdu: The Publication House of Chengdu University of Science and Technology, 29-33;79-90. (in Chinese)

15. LUO Defu and MAO Jizhou, 1995. Mountain hazards and management strategies along thesouth branch of Sichuan-Tibet highway (precinct of Tibet Autonomous Region). Beijing:Science Press, 59-116; 179-187. (in Chinese)

16. REN, Jishun, JIANG Chunfa, ZHANG Zhengkun et 01., 1980. Geotectonic and it evolution ofChina. Beijing: Science Press, 80-90. (in Chines)

17. SHI Yafeng et 01., 1964. The glacier debris flow in Guxiang area, Tibet. Chinese ScienceBulletin (6): 542-544. (in Chinese)

18. TANG Bangxing et 01., 1995. Natural hazards and counter-strategy of hazards-reducing inSichuan Province. Chengdu: Chengdu Electronic Science and Technology Press. (in Chinese)

19. YUAN Shengxin, 1993. Discussion of ecological agriculture development of QinghaiProvince. Qinghai Environment, 3(3). (in Chinese)

20. ZHANG Mingtao, LI Mingsen, SHEN Lei, et ai., 1996. Sustainable development of QinghaiXizang (Tibetan) Plateau. In Sun Honglie and Zheng Du (eds.): Formation, Evolution andDevelopment of Qinghai-Xizang (Tibetan ) Plateau, Guangzhou: Guangdong Science andTechnology Press, 297-350. (in Chinese)

21. ZHANG Xiangsong and CHEN Xiaobai, 1992. Studies on disasters of ice-snow andengineering freezing and their prevention. In: Shi Yafeng, Huang Dingcheng and ChenBanqin (eds.), Disasters Conditions Analyses and Hazards Reduction Countermeasures forthe Natural Hazards in China, Wuhan: Hubei Science & Technology Press, 253-258. (inChinese)

22. ZHENG Du, YANG Qingye and LlU Yanhua, 1996. Chapter 6 Natural environment andzones differentiation. In: Sun Honglie (ed.), Formation and Evolution of Qinghai-Xizang


Plateau, Shanghai: Shanghai Science & Technology Press, 262-323. (in Chinese)23. ZHENG Yuanchang and TANG Zhongshi, 1995. Preliminary research on desertification of

grassland in the northeastern Qinghai-Tibetan Plateau, In China's Society on the TibetanPlateau (ed.): Proceedings of symposium for the Qinghai-Tibetan Plateau and GlobalVariations, Beijing: China Meteorological Press, 135-140. (in Chinese)

24. ZHOU Xingmin, 1989. Rational utilization and sustainable development strategy of thegrassland resources on the Tibetan Plateau. In Development of grassland science andgrassland production of China, Beijing: Science Press, 178-181. (in Chinese)

25. ZHOU Xingmin, WANG Qiji, ZHANG Yanqing, et al., 1995. Present condition ofdegeneration grassland, regulation tactics and sustainable development in Qinghai-XizangPlateau. In Haibei Research Station of Alpine Meadow Ecosystem, the Chinese Academy ofSciences (ed.): Alpine Meadow Ecosystem (Fasc.4), Beijing: Science Press, 263-268. (inChinese)

26. ZHU Haizhi, 1993. The key earthquake hazards and the hazard-reducing strategies in China.In: The key natural hazards and hazard-reducing strategies in China (Branch volume). Beijing:Science, 22-76. (in Chinese)

27. ZHU Zhenda, CHEN Guangting et al., 1994. Sandy desertification in China. Beijing: SciencePress, 81-86. (in Chinese)

CHAPTER 11 NATURE CONSERVATION

LI Bosheng

Nature conservation implies the conservation of natural environments onwhich the existence of human beings and other organisms depends directly orindirectly, and the conservation of natural resources that maintain sustainabledevelopment of society and social economy.

11.1. An Outline of Nature Conservation

Natural environments and natural resources do not only exist on the earth'ssurface, they are organically combined together and form themselves into differentecosystems, and jointly make up the biosphere inhabited by human beings. To reachthe goal of natural conservation, it is advisable to adopt following principles for theuse of natural resources: 1) to protect ecosystems and their services on which theexistence of human beings and other organisms depends; 2) to protect speciesdirectly and to ensure resource reserves for sustainable use by human beings; 3) toprotect species genetic diversity and to ensure bio-safety by prudent application ofgenetic engineering organisms (GEOs) and genetic mutant organisms (GMOs); and4) to protect well natural historic mementos.

The Tibetan Plateau is a unique geographic unit formed in the third pole andfeatures numerous globally significant natural heritages, distinctive ecosystems,species and genetic diversities. It is also the place of origin of many Asian big rivers,such as the Yangtze, the Yellow River, the Indus, the Ganges, the Yarlung Zangbo,the Nujiang, and the Lancang River. It is of great importance in world natureconservation. In recent years, reviewed by experts of the World Conservation Union(mCN) and the World Wildlife Fund (WWF), the Himalaya Mts. on the plateauedges and the main part of the plateau have been listed as key "bio-geographiczones" for world nature conservation. For implementing the Convention onBiological Diversity (CBD), the Chinese Government has worked out state plans:"China biodiversity Action Plan" and "China biodiversity: A country study", inwhich the Tibetan Plateau is at a very important position. For example, many areasin the plateau have been listed in the "the Action Plan" as prime protected areasrespectively located in tropical, subtropical and temperate regions of China forestecosystems, such as south plateau, south and north sections of the Hengduan Mts.,the plateau high-cold areas, the Qilian Mts., the Altun Mts., the Hoh Xii Mts., thebird island in Qinghai Lake, and the Zoigewetland in Sichuan. Ecosystems of

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224 LI B. S.

grassland, desert, wetland and waters all on the plateau are of global significance asimportant protected areas. The south section and north section of the HengduanMts., the plateau and mountainous region at the juncture of Xinjiang, Qinghai, andXizang have been listed in "Country Study" as three of the 11 critical regions ofChina's bio-diversity terrestrial key protected areas and they are placed respectivelyin the first three ranks for protection. Obviously, the Tibetan Plateau is of extremelyimportant significance for nature conservation both in China and in the world.

The importance of the Tibetan Plateau in nature conservation has long beenrecognized in Chinese scholars and administrative personnel in differentdepartments of the government. In 1956, at the third session of the First NationalPeople's Congress (NPC), scientists put forward No.92 proposal "asking thegovernment to designate natural forest areas prohibiting on cutting and choppingtimbers in each province and prefecture throughout the country, in order to conservenatural vegetation for scientific studies". As a result, the first bunch of designatednature reserves consisted of those located in the plateau region of Qinghai, Sichuan,and Gan$u provinces. However, due to various reasons, many of these naturereserves (including those in the plateau) were not workable. In 1962, upon thespecial instruction of the State Council "on active protection, management andutilization of wildlife resources", the giant panda, a world-known rare animal,inhabited in the east of the Tibetan Plateau, was first given attention. Consequentlyin 1963, a bunch of nature reserves including Wolong-Wanglang, Nabahe, Baihe oneast edge of the Tibetan Plateau were established. Afterwards, the work on naturereserves was stopped due to the Cultural Revolution (1966-1976). Later, after 1976,the construction of nature reserves was gradually resumed, but mainly forconservation of pandas. In 1979 four more nature reserves inhabited by pandas wereestablished, such as Wolong, Jiuzai Guo, Tangjiahe, etc. In 1985, six nature reserveswere established in Xizang; of which, the Medog Nature Reserve was listed fornational protection. Meanwhile, a group of nature reserves located in the plateauregion of Yunnan, Qinghai, Xinjiang, and Gansu, e.g., Altun Shan Nature Reserve,were established successively. From then on, the construction of nature reserves inTibetan Plateau develops fast. Up to the end of 1997, there were 76 nature reservesin the plateau, taking 8.3% of the total number countrywide then. Of the 76 reserves,16 are designated for national protection, 53 for provincial protection and 9 forcounty protection; total covering on area of 51,631,684 ha, occupying 21 % of theplateau land, far exceeding the proportion that the countrywide terrestrial naturereserves accounts 7.64% of the total Chinese land. According to the national planfor development of nature reserves, more nature reserves will be established inTibetan Plateau where some provincial reserves will be elevated for nationalprotection and some national reserves are ready to be nominated for their inclusionin World Natural and Cultural Heritage Sites. In general, the endeavor of naturereserves in Tibetan Plateau is vigorously developing. (Attached List: A list of naturereserves of Tibetan Plateau).

NATURE CONSERVATION

11.2 Nature Reserves and Type Classification

225

The most important way and approach adopted for attaining the goal of natureconservation is to establish nature reserves and to use them as bases for conductingnature conservation work.

11.2.1 NATURE RESERVES

Nature reserves, used for conservation of natural environments and naturalresources, are a general name of the divided areas of specific values (e.g., naturalareal of rare and precious plants or animals, important natural scenic spots, watersource protected areas, distinctive natural geologic sections or fossil sites, importantnatural or historic locations), and areas set aside to be specially protected andmanaged for education, scientific research, or recreation.

Nature reserves conserve original ecosystems on the earth, and so providehuman beings a natural "background" of ecosystems to understand nature and theirenvironments; nature reserves conserve rich ecosystems, species and their variouskinds of genes. Nature reserves are natural storehouses of biological resources forsustainable development of human society and economy; nature reserves are naturallaboratories for people to probe secrets of nature; nature reserves are also naturalclassrooms to educate the public on ecological and environmental awareness. Inaddition, nature reserves have played an irreplaceable role for conservation ofecological environments for people's recreation, tourism and holidays.

11.2.2 TYPES OF NATURE RESERVES

Nature reserves are a concept in a broad sense. They can be different in object,goal, size, and administration level of protection. According to various speciallydesignated targets, nature reserves are classified for special management. At present,each country has its own classification system and managing law for nature reserves.In 1978, the World Conservation Union (IUCN) strove to work out a unifiedclassification scheme of nature reserves, and so nature reserves are grouped as thefollowing 10 types: 1. strict nature reserve and scientific research reserve, 2. manmaintained nature reserve; 3. biosphere nature reserve; 4. national park; 5. naturalmemorial reserve; 6. land use and landscape reserves; 7. natural resource protectedarea; 8. natural resource management reserve; 9. anthropological reserve; and 10.world natural and cultural heritage site.

Nature reserves in China are under the jurisdiction of various departments; it ishard to classify them into the above types. According to China's concrete situation,nature reserves of the plateau are divided into the following types:

(1) Synthetic (natural ecosystem-type) nature reservesThis type of nature reserve is aimed at full conservation of certain primitive

natural ecosystems, especially those of typical representative significance(horizontal zone or altitudinal belt). It is large in size and so effective for full and

226 LI B. S.

complete conservation of biodiversity within the ecosystem. It is of basicsignificance for its represented zones and so takes the most important positionamong all types of nature reserves. Nature reserves of this type are usually undernational protection and some of them are worthy to be included in the WorldNatural and Cultural Heritage Sites.

As regards ecosystem-types in the Tibetan Plateau, the natural ecosystem-typeconsists of two major types: the plateau high-cold arid, semi-arid and subhumiddesert, steppe, meadow ecosystem-type on the proper and northwestern parts of theplateau and montane humid, subhumid forest ecosystem-type on the southern andsoutheastern edges of the plateau. The first type of ecosystem is a typicalrepresentative of plateau ecosystems. Nature reserves representing this type ofecosystem include the Qiangtang Nature Reserve (Xizang), the Altun NatureReserve (Xinjiang) and the Hoh Xii Nature Reserve (Qinghai). In fact, these threenature reserves link together occupying core areas of the plateau and are dividedinto three only because of different administration. They are all national naturereserves and of global influence. The second is a typical representative of theecosystem-types spread in the transitional bio-geographic ecotone in the TibetanPlateau and its southern and southeastern lowlands. Its examples include the wellknown Mt. Qomalangma Nature Preserve, the Yarlung Zangbo Grand CanyonNature Reserve, the Nujiang Nature Reserve, the Yulong Xueshan Nature Reserve,the Gongga Shan Nature Reserve, and the Jiuzhai Gou Nature Reserve. Thesenature reserves are located at the windward side of the plateau where southwesternand southeastern monsoon can directly reach; topographically there are mountainranges with deep valleys between high mountains; and climatically there is a wetand vertically distinct climate. Obviously, these nature reserves are extremely richin biodiversity, and so as a biodiversity conservation key area has attracted worldattention.

(2) Rare wildlife-type nature reservesThis type of nature reserve is aimed at protection of rare wild animals and

those of specific value. These nature reserves are designated upon habitats ofprotected animal species. Nature reserves specially established for protection of thepanda include the Wolong, Wanglang, Tangjiahe, Fengtongan, Anzihe, andHeishuihe nature reserves. Nature reserves designated for protection of other rareand valuable animals include the Mangkang (Rhinopithecus brelichi, Xizang snubnosed monkey), Baihe (R. roxellanae, Sichuan snub-nosed monkey), Xinlu Hai andLuoji Shan (Cervus albirostris, thorold's deer), Napa Hai and Shenza (Grusnigricollis), Dongjiu (Naemorhedus cranbrooki), and Honggan Ba (Budorcastaxicolor, takin) nature reserves. The Tibetan Plateau has diversified species of rareand valuable animals and they usually live in ecosystems of the same type.Therefore, many nature reserves in the plateau focus their attention on protection ofvarious species of rare animals. For example, the nature reserves at Qianfo Shan,Xiaohe Gou, Sier, Wawu Shan, Baoding Gou, Baiyang, Wujiao, and Zhilei forprotection of pandas, takins, and Sichuan snub-nosed monkeys; at ChangshaGongma for protection of thorold's deers, Tibetan wild asses (Asinus kiang) and

NATURE CONSERVATION 227

Poephagus mutus; at Mosika for protection of thorold's deers and snow leopards(Panthera uncia); at Kasha Lake for protection of black-necked crane (Grusnigricollis) and Mergus squamatus; at Chaqing Songduo for protection of thorold'sdeers and leopards (Panthera pardus); at Zhubalong for protection of Pseudoisnayaur and snow-leopards; at Taxkorgan for protection ofargalis (Ovis ammon) andsnow-leopards; at Qinghai Lake for protection of various species of rare andvaluable waterfowls. This type of nature reserves takes great number and priority ofthe protected areas.

(3) Rare plant species and plant community-type nature reservesThis type of nature reserves is aimed at protection of various rare and valuable

natural plant species, plant communities or vegetation-types. They are quitedifferent in size. In the Tibetan Plateau, the most typical examples of this type ofnature reserves are those nature reserves specially designated for protection of rareand valuable species Picea crassi/olia; similar natures at Bajie for protection ofCupressus gigantea, at Bitahai for protection of sub-alpine coniferous forests, atGuoza Gou for protection of Picea purpurea, and at Huanghe Shouqu for protectionof high-cold meadows.

(4) Natural historical remains nature reservesThis indicates those nature reserves specially designated for protection of

natural historical remains that are formed with non-biological resources such asgeologic sections, fossil sites, volcanoes, thermal springs, karst and glaciers.Because these protected objects usually exist in nature reserves of different types, itis seldom seen in China nature reserves specially designated for any single one ofthem. However, on the east edge of the Tibetan Plateau, the Huanglong Si NatureReserve is aimed at protection of limestone terraces and the Gongga Shan NatureReserve for protection of glaciers. Nature reserves of this type which are scheduledfor construction before long will be at Qiangtang in Gongga County for protectionof crustal suture, at Yaba in Dagze County for protection of karst landforms, atMaxiang in Doilungdeqen County for protection of stratigraphic non-conformitycontact, at Burang for protection of palaeontological remains, and at Dagejia inAmen County for protection of terrestrial thermal geysers.

(5) National parksNational parks are the areas of beautiful scenery and tourist attraction, and

with many natural historical remains, rare species, and valuable cultural heritages asprotected objects. This type of nature reserves, besides well keeping their protectedobjects, should set aside some area for tourists, students and scientists. In theTibetan Plateau, many protected areas should be defined to this type of naturereserves. However, at present in China, only national forest parks are namednational parks. Speaking about the functions, in fact, the Jiuzhai Gou NatureReserve in Sichuan should be a good example of national parks. Yulong Xue Shanin Yunnan, Mengda in Qinghai, and Siguliang Shan in Sichuan should also be putinto this type of nature reserves.

It is necessary to pointed out: mentioned above types of nature reserves are notabsolutely delimitated. Many nature reserves are designated for multiple purposes,

228 LI B. S.

so they should be put into a certain type of nature reserves upon their prime goalsand conservation tasks. In the near future, when our conservation undertakings havemore collaboration with other countries, nature reserve types will definitely begradually modified. In general, absolute conservation can only be adapted to a fewnature reserves. To most nature reserves, besides well keeping their protectedobjects, they should be partially open to the public. In this way, they can meet withneeds of tourism on the one hand, and they can actually display their function toimprove ecological and environmental services to the public on the other hand.From this point of view, many nature reserves should be turned to be national parks.

11.3 Typical Nature Reserves

Among 77 nature reserves of the Tibetan Plateau, Mt. Qomolangma NaturePreserve (QNP), Altun Shan Nature Reserve (ASNR) and Qinghhaihu Niaodao(Birds Island) Nature Reserve (QNNR) are selected representatives and describedas follows:

11.3.1 MT. QOMOLANGMA NATURE PRESERVE (QNP)

The Mt. Qomolangma Nature Preserve falls in the four counties: Tingri,Gyirong, Nyalam, and Dingye in southern Xizang on the northern slope of the mainHimalaya Range. It is situated at 27°48'-29°19'N latitude, 84°27'-88°00'E,longitude covering an area of3,391,022 ha (LI Bosheng. 1993).

Principal landforms of the QNP are extreme highland of the main HimalayanRange, plateau and lake basin in southern Xizang. The former consists of loftymountains with deep valleys between. The mountains are 6,000-8,000 m inelevation while the valleys are 1,400-2,400 m, the relative height-contrast is 6000m. Dozens of mountains in the QNP are over 7,000 m in elevation and 5 ofthem areover 8,000 m; of Which, Mount Qomolangma is the highest peak in the world.Among these mountains, many big continental glaciers have been formed. Thelatter is composed of the undulating land of plateau and lake basins at elevationsbetween 4,500-6,000 m asl. Geologically, stratum of southern part of the preserveis formed by badly weathered crystalline rock of the Proterozoic Era while that ofthe north is formed by marl, sandstone, slightly weathered shale, and slate ofsuccessive marine deposits from the Cambrian period to the Tertiary period.Climatically, the QNP varies greatly. It has a warm and moist tropical to subtropicalmontane monsoon climate in the southern deep valleys, with an annual meantemperature of 11°C (6.3°C in January and 17.3°C in July) and an annual rainfall of2802 mm; pedologically, from down to up it has mountain yellow soil, mountainyellow-brown soil, mountain brown soil, sub-alpine gray soil, alpine meadow soil,and alpine tundra soil. In northern part of the preserve, there is a cold, semi-aridplateau climate, with an annual mean temperature at 0.7°C (-II.3°C in January and10.9°C in July), an annual rainfall of 236.2 mm and a relative humidity of 45%;pedologically, from down to up, it has alpine steppe soil, alpine meadow soil, and


alpine tundra soil. The Pengqu River, 384 km in length, the longest river in thepreserve, rises from Mt. Xixabangma, runs west-eastwards through the wholePreserve, takes a sudden tum southwards at Xining and flows into Nepal viaChentang. In addition, there are other rivers of Indian Ocean water system in thePreserve, such as the Rongxiaqu and Boqu rivers. North of Mt. Xixabangma, PaikuCo is the largest lake in the Preserve, covering an area of300 km2

•

Floristically, the QNP has 2348 species of vascular plants; of which, 2106species are angiosperms, 20 species gymnosperms, and 222 species pteridophytes.In addition, it has 472 species of bryophytes, 172 species of lichens, and 136species of fungi. Phytogeographically, the QNP flora mainly possesses SinoHimalayan elements of the Holarctic flora, and elements of north temperate andarctic-alpine floras. In addition, it has a few tropical elements of the Indo-Malayanflora in the south low-altitude valleys. The QNP consists of two major ecosystems:the one in southern Himalayas is subtropical moist montane forest with evergreenbroadleaved forests as its base zone, while the other in northern Himalayas ofsouthern Xizang is composed of temperate arid scrubs and steppes. Those twomajor ecosystems are vertically destinct: the former, in an order from valley bottomto ultimate of the mountain, has the distribution of montane subtropical evergreen,semi-evergreen broad-leaved forest belt dominated by Castanopsis hystrix andCyclobalanopsis lamellosa, montane (warm) temperate needle-leaved and broadleaved mixed forest belt dominated by Tsuga dumosa and Quercus semicarpifolia,sub-alpine coniferous forest belt composed of Abies spectabilis and apline sub-coldbelt dominated by Rhododendron spp., Sabina spp. and Artemisia spp.; the later, inan order from the plateau surface to ultimates of the mountains, has the distributionof plateau temperate scrub-steppe belt dominated by Caragana tibetica, C.versicolor, Sabina pingii var. wilsonii, Pennisetum flaccidum, Orinus thoroldii, andStipa purpurea, plateau temperate scrub-steppe belt dominated by Artemisia spp.,alpine meadow belt dominated by Kobresia spp., subnival belt and nival belt bothcomposed of sparse plants. The QNP's ecosystem diversity makes the rise of its richplant diversity. Many plant species in the QNP take priority for national protection,which include Magnolia wilsonii, Tetracentron sinense, Trillium govanianum, Piceasmithiana, Pinus roxburghii, Taxus wallichiana, Begonia yunnanensis, Panaxpseudo-ginseng, Picrorhiza scrophulariiflora, Sinopodophyllum emodi, Castrodiaelata, Dendrobium candidum, etc (LI Bosheng 1994b).

The QNP has 283 species of vertebrates; of which S3 species are mammals,206 speecies birds, 6 species reptiles, 8 species amphibians, and 10 species fishes.Zoogeographically, the QNP fauna is situated at boundary of the oriental realmfauna and the paleo-arctic realm fauna and so it possesses elements of the bothfaunas. The following QNP animals enjoy priority for national protection: Presbytisentellus, Macaca assamensis, Hemitragus jemlahicus, Panthera pardus, P uncia,Asinus kiang, Crus nigricollis, Haliaetus leucogaster, Tragopan satyra,Lophophorus impejanus; Ailurus fulgens, Ursus arctos, Selenarctos thibetanus,Aonyx cinerea, Lynx lynx, Moschus sifanicus, M cephalophus, Naemorhedus goral,Capricornis sumatraensis, Procarpra picticaudata, Ovis ammon, Pseudois nayaur,

230 LI B. S.

Felis chaus, F temmincki, F bengalenses; Tetraogallus tibebanus, Ithaginiscruentus, Lophura leucomelana, Gyps himalayensis, Aquila rapax, Strix aluco, etc.Among them, Presbytis entellus, Hemitragus jemlahicus, and Macaca assamensisare Himalayan endemic species or subspecies, very rare and encountered only in theHimalayas. However, the most conspicuous rare animal in the QNP is the snowleopard (Panthera uncia), which is endemic to Middle Asia, with a wide range butmainly concentrated in the QNP.

Approved by the People's Government of Tibetan Autonomous Region inOctober 1988, the QNP was established as a nature preserve of the TibetanAutonomous Region; on April 4, 1994, it was elevated to a national class preserve.

1. Demarcation The QNP is located in southern Tibet, linking withinternational boundary between China and Nepal in the south, extending to thewatershed of the Yarlung Zangbo River (in Gyirong County) and the southern Tibetdivide (in Tingri County) in the north, bordering the divide of the Dangqu and Haqurivers, the divide of the Pengqu tributary-the Yarlung Zangbo River and the lowerreaches of the Jibonong river, and the watershed of the Pengzuopuqu andNadongzawu rivers in the east, and linked with the divide of the Awagaqu,Wengboqu, and the Sangzuoqu and Xiyuedezangbo rivers in the west. In the QNP,Tuolonggou, Rongxia, Xuebogang, Jiangcun, Gongdan, Xixabangma andQomolangma are designated as core zones; Chentang, Pazuo-kada, Nyalam,Gyirong and Gongdan are designated as buffer zones, and Tingri as a peripheralzone (LI Bosheng, 1994a).

2. Institutionalframework The QNP Working Commission is formed witha vice secretary general of the Autonomous Region Government as the director, andthe leaders of other related departments (forestry, environment, education, science& technology, tourism, physical culture & sports, culture; public health, etc.) asmembers. Under the Working Commission, there are specialists groups, an office,and the QNP Management Bureau. In the Management Bureau, there are 7 staffmembers who are responsible for practical management of the preserve. Under theQNP Management Bureau, there is a branch with 3-5 workers in each of the fourcounties.

3. Activity Mt.Qomolangma is one of world's greatest tourist attractions,and so tourism is the QNP's major business, while developing the manufacture ofcommodities characterized by local minorities for tourists comes second.

11.3.2 ALTUN SHAN NATURE RESERVE (ASNR)

The ASNR, located in the Nanshan region of Ruoqiang County, southeast ofUyqur Autonomous Region of Xinjiang, lies in great depressed basin on northernslopes of the Kunlun Mts., south of Taklimakan Desert and Qaidam Basin, at thenorthern edge of the Tibetan Plateau, approximately at 36°-37°48'N latitude and800 10'-90o18'E longitude, occupying an area of 4,500,000 ha.

Topographically, the ASNR is a plateau basin, at elevations from 3876 m ofAyakkum Lake in the north to 6973 m of Mt.Muztag in the southwest, meanly 4500


m; with about 100 mountains over 5000 m as!. In center of this great-depressedbasin, there are two lake basins asymmetrically separated by hilly lands, whichmake landforms of the ASNR "small basins within a big basin". Most area of theReserve is covered by alpine, sub-alpine meadow-steppes; in the south, the areaabove 6000 m is occupied by glaciers, snow, or naked rocks; in the north, there is alarge area of high-cold desert inlet with naked rocks, alpine scrubs, meadow steppes,plateau sandy desert, rivers, lakes, swamps, volcanic orifices, and weathered castles.In the Reserve, there is a development of ancient Karst, which does not match withmodem climate.

The ASNR has a climate of plateau features: cold, dry, windy, intensiveevaporation, frosty all year round; annually, with a cold season and a short humidand warm season; with a diurnal mean temperature at O°C in low altitude areas, anda maximum diurnal temperature from -2 to 2°C in July-September; yearly rainfallvaries from 100 to 200 mm. Impacted by Taklimakan Desert, north and northwestparts of the ASNR is extremely arid. Owing to basin-shaped landforms, the Reservetakes the two big lakes as its home water system: Aqqikkol Lake in southwest andAyakkum Lake in northeast, both inlets by some small lakes. River runoff variesgreat seasonally, when ice melts, it varies daily. Spring water can provide stablewater current that is of great importance to wildlife and local people. ShaziquanSpring, at foot of northern slopes of Mt. Kumukul, has three mouths at an elevationof3920 m, one of the three is over 200 m in diameter and the other two about 50 m.Among the 5 lakes in the Reserve, Aqqikkol and Ayakkum are saltwater lakes;Yixikepati and Kelakuk are fresh water lakes; and Jingyu Lake in southern Reserveis a fresh water minilake at the inlet, and a big saltwater lake at its main body.Glaciers and melted snow are main source of rivers and spring water in the Reserve.

The ASNR has 241 species of vascular plants in 92 genera of 27 families,dominated by the species of the Gramineae, Compositae, Cruciferae,Rannuculaceae, and Cyperaceae, and 6 species new on record. Floristically, theASNR falls in the transitional zone between the Middle Asia desert sub-region andthe Tibetan Plateau vegetation region. Its flora possesses mainly elements of MiddleAsian desert flora at low altitude region, and elements of the Tibetan flora at highaltitude region. Northern edge of the basin is drier than southern edge; hence, semifrutex desert occurs in front of mountains north of the basin, and alpine steppeappears south of the basin. In the Reserve, the coverage of vegetation in the east islarger than that in the west. Upper limit of vegetation is at permanent snowline,approximately 5,000-5,500 m as!. In the ASNR, vegetation is classified into 10units as follows:

(1) Wet salt meadow, appearing by springs, lakes, and riversides, north andeast of the Reserve;

(2) Wet paludal meadow, occurring by springs, lakes and riverside, east, andnorth of the Reserve;

(3) Dune vegetation, distributed in center of the Reserve;(4) Dwarf semi-frutex desert, occurring in valleys of 4.050-4,200 m, north and

east of the Reserve;

232 Ll B. S.

(5) High-cold desert, occurring in north and northeast of the Reserve; it is atransition at the zone from dwarf semi-frutex desert up to polar cold desert;

(6) Polar cold desert, developed on mountain slopes above 4350 m, north andeast of the Reserve

(7) Desert grassland, occurring in low hilly land and valley bottoms at4,050~4,200 m asl;

(8) Cold, arid steppe, appearing in center of the Reserve at 4,200~4,350 m asl,which is slightly subhumid than desert grassland;

(9) Polar cold grassland, found in east and center of the Reserve at4,200~4,400 m asl.

(10) Alpine cushion vegetation, occurring at 4,400~4,500 m asl in upper partsof mountains.

The ASNR has 63 species of vertebrates; of which, 29 species mammals, 34species birds, and I or 2 species reptiles; in addition, about 250 species of insects.Among these animals, Ovis ammon, Lemmus sibiricus and Aquila chrysaetos,belonging to Middle Asia bio-geographical community, are mainly distributed innorth of the Reserve, while Equus kiang, Pantholops hodgsoni, and Poephagusmutus, belonging to the Tibetan Plateau bio-geographical community, mainlyappear in south of the Reserve. Among the mammals, Pantholops hodgsoni has thegreatest population, approximately 70,000-100,000 individuals, found on slopes, ingrassland, deserts, and sand dunes in the Reserve from 3,900 to 4,400 m. Asinuskiang comes second, it has a total population of about 30,000, found in steppes from3,900 to 4,400 m, its largest population can be up to 500 individuals, it lives in thewest in spring and summer, and migrates to the east at lower altitudes in winter.Ovis ammon has a population less than 10,000, mainly appearing in inaccessiblehigher mountains; Procapra picticaudata less than 10,000 individuals, found in theeast of the Reserve; Pseudois nayaur, a population of about 10,000 individuals,found in rugged mountains; Ochotona curzoniae has the biggest population amongrodents of the plateau type. The representatives of birds include Anser indicus,Tetraogallus tibetanus, Grus nigricollis, Larus brunnicephalus, Syrhhaptestibetanus, Melanocorypha maxima, etc.

The ASNR has relatively less species of insects. Impacted by naturalconditions, insects present some adaptive features such as small in figure, dark incolor, weak in flying, with a thick coat, and mostly are terrestrial inhabitants.

In the ASNR, the national class protected animals include Poephagus mutus,Asinus kiang, Pantholops hodgsoni, Capra ibex, Panthera tigris, Grus nigricollis,Aquila chrysaetes, Procarpra picticaudata, Ovis ammon, Pseudois nayaur, LynxLynx, Felis manul, Martes foina, Ursus arctos, Tetraogallus tibetanus, Frlcocherrlug, etc.

The ASNR was established and elevated to a national class reserve in January1983.

1. Demarcation Upon goals of the Reserve, the ASNR is composed of acore zone and a buffer zone; the buffer zone is located in the northeast of theReserve, where there is a designated game-preserve.


2. Institutionalframework The Reserve has 4 protection stations: oneseasonal protection station in the core zone, two perennial and one seasonalprotection stations in the buffer zone.

3. Activity In the ASNR, a supper basic rock as long as decades of km wasdiscovered; a east-westward hundreds-kilometer long fracture is recognized as animportant regional physical boundary; the discovery of large scale alpine steppe andalpine meadow soil is a new evidence for meteorological study. The glaciers, snowcapped mountains, 10,000 km2 ancient karst landforms, plateau lakes, springstreams, and deserts constitute a peculiar landscape of the ASNR. The scatteredhistorical remains left over by human activities are of important significance tomultidisciplinary scientific studies.

11.3.3 QINGHHAIHU NIAODAO (BIRDS ISLAND) NATURE RESERVE(QNNR)

The QNNR (approximately 56,000 ha) is situated on the northern bank of themouth of the Buha River northwest of Qinghaihu (Qinghai Lake) in Gangca County,northeast of the Tibetan Plateau, at 36°45'-37°10' N latitude and 99°55'-100 °35' Elongitude (Figure 11-1).

Figure 11-1 Photo of the Bird Island (photo by ZHENG Du)

234 LI B. S.

Qinghai Lake is the largest inland saltwater lake in China. The Riyue, Datongand Qinghai Nanshan Mts surround Qinghai Lake, extending southeastnorthwestward 106 lan, northeast-southwestward 63 km, covering an area of 4340lan2• Birds Island falls in the northwest of Qinghai Lake, with large patches ofswamps and wet grassland along edges of the Lake. Embraced by lake water andwith smooth terrain, this inaccessible, quiet, and secluded island is an idealecological environment for conservation of birds. The Reserve has a continentalsemi-arid climate with annual mean temperature at 4°C, from -13°C to -15°C inJanuary, and II-13°C in July, and an annual rainfall 336.8 mm. From December toMarch next year, the lake is ice-bounded and the ice cover can be as thick as 60~80

cm.The water of Qinghai Lake comes from the Buha River, Shale River, and many

other streams that originate from the melted snow in southern and northernmountains. Because of desiccation tendency, Qinghai Lake is gradually shrinkingand the depth of its water has dropped from 31 m to 27 m.

The QNNR has over 1,000,000 migratory, resident, and traveling birds of morethan 100 species of 32 families in 14 orders. Anser indicus has the largestpopulation of approximately 2300 pairs, Phalacrocoray carbo over 500 pairs, Larusbrunnicephalus, 6,500 pairs, L. Ichthyaetus hundreds of pairs, and other preciousfowls including Mergus squamatus, Ayth ya, Tadorna terruginea, and Thalasseaszimmermanni. In Qinghai Lake, there is only one species of fish, i.e. Gymnocyprisprzewalski,i which is imperative as a food for birds.

In the reserve migratory birds are main waterfowls, both summer and wintermigratory birds. The reserve is also inhabited by traveling birds especially eaglesand ducks when they pass there in spring and autumn. The investigation taken placein April 1984, found that there were only 1,000 individuals of Anser indicus, 600birds of Tadorna terrugine, 400 individuals of Anas acuta, 2,000 birds of Ayth ya,150 individuals of Copsychus saularis pros-thopellus and 25 birds of Mergussquamatus. From late March to early April every year, Anser indicus,Phalacrocorax carbo, Larus brunnicephalus and Grus nigricollis fly here toreproduce and brood. Anser indicus with thick feather does not adapt itself to hotand rainy summer in the south and needs a cooler, quiet and open place withplentiful water and plants for reproducing offsprings. In this reserve, Grusnigricollis, Haliaetus leucogaster, and Cygnus cynus have the first priority fornational protection.

The QNNR has about 50 species of vascular plants and all of them areherbaceous. Wet grasslands and swamps are dominated with Aneurolepidiumdasystachys, Poa tibetica, Stipa spp. and some plants of the Cyperaceae,Compositae, and Chenopodiaceae. Along lake bank, there are short willows. And inshallow area of the lake there is a lush growth of aquatic plants, such as Typha spp.and many plankton, which provides plenty of food for birds and the bird dungfertilize the soil and vegetation; consequently a natural eco-circulation system isformed.

The QNNR was established as a provincial nature reserve in 1976 and was


elevated for national protection in 1997.1. Demarcation The QNNR is composed of Birds Island, Haixinshan,

Guchashan, Shadao, Erlangjian, Quanwan, Haixipi, Yuoutan (Anser ichthyaetusshaol), wet grassland and swamps from Laduoze to Birds Island.

2. Institutional Framework An administration office was set up especiallyfor management of the Reserve, which is under the Agriculture and ForestryAgency of Qinghai Province.

3. Activity The QNNR administration office has a small Management andResearch Station. In 1987 an observation post was established in the mainreproduction area of eagles and gulls. The Northwest Plateau Institute of Biology,Chinese Academy of Sciences has conducted studies on wildlife and meadowecosystems of Qinghai Lake. In 1983 the National Bird Banding center did bandingon Anser indicus and Larus brunnicepualus.

11.4 Rare and Precious Wildlife

Composition of biodiversity in Tibetan Plateau is characterized by abundantendemic species. Many of them are relic species in local habitats and endemicspeciation in specific habitats. Owing to narrow distribution areas with rarepopulation, most of them are becoming rare and precious species. More than 80species of animals belong to rare, precious and threatened species. Representativesof them are as follows:

11.4.1 SNOW LEOPARD (PANTHERA UNCIA)

China national first class protected animal; Order Carnivora, Family Felidae;fur is long, gray-brown; the body and tail are spotted with solid circles; length ofhead and body about 1.3 m, tail 0.9 m. It is mainly distributed in northwesternChina, the Tibetan Plateau, Russia, Mongolia, Nepal, Bhutan, and Pakistan;appearing in rugged mountains at elevation of 3,000-6,000 m asl; the male andfemale often stay together, active at night. It feeds Pseudois nayaur, Moschus spp.deers, hares, and birds. The snow leopard is a typical alpine and plateau animal ofthe paleoarctic realm. Its existence is mainly threatened by decline of population ofherbivorous animals (the proportion of the snow leopard to Pseadois nayaur inquantity for ecological balance should be 1:200). Hunting also jeopardizes theexistence of the snow leopard because of its economic value lying in its beautifuland cold-resistant fur and its medicinal value lying in its bone that is used as asubstitute for tiger's bone. At present, the Qomolangma Nature Preserve (QNP) ofChina has the largest population of the snow leopard. After the establishment of theQNP, the wildlife has been effectively protected. Consequently, Pseudois nayaur isgradually increasing in population and the snow leopard is also increased in number.In addition, the snow leopard is also distributed in the nature reserves in Qiangtang,Altun Shan, Hoh Xii, Qilian Shan, and Taxkorgan (FENG Zuojian, et al., 1986).

236

11.4.2 PANTHOLOPS HODGSONI

LI B. S.

China national first class protected animal; Order Artiodactyla, FamilyBovidae; length of head and body up to 120 cm; shoulder height 100 cm; weight 70kg. The horns, present in males, flat at lateral, pitch-black and shiny, with about 20arched ridges all over, except at the tip, length 60-70 cm. The nose is hairy at thetip; the big nostril slightly curves down, inside with dilators and developed groinglands. The hoofs are small at the tip. The males have big mouths, free from glandsin eyes and feet; the body yellowish-brown, with dense reddish-brown hairs on theback and white on the underside. The males are black on the face, white on the headand neck, gray-white on the four legs, and with dark-brown or black wrinkles on thefront of the face. This animal is sharp-witted, always gathering in groups. In thematting season (late winter), many individuals get together, a magnificent sight isformed when the males are fighting for females. In June every year, the pregnantfemales move in groups to the wild hinterland on the Plateau and after a gestation of6 months deliver a single young. Pantholops hodgsoni is endemic to China,concentrating in northwest Tibetan Plateau where is covered by cold steppes anddeserts. Although the species has not reduced to a dangerous low population, itsexistence is threatened by hunting for its wool that is sold in international marketsat high prices. In recent years illegal hunting is getting more serious, at least up to10,000 individual were killed for wool in the past decade. Hence, it is highlynecessary to adopt effective measures for protection of this endemic species. In thenational nature reserves at Qiangtang, Altun, and Hoh Xih, protection of this animalhas obtained remarkable results by strengthening patrol and applying severesanctions on illegal hunting. However, owing to the wide range, the effectiveprotection of Pantholops hodgsoni is directly inhibited by inadequacy of labor,funds, vehicles, and communication facilities (FENG Zuojian et al., 1986).

11.4.3 WILD YAK (POEPHAGUS MUTUS)

China national first class protected animal; Order Artiodactyla, FamilyBovidae; adult shoulder height up to 1.6 m; weight 500-1,000 kg; the appearance issimilar to that of a domestic yak. It is ancestor of domestic yak. It has no dewlap onthroat but a flesh ridge on center of the shoulder and flat on the hind part. It ismuscular and heavily built with stout legs. Its hoofs are small but solid as rock. Thebody is dark brown; the head and back are covered with short, glossy hairs; a palestripe-shaped pattern running across the back ridge; brown and white hairs mixedon the mouth and nose. Old individuals are gray on the face, red on the back; theunderside including the neck, chest, and the hind part are covered with long anddense hairs; hairs on the tail are drooping to the hoofs, length of hairs on theunderside is up to 70 cm. The horns are rounded with a broad base and are presentin both sexes. This animal gathers in groups that can be of several up to hundredindividuals. In summer it looks for food in high mountains at elevations of5,000-6,000 m asl and in winter it feeds in alpine meadows at 3,000-4,000 mas\.


Breeding happens in late autumn. Gestation lasts 8 or 9 months, after which a singleyoung is born. This rare and precious animal is endemic to the Tibetan Plateau, andmainly lives in nature reserves at Qiangtang, Altun, and Hoh XiI, Qiangtang withmore individuals. Threatened by grazing and hunting activities, Poephagus mutus isgradually migrating to hinderland of the Tibetan Plateau where natural conditionsare even worse. Its population is extinct in headwater areas of the Yarlung ZangboRiver. In past decades, its range gradually shrunk that endangers its regeneration. Inrecent years the above mentioned nature reserves made great efforts to natureconservation and so the population of this animal is increasing (FENG Zuojian etal., 1986).

11.4.4 TIBETAN WILD ASS (ASINUS KIANG)

China national first class protected animal; Order Perissodactyla, FamilyEquidae; length of head and body 2.3-2.4 m; shoulder height about 1.3-1.4 m;weight up to 300 kg. The head is slightly short and broad; the mouth is slightlyrounded; Hairs on the neck are short and straight. It is heavily built with stout legs.Lips are milky white. Inside of ears there are dense white hairs. Hairs are brownishon upside, yellow-white on underside, slightly paler on legs than that on upside,milky white on inside of legs, and drab-brown on the tail. From shoulder to tail, theupside is barred with a distinctive brown stripe. Wild ass is good at running, it canrun 40-50 km without a break; the fastest speed can reach up to 60 km. They live ingroups. In late autumn, it gathers up to hundred individuals and migrates southward.Matting in August and September, after II-month gestation, a single offspring isborn. This rare and precious animal is endemic to the Tibetan Plateau and is onlyconfined to this region. Economically, wild ass is less valuable than Tibetanantelope and wild yak, and so it is seldom subject to illegal hunting. It has a fairlywide range. Besides in nature reserves at Qiangtang, Altun, and Hoh Xii, it alsoappears in Xainza County and in the Qomolangma Nature Preserve on northernslope of the Himalayas. Owing to strict protection offered to wildlife in the QNP,wild ass has been reproduced up to hundreds of individuals that often look for foodand stay pleasantly with domestic animals in the vast grassland of Paiku Co. It is awell-known tourists landscape. Along with development of nature conservation inthe Tibetan Plateau, this animal of graceful shape and magnificent groups will be avaluable source for eco-tours in the plateau. At present, its population is growing inthe QNP and they often go to nearby vi11ages and eat crops there. This has caused aproblem to local inhabitants. Wild animals fight for grassland with domesticanimals is another problem. All these new issues are highly necessary to be studiedand solved for development of nature conservation in the Tibetan Plateau (FENGZuojian et al., 1986).

11.4.5 BLACK-NECKED CRANE (GRUS NIGRICOLLIS)

China national first class protected animal; Order Gruiformes, Family Gruidae;

238 LI B. S.

length of head and body 120 cm; bill 12 cm; weight of male about 7 kg, femaleabout 5 kg. This bird is named after its black and long neck. Its black head has anorange crown that is smaller in size and darker in color as compared with that onthe head of red-crowned crane. It is generally gray-white, but black on the wingbars,tail, bill and legs. Omnivorous, mainly plants, especially underground parts. Blacknecked crane is a migrate bird; in October it flies to Yunnan and Guizhou, andspends winter there; in summer it flies back to the Tibetan Plateau and doesbreeding in swamps by lakes there. It is the only crane that can breed in the plateau.Nest is built at herbage in swamps by lakes; internal diameter of the nest 40 cm,external diameter 100 cm, depth 7-8 cm; laying eggs about one month; baby cranesalways fight violently and generally only one can survive. Genus Grus has 15species and Grus nigricollis is the smallest member in population. It is a valuablewild bird both to China and to the world. In 1993, in Xainza County of Xizang a4,000,000 ha nature reserve was established as a breeding base of black-neckedcrane and a nature reserve was especially designated for protection of the plateauwetland ecosystems. Before then, in 1992, in Luqu County of Gansu Province,Gahai nature reserve was established especially for protection of black-neckedcrane and the swamp wetland; in 1986, in Yushu County of Qinghai Province,Longbao Black-necked Crane Inhabit Nature Reserve was established. Naturalpopulation of black-necked cranes is increasing and they are now always found inwinter in the valleys of the Yarlung Zangbo River and its tributaries (ZHENGZuoxin et al., 1983).

KUlllun )1(5.

90'

.0'

.,'

9S'·

100'

)0

Figure 11-2 Main nature reserves in the plateau

References


1. FENG Zuojian, et al., 1986. The Mammals ofXizang. Beijing: Science Press. (in Chinese)2. lIN lianming, 1991. An Introduction to Nature Conservation. Beijing: China Environmental

Science Press. (in Chinese)3. LI Bosheng, I984.Vertical Vegetation Spectrum in Mount Nangabarwa Area. Mountain

Studies 2(3): pp. I74-289. (in Chinese)4. LI Bosheng, 1988.Semi-broadleaf forest in south slope of east Himalayan Range .Journal of

Botany 27(3): 334-336. (in Chinese)5. LI Bosheng, 1993. A Preliminary Evaluation of the Mount Qomolangma Nature Reserve.

Journal ofNature Resources. 8(2): 97-104. (in Chinese).6. LI Bosheng, 1994a. Integrated regionalization of the Mt.Qomolangma Nature Preserve. In:

East Asia Covered with Green Colour, 529-546, Beijing: China Environmental SciencePress. (in Chinese)

7. LI Bosheng, 1994b. On the ecosystems of the Qomolangma nature consesvation. In: EastAsia Covered with Green C%ur, 670-687, Beijing: China Environmental Science Press.(in Chinese)

8. LI Bosheng, 1996. Biodiversity of the Qinghai-Xizang Plateau and its conservation.Protected Areas and Nature conservation in East Asia A Joint Publishing (Hong Kong)Company Limited, 215-264.

9. LIU Donglai, 1996. Nature Reserves in China. Shanghai; Educational Press. (in Chinese).10. SHEN Zhibao, 1984. Meteorology in Xizang. In: chapter 5. Meteorology Zoning of Xizang

(Tibet). Beijing: Science Press, 142-170. (in Chinese)11. State Environmental Protection Administration of China. I994. China Biodiversity

Conservation Action Plan. Beijing: China Environmental SCience Press.12. State Environmental Protection Administration of China. 1998.China's Biodiversity Study.

Beijing: China Environmental Science Press.13. YE Duzheng, Gao Youxi, 1979. Meteorology of the Qinghai-xizang (Tibet) Plateau. Science

Press. Beijing. (in Chinese)14. YANG Yichou, GAO Dengyi, LiBosheng, 1989. Study on the Moisture Passage on the

Lower reaches of the Yarlung Zangbo River. Science in China (series B). 32(5). PP.580-593. Beijing.

15. WU Zhenyi, 1987. Source and Transformation of Tibetan Flora. Vo1.5. Beijing: SciencePress, 580-593. (in Chinese)

16. ZHENG Zuoxin et al., 1983. The Avifauna ofXizang. Beijing: Science Press. (in Chinese)

240

Attach List

LI B. S.

List of the Nature Reserves in The Tibetan Peateau(by the end of 1997)

No Name ofNature Location Area (ha) Categories Estab. Grade SectorReserves year

Sichuan Province, Number of nature reserves: 38, Area: 2,S93,888ha

01 Longxihongkou NR Dujiangyan City 34,000 FE 1993 P EP

02 AnziheNR Chongqing County 11,000 WA 1993 P FO

03 HishuiheNR Dayi County 31,800 WA 1993 P FO

04 Xiaozhaizigou NR Beichuan County 6,725 WA 1979 P FO

05 Piankou NR Beichuan County 83 WA 1993 P FO

06 WanglangNR Pingwu County 32,297 WA 1963 P FO

07 Qianfoshan NR Beichuan County 17,700 WA 1993 P FO

08 Xiaohegou NR Pengwu County 13,800 WA 1993 P FO

09 SierNR Pengwu County 26,000 WA 1993 P FO

10 Tangjiabe NR Qingchuan County 40,000 WA 1978 N FO

11 LabaheNR Tianquan County 23,872 WA 1963 P FO

12 Fengtongzhai NR Baoxing County 39,039 WA 1979 N FO

13 Wuolong NR (21)· Wenchuan County 200,000 WA 1975 N FO

14 Baodingqou NR Maowen County 19,600 WA 1993 N FO

15 Huanglongsi NR Songpan County 40,000 WA 1983 P FO(25)

16 BaiyangNR Songpan County 76,700 WA 1993 P FO

17 Jiuzhaigou NR (22) Jiuzhaigou County 60,000 WA 1978 N FO

18 Baihe NR (23) Jiuzhaigou County 20,000 WA 1963 P FO

19 Wujiao NR Jiuzhaigou County 16,200 WA 1993 P FO

20 Xiaman NR Zoige County 176,000 WE 1994 P FO

21 Tiebu NR (24) Zoige County 20,000 WA 1983 P FO

22 Gonggashan Mts. Kangding , Luding 400,000 FE 1997 N CNNR (26) Counties

23 Jintangkongyu NR Kangding County 23,600 WA 1995 C FO

24 MosikaNR Danba County 13,700 WA 1995 C FO

25 HongbaNR Jiulong County 36,000 WA 1995 C FO

26 Siguniangshan Mts. Xiaojin County 48,500 WA 1996 N EPNR

27 Kashahu NR Luhuo County 120 WA 1985 C. CN

28 Gexigou NR Garze County 19,200 WA 1987 C OT

29 Xinluhai NR Dege County 287 WA 1987 C OT

30 Queershan NR Dege County 24,500 WA 1987 C OT

31 Chaqengsongduo NR Baiyu County 50,200 WA 1995 P FO


32 Luoxu NR Serxu County 155,400 WA 1995 P Fa33 Changshagongma Serxu County 669,800 WA 1995 P Fa

NR

34 Jubalong NR Batang County 14,200 WA 1995 P Fa35 YadingNR Daocheng County 56,000 FE 1995 P EP

36 Haizishan Mts. ~R Daocheng County 136,600 WA 1995 P Fa37 Luopishan Mts. NR Xichang, Dechang 22,965 FE 1986 N Fa

and Puge Counties

38 Zhile Mianning County 18,000 WA 1995 P FaYunnan Province, Number of nature reserves: 8, Area:651,495ha

01 Yulongxueshan Mts. Lijiang 25,996 FE 1984 P FaNR Atuonomous

County

02 Luguhu Lake NR Ninglang 8,133 WE 1986 P FaAutonomousCounty

03 Fuheshan Mts. NR Fugong county 13,300 FE 1993 C aT04 Nujiang River NR Gongshan and 375,433 FE 1986 P Fa

Fugong Counties

05 Habaxueshan Mts. Zhongdian County 21,908 FE 1984 P FaNR (18)

06 Bitahai NR (19) Zhongdian County 14,181 FE 1984 P Fa07 Napahai NR (20) Zhongdian County 2,400 WA 1984 P Fa08 Baimaxueshan Deqen County 190,144 FE 1983 N Fa

Mts.NR(l7)

Xizang Autonomous Region, Number of nature reserves: 10, Area: 33,374,500 ha

01 Pengbo Black- Lhunzhub County 9,680 WA 1993 P Fanecked Crane Nr

02 RiwoqeNR Riwoqe County 63,700 WA 1993 P Fa03 Markam NR (4) MarkamCounty 185,300 WA 1993 P Fa04 Qomolangma NR (1) Tingri, Gyirong, 3,381,000 FE 1989 N Fa

Nyalam andDinggye Counties

05 Xainza NR (7) Xainza County 4,000,000 WA 1993 P Fa06 Qiangtang NR (8) Shuanghu, Wennan 24,712,000 DE 1993 P Fa

and GerzeCounties

07 Bajie NR(6) Nyingch County 8 WP 1985 P Fa08 Yarlung Zangbo Medog Nyingch 916,800 FE 1985 N Fa

Canyon NR (2) Mainling BomiCounties

09 Zayu NR(5) Zayu County 101,412 FE 1985 P Fa10 Gang NR (3) Bomi County 4,600 FE 1985 P Fa

242 LI B. S.

Gansu Province, Number of nature resercves: 14, Area: 3,789,257ha

01 Qilianshan Mts.NR Jiuquan and 2,653,000 FE 1987 N FOZhangyePrefectures

02 Yanchiwan NR Subei Autonomous 424,800 WA 1982 P FOCounty

03 Dasuganhu NR Aksay 3,500 WA 1982 P FOAutonomousCounty

04 Xiaosuganhu NR AksayAutonomous 850 WA 1982 P FOCounty

05 Annanba NR Aksay 396,000 WA 1982 P FOAutonomousCounty

06 Changlingshan Gulang County 3,679 FE 1980 P FOMts.NR

07 Guiqing shan Zhang County 1,400 FE 1992 P FOMts.NR

08 Baishuijiang NR Wenxian and 213,750 WA 1978 N FOWudu Counties

09 Jianshan NR Wenxian County 10,040 WA 1992 P FO

10 Huanghessanxia NR Yongjing County 19,500 WA 1995 P FO

11 Lianhuashan Mts.NR Jone & Kangle 12,551 FE 1983 P FOCounties

12 Guozhagou NR Jone County 2,687 FE 1982 P FO

13 Huangheshouqu NR Maqu County 37,500 WE 1995 C FO

14 Gahai NR Luqu County 10,000 WA 1982 P FO

Qinghai Province, Number of nature reserves: 4, Area:5,222,544 ha

01 MengdaNR Xunhua 9,544 FE 1980 N FOAutonomousCounty

02 Qinghaihu Niaodao Gangcha County 708,000 WA 1975 P FOIsland NR

03 Hoh Xii NR Zhidoi County 4,500,000 WA 1995 P FO

04 LongbaoNR Yushu County 5,000 WE 1984 N FO

Xinjiang Uygur Autonomous Region, Number of nature reserves: 2, Area:6,OOO,OOOha

01 A1tun Mts.NR Ruoqiang County 4,500,000 DE 1983 N FO

02 Taxkorgan Wild Taxkorgan 1,500,000 WA 1984 P FOAnimalNR Autonomous ounty

* Numbers In the bracket ( ) are cOincIded WIth those marked In FIgure 11-2.

CHAPTER 12 REGIONAL SOCIAL-ECONOMIC SUSTAINABLEDEVELOPMENT

LIUYi

12.1 Sustainable Strategic Objects and Policies

12.1.1 POSITION OF TIBETAN PLATEAU IN CHINA

Tibetan Plateau plays an important role in China, which is decided by itsnatural and social performance.

Population and economic conditionsProportion of population and ration of economy to national gross value are

important indexes to show a region's role-played in national economic development.From which, we can see the Tibetan Plateau is being developed at very low levelwith great potential.

1) Proportion of populationResidents on the plateau was about 7.4 million in 1997, of which, the

proportion of minority accounted for 54.7%, and 5.5% in total minority in China.Small population will restrict development in general. Because limited labor is

difficult to exploit resource in large scale and develop industry. At the other side, itwill increase the press on ecological environment from people.

Small population will limit regional market scale, and have to develop itscharacteristic economy and integrate local demand and exploit outside market.

Table 12-1. The proportion of population in Tibetan Plateau to that of nation in 1997

Gross population Minority population Proportion of minority toNumber (M) Ratio (%) Number(M) Ratio (%) national gross population (%)

State 123626 100 7448 100 6.02

Tibet 248 0.20 232 3.11 0.19

Qinghai 396 0.40 175 2.35 0.14

Total of the744 0.60 407 5.46 0.33

plateau

Note: allfigures comes/rom Chmese statistic yearbooks. 1998.Chmese statistic publlshmg house,Beijing, 1999

243

ZHENG Du. ZHANG Qingsong and WU Shaohong (eds.), Mountain Geoecology and Sustainable Development oftheTIbetan Plateau. 243-264.©2000 Kluwer Academic Publishers.

244 LIUY.

2) Economic conditionEconomic condition reconstruction in Tibet Plateau was very slow and limited

in scale before 1978. After that period, proportion of industrial reconstructionprojects were significantly increased on the plateau, thus its economic position innational economy has heightened. However, industry economy scale in the plateauand the ratio of GDP in the plateau to that in China is being relatively decreased.

Which is caused by development in east China in the past 20 years, anddisparity of economic development level between the plateau and east China isascending. So, the economic development trend on the plateau has declinedsignificantly (Figure 12-1, Table 12-2).

- - - - - _. - .- -- _.- .. - - - - -. - .- "::""-':""l_D-(:>-~~

ratio(%)

O. 70

0.60

0.50

0.40

0.30

0.20

0.10

0.00

~Total ~Tibet -+-Qinghai

Figure 12-1 Ratio ofGDP on the Tibetan Plateau to that in state

Table 12-2 Comparison ofGDP per-capita between Tibetan Plateau andneighboring provinces (unit: yuan)

1980 1985 1990 1995

Absolute ratio Absolute ratio Absolute Ratio Absolute ratio

Value value value value

Tibet 471 2.15 894 2.13 1276 1.58 2392 1.29

Guizhou 219 1 420 1 810 1 1853 1

Qinghai 473 1.15 808 0.99 1558 0.87 3430 0.71

Xinjiang 410 1 820 1 1799 1 4819 1

Note: all the figures come from Chmese regional economy after J7years ofreform and openmg.Chinese statistic publishing house, Beijing, J996

REGIONAL SUSTAINABLE DEVELOPMENT 245

In addition, the proportion of GOP in the plateau to that of China is lower thanthat of population, which means the plateau has become one of poorest regions inChina..

Natural and social conditionsThe basic natural features of the plateau have been described in previous

chapters. Its major human features are the source of Tibetan nationality and culture.Therefore, the basic social-economic sustainable development strategies of TibetanPlateau should be connected exploitation and protection of human and naturalresources.

Tibetan Buddhism has played an important role in the development of Tibetanculture. It is particular culture environment and tradition that lead its unique custom,value idea, religion, culture and art. All of these are integrated into humanlandscape and became the precious treasure in spirit and culture of wold and humanhistory. It is one of main indexes to measure the sustainable development of TibetanPlateau.

Tibetan Plateau, over 4000 m asl in height, with an area of 2.50 millionsquare-kilometers, accounts for 23.44% of gross land in China. It is a keyecological source region in China and on earth, counted for environment securityand resource assurance to China's survival and development.

The environmental press in the Tibetan Plateau comes both from nature andhuman. The climate resulted in the fragility, volatility and instability of naturalenvironment. Even the forest ecosystem in the south east of plateau is also sufferedvarieties of hazards, like landslide, debris and mudflow and bushfire etc. Growseason for plateau ecosystem is short, especially on higher altitude.The fragility of natural environment and irreversibility of ecosystem successionrestrict resource exploitation and regional economic development on the plateau.

Role ofTibet area in Chinese regional developmentThe economic deployment of traditional plan-economy is based on regional

balance. After reform and opening, central government took a model of unbalanceddeveloping and focused on the development of coastal region where has resulted insome great effects to the plateau and west China. Harmonized development isimportant in general regional development policy. Now the central government haspaid great attention to the poor area and minority area for accelerating development.

Economic development in the plateau will ecological1y effect on downstreamregions. By Yangtze River flood and Yellow River water flow stop, Chinesegovernments people realized that the development situation in minority and poorregions on the upriver area is closely related to the sustainable development inChina.

Tibetan Plateau is a typical area where the distribution of minority nation andimpoverished population are inoculated in geography, which wil1 make economicproblem complicated. Also, the position neared to borderline not only endows themeaning of security and stable to regional economic development, but also becomes

246 LIUY.

an important element of Chinese all-sided opening outside frame.Its area is wide and the resource of water, land, grass, forest, energy and ore

are plenty, but it is low of the degree of exploitation. It is still a region with somedevelopment potential in our country.

12.1.2 THE REVIEW OF CURRENT DEVELOPMENT WAYS OF TIBET AREA

There is significant effect of regional economic development in Tibet areafrom 1990s. In the stage of eighth-five plans, the Qinghai national economy isincreasing and average growing speed is 7.6%. The economic strength is markedlyenhanced and position oHarming and animal husbandry is elevated. Also, the grossproduct of farming and animal husbandry is increased in the trend of stable.Particularly, the economy of pasturing area in rural region has developed all-sidedand the gross product value of township enterprises is 2.21 billion yuan and whichis the half of gross rural product value and its annual average increasing speed is30%. The step of resource exploitation is speed up and so as to development ofenergy and row material industry. Because gross permanent asset is increased andsome infrastructures have been improved, a set of irrigation work, transport,communication and electric power projects has been put in operation. There is fasteconomic development in Tibet authority region in the stage of eighth-five plans too.The annual average increasing speed is 8.3% and highest among of all five-yearplan stage. Because of the increasing plunge into farming and animal husbandryindustry, the projects of integrated exploitation of middle drainage area of the'region of Brahmaputra, Lhasa River and Nyang Qu River', first-stage process ofLhasa '3357' and prevention and counteract base in the north of Tibet have played agood role. In addition, infrastructure building is still key field of Tibet permanentassets investment, and some important projects have been completed and utilized.

The main conceives of industry development in the 90's of Qinghai provinceare: (1) to exploit hydro-power in the upper reach of Yellow River energetically; (2)to speed up the exploitation of salt lake resource in Qaidam Basin; (3) to develop oiland gas resource actively; (4) to accelerate the production of non-ferrous metal andgold; (5) to emphasize on the development of structural materials industry; (6) tocatch hold of reconstruction and rebuilding of electromechanical industry; (7) toenforce farming and animal husbandry base ulteriorly; (8) to carry out prophasework of the project of 'transferring water from south to north' in the west line.

Tibet put forward its industry structure adjustment too. Firstly, it is to take holdof guideline of based on farming and animal husbandry industry and change itsfragile condition, and make its integrated development well. Secondly, it is to makethe development of land transport and aviation simultaneously. Thirdly, it is toaccelerate energy development. Fourthly, it is to development ore exploitationenergetically.

Main conflicts in the industry economic development1) The economy in farming and pasturing areas is relatively dropped behind


It is important of farming and animal husbandry in Tibet area. However, at oneside, the farming and animal husbandry basis are fragile and still been main body ofagriculture. The situation of 'food depended on natural' and 'herd depended onnatural' are still existed and the output of corn and livestock product is increasedslowly. Traditional farming and animal husbandry is still the main body of localeconomy, and the portion of farming and animal husbandry to rural economy is90%. Apart from low economic interest, the destruction of agriculture environmentis seriously. In addition, it is an area where the family plan is out of control andincreasing population has counteracted the fruit of increased economy product inmuch degree. In 17 years after reform and opening, the number of farmer andherdsman in Tibet area increased 0.5 million and annual rate of growth is 1.68%,but the rate of growth of product increased at the same stage is 5.4%. As forQinghai, the annual rate of growth of rural people is 1.44% and which of firstindustry is 3.81%. In this corresponding period, the two indexes of country are0.79%,5.12%.

2) The disparity of economic development between different areas is enlargedAs same as national regional economic policy that is emphasized on developingimportant region and carrying out economy increasing unbalanced, the economicdisparity inside region is enlarged in Tibet area. On account of the effects of naturalcondition, resource endowment, historic reason and policy orientation of centralgovernment, the economic development of different region is unbalanced insideplateau. The raw material industry is developed comparatively in Hehuang valleyand Qaidam Basin, and development level of agriculture and industry is highcomparatively in the 'region of Brahmaputra, Lhasa River and Nyang Qu River' inTibet. However, in the wide farming and pasturing area and poor area, the level ofliving and producing is laggard, and it is very hard to the work of 'out of povertyand enriching people' .

Main problem in the change ofecological environmentThe ecological environment quality is descendent in farming and pasturing

areas and undeveloped area.It is mainly showed that the lands are decelerated and the resources of untamed

animal and plant are reduced seriously. Overgrazing has leaded to grasslanddegraded in much size, also resulted that the proportion of degraded and desertedgrassland in all the grassland area in Qinghai province is over one-fifth. There are22% of which is highly degraded, and at the annual rate of 67 km2

• The area ofdegraded grassland has been 0.15 billion mu, and the product of grass has dropped30-50%. The portion of degraded grassland in all grassland in Tibet authority regionis near to one-fifth. Many unreasonable resource exploitation activities such as overhag and opening up wasteland have result to many lands deserted. Soil erosionmainly takes place at eastward crossing mountain and it is the result of man-madedestroying forest and plant such as over deforesting, destroying forest to open upwasteland, lacking of rural energy so as to over hag. In addition, the slope of currenttillable fields is so slump, and many tillable fields lie on slope more than 25° and

248 LIUY.

extensive cultivation institute that lead to soil erosion.The number of natural animal and plants is reduced rapidly. There are plenty

of natural animals and plant resources in Tibetan Plateau and some kinds areunusual. However, because of the rapid reduction, degradation and over catchingand digging of forest and grassland, which was destroyed seriously.

12.1.3 PRINCIPAL AND STRATEGY OF EXPLOITATION OF TIBET AREA

Principal ofexploitationBased on national or world interest, the basic principal of economic

sustainable development in Tibetan Plateau is to protect culture, national security,social stability and ecological interest firstly and not to be the common problem ofindustrial structure and regional economy. In this regard, the development ofindustry and ore focused on exploiting resource cannot be important select ofindustry in Tibetan Plateau. Beside that it is easy to bring damage to ecologicalenvironment and it is hard to harmony industry with culture protection, theseprojects always request much one-off labor and easy to trigger large size ofimmigration and leave hidden troubles to population and environment of Tibet infuture. Additionally, the economic benefit of energy and primary raw materialindustry was not satisfying. With the forming of national market and deepening ofopen-outside, the highly polluted industry department at the expensive ofenvironment is not the choice of strategy to rapid development in the long term. Inthe same way, forest hag in large size is not the selected developing strategy too.

Based on the local interest, our targets must aim to prosper local economy andaccelerate the process of enriching people. Under the premise of general interest,we must realize the harmony between central government and local interest throughreasonable industrial orient selection. So, the important field of industry selectionshould be culture industry focused on tourist, modem agriculture and herds industryand industrial property without or little pollution.

Therefore, the sustainable development strategy should follow these principals(1) to pay great attention to ecological environment protection; (2) to inherit anddevelop traditional culture, and make precious culture heritage become superiorityand driving force of regional development; (3) to accelerate the development ofculture, education and health and improve labor quality in the meantime to controlpopulation number. At the other side, it will build culture system focused ontourism and modern farming and animal husbandry system increase living standardand improve live quality.

Development policyTo develop industry will benefit local farmer. From now then, it should make

the farming and animal husbandry economy modernized, develop agriculture andsideline product processed industry and drive forward the progression of agricultureindustrialization and rural urbanization. Due to the limit of condition in farming andpasturing area, the industrialization of economic structure in Tibet is not mainly


depended on the driving of itself industrialization in farming and pasturing area. Itwill rely on creating job in urbanized area and changing the structure ofemployment by admitting surplus labor of farming and pasturing area. The new jobopportunity is mostly centered on followed industries, such as service andrestaurant industry, transport and communication, tourist goods handcrafted andcirculating industry and building industry in city and tourist center.

To make economy and ecology harmony, and economy and culture harmonyThe guideline of regional development in the Tibetan Plateau, which emphasizes onthe economic interest united to ecological interest and economic united to culture,must be upheld. Central government needs to coordinate the interest betweendeveloped region and undeveloped region. At present, it is necessary to a pay-offmechanism to ecological protection in the plateau. The value of all ecologicalresources should be calculated out, and make it counted in the cost of nationalproduction. Then, with the tools of tax and finance, to expropriate cost based onregional ecological cost. Finally, transfer these costs to upstream areas in variousways and let people of Tibet benefited from the protection of ecologicalenvironment really.

The policy to emphasize on the cooperation with developed region and openingoutside to foreign country

The main problem of development of Tibet area is short of capital, technologyand market. After 20 years rapid development of east region, there is somesuperiority in these elements. How to use the capital, technology of east region toaccelerate plateau development is important problem concerned by regionaldecision-maker.

As for the opening outside, it should adjust strategy and make 'far' connectedto 'near'. The 'far' means that keeping emphasize on taking advantage of theopportunity of opening along the borderline and developing border trade toaccelerate the prosperous of export-oriented economy. At the other side, the 'near'means to take good use of the charm of natural and human landscape in plateau, toattract foreign investment and particularly of Europe and America countries, anddrive the development of local economy with tourism, researching exploitation andculture communication.

12.2 Fiscal concern With Central Government

Different from the development way of other regions, there is strongdependence of development of Tibetan Plateau in short-term and long-term oncentral government's support. So, the support policy of central government to Tibetarea is the basis to realize the sustainable development in Tibetan Plateau.

12.2.1 MAIN POLICY OF CENTRAL GOVERNMENT SUPPORTINGECONOMIC DEVELOPMENT OF TIBET AREA

250 LIUY.

The special regional policies of central government to Tibet area are mainlyshowed in following three aspects:

1) the leaning policy of capital investmentIn order to develop necessary local infrastructure and improve people's living, thereare sizable aids financially from state revenue. After the tax reform in 1994, Tibetand Qinghai are on the top of list of central finance returns per capita. Beforereform and opening policy, the building on 'third-line' region accelerates theforming of pillar industries of Tibet area, particularly in Qinghai province. In recent·21 years, the investment policies with significant effect are infrastructuredevelopment projects emphasized on resource exploitation focused on energy andtransport and hydro building. In addition, the international aids have been theimportant way to abate the short of capitals.

2) The favorable policy of reform and openingOn account of the statistic of Chinese Custom, the total value of import and

export of China with neighbor countries increased continually, and have raised upfrom 5.7 billion dollars in 1990 to 10.9 billion dollars in 1996. The border tradevalue of Tibet has been 220 million dollars at the end of 1994. It is clear that theopening along the border plays an important role in importing and exporting tradeof Plateau. To the end of 1995, there have been four first-degree open ports in Tibet,such as Burang, Zham, Jilong and Riwu, and they all are land ports. Though thenumber is little, they are important part to whole opening frame of Chinese landopening.

Viewed on effects, it is low in level and small in scale of Tibet opening alongthe border, which is on the stage of international trade along border (Table 12-3).Via the analysis of limited elements of development, the geo-economic condition ofTibet opening along border is relatively weak and it is lagged of economy andtechnology in neighbor countries. So, it is little possible to introduce capital andtechnology. Also, it is relatively lagged of economy and technology in Tibet, andnot holds the ability to dilate capital and transfer technology. Therefore, it is hard toimprove the level of cooperating and communicating in short term. The trades alongthe borderline in Tibet are connected through mountain pass, so the transport is notflowed and the synthetic function of city is limited and hard to form export processbase.

Table 12-3 The trade between Tibet and neighbor government

Neighbor Exporting goods Importing goodsgovernment

Tibet India, Nepal, Articles of artistic industl)', raw Local product of farming and animal

Bhutan, Sikkim,material, golden bracelet, TV, husbandl)', national handicraft,sonic equipment, motor part, carpet, allover, fleece and salt

Burma herbal medicine, gem andjewell)'


3) The policy of supporting and helpingMain support actions are:(1) To build regional economic cooperation area and go on development under

the common targets. Based on local superiority, oriented by market and took theform of horizontal cooperation, regional economic cooperation area was formedwith the character of 'complement superiority each other'. Qinghai provincebelongs to west-north economic area and also as a partner of multinationaleconomic developing area in the upstream of Yellow River (including Qinghai,Gansu, Ningxia, Inner Mongolia). Tibet belongs to five provinces and seven sideeconomic coordinating community in southwest of China (including Yunnan,Guizhou, Guangxi, Tibet, Chongqing and Chengdu). These economic andtechnological coordinating areas have play important role in common infrastructurebuilding, regional market system constructing and communication of person withability and information, and advanced the development of society and economy inTibet area.

(2) Pertinent support. Central government has organized some developedregions to support minority region pertinently from 1979. For example, Shangdongsupports Qinghai and all region support Tibet. In order to expedite the process ofpoverty alleviation, in may, 1996, the leading group of anti-poverty in StateDepartment deployed that there are nine developed cities and four cities directlyunder State planning assist ten undeveloped provinces respectively. For example,Liaoning assists Qinghai. Through pertinent support and assisting frontierintellectually, it has advanced the economic development of minority areas. Withregard to pertinent support, the benefit of Tibet is more than that of other nationaland poor areas.

12.2.2 THE EFFECT ANALYSIS OF CENTRAL GOVERNMENT'SFINANCIAL INVESTMENT

The comparative analysis 0/live standardAccording to GDP per capita, it is low of Tibetan Plateau economic

development and there is large disparity of economic strength between it with eastregion. In fact, this index only reflects the level of economic development and cannot reflect true people's lives disparity objectively. Especially to the regions wherethe proportion of subsidy come from central government is large, it only takesaccount of local production and conceals the true effect of outside support. So, it isthe investigating the real people's live standard and improving people's livingcondition that will be important contents of regional sustainable development.

Taking income and expenditure as indexes, let's investigate the difference oflive standard between Tibet and whole country (Table 12-4). Apparently, there aresome disparity existed really.

252 LIUY.

Table 12-4 The comparison of income in Tibet area in1997 (unit: RMB yuan)

GDPper Resident's expenditure Wage of Wage of Pure income percapita rural urban worker cadre capita of peasantaverage

Country 6079 2936 1930 6048 6470 6981 2090

Qinghai 4066 1965 1153 3886 7091 7803 1321

Tibet 3194 1471 939 4744 10098 11959 1195

(I) There is difference of disparity between the index of live standard percapita and that reflected by GOP per capita, particularly in Tibet where theproportion of subsidy come from central government is so high. The economic levelof Tibet is only half of that of national average, but its income and expenditure levelare on the contrast.

(2) The income of urban worker and cadre are higher than that of nationalaverage, particularly, Tibet is one of high regions in country. In contrast, the poorareas in Tibet area are mainly concentrated in rural area. So, the focus of 'enrichingpeople' policy is to increase the living standard of peasants.

(3) With regard to resident's consuming condition, there are difference incompare poverty between Qinghai and Tibet. It is much low of consuming standardin Tibet rural areas. The disparity of urban resident's consuming standard betweenQinghai and national average is very great. The phenomenon of laid-off worker inQinghai is very serious and there is 50% worker laid-off. So, it should different ofdeveloping policy in short term between Qinghai and Tibet. Tibet should liable toimprove the living standard and living style of farmer and herdsman. On the otherside, Qinghai should focus on solve the conflict of urban employment and income.

Of course, the conflict between government revenue and expenditure structurewill be the hinge on harnessing the governmental and local financial resource andrealizing the aims of regional sustainable development strategy.

The financial situation of Tibet areaThe keystone to underpin the living standard maintain of Tibet at some level is

the financial subsidy and aid assistance of central government in other way. Fromlong time ago, local finance of Tibet has depended on aid financially of centralgovernment. It has been more than 30 billion yuan of financial subsidy, rating aid,various constructing investment and special assistance which central governmentgave to Tibet.

I) The characters of government revenue and expenditures of Tibet authorityarea.

According to the basic regulation of reformation of system of tax divisionbetween central and local government, there are three channels by which Tibet gotfinancial assistance from central government in 1998:

(l) The special favorable policies which central government gives to Tibet.


The 75% of value-added tax that was handed in central government have beenreturned to Tibet actually, and the whole value is near 150 million yuan.

(2) Through the way of transfer payment. According to the calculation, afterthe reformation of system of tax division between central and local government, thefinancial ability per capita has been on the top of list of whole country. However,central government still takes Tibet as important target of financial transfer payment.At the beginning, it ascertained the value of transfer payment as 100 million yuan,and with the increasing of central financial strength, it increased to 180 millionyuan in 1997.

(3) Special financial allocation. It mainly includes support poor area andbuilding of frontier area. The value is always large and totally is 1.1 billion yuan.The policy subsidy which central government paid to Tibet is 1.5 billion yuan everyyear. If we add three items above up, the capital, which the central governmentsupports to Tibet, will more than 2.9 billion yuan. As the government revenue ofTibet itself is only 300 million yuan, the total financial strength will be 3.28 billionyuan, of which the portion of central financial capital is 91%. How significantlyTibet depended on Central government (Figure 12-2).

~ financial transfer payoutEJ mechanicis subsidyE:l1ocal revenue

mspecial funds• favorable returns

Figure 12-2 The structure of Tibet govenunent revenue

According to actual investigation, there are over 120 thousand peopledepended on government revenue and the cost of capita is 80% of total financialexpenditure. Main financial expenditure item are education investment 399 millionyuan, support to agriculture 370 million yuan, the import subsidy of oil, corn andagriculture machine 190 million yuan and basic construction 300million yuan.

254 LIUY.

2) The characters of government revenue and expenditures of Qinghaiprovince It is subsidizing finance of Qinghai province in the long time. In 1996,there are 1 billion yuan of government revenue, and 3.2 billion yuan of expenditure.So there are 2 billion yuan of central assistance and special financial allocation(Figure 12-3). This financial situation only ensures 100 million used toinfrastructure, 30 million to technological restructure. As for its population size, thenational structure of impoverished population and ecological environment inplateau, it is worse of Qinghai than that of Tibet. However, the value of its centralfinancial subsidy per capita is much lower than that of Tibet. So, it is very bad of itsfinancial situation. Up to mow, it is able to pay wages in time in Tibet, but it isnormal of wages in arrears in Qinghai province. In 1996, the financial deficit is 500million yuan in Qinghai, and, there are 85% counties of its 48 counties withfinancial deficit, and there are 75% states of its 8 states with financial deficit. Thearrears of various finance to workers on administrating enterprise per person are190 million yuan. It is financial hardy that limits the development of social andeconomic enterprise in Qinghai.

unit (million)250000 ..------------------------.,

......central subsidy ~ local financial income

200000

150000

100000

50000

oL..-_......_...-l__......._.....l.__..I..-_...... """-_.....l._----I

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996

Figure 12-3 the comparison of local government revenuein Qinghai with central government subsidy

3) The synthesizing analysis of government revenue and expenditures in Tibetarea.

Tibet and Qinghai is the first and third rank province of receiving centralfinancial returns per capita respectively (Table 12-5).

It can be clearly seen that the support strength from central government toQinghaiOTibet plateau is sizable.

However, in the financial structure of Tibet area, it is limited to develop itseconomic building and the finance mainly used to food its people (Figure 12-4).

REGIONAL SUSTAINABLE DEVELOPMENT

Table 12-5 Comparison of fmancial situation in Qinghai and Tibet

255

Local govenunent Local financialGovenunent revenue Financial expenditure returns of central(100 million yuan) (l00million yuan)

revenue per capitagovenunent per capita

(yuan)(yuan)

1990 1996 1990 1996 1990 1996 1996

Tibet 0.18 2.4 12.92 36.80 8.26 98.36 1409.84

Qinghai 7.24 9.60 17.13 32.70 161.72 196.72 473.36

40

30

20

10

olo!!!:!;";';':;';';';~":=";':";';";';':;';';';~":=";':";';";';':;';';';~":=";':";''';':'';';':'>

cost of infrastIUcture and technology cost of enterprise managemantrefonnation

~ Total E!I Tibet mQinghai

Figure 12-4 The comparison of fmancial structure between Qinghai and Tibet

It is important in: the Tibetan Plateau to harness financial resource efficiently,to adjust the fmancial structure and to enrich people.

Table 12-6 The comparison of worker structure

Cadre for tech-education and cultureInside: cadre of central govenunent

and health

Total number (million) Ratio ('Yo) Total number (million) Ratio ('Yo)

Whole country 3126 21.31 1080 7.36

Qinghai 15.6 24.49 6.2 9.73

Tibet 8.3 49.7 4.5 26.95

Total of Tibet 23.9 29.73 10.7 13.31

256 LIUY.

Investment andpoverty reliefBeside from in the field of finance, central government supports Tibet area in

the field of investment and poverty alleviation to accelerates local economicdevelopment.

1) InvestmentNormal direct investment came from central government will smaller.

However in Tibet area, the portion of central government's input is relatively large.In 1997, the total investment in fixed assets in Tibet is 3.45 billion and which

in Qinghai is 9.766 billion yuan. Of which the portions of state-owned units in twoprovinces are 92% and 78% respectively. The portions of collective-owned uniteconomy and other types of ownership are rarely low. Based on the structure ofinvestment in fixed assets (Table 12-7), there are different between Qinghai andTibet. It is mainly of infrastructure and immaterial production sector in Tibet, and ofbasic raw material industry in Qinghai.

Table 12-7 The industrial structure of investment in fixed assets in Tibet area

Tibet Qinghai

Item Total Ratio Item Total Ratio

(million) (%) (million) (%)

Total 316286 100 Total 813578 100

Transportation, postal and 82507 26.09 Electric power and water 234881 28.88telecommunications supplyservices

Electric power and water 75097 23.74 Mining and quarrying 140969 17.33supply

Agencies and social 54344 17.18 Manufacturing 135324 16.63organization

Farming, forestry, animal 17245 5.45 Transportation, postal and 98751 12.14husbandry and fishery telecommunications services

Education, culture and art 15920 5.03 Agencies and social 50417 6.20organization

Social services 15097 4.77 Farming, forestry, animal 29247 3.59husbandry and fishery

Banking and insurance 12335 3.90 Real estate management 25149 3.09

Note: it is calculated withfinishedfued assets data. Data resource: Qinghai statistical yearbook,Beijing, China Statistic Publishing House, page 85, 1998; Tibet statistic yearbook, Beijing, ChinaStatistic publishing House. page 81, 1998

2) The poverty relief in Tibet areaThere are 450 thousand impoverished population in Tibet area in 1999 and

incidence rate of poverty is near to one-third, the proportion of impoverishedpopulation in all over country is 77% (Table 12-8).


Table 12-8 Impoverished county and population in Tibet

257

Important impoverished countries in national '8-7'poverty Distribution

Numbereduction plan pf8000

pf Number of ~atio of Irotal rural Impoverished Incidence~illionimpoverished

Area ounty impoverished impoverished population population ate of population(unit) ~ountries countries 10000 10000 poverty

10000unit) %) lPersons) persons) %) persons)

Tibet 77 5 6.49 20.1 3.4 16.92 11.7

Qinghai 39 14 35.90 137.8 41.7 30.26 53.1

National2142 592 27.27 19203 5858.9 30.51 8065.5

total

Ratio ofTibet to 5.42 3.21 1.76 0.77 0.80national -total(%)

Data resource: '95 China population and resource and environment report, page 124, Chinastatistical yearbook 1993, page 3

Central government are making down various policies and boosting forwardsthe poverty alleviation in poor area. At the same time, local governments are takingpoverty alleviation as important task of regional economic development too. Thepolicies of support poor area can be classified into two types. One is aimed to allimpoverished areas, and the other is particular to minority regions.

3) Universal poverty alleviation policy.With a set of poverty alleviation policies, the impoverished population of

Qinghai province has been dropped down from 1.19 million to 830 thousand in thethree years from 1993 to 1995.

12.3 Industrial Restructure Orientation and Allocation

12.3.1 PRESENT SITUATION OF STRUCTURE OF INDUSTRY ANDINDUSTRIAL DISTRIBUTION

Industrial structure of Tibet area has obvious geo-diversity. There are somefeatures of structure of industry and industrial sector.

Parent ofstructure ofindustry ofTibetFarming and animal husbandry are main body of Tibet economy in long term.

The output value of primary industry is accounted for 51 % of GOP in 1978 and42% of GOP in 1996, which still is maximal among thrice industrial structure.There is huge change of industrial structure of in Tibet area in 1997 for the firsttime, and the tertiary industry become main sector, which accounts for 40% of GOP,

258 LIUY.

exceed the first industry over 2 %. Industrialized degree of Tibet is low. Theindustry is accounted for 9% of GDP in early days of reform and opening and onlyincreases 2% in 1997 (Figure 12-5).

100% M!!"J""""II!!~!!!!I""""""''''''''''""''''II!!~!!!!I"''"''''''' r''''''I!''-''''''''''''''-'''''''''''''''''''''''' '''''''''""''''II!!~'''''

90%80%70%60%50%40%30%20%10%0% LIC.I'-'-IIl.......IC.I..I..JC.I."""""I",o..,KOI....o.Ja...JU,.o..Ja...o..K......u....JCL"oJa-..IC.L..Ul:..L.o.JCL"...u.-...!UL.......I!:olI...<.JlU.J

1978 1980 1982 1984 1986 1988 1990 1992 1994 1996

EI primary industry E:I secondlily industry

~ construction EI ternary industry

Figure 12-5 The changing of industrial structure in Tibet

In 1997, gross output value of farming accounts for 53% of generalizedagriculture, which exceed over animal husbandry by 8%. The output values of Tibetsmall-scale industrial enterprises contribute 96% to gross output value of industry(no including large-scale enterprise). Of which the percentage of heavy industrialoutput value is 65%, and 66% to that of state-owned enterprises. With the analysisof sector structure and branch structure (only of industrial enterprises at and abovetownship level), the pillar industries in Tibet successively are raw industry, miningand quarrying, light industry using farm products as raw materials (Table 12-9).

Table 12-9 The structure of industry sectors in Tibet

Light industry Heavy industryUsing

Using fann non-fann..

Rawindustry mmg ManufacturingTotal products as products Total and material industryraw materials as raw quarrying industry

materialsValue

(million 98741 30651 20890 9761 68090 23203 37853 7034Yuan)Ratio 100 31 21 10 69 23 38 8(%)

..Note: It IS mdustnal enterpnses at and above townshIp level and the data a/value a/products arecalculated at current prices. Resource: Tibet statistic yearbook, 1998, Beijing, China statisticpublishing house, page 190.


Also, electricity power, nonmetal minerals mining and its products (mainly atcement), ferrous and nonferrous metals mining and dressing, food processing,timber processing and transport equipment are eight pillar branches of industry andwhich contribute 64% to gross industry output value.

Major industrial products are electricity (578 million kWh in 1997, samenessto following), chromate (122 thousand tons), cements (322 thousands tons) andtimber (100 thousand m3

). Also, there are foods and textile product.With regard to structure of employed persons, the tertiary industry in Tibet is

mainly relying on commerce and trades, administrating management, transport, postand communication, culture and arts and education. The proportion of theiremployed person to total employed persons of tertiary industry is 26%, 21%, 15%,and 13% respectively. It must be said that although the main body of Tibet economyis state-owned economy, the portion of other ownership has increased markedly intertiary industry. For example, in the field of commerce and trade, non-stateownership economy has been pillar sector and the number of person~ employed inthe urban private enterprise and industry and commerce run by the individuals isnear to 60% of the number of total employed person in this field.

The current situation ofindustrial structure in QinghaiThe value of output of secondary industry accounts for 50% of the value of

GOP, of which industry accounts for 36% and as largest portion sector until 1995.In that year, the value of the proportion of industry is 40% and on the top of threeindustries. In 1996, it is fIrst change in industrial structure and tertiary industrybecame largest output sector. Its proportion is 40% and over than secondaryindustry by 1%. The ratio of three industries in 1997 is 20:39:41, and of which theportion of industry is 29% (Figure 12-6).

100% f'"II!!II""""I!'!!!r"'1 r-I! ""1!!!!I"""'1!!!r-1_"E'I'"--elI'"""'E!!I'"""1I!!!1'"" F""""I!_'Er""'Er1

90010800/0

700/0

600/0

500/0400/0

300/0

200/0100/00% L...r.a.......-.4...l.J~..L.4."""""L.J.J:4..L..Ia..~~L.L.Jr.a.......Ila.~I..I..IIi"'-'-La...l...u.......r.£l...l..I:4-&...Ia...1...£4-1

1978 1981 1983 1985 1987 1989 1991 1993 1995 1997

rJ Primary industIy~ Construction

Ell Industrye TertiarY industIy

Figure 12-6 The change of industrial structure in Qinghai (lack of data in 1979)

260 LIUY.

Based on the analysis of sector structure and branch structure, it is mostimportant of raw material industry, and successively is mining and quarrying,manufacture industry and light industry using farm product and non-farm product asraw materials (Table 12-10). Of which the industries such as ferrous and nonferrousmining and dressing, petroleum extraction, electricity power, ordinary machinery,nonmetal mineral products, raw chemical material and textile industry are ninepillar industries and whose proportion to value of output of gross industry is 81 %(Table 12-10). Main industrial products are following: such as petroleum (1.6million tons, in 1997, same as following), steel (430 thousand tons), ten kinds ofnonferrous metals (210 thousand tons), ferroalloy (170 thousand tons), electricity(8.4 billion KMH), fertilizer (230 thousand tons), raw salt (160 thousand tons),cements (770 thousand tons), metal-cutting machine (236 units), carpet (120thousand units) and cloth (24.07 million M).

Table 12-10 Industrial structure of Qinghai

Light industry Heavy industry

Using UsingIndustry farm non-farm Mining Raw

ManufacturingTotal products products Total and materialas raw as raw quarrying industry

industry

materials materials

Value(million 1474104 242398 182641 59757 1231706 314860 697775 219071Yuan)

Ratio (%) 100 16 12 4 84 21 47 16...

Note: It IS industrial enterprises at and above township level and the data o/value o/products arecalculated at current prices. Resource: Qinghai statistic yearbook. /998. Beijing, China statisticpublishing house, page 203.

The basic frame ofregional economic distribution in Tibet areaThe high inequality of regional economic distribution is common character

inside Tibet area. Because of the problems of indicators of statistic reference andregion dividing in Tibet, we could only demonstrate the particularity of Tibetregional economic distribution with the indicators of local government revenue andvalue of gross agriculture products. Though the synthetic comparing and analysis ofpopulation with other two indicators, it can be seen that the distribution of grossnational economy products centered around Lhasa city, and Xigaze, Shannan andNyingchi are important economic region in Tibet too. On the contrary, the economicstrength in Qamdo, Nagqu, and Ali area is relatively weak. The main industry andtertiary industry center at Lhasa, and it is important agriculture area of Xigaze andQamdo (Table 12-11).


Table 12-11 Regional economic distribution of Tibet in 1997

261

Population Government revenueGross output value of

primary industry

Total (10 Ratio Total (10 Ratio Total (10 Ratiothousand yuan) (%) thousand yuan) (%) thousand yuan) (%)

Lhasa 39.28 16.2 12791 37.9 58087 14.1

Qamdo area 54.46 22.4 3275 9.7 103000 25.1

Shangnan31.16 12.8 3701 11.0 44558 10.8

area

Xigaze area 61.77 25.4 4485 13.3 116097 28.2

Nagqu area 34.49 14.2 2798 8.3 43111 10.5

Ali area 7.16 2.9 1944 5.8 16718 4.1

Nyingchi14.43 5.9 4793 14.2 29539 7.2

area

Data resource: Tibet statistic yearbook in 1998. Beijing. China statistic publishing house. and1998

The population of Qinghai province is centered on the area east of Qinghai lake. It is Xinning City and Haixi State that economic output centered on and thelatter is the effect of integrates development of Qaidam Basin. Also, many statesaround lake are relatively developed. The distribution of tertiary industry is notconvergent as industry. Except for in developed areas such as Xining and Qaidam,Haidong area is well developing area. The economy in Yushu and Golog is weakand low of their industrialization.

12.3.2 MAIN CONTENT OF NEW PILLAR INDUSTRY DEVELOPMENT

Foster culture industry focused on tourism as new pillar industries into 21stcentury

In the long run, culture industry refers to omni bearing tourism and takes it ashead to enrich and perfect culture industrial system. It includes cultivatingeducational industry according to Tibet Buddhism and culture, art industry andmanufacturing and trading industry of substantial culture products. In the short run,its development will begin with tourism and bring about the development of otherindustries. It includes catering services, transport and information industry, touristsouvenir and foods and constructions.

Therefore, it can be said that tourism will be strategic and pillar industry inTibet to across century. It is also a protective industry based on local culture andnatural resource superiority. Because of its heritage and development of traditionalculture and being favor to ecological environment, it can be said an industry thathaving strong sustainability, enforcing the communication between Tibet withoutside world, demonstrating the character of plateau, accelerating development ofother industries and doing benefit to local people.

262 LIU Y.

Impel the modernizing progress offarming and animal husbandry industry, andpromote significantly the living level ofthe farmers and herdsman

The kernel task of the construction of farming and animal husbandry industryis to make elevating the living level of the farmers and herds as the tenet. In order toimprove the fundamental living condition of the farmers and herds, raisingproduction level and supporting the poor should be pay equal attention, and theeconomy growth mode should be transmitted from extensive management tointensive management. In the well-conditioned region, the aim of comparativewealth should be achieved in the 15-20 years, and the goal of wealth in wholeagricultural and pasturing region should be implemented step by step.

1) It should play the farming and animal husbandry industry on the first placeof the national economy and increase the fund and technique investmentsignificantly. Then, it should complement existing favorable policy, and with thehelp of the power of deepening the reform in the pasturing area, mobilize theenthusiasm of the farmers and herds to increase the devotion proportion ofcollectivity and individuals. Also, with the comprehensive exploitation, optimizingthe construction, developing agriculture vigorously by science and technique,excavating the potential, enhancing the construction of fundamental establishment,advancing the capacity of disaster prevention and fighting and making agriculture,industry, commerce, planting and breeding integrated, let's build up the selfdeveloping capacity and stamina, develop roundly the economy of the pasturingarea, ensure the achievements of two targets. Which are affective supplying of themain agricultural and pasturing production, increasing the income of farmers andherds.

2) Still put emphasis on the development of planting. Implement the guideline"enlarging the tilth, increasing the production of unit area, founding base andgaining stamina", stick to combining the deep development and the extentdevelopment, and carry out distinguishing developing policy according the distinctregion characteristic. The focus of construction of east region of Qinghai are toreconstruct middle and low yield field, to start construction of terrace, to control thesoil and water erosion and to raise the index of double cropping. Also, it shouldbuild the base of commodity com, control plowland used for non-farmingproduction and to build primary farmland protection area. As for the developmentof west region of Qinghai, it should based on current state-owned farming andpasturing fields and renew the black fallow designedly, cultivate badlands which issuitable for farming, and expand the oasis irrigated farming which conjuncts thefarming, forest and herds. While, Tibet should play its emphasis on thecomprehensive development of farming and animal husbandry in the region ofBrahmaputra, Lhasa River and Nyang Qu River middle valley in order to drive theoverall situation by the development of this area. At the same time, it should expandstage by stage the comprehensive exploitation of valley of Niyang River, east Tibet"three River" and their first and second-rank branches. At the time putting inpractice on comprehensive development and enhancing the construction of cropland


and irrigation works, the fundamental construction of farmland which is centered onwater conservatory and soil control should be unfolded. Also, it should rebuild themiddle and low yield land vigorously, and cultivate badlands that are suitable forfarming within measure. All kind of measures should be taken pressingly to elevatethe level of scientific farming. All these measures will be favor to mobilize theenthusiasm of all sides, increase the devotion to framing from many channels andmake the provision production of Qinghai-Tebet area increased to a morecomparative scope, and create condition for the basic achievement to self-support.

3) According to the guideline that "stable livestock by grass, increase livestockby adding grass, adjust frame and aggrandize commodity", transformed step by stepfrom traditional stock raising to modernized stock raising in order to form thenational livestock production base. In the area where the livestock raising iscentralized, it should through the projects such as synthetically developing livestockindustry to speed up the construction of the disaster prevention and fighting base.

Develop mixed farming adjusted to local conditions and develop townshipenterprise. Based on the construction of mixed farming, animal and husbandry, thetownship enterprise in Tibet should be developed. Also, its development should besuitable for the need of this area's frame modulation, guided by the market,centered on the economic benefits and based on the towns and importantconstruction area. In addition, it should implement the guideline "laying out entirely,supporting positively, guiding correctly and developing vigorously"..Therefore, according with the collectivity aim of sustainable development, Tibetarea should rely on the local comparative predominance resource, throughinheriting, developing, competing to achieve the transformation of industry framefrom raw material type to light industry type and set up industry image with localfeature.

12.3.3 TARGETS OF REGIONAL ECONOMIC ALLOCATION OPTIMIZATION

In future, key points of regional economic distribution of Tibet area, as forQinghai province, firstly it should move from Hehuang Valley westward to roundlake economic ring and be formed aggregate economic core area with strongeconomic ability, corresponded development of the light and heavy i.ndustry andintegrated exploitation of tertiary focused on tourism and agriculture. Secondly, itshould make the general development of Qaidam Basin improved as emphases, andbe formed new economic core area of Tibetan Plateau on the base of connection ofgrowth of urban economy and construction of around agriculture base. As for theregional economic construction of Tibet, firstly it should complete the generalexploitation of 'Lhasa-Xigaze-Jiangzi-Shangnan region, build new industrial corearea taking these cities as important areas and make it economic core area with thespecial character of Tibet area. Secondly, it should take border port as head, developborder county economy and expand the industrial allocation of Tibet.

264

References

LIU Y.

I. YAN Maochao, 1998. Energy analysis and sustainable development study of ecologicaleconomic system in Tibet. Journal o/natural resources, 1998 (2): 116-125. (In Chinese)

2. WANG Jinhong, 1997. Investigation of social development in south mountain area of Tibet.Society Research, 1997 (4): 1-12. (in Chinese)

3. ZHANG Keyun, 1997. Selection of strategy enterprise and development direction. Tibetresearch, 1997, (3): 20-26. (in Chinese)

4. JUE Se, 1997. Mineral enterpise and its development. Tibet research, 1997 (I): 1-8. (inChinese)

5. LV Minglun et al., 1996. Economic development and adjustment of enterprise structure.Natioanl and regional economy. 1996(4): 24-31. (in Chinese)

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7. LANG Yihuan, 1990. Industry development of natural resources. Development research,1990(6): 36-41. (in Chinese)

8. SUN Changzhi, 1990. Basic ideas for the economic development of Tibet. Developmentresearch, I990(6): 36-41. (in Chinese)

9. Commission of planning economy of Tibetan municipality. 1996. Programming of Tibetanmunicipality (1996-2000). (in Chinese)

10. Commission of planning economy of Tibetan municipality, 1996. Programming of nationaleconomy and social development of Tibetan municipality (1996-2010). (in Chinese)

II. Annual Report of Tibetan municipality, Statistical bureau of Tibetan municipality, 19951999. (in Chinese)

12. Commission of planning economy of Qinghai Province, 1996. Programming of QinghaiProvince (1996-2000). (in Chinese)

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14. Annual Report of Qinghai Province, Statistical Bureau of Qinghai Province, 1995-1999.

CHAPTER 13 GEO-ECOLOGY OF MTS. NAMJAGBARWAREGION

PENG Buzhuo, BAO Haosheng and PU Lijie

Mt. Namjagbarwa, with the peak at altitude of 7,782 m asl, is the highest onein East Himalayas. The high mountains standing beside deep valley, is located atthe inner of moisture corridor around the bending of the Yarlung Zangbo River,having rather complete vertical natural belts.

13.1 Moisture Corridor Areas

With intensive uplifting of the Tibetan Plateau, the Yarlung Zangbo cut downacutely and eroded towards the plateau. A horizontal distance between southern andnorthern slopes is only 40 km while vertical ranges of southern and northern slopesare 7,000 m and 5,000 m respectively. Because the uplifting ranges differ in varioussites, the differences in height and size of Mt. Namjagbarwa and surrounding areasare rather obvious, which in addition to variations of development degree andinfluence intensity of existing glaciers had profound impact on the forming andregional differentiation of vertical belts.

Uplift of the Tibetan Plateau enforces monsoon circulation of lower altitudethrough heating function and obstruction mechanism of the plateau. In summer, airtemperature above the plateau is much higher than that of surrounding atmosphereowing to strengthening of ground surface radiation of the plateau. The plateau warmlower pressure superimposes on the southern Asia warm lower pressure, and thusstrengthens the latter, which attracts strongly southeast trades of the NorthernHemisphere, bringing about the result that southwest monsoon of south Asia havebeen strengthened.

Existence of the Tibet Plateau and the Himalayas protrude towards southforces southwest monsoon to move northwards along the plateau. Deep-cut valleyflowing from north to south along the Yarlung Zangbo provides natural corridor fortransportation of moisture and energy, and thus tropical landscapes at low-altitudeextend along the valley to nearly 29°N, becoming the northern limit of tropical zonein continents of the North Hemisphere. It provides favorable conditions for theformation and development of vertical natural belts ofMt. Namjagbarwa Region.

In winter half-year prevailing westerlies and the weather is clear with lessprecipitation; in summer half-year controlled by warm and humid air currents ofsouthwest monsoon the weather is hot with more precipitation. Mt. Namjagbarwa

265

ZHENG Du, ZHANG Qingsong and WU Shaohong (eds.), Mountain Geoecology and Sustainable Development oftheTIbetan Plateau, 265-282.©2000 Kluwer Academic Publishers.

266 PENG B. Z., BAO H. S. and PU L. J.

obstructs warm and humid air currents from the Indian Ocean resulting in differentclimate between southern and northern slopes. Special landforms as the big bendingof the Yarlung Zangbo have created an important corridor for moisturetransportation, giving obvious impact on Yi'ong and Bomi due to air currentsmoving along the valley ofPalung Zangbo from top of the bending.

Warm and humid air current from Indian Ocean split into two when movingupwards along the Yarlung Zangbo at Ganglang. One moves northwards alongPalung Zangbo valley and the other keeps on moving westwards. The one movingnorthwards splits again at Tongmai with one moving westwards along the Yi'ongZangbo and the other along the Palung Zangbo. Air currents could move throughlow mountain passes and enter valleys at middle reaches of the Yarlung Zangbo. Itis observed that more moisture enters into Yi'ong Zangbo than that into PalungZangbo and that one moving westwards along the Yarlung Zangbo is the least(GAO Dengyi et al., 1985) (Table13-1).

Table 13-1 Comparison of precipitation in some sites of Mt. Namjagbarwa region(PENG Buzhuo et al., 1996)

Watershed Station Annual mean precipitation (mm) Period

Yi'ong Zangbo Yi'ong 958.8 1966-1971

Palung Zangbo Bomi 762.2 1961-1980

Yarlung Zangbo Mailing 662.1 1979-1981

From the point of view of aerology moisture corridor has two definitions.Firstly, warm and humid air current from Indian Ocean transfers through valley oflower reaches of the Yarlung Zangbo to hinterlands of the Tibetan Plateau.Secondly the amount of moisture transfers through valley of the Yarlung Zangbo tohinterlands accounting for the largest part of total amount of moisture transfer tohinterlands of the plateau. Based on observation data of two stations at the bendingof the Yarlung Zangbo and 14 stations around the plateau from July to August in1983 the amount of vapor could be calculated. In the calculation there are twohypotheses: I) the vapor at 700hpa (at altitude of 3000 m asl or so) and higheraround the Tibetan Plateau could all tramp over on to the plateau. 2) The vapor at750hpa (close to the ground of valley) and higher at the Yarlung Zangbo areconsidered as vapor transferring to the plateau. The amount of vapor through valleyof the Yarlung Zangbo reaches 500-1000g*cm-l*s·l, while vapor transferringthrough other paths only comes to 100-400g*cm·l*s·l, which justify the importanceof moisture corridor. The direction of moisture corridor is: first transfersnortheastern along the Brahmaputra, then moves along valley of lower reaches ofthe Yarlung Zangbo towards north and at last transports along the bending ofYarlung Zangbo towards northwest (YANG, et al., 1987).

There are greatly different landscapes and ecological conditions betweensouthern and northern slopes of the Himalayas. While large amount of energy andvapor are transferred through moisture corridor from southern slopes to the north,

GEO-ECOLOGY OF MTS. NAMJAGBARWA REGION 267

reducing differences in moisture and temperature conditions in areas influenced bymoisture corridor.

As precipitation decreasing westwards and eastwards from the tongue-likeregion, aridity increases from less than I.l of tongue-like region to 1.0-1.5 in Bomiand Mailing. Climate of southern slope is characterized with hot and humid withabundant in precipitation. In Medog at altitude of 1100m asl annual meanprecipitation is about 2276.6mm. Annual precipitation curve has two peaks with thelower one from April to May and the higher one in June. Monthly precipitationdistributes rather evenly and only that from November to next January is less withmore fog days and high humidity making up for insufficient precipitation.Therefore vertical belts of southern slope have the monsoon features. Bycomparison, precipitation of northern slopes is less with aridity of about 1.0-1.5,e.g., annual mean precipitation in Dan'niang at altitude of 2,920m asl is about512.1 mm and mainly concentrated in period from May to September, accountingfor more than 70% of annual precipitation. Vertical belts of northern slopes arecharacterized with the monsoon sub humid type group (ZHANG et al., 1982; LIN etal., 1984; PENG, 1984).

The Yarlung Zangbo valley nearby Medog, extending from northeast tosouthwest with altitudes of 700-1,1 OOm asl, where the ecosystem is characterizedby features of tropical zone. It could be divided into lower montane tropicalmonsoon forest belt or tropical semi-evergreen forest belt (ZHENG, et al., 1981).The latitude of Medog County (29°18'N) is equal to that of Jiujiang County inJiangxi Province, which belongs to subtropical zone (Committee of AgriculturalRegionalization of China, 1984). Definitely identifying ecosystem features of thevalley nearby Medog will help us not only to understand comprehensively physicgeographical pattern of the Tibetan Plateau but also to identify the base belt andmain features of vertical belts, as well as guide us in arrangement of agriculturalactivities.

In Medog mean temperature of January is 8.1°C and that of July is 22.2°C.Annual mean temperature is 16.1°C with extremely minimum temperature of O°C.Accumulated temperature of ~10°C is 5300°C with its duration of more than 300days and frost-free period of more than 330 days. Medog and Yueyang (HunanProvince) at the same latitude have almost equal active accumulated temperaturebut average temperature of January in Medog is 4°C higher and period ofaccumulated temperature 62 days longer than Yueyang. It is shown that the studiedregion is not affected by cold waves and has much better temperature and moistureconditions. According to temperature criteria for demarcating tropical zone byIntegrated Physical Regionalization of China (1959), accumulated temperature of~10°C should be more than 8000°C, average temperature of the coldest monthshould be more than 16°C, and mean extremely minimum temperature of above5°C. Temperature criteria for south subtropical zone are that accumulatedtemperature of ~lO°C should be 6500-8000°C, with average temperature of thecoldest month 10-16°C, period of temperature ~10°C more than 300 days, andannual precipitation of 1400-2000mm. According to criteria of marginal tropical


zone by Outlines on Physical Regionalization of China (1984), accumulatedtemperature of ~10°C should be 8200-8700°C, with period of temperature ~10°Cthe whole year round, average temperature of the warmest month of 24-28°C,while of the coldest month IS-20°C and mean extremely minimum temperature of0-5°C. Criteria of southern subtropical zone are that accumulated temperature of~lOOC should be 6500-8200°C, with period of temperature ~lOoC lasting 286-365days, average temperature of the warmest month of 20-28°C, while of the coldestmonth 10-15°C and mean extremely minimum temperature ofO-5°C. According tothe above mentioned criteria, it comes to the conclusion that it is more reasonable todescribe the studied region as having subtropical ecosystems. Main differencebetween criteria and ecosystems lies in active accumulated temperature. Studiedregion is warm in winter with much higher effectiveness of accumulatedtemperature than that of East China (PENG and DOU, 1996).

Under favorable temperature and moisture conditions composition andstructure of vegetation at valley areas are characterized with obvious features oftropical zone. Representative vegetation is monsoon forest (or semi-evergreenforest) with main species of tropical elements. The layer differentiation of forest isnot obvious with stable and complicated structure. Liana, epiphyte and buttressroots are commonly met with in monsoon forest. Most of which belong to flora ofpan-tropical zone. Nevertheless typical plants of tropical zone such asDipterocarpaceae could only be seen at typical tropical valley bottom below altitudeof600m asl. In addition, fruit of tropical zone such as bananas and pineapples couldgrow in studied region. Consequently, the vegetation in studied region hastransitional features from tropical to subtropical zones. Because of this kind ofecosystems and climate, soil-forming process has transitional characters, such as SiAl ration between 2.6-2.9 and silica-sesquioxide ratio of about 2 in soils (PENG,1985) and so on. The allitization and bioaccumulation of soil are weaker than thatof laterite soil developed under typical tropical monsoon forest while stronger thanthat of red soil developed under subtropical evergreen broad-leaf forest, so it hasfeatures of lateritic red soil. Because of high moisture in soils, oxide of Fe is yellowin color after hydration. The soil develops into lateritic yellow soil belonging to thesubgroup of lateritic red soil.

Accordingly, whether vegetation or soils of studied region, all have features oftropical zone though not typical. It is improper to identify characteristics of naturalecosystems in the region based on temperature criteria of the tropical zone in EastChina. We think that the base belt of southern slopes of Mt. Namjagbarwa hastropical character; therefore, it is better to deem it as quasi-tropical (or marginaltropical) zone (REN et al., 1979).

Altitudes of base belt in northern slopes are higher, usually with altitude of2,800m asl or so at valley bottoms. Mean temperature of January is -1.2°C and thatof July 16.6°C in Dan'niang with annual mean temperature of 7.9°C. If averagetemperature (10-18°C) in July used as main criteria, base belt of vertical belts invalley areas below altitude of 3,200m asl belong to warm temperate zone (ZHANGet al., 1982).


Similar to the Hengduan Mts. lower reaches of the Yarlung Zangbo providenot only natural corridors for vapor and energy, but also special habitats forspeciation of new varieties and shelter for ancient creatures, which play importantroles in formation and development of natural ecosystems of the studied region.Climate varies vertically with increase of altitudes with descending ratio oftemperature O.S8°C /lOOm and frost-free period of 7 days shorter in an increase ofevery 100m. Precipitation increases in ascending altitudes within certain ranges,with the highest precipitation at altitudes of 2,SOO-3,OOOm asl in southern slopesand 3,SOO-4,OOOm asl at northern slopes. Vertical variation of moisture andtemperature conditions restrains vertical distribution of vegetation and soils, as wellas vertical belts of Mt. Namjagbarwa (PENG et al., 1997).

13.2 Geo-Ecological Observation in Vertical Natural Belts

Yarlung Zangbo River turns around Mt. Namjagbarwa with altitudes of valleybottom decreasing from 2,800m asl in the northwest to SOOm asl in the south.Owing to differences in elevation and corresponding biological and climaticconditions, vertical belts of southern slopes and northern slopes differ incharacteristics and base belts.

Mountainous vertical belts developed with influences of combination,interaction of zonal and azonal factors. Furthermore, landform characteristics ofmountains including relative height and trend of mountain range, as well as regionallandform features, and redistribution of moisture and temperature according to theformer are foundation for the formation of vertical belts. Types of vegetation andsoils indicate directly conditions of moisture and temperature. So we use moistureand temperature conditions as principal indexes, differentiation of vegetation andsoils as primary sign to identify vertical belts (PENG and DOU, 1996).

13.2.1 ECOSYSTEM CHARACTERISTICS OF VERTICAL BELTS INSOUTHERN SLOPES

Quasi-tropical monsoon forest and subtropical evergreen broad-leaf forest aremain characteristics of natural ecosystems of southern slopes in studied region(REN, 1982). Monsoon forest is abundant in plant species, with indistinctdifferentiation in vertical structure of communities. Leaves of higher arbor fall atthe end of dry season, while lower arbors consist mainly of evergreen species andcomplicated in structure with buttress roots and flower-stalk, as well as abundant inliana and epiphyte. Evergreen broad-leaf forests of subtropical zone, characterizedwith round waves shape crowns, high canopy density and various layers, are chieflycomposed of Sino-Himalayan floristic elements. Subtropical semi-evergreen broadleaf forests are located at higher altitude where precipitation is the highest (Ll,1985). The forests, usually called mossy forest, are quite humid and coveringwidespread with mosses. With increasing of altitudes temperature drops andvegetation gradually turns into coniferous forests and alpine meadows.


Climate is hot and humid, with dominant bio-chemical weathering and strongsoil eluviation represented by acid or strong acid reaction. Because of relativelyshort forming period of soil, it is characterized with thin soil layers andincompletely developed soil. Corresponding with increase of altitudes obviousvertical changes in soil types' occur in studied area. Soil formation is restrained bybio-c1imatic conditions, allitization is gradually replaced by podzolization andmeadowlization, and while Si-AI ratio and silica-sesquioxide ratio become largerwith organic matter content increasing.

Animals at southern slopes consist of two faunae from monsoon forests andevergreen broad-leaved forests where animal species are abundant. Most of theanimals belong to Oriental region, including many species of quasi-tropical andsubtropical zones. Such as mammals of Presbytis entellus, Macaca mulatta,muntiacus muntiak, etc., birds of Garrulax spp., Cuculus poliocephalus, Treronsphenura yunnanensis, etc., amphibians include Rufo himalayana and Rana liebiggi,and reptiles of Japalura kumaonensis, and Trachischum tenuiceps prevail in studiedarea. Upwards from coniferous forest belt animals consist mainly of Palaearcticregion and decrease in both species and quantities. Fungi in tropical monsoon forestand subtropical evergreen broad-leaved forests include Pleurotus sajor-caju,Oudemasiella mucida, Marasmieillus ramelis and so on.

At southern slopes of Mt. Namjagbarwa the Yarlung Zangbo and its branchesare of high gradient ratios, with rapid flow speed, strong runoff intensity, and runoffdepth of 1,OOO-2,OOOmm. Coefficient of variation of annual runoff is less than 0.3with small perennial variation of runoff intensity. Flood begins from rainy seasonfrom May and ending in middle of October. Obvious variation in monthly runoffreflects hydrological features of rain and underground water as main compensationorigins. Mineralization degree of the river is low, usually below 50mg*L,1 inbranches, while more than 100 mg*L" in mainstream. Most of hydro-chemical typeis of HC03-S04-Ca-Mg. There also exist vertical variations in degree ofmineralization and hydro-chemical types of the river.

Vertical belts upwards at southern slopes of Mt. Namjagbarwa region are asfollows:(1) Lateritic zheltozem belt under quasi-tropical monsoon forest at valley bottoms(2) Zheltozem belt under montane subtropical evergreen broad-leaf forest(3) Yellow brown soil belt under montane quasi-subtropical semi-evergreen broad

leaf forest(4) Montane brown soil belt developed under coniferous forest of warm- temperate

zone(5) Montane podzolic soil belt under montane coniferous forest of cool temperate

zone(6) Subalpine meadow soil belt under subalpine shrub and meadow of frigid zone(7) Alpine meadow soil belt of cold zone

I Chinese soil taxonomy (2nd draft)

GEO-ECOLOGY OF MTS. NAMJAGBARWA REGION

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4300- Alpine cold desert soil belt under alpine crust lichen2-3 200-120 39-23 6.9-5.4

~ offreezin p and weathering:3900- Alpine meadow soil belt of cold zone 12.0 67 5.2-5.8

143003600- Sub-alpine shrub meadow soil belt under sub-alpine

13.6 410-310 24-10 4.1-5.413900 shrub and meadow of cold zone2800- ~ Montane podzolic soil belt under dark coniferous Mg'+ 13-14 510 53 4.0-4.73600 ;;; forest of cool temperate zonenoo:- ~ Montane brown soil belt under montane coniferous Ca'+ 2-5 450-280 42-8 4.6-5.312800 and broad-leaf mixed forest of warm temperate zone

'" 34.7-1900- Montane yellow brown soil belt under montane sol 9-10 420-370 4.8-5.\12300 IQuasi-subtrooical semi-evergreen broad-leaf forest 23.81100- Montane zheltozem belt under montane subtropical

HCO; 8-9 380-150 13-5 5.4~ evergreen broad-keaf forest600- Lateritic zheltozem belt under quasi-tropical

2-25 390-290 27-21 4.41100 monsoon forest at valley bottom4700- Alpine cold desert belt under alpine cruit-like lichen Na+ 2-3 200-120 39-23 6.9-5.4

15000 of freezin<> and weathering:4500- Alpine meadow soil belt under alpine meadow of

\4.5 290-210 38-52 5.0-5.1~ 8. cold zone sol4\00- ~ Sub-alpine shrub meadow soil belt under quasi- HCO l 4-5 220-770 22-14~ '€ aloine thicket ofcold zone Ca2+3200- ~ Montane podzolic soil belt under dark coniferous Mg2+

9-10 182-30 165-23 5.0-5.1~ forest of cool temoerate zone

<3200Montane brown soil belt under coniferous and HCO,

3-4 160-90 34-19 6.9broad-leaf mixed forest of warm temperate zone Ca2+ .

Figure 13-1 Comprehensive profile of main ecological characteristics of vertical belts at Mt.Namjagbarwa Region (PENG and DOU,1996)


13.2.2 ECOSYSTEM CHARACTERISTICS OF VERTICAL ZONE ATNORTHERN SLOPES

Natural landscapes at northern slope are characterized with dense forestsdominated by Picea likiangensis and Abies georgei, and simple structure. Treecanopy of Abies forests is in good shape and mosses grow rapidly on the grounddue to increasing of humidity with higher altitude. Coniferous forests are composedof Sino-Himalayan elements. Corresponding with increase of altitude vegetationturns gradually into alpine meadow. Podzolic soils under montane coniferous forestdominate in the vertical belt. Under cold and humid climate bio-chemicalweathering is main process. Podzolic soils are characterized with underdeveloped,obscure boundaries between layers, obvious accumulation and high content oforganic matter. Without CaC03 in soils leaching is strong though weaker than thatat southern slopes. Accumulation of Al and Fe is obvious at certain depth. Verticalchanges of soils and vegetation are notable.

Animals are abundant in species, consisting mainly of fauna from Palaeoarcticregion, such as mammals of Moschus sifanicus, Mustela sibirica, etc; birds ofPhylloscopus trochiloides and Tetrastes sewerzowi. Species of amphibian andreptile such as Rana temporaria and Japalura splendida. Fungi include Tricholomamatsutake, Cortinarius torvus and so on.

In middle reaches of Yarlung Zangbo the valley becomes broader with slowerflow of the stream. It flows into lower reaches at Yidian, Paiqu, Mainling Countywith rapidly river flow. Tributaries of Yarlung Zangbo at northern slopes, exceptNyang Qu and Palung Zangbo, are shorter than those of southern slopes and havelarger gradient ratio and many falls. Due to lower precipitation, intensity of runoff,supplied mainly by melting water from snow and ice, is relatively smaller and depthof less than 600mm. Degree of mineralization of tributaries is of more than60mg*L'( and higher than that of tributaries at southern slopes. Hydro-chemicaltype is HC03-S04-Ca-Mg (PENG & DOU, 1996).

Vertical belts at northern slopes of Mt. Namjagbarwa region are as follows:(1) Montane brown soil belt under broad-leaved and coniferous mixed forest of

warm temperate zone.(2) Montane podzolic soil belt under coniferous forest of cool temperate zone.(3) Shrub meadow soil belt under sub-alpine cold zone.(4) Alpine meadow soil belt under alpine meadow of cold zone.(5) Alpine cold desert soil belt under crust-like lichen of alpine freezing weathering

process.

13.3 Structure and Regional Differentiation of Vertical Zonation

In a broad sense ecological characteristics of Mt. Namjagbarwa region can bedivided into two structural groups: humid structure-type group on southern slopesand subhumid structure-type group on northern slopes (ZHANG Rongzu et al.,


1982; ZHENG Du et al., 1985). They are further subdivided as follows (PENG andDOU, 1996):

Humid structure-type group(1) Valley quasi-tropical belt with monsoon forest and yellowish lateritic red

soil(2) Montane subtropical belt with evergreen broad-leaved forest and montane

yellow soil(3) Montane quasi-subtropical belt with semi-evergreen broad-leaved forest

and montane yellow brown soil Semi-humid structure-type group(4) Montane warm temperate belt with broad leaf and coniferous mixed forest

and montane yellow brown soil(5) Montane frigid-temperate belt with montane coniferous forest and bleached

podzol.Apparent differences in vertical zonation on northern and southern slopes can

be explained in terms of variation in moisture corridor along the Yarlung Zangbo,the effects on studied region of snow and ice cover, and development oftemperature inversion (PENG, 1996).

13.3.1 INFLUENCE OF MOISTURE CORRIDOR

Moisture corridor influences precipitation both in spatial distribution and rainyperiod. The 1,000mm isohyet extends along the bending of Yarlung Zangbo withYi'ong in the north forming a tongue-like high precipitation area. Stretchingorientation of the tongue-like area conforms to moisture transferring direction.Rainy period at the north of Himalayas is usually one or two months later than thatat the south of Himalayas due to the obstruction of mountains (GAO et al., 1985).Aridity at the tongue-like area is less than 1.0 and increasing to 1.0-1.5 at Bomi andMailing. It makes characteristics of vertical zonation changing from humidstructure-type group to subhumid structure-type group as mentioned above.Existence of moisture corridor also brings about differences in geo-ecologicalfeatures of some vertical belts. For example, montane warm-temperate broad-leavedand needleleaved mixed forests on southern slopes of Mt. Namjagbarwa aredominated by Tsuga durnosa, Acer caudaturn, and other species demanding highhumidity, such as epiphytic lichen Usnea longissirna. Montane acid brown soil hasobvious humus accumulation, strong leaching and eluviation. In northern slopes themixed forest consists chiefly of dominant species with certain drought-resistantplants, such as Pinus densata and Quercus aquifolioides. Montane brown soil ischaracterized with a neutral reaction, less humus accumulation, and weak leaching.Existence of moisture corridor causes altitude variation of vertical belts. Spectrumwidth differs at northern and southern slopes due to influence of aridity andespecially of slope exposure.

Moisture corridor has given rise to strong influence on creatures in studiedregion. Humid tropical montane forest ecosystem extends along the valley at lowerreaches of the Yarlung Zangbo to 29°30'N, where most of typical tropical creatures


reaching their northern limits in horizontal distribution and upper limits in verticaldistribution. Because of the corridor linking up mixture access and acceleratingintercourse and intermix of creatures between northern and southern slopes, lowerreaches of the Yarlung Zangbo become an important center for speciesdifferentiation and speciation due to forming of various habitats. Moisture corridor,providing superior vertical ecological conditions and shelter for ancient species,plays an important and decisive role in forming of Sino-Himalaya Realm. Thecorridor area is abundant in creature species of the Tibetan Plateau (YANG et al.,1987).

13.3.2 IMPACT OF SNOW AND ICE COVER ON VERTICAL ZONATION

Proximity to ice and snow fields in mountainous terrain leads to two sets ofprocesses, which influence vertical ecological zones. First, prevalence of physicalweathering combined with steep gradient results in abundant rock fal1s, debriscones and other mass movement activities. Slope instability can 10cal1y interruptsoil formation and development, as well as establishment of alpine meadowvegetation. Secondly, snow cover has an influence on microclimate. A localcirculation, known as "glacier wind" develops on margins of snow cover and cansignificantly reduce boundary layer temperature on land adjacent to snow patches.More important is difference in temperature. Characteristics between the underlyinghorizon of snow and ice cover, and the non-snow and ice cover are quite different.Snow and ice cover has a strong ability in reflecting short-wave radiation and thealbedo could be higher than 0.7. Temperature on snow and ice cover is much lowerthan that on non-snow and ice cover, which leads to variation in distribution limit ofvertical belts at southern and northern slopes. Local variations in transition betweenvertical zones results in central part of Mt. Namjagbarwa massif where mountainpeaks are snow covered, the upper limit of montane frigid-temperate zone with darkconiferous forest and montane bleached podzol is typical1y at elevation of 4,000mas!. By contrast, in the front range mountains without snow cover the upper limit ofmontane frigid-temperate zone extends to altitudes of 4, 100-4,300m as!. This isfurther exemplified by Suila Pass in the Gangrigabo Ridge: here the dark coniferousforest extends to 4,300 m asl in the absence of snow-covered peaks, so that anysequasite subalpine shrub zone is highly compressed and soon gives way to alpinefrigid meadow zone (PENG et al., 1997).

Local circulation and strong weathering process often superpose on each otherand thus have a more obvious influence on neighboring vertical belts.

13.3.3 INFLUENCE OF TEMPERATURE INVERSIONS ON VERTICALZONATION

Temperature inversion, caused by nature of topography, is a naturalphenomenon. Where landforms benefit the forming of temperature inversion thephenomenon becomes more apparent. Influence of temperature inversion on


distribution limit of vertical zonation and development of landscapes has got muchattention (PENG et al., 1980).

Yi'ong basin has width of 2-3km and a relative height of 3,000-4,000 m frombasin floor to surrounding mountains. According to sounding data, lower inversionlayer of Yi'ong may reach to 250-300m in July and August, the height of inversionlayer may extend up to about 2,400-2,500 m asl in summer and about 2,500-2,600m in winter. Mean temperature in Yi'ong basin for January and July are 3.3 and18.1°C respectively and temperature gradient above the inversion layer increases at0.59°C per 100m. ThoC refore mean temperature of warmest month of the inversionlayer exceeds 19°C and the coldest at about 4.5-5.0°C. Although the montanequasi-subtropical zone with semi-evergreen broad-leaved forest and montaneyellow brown soil is commonly met with between altitudes of 1,900 and 2,300 masl in Mt. Namjagbarwa area, its upper limit in Yi'ong basin increases to2,500-2,600 m asl due to the influence of inversion. However there is no inversionof vertical zonation. In Mt. Namjagbarwa region the montane yellow soil beltdeveloped under evergreen broad-leaved forest of subtropical zone has meantemperature of the warmest monthly of 19-22°C and the coldest temperature of6_10°C. Temperature on top of the inversion layer at Yi'ong basin is lower thantemperature conditions demanded by forming of montane yellow soil and growth ofevergreen broad-leaved forest of subtropical zone. Montane yellow soil belt couldnot develop in areas around the inversion at Yi'ong basin and so there is noinversion of vertical zonation (PENG & DOU1996; PENG et al., 1997).

13.4 Land Utilization and Conservation

Mt. Namjagbarwa Region is low in population density and abundant in naturalresources. Due to difficult of access and inconvenient transportation most areas offorests haven't been fully exploited. Economic foundation is still weak despite thenotable growth in national economy. Average food yield per ha of Mt.Namjagbarwa Region is far too lower than that of the whole country because oflagging-behind management and techniques. Debris flows and water-induced soilerosion threatens human environments and influence social and economicdevelopment. Under available social, economic, technical and managementconditions abiding by evolvement law of nature reasonable counter-measures havebeen proposed to solve existing problems and to protect land resources for furtherutilization.

13.4.1 LAND UTILIZATION SITUATION

With population of more than 50,000 in Mt. Namjagbarwa region, the industryand agriculture production value accounts for 1/10 of that of Tibet. Agriculture,with agricultural production value of 85% of GOP, is prop of regional economy instudied region. Proportion of farming in total output value is much larger than thatof other three sub-sectors. Proportion of farming land accounts for only 0.27% of


total land area, of woodland 35.75% and of pastureland 32.80%. Out of proportionbetween structure of agricultural output and land structure hints problems in landutilization (BAO Haosheng, et al., 1996).

Decrease offorest resources and imbalance offorestry environmentBased on inventory in Mt. Namjagbarwa Region there are forest areas of about

1,297,000 ha with timber accumulation of 283 million m3 (Table 13-2). Annualproduction of timber could reach 2.5 million m3, while annual exploitation only273,000 m3

• Forest areas and standing crop are decreased year by year due to lackof comprehensive forest planning and low level of management.

Table 13-2 Forest resources in Mt. Namjagbarwa Region (BAO Haosheng, et aI., 1996)

Total land area Area of wood land Coverage (%) Timber stockingCounty (10,000 ha) (10,000 ha) (100 million m3

)

Medog 89.5 55.6 62.1 1.39

Bomi 148.8 40.9 27.5 0.70

Nyingchi 76.8 20.1 26.9 0.47

Mailing 47.7 13.1 27.4 0.27

Total 362.8 129.7 2.83

Decreasing of forest resources, caused by over logging without planting, isquite serious at areas along main roads and around villages. By rough investigationforest areas in Nyingchi County were 2,300 ha decline. Forest fire usually causesreduction of forest areas, for example, forest caught fire 9 times and loss forest ofmore than 1,300ha in Mailing County in 1980. In addition, most of forests are overmatured to suffer decay and illnesses; therefore, average timber accumulation offorest comes to 200m3 per ha accounting only for 1/4 of peak yieW of the forest (L1Wenhua, et al., 1985).

Imbalance of forest ecosystems caused by over logging leads to loss of wildplants and animals. In Nyingchi Country 22kg of muskiness could be supplied eachyear in the 60s while only 1kg could be supplied in the 70s. Deterioration ofenvironments also affects lives of dwellers, sometimes even forces them to migrateto other places.

Extensive cultivation system hasn'tfully exploited the potential ofarable landCultivation land, with an area of 9.76 thousand ha, distributes sparsely along

Yarlung Zangbo River valley up from Yidian, the Palung Zangbo valley up fromTongmai and broad valleys of Nyang Qu and Jinzhu Qu. As regards land utilizationstructure cereal crops account for 88.88%, while the rest for economic crops, suchas ripe, cotton, hot pepper, tobacco and tea. Rice is main crop in Medog County,while winter wheat, corn and buckwheat in other counties. Food production

2 LI Wenhua, Forest in Tibet, 1983


increases four times in recent 20 years, with annual yield of 2.4million kg. It couldbe self-sufficient basically and sometimes the surplus could be used to support otherregions.

Moisture and temperature conditions in Mt. Namjagbarwa Region arefavorable with organic matter content in soil of about 4%, which are good for cerealcrops growing. Cereal yield with 3.95 ton'ha- ' is higher in Medog County, whileaverage yield is only 2.49 ton'ha- ' in Mailing County. Average yield per unit area ofabout 3 ton'ha- I in studied region is much lower than that of whole country. There isstill much room for improvement in cereal yield per unit area.

Farming lands only account for 0.27% of total land area in studied region.With average cultivated land per person of 0.2 I ha each labor should share burdenof 0.53-6.0 ha. Poor personal quality, low management level, inconvenienttransportation and extensive cultivation system prevent full exploitation of cerealproduction potential. In addition, most farmlands are seldom fertilized and withoutguarantee of irrigation availability, suffering from illnesses and harmful insects, andbringing about decrease of the output. Low-yield farmland with an area of 533.3 haaccounts for about 1/4 of the total area of cultivated land in Mailing County.

Improper cultivation gives rise to waste of land resources. Dwellers burn forestfor arable lands and after several years of extensive farming they migrate to otherareas to repeat same activities. The land they left behind becomes wasteland andcould not be utilized anymore due to thinner soil layer. This situation is especiallyserious in areas where inhabit minority of Menba and Luoba nationalities. Localdwellers reclaim on alluvial and diluvial fans on which soils are usually sandy intexture with low in fertility, water-leakage and usually threatened by flood. Averageyield is 1.5-2.25 ton'ha- I in ordinary years and less than 750kg'ha-1 if there isdrought. Before land reclamation soils are characterized with soil layer of 70-80cmin thickness, ashy black in color and high content in organic matter. But afterreclamation soil layer rapidly decreases to 40-50cm with content of organic matterof 1%-2%, which even makes no grass could grow on the soil after it has beenutilized for several years.

Over herding causes degradation ofpasturesAnimal husbandry is not important in internal structure of agriculture,

although livestock has doubled to 229 thousand since the 1950's. It is hindered bylack of forage. There are 80 thousand domestic animals in Mailing County withpasture areas of 8.44 thousand ha increased by 25% in the last 20 years.

Winter pastures in southeast Tibet are usually located below altitudes of4,000m asl and summer pastures at altitudes up to 4,500m asl. Below altitudes of4,000m asl there are broad-leaved and needle-leaf mixed forests on sloping-lands.Shrub pastures only distribute at river terraces in broad valleys and on diluvial fans.Although these pastures could be utilized for grazing they are poor in grass qualityand in contradiction with cultivated land for crops. The phenomenon is quitedistinct in Mailing County. Pastures in subalpine shrub meadow and alpine meadowbelt above altitudes of 4,000m asl are large in areas and good in grass quality, but


due to inaccessibility with poor transportation and beast threaten by wild animalsthey have not been utilized yet. Limited pastures especially lack of winter pasturesrestricted further development of husbandry in Mt. Namjagbarwa Region. Poormanagement, lack of improvement in breed and backward techniques lead toincreasing frequency of illness in animals and low commodity rate, so animalsshould be imported through exchanges each year to satisfy dwellers' need.

Degradation of pastures is especially serious in areas around dwellings, whereshrub grasslands are over-herding and degenerating into shrubby thickets withcoverage decreasing from 600/0--70% to 200/0--30%. Animal husbandry is threateneddue to grass quality declined and production decreased.

Water induced soil erosion intensifies and land resources damagedDue to active neo-tectonics land surfaces are cut and sawed strongly with steep

sloping-lands everywhere in Mt. Namjagbarwa Region. Corresponding withchanged environments water induced soil erosion readily happens and acceleratesdebris flows.

Large area of forests has been logged with irrational land utilization and overherding has caused decreasing of land coverage. All these lead to intensification ofwater induced soil erosion. Owing to mud and sand content in rivers increasing andriverbed heightened the flood keeping ability decreases which make landssusceptible for floods. Water induced soil erosion encroach not only directly landsfor agriculture but also lead to loss of land resources indirectly. Frequency of floodis increased with heightening of riverbed in Nyang Qu. Farming lands of 113.3 hawere inundated in 1980 and 111.3 ha were destroyed in 1982. Debris flowsaccelerated by intensification of water induced soil erosion also damage a lot ofarable lands.

13.4.2 REASONABLE UTILIZATION AND PROTECTION OF LANDRESOURCES

In Mt. Namjagbarwa Region the people lived in poverty with crude andextensive cultivation system in the long-time. Since 1950's productivity has beenenhanced but the national economy foundation is still weak. With increasing ofpopulation the pressure on land resources becomes heavier. Without guide ofscience and technology, irrational land utilization leads to deterioration ofenvironments, which hinders further development of economy and society.According to studies on land utilization in Mt. Namjagbarwa Region severalstrategies in land utilization and protection have been proposed as follows (BAOHaosheng et al., 1996):

To make good planning for land utilization according to natural and socialconditions

Vertical variation in land utilization is quite obvious in Mt. NamjagbarwaRegion. Lands are utilized for farming, forestry and animal husbandry. Farming


land is mainly located at valley bottoms or part of sloping lands. Natural forestsusually occur on mountains and in between small patches of grasslands. From upperforest limit upward the alpine belt are commonly used for pastures. Two crops,including winter wheat, rice, and corn could grow at altitudes of 2, IOO-2,300m aslin valley bottom of the region. Main crops such as corn, buckwheat, potato, springwheat and winter wheat are usually of one harvest a year or three harvest two yearsin lands or sloping lands from altitudes of 2,100-2,300m to 2,800-3,100m as!.Main crops, including winter and spring wheat may grow at altitudes of above2,800-3,lOOm asl in valleys of branches. According to vertical differentiationpattern of arable lands the Mt. Namjagbarwa Region with suitable temperature andmoisture regimes is favorable for agriculture development. The limited arable landsshould be made full use for rice and tea production in recent years while in thefuture focus would be put on timber forests and economic forests(CHEN,etal.,1983). Forest resources exist mainly in humid and sub-humid region, being mainlogging areas of Tibet. Agriculture development would focus on cereal crops incultivated land and timber forest production.

To strengthen basic construction offarming lands and enhance per unit yieldBasic ways to increase food production include innovation of extensive

farming system, strengthening field management, focusing on farming landconstruction and enhancing ability to resist natural disasters. Precipitation inNyingchi, Bomi and Mailing counties is abundant and thus it could satisfy needs ofwinter wheat having a higher demand for water consumption. Crops yield onirrigated lands could increases greatly provided that irrigation systems are better.Irrigated lands account for about 50%....60% of total area of farmlands, butproportion of effective irrigated land is less than 40% due to lack of maintenance ofirrigation systems. Abundant water resource has not been fully utilized. Farmlandson alluvial fans at valley entrances to river branches are susceptible for flood inrainy season and drought in dry season. More attention should be paid toconstruction of hydraulic engineering in order to enlarge irrigated land areas.Resistant ability of farmlands to natural disasters should be enhanced. Landutilization and protection should be combined together to improve soil fertility.Farmlands on slopes should be turned into terrace lands or platform lands to keepfertility and conserve water and soils.

Mt. Namjagbarwa Region, characterized with intensive solar radiation, andheat availability, is favorable for wheat cultivation. Crops with longer growingperiod have higher yield. Average yield per unit area is far below the highest yieldthat could be achieved. Measures, such as strengthening field management,extension of good varieties, prevention of illness and harmful insects, improvementof soil properties and water .conservation should be taken to increase yield per unitand establish a better agro-environments.

Deforestation for reclamation should be prohibited and extensive farmingsystem should be changed in areas inhabited by Menba and Luoba nationalities.Reclaimed lands should have a longer fallow period to restore soil fertility and


farming lands should not be enlarged. Non-tillage cropping would be extended torestore soil fertility in areas where labor is insufficient. Fertilizer and pesticideutilization should be strictly controlled. Crop rotation and inter-cropping withleguminous plants could be used to prevent illness and harmful insects so that yieldcould increase.

To strengthen forestry planning andprotectforest resourcesStrengthening forestry planning and protecting forest resources will benefit

economy development and soil and water conservation in Mt. Namjagbarwa Regionand improve production conditions of farming and animal husbandry.

Forests, with high stocking amount per capita and low illness and rotten ratio,grow rapidly in long growth duration. According to investigation on Picea forestwhose dominant growth duration lasts 200years in Bomi County, forest-stockingamount per ha is about 2,000m3 with annual mean growth amount of more than 10m3'ha-1 and low illness and rotting rate. From Bomi to Nyingchi with ascending ofaltitude and decreasing of precipitation trees are usually lower than 50m in heightwith stocking amount per ha of less than 800 m3

• Average stocking is 200 m3·ha- 'with annual average growth amount of 2 m3'ha- ', which shows much potential inforestry development in Mt. Namjagbarwa Region.

Forestry planning should be carried out in order to exploit forest resourcesrationally. Exploitation of mature and over-mature forests under precondition ofwater and soil conservation would be reasonable way for coordinating developmentand environments in Medog County. Natural regeneration of forest accompanied byartificial renewal is usually helpful for forest restoration. Management of loggingshould be strengthened in Bomi, Nyingchi and Mailing counties. Updating speed offorest regeneration should catch logging speed and logged woodland could berestored. Much attention should be paid to construction of timber forests, fuelforests and protection forests of farming land in Nyang Qu, so that timber and fuelneeds could be satisfied and preventing soil from water induced erosion. In addition,training for forest workers and enhancing management abilities are necessary forsustainable utilization of forest resources.

Establish production bases for economic crops and develop diversified economyQuasi-tropical climate is characterized with annual mean temperature of above

16°C and frost-free in winter at altitude of below 1,000m asl in the Yarlung Zangbovalley in Medog County. Economic crops and fruits of tropical region, such ascoffee, cocoa, and mango, pineapples, etc. could try planting in the future. Ataltitude of 1,100;'"I,400m in valley areas subtropical climate is characterized withmean temperature of more than 17°C in warmest month and annual precipitation ofabout 2,000-3,000mm. Economic crops such as sugarcane, tobacco, hot pepper andtea have been planted. Hot pepper with large planting area is one of main exchangeproducts for Menba and Luoba nationalities in Medog County. Hot pepperproduction would be enhanced in Medog County. There are more than 20 ha teagardens with annual production amounting to 15,000 kg in Medog, Bomi and


Nyingchi counties. It should be built as one of tea production bases in Tibet. Fruits,such as banana and orange of subtropical region have been planted and maydevelop gradually to satisfy needs of local people.

Warm temperate climate is suitable for growth of walnuts, apples, pears, andpeaches and so on in Mailing, Nyingchi and Bomi County. Wild walnut with highcontent in oil could be widely planted. Apple production reaches 130,000 kg a year.If transportation, processing and storing problems could be resolved and improved,there will be much potential of fruit development in the region. If then, Mt.Namjagbarwa Region would be an important production area for fruits andeconomic crops in Tibet.

Control development ofanimal husbandry and improve livestock qualityAt valley lands below altitude of 2,500m asl there are a few grasslands for

seasonal grazing of animal husbandry with stockbreeding, consisting chiefly ofcattle, pigs and goats. Cattle and goats graze mainly at higher altitude between2,500~3,000m asl where farming, forestry and animal husbandry combiningtogether, because grass yield and coverage are high with unpalatable. At altitude of4,000m asl where meadow pastures spread only yak could be raised in summer,because of inconvenient transportation and lack of forage in winter. Therefore,natural conditions are unsuitable for animal husbandry development in the region.

There are already some bases for animal husbandry and production of butterneeded by Tibetan people in daily lives could not depend on other regions. So it isnecessary to keep stocking at a stable scale and focus on development of edibleanimals. Key issue is to solve problem of insufficient forage in winter by measuressuch as strengthening management, improving grass variety, increasing grass yieldper unit area and constructing winter pastures. At the same time stocking structureshould be adjusted, such as discarding old or ill animals, raising ratio of dam,introducing good breeds and hybridize technology to improve breed and increasemeat production. Reasonable ratio of pigs, cattle, sheep to goat should be 4:3:2:1 inwhole stocking structure.

References

1. BAO Haosheng, PENG Buzhuo and YAN Weiyun, 1996. Rational utilization andconservation of land resources. In: Physical Geography and Natural Resources in theMount Namjagbarwa Region. Science Press, Beijing, 362-373. (in Chinese)

2. CHEN Hong, et aI., 1983. Regional differentiation of agriculture on the Qinghai-XizangPlateau. Natural Resources o/Xizang, CISNAR, 283-289. (in Chinese)

J. Committee of Agricultural Regionalization of China, 1984. Outlines on PhysicalRegionalization o/China. Science Press, Beijing. (in Chinese)

4. Committee of Physical Regionalization of China, 1959. Integrated Physical Regionalizationo/China. Science Press, Beijing. (in Chinese)

5. GAO Dengyi, ZOU Han and WANG Wei. 1985. Influence of the vapor corridor of YarlungZangbo River on precipitation. Mountain Research, 3 (4): 239-249. (in Chinese)

6. LI Bosheng, 1985. Horizontal belts of vegetation in Mt. Namjagbarwa Region. MountainResearch, 3 (4): 291-298. (in Chinese)

282 PENG B. Z., BAO H. S. and PU L. 1.

7. LI Jijun, et al., 1979. A discussion on the period, amplitude and type of the uplift of theQinghai-Xizang Plateau. Scientia Sinica, (6): 608-616. (in Chinese)

8. LI Wenhua, et al., 1985. Forests ofXizang (fibet). Science Press, Beijing. (in Chinese)9. LIN Zhenyao and WU Xiangding, 1984. Vertical climatic belts ofMt. Namjagbarwa Region.

Mountain Research, 2 (3): 165-173. (in Chinese)10. MAO Xiaolan, 1985. Fungus resources of Mt. Namjagbarwa Region. Fungus Acta, 4 (4):

197-207. (in Chinese)II. Nanjing Institute of Soil Science, CAS, 1978. Soils of China. Science Press, Beijing. (in

Chinese)12. PENG Buzhuo and DOU Yijian, I996.Landscape characteristics of vertical natural zones. In:

PhysicalGeography and Natural Resources in the Mount Namjagbarwa Region. SciencePress, Beijing, 239-268. (in Chinese)

13. PENG Buzhuo and NI Shaoxiang, 1980. Vertical natural belts on Mt.Tomur, Tianshan,Xinjiang. Journal ofNanjing University (Nature science), 26(4): 131-148. (in Chinese)

14. PENG Buzhuo and YANG Yichou (ed.), 1996. Physical Geography and Natural Resourcesin the Mount Namjagbarwa Region. Science Press, Beijing: 1-387. (in Chinese)

15. PENG Buzhuo, 1984. Preliminary research on vertical belts of Mt. Namjagbarwa Region.Mountain Research, 2 (3): 182-189. (in Chinese)

16. PENG Buzhuo, 1985. Soil Types of Mt. Namjagbarwa Region. Mountain Research, 3 (4).(in Chinese)

17. PENG Buzhuo, 1996. Regional differentiation of vertical natural zones and distribution oflandscape Types. In: Physical Geography and Natural Resources in the MountNamjagbarwa Region. Science Press, Beijing, 268-275. (in Chinese)

18. PENG Buzhuo, PU Lijie, BAO Haosheng and D.L.Higgitt, 1997. Vertical zonation ofecosystem characteristic in the Namjagbarwa Mountain massif of Tibet, China. MountainResearch and Development, 17( I): 43-48.

19. REN Mei'e et aI., 1979. An Outline ofChina's Physical Geography. Commercial PublishingHouse, Beijing. (in Chinese)

20. REN Mei'e, 1982.Quasi-tropical zone in China. Journal ofNanjing University (geography).6 (I). (in Chinese)

21. WANG Zuxiang, 1982. Realm Belongs of birds in Medog County. Tibet. Journal ofPlateauZoology, (I). (in Chinese)

22. YANG Lihua and LIU Dongsheng, 1974. Neotectonics movements at Mt. Qomolangma.Geology Science. (2). (in Chinese)

23. YANG Yichou, GAO DengYi and LI Bosheng. 1987. A preliminary study on the vaporchannel in the lower reaches of the Yarlung Zangbo River. Scientia Sinica (B), (8): 893-902.(in Chinese)

24. ZHANG Rongzu, ZHENG Du, and YANG Qinye, 1982. Physical Geography of Xizang(Tibet). Science Press, Beijing. (in Chinese)

25. ZHANG Xinshi, 1978. The plateau zonality of vegetation in Xizang. Acta Botanica Sinica,20 (2): 140-149. (in Chinese)

26. ZHENG Du and CHEN Wei lie, 1981. A preliminary study on the vertical belts of vegetationof the Eastern Himalayas. Acta Botanica Sinica, 23 (3): 228-234. (in Chinese)

27. ZHENG Du and YANG Qinye, 1985. Some problems on the altitudinal belts in southeasternQinghai-Xizang Plateau. Acta Geographica Sinica, 40 (I): 60-69. (in Chinese)

28. ZHENG Xilan, 1979. Geological features at the lower reaches of Yarlung Zangbo River.Geology Science, (2). (in Chinese)

CHAPTER 14 DRY VALLEYS IN HENGDUAN MTS REGION

YANG Qinye

Dry valleys, in terms of "Gan Bazi" (try valley) or "Game Bazi"(try and hotvalley) by local people, are widely distributed in deep cut river valleys in mountainreanges surrounding the south and east Tibetan Plateau, but more concentratelypositioned in the Hengduan Mountains along Nujiang (Salwen River),Langcangjiang (Mekong River) and tributaries of upper reach of Yangtze River inwest Sichuan and northwest Yunnan Provinces. In these dry valleys, with highertemperature and less precipitation, farmland on terraces and slopes, which accountabout 90% of total farmlands, are most important in the mountains area, and riverwater can be barely irrigated. So population density is also relatively high there.Thus research on the try valley is not only attentioned by geo-ecologists but also bythe local people and governments to meet requirement of sustainable mountaindevelopment.

14.1 Geo-Ecological Features and Type Classification

The dry valley phenomenon, on the viewpoint of physical geography, refers tobottom of dry valleys that surrounded by more humid environments relatively, i.e.,dry valley is incorporating humid, sub-humid, or semiarid landscapes. Suchphenomena were noted in the Alps and Himalayas. In middle Himalayas, there issmall leafed thorny shrub from Nepal to Bhutan, such as Euphoria royleana. EvenZayuhe Valley with Pinus yuannanensis is also regarded as typical dry valley,which is, however not the same as humid forests types surrounded (LIU Dongshen(ed.), 1981; Schweinfurth, 1972).

In general, xerophyte of vegetation type and plant ecotype is visible, which isrelated with climate condition. But many types of vegetation have wide range ofadaptability in any secondary development situation, which may not reflect themacro-scale climatic situation. In terms of "Gan Bazi", it also contains socialeconomic meaning. So, dry valleys are neither evaluated by absolute climatologicindices, which are usually to classify drought types, nor do reflect desert or desertsteppe and desert soil. However, the bottom boundary of mountain forest isconspicuously restricted by moisture factor.

Annual aridity is generally used as a main reference to demarcate dry andhumid climatic types. Potential evapotranspiration is the greatest potentialevapotranspiration capability when water is provided sufficiently. Generally, it is

283

ZHENG Du, ZHANG Qingsong and WU Shaohong (eds.), Mountain Geoecology and Sustainable Development oftheTibetan Plateau, 283-302.©2000 Kluwer Academic Publishers.

284 YANGQ. Y.

calculated by mathematical function. We use H.L. Penman function for calculatingevapotranspiration, which is rectified by altitude. Aridity is an important criterion inrepresenting status of moisture in certain region. Table 14-1 shows comparedcriteria of aridity that were used by precursors in classification of moisture status.

Table 14-1 The comparison of criteria on aridity

Classification Humid Sub-humid Semi-arid AridExtremely

Referencearid

>2.0

<1.0 1.0-1.5 Steppe, LIN Zhiguang,1.5-2.0Whole China Forest, Steppe forest, Desert - QIAN Jiliang,

Brush-field Shrub-steppeSteppe

steppe, 1965

desert

CHEN Jixian andWhole China <0.99 1.00-1.49 1.5-3.99 >4.0 - ZHANG Baokun,

1965

The world <1.33 1.33-2.0 2.0-5.0 5.0-33.3 >33.3 UNESCO, 1977

3.5-16 "Physic-geography<1.0 1.0-1.6 1.6-3.5 >16.0

Whole China Semi- in China-Clamate"Forest Steppe-forest Steppe desert

1984desert

6.0-20.0 ZHENG Du,Tibetan 1.0-1.5

<1.0 1.6-6.0 Desert >20.0 ZHANG Rongzuplateau of

ForestForest

Steppe steppe, desert and YANG Qinye,China meadow

desert 1979,1982

In comparison with indices of climatic regionalization in China, annual aridityin dry valley is about 1.5-5.0. Annual aridity at most stations in dry valleys ofHengduan mountains area vary between 1.5-3.99 belonging to semiarid type excepta few stations which annual aridity more than 4.0. Some parts are also regarded asdry valleys because of poor vegetation covering, intensive soil erosion and shortageof irritate water resources. In fact, these valleys are not real dry valleys. Evidencesshow that these valleys had ever been covered with mountain forests and physicgeographical conditions are beneficial to mesogenous arbor and shrub woods thatare easier to recover after destroyed.

Dry valleys in Hengduan Mountains could be classified into three types, i.e.,dry-hot, dry-warm and dry-temperate (Table 14-2), reference to vegetation, soil, andcrops. Further more, the three types of dry valleys may be classified into three subtypes, i.e., semi-arid which inclines sub-humid, semiarid, and semiarid whichinclines arid (Table 14-3). Therefore, three types and nine sub-types based oncombination of temperature and moisture, can be distinguished (Table 14-4).

Distribution of dry valleys in Hengduan Mountains is shown in Figure 14-1.

DRY VALLEYS IN HENGDUAN MTS REGION

Table 14-2 Criteria for the classification of dry valleys in Hengduan Mts. Area

285

Type Dry- hot Dry- warm Dry- temperate

Average temperature >12 (0C) 12-5 (0C) 5-0 (0C)in the coldest month

Average temperature 28-24 (0C) 24-(20)22 (0C) 22-16 (0C)in the hottest month

Days of over lOOCdiurnal average >350 (0C) 350-251 (0C) 250-151 (0C)temperature

*Shrub-grass with * Shrub-grass with* Broad-leaved deciduous

trees scattered (Dry trees scattered (Pineshrub (Pine or oak forest)

Extant vegetation monsoon forest), or oak forest) * Small-leaved thorny

(Original vegetation) * Small-leaved meso- * Small-leavedshrub (Pine Huniper forest)

* Small-leaved thorn letshrub (Pine or oak deciduous shrub (Pineshrub (Open pine-juniperforest) or oak forest)forest)

Type of soil Dry laterite Brown laterite Brown earth

Sugarcane, double Sugarcane, wheat, Wheat, corn, generallyAgricultural status cropping of rice, three rice, harvesting double-harvesting by dry

harvests a year biannually farming

Table 14-3 Sub-types of dry valleys

Sub-typesSemiarid inclines sub-

Semiarid Semiarid inclines aridhumid

Annual aridity 1.5-2.0 2.1-3.4 3.5-5.0

Aridity during<1.0 1.0-0.4 1.5-3.9

rainy season

Precipitation is in time Precipitation is in time Low production andAgricultural status high production with relatively low production instable without

irrigation without irrigation irrigation

Table 14-4 Sub-types of dry valleys

Sub-types

1. Semiarid inclines sub-humid

2. Semiarid

3. Semiarid inclines arid

I. Dry-hot II. Dry-warm III. Dry- temperate

The classification mentioned above is conducted by analysis and comparisonof data from meteorological stations hydrographic stations along rivers. In addition,on account of secondary environment impacts, some dry valleys may be ignored orenhanced.

286 YANGQ. Y.

-_=:t=:'m.i 1aJ

<:::::::::::, H D'Y·........, 1- ...-.:u... ........2-Se.uuid

~::;. T Dry- 1Unpm&e \'alley 1- Seal6Idd dLa

iDcIuarid

Figure 14-1 Map of dry valleys in Hengduan Mountains

14.2 Formation and Regional Differentiation

14.2.1 REGIONAL DIFFERENTIATION OF THE DRY VALLEYS IN THEHENGDUAN MTS. REGION

Three types of dry valleys vary gradually from southeast to northwest wheremarkedly present regional differentiation. Dry-hot valleys are mainly distributedsouth of 27°N, and the altitude of bottom of valley is 800-1200m. The dry-warmvalleys lie to southeast edge of Tibetan Plateau and the altitude of bottom of valleyis about 1300-2000m. The boundary between dry-warm valleys and dry-temperatevalleys lies on Danba, Bawolong , Dongyi and Benzilan which stretches fromnorthwest to southeast.

DRY VALLEYS IN HENGDUAN MTS REGION 287

With regard to difference of moisture, distribution of subtype of dry valley alsomarkedly shows regional differentiation. Subtype of semiarid inclines sub-humid ismainly distributed the southeast edge of Tibetan plateau, along Minjiang River,Daduhe River, Yalongjiang River and Jinshajiang River. Subtype of semiaridinclines arid is mainly distributed in rainless center in southwest of Hengduan Mts,such as Derong, Batang, Benzilan, Yanjing and Nujiangqiao. Other regions, such asJinchuan, Xiaojin, Yajiang and Changdu etc. belong to semiarid types.

Shrub belt in dry valleys is located in between montane shrub-steppe andmontane coniferous and broad-leaved mixed forest in a correlated diagram oftemperature and moisture regimes of the plateau's natural zones, which is roughlyequal to transition zone from forest to steppe. Dry valleys generally lie on the basebelt montane vertical zones in the Hengduan Mts. Its upside abuts on more humidvegetation zone, which consists of evergreen broadleaf forest, montane warmconiferous forest, montane sclerophyllous. Boundary of environmental managementof dry valleys broad-leaved is mixed forest or montane dark coniferous forest. As abase belt of vertical natural zone, the shrub belt of dry valleys generally adjoins todark coniferous forest belt in the central and northern sections of Hengduan Mts. So,most shrub types in dry valleys of Hengduan Mts. region should be regard as avariant of mountain coniferous and broad-leaved mixed forest. Altitude of upperlimit of shrub belt in dry valleys increases from south to north. More visiblechanges appear from edge to central section. For example, it rises over 3100mabove sea level in central section, whereas it is only 1600m in east edge. Suchregional variation is closely related with gradual elevation of valley bottom fromsouth to north.

Vertical distribution ranges of all dry valleys mainly depend on aridity, widerin slight dry nalley and narrower slight moisture vaIley.

Variation of vertical distribution range of dry valleys also markedly occurs inperipheral mountains. For example, it is only 200-300m at Resuoqiao of JilongCounty of southern cordillera of middle Himalayas, reaches a height of 1000m atnorthern cordillera of Karakorum Mountain.

14.2.2 FORMATION OF THE DRY VALLEYS IN THE HENGDUAN MTS.REGION

Formation of dry valley is more complicated. Many local factors may playimportant roles in the formative process, and impacted from different ways alongwith different regions (Figure 14-2, Figure 14-3).

General circulation and geographical position. Middle and low latitudes ofsouth Asia, including Hengduan Mts. region is just in swing range of subtropicalhigh pressure zone. Owing to existence of Tibetan Plateau and thermal low pressure(depression) over the plateau, subtropical high pressure zone above this area isbroken and Asia monsoon circulation intensified. Effected by intense southwest andsoutheast monsoon, this area is different from the northern Africa and western Asiawhere desert and savanna well developed.

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290 YANGQ. Y.

Monsoon passage blocked by mountain chains. Angle dimension betweenmoist air stream and Hengduan Mountain chain also affect on formation of dryvalleys. Wind can be guided by valley while a small angle occurred betweendirection of air stream and trend of valley, landscape of dry valley appearsunconspicuously. However, canyons on upper reaches of Jinshajiang River,Lancangjiang River and Nujiang River are located on hinterland surrounded bymountain chains, where moist air stream are rare. Thus, dry valley landscapeformed. Furthermore, precipitation at windward slope and leeward slope in highermountain is also quit 1+654-98different.

Table 14-5 Precipitation comparison between windward slope and leeward slope

MountainsClimatic Altitude

Sides wardAnnual precipitation

Durationstation (m) (mm)

Gaoligongshan Tengchong 1647.8 Windward 1463.8 1951-80mountain Baoshan 1653.5 Leeward 966.4 1958-80

Jiajinshan Tianquan 770.2 Windward 1732.0 1960-80mountain Luding 1321.2 Leeward 636.8 1966-80

Tongdashan Xinduqiao 3460.8 Windward 923.6 1958-80mountain Yanjiang 2600.9 Leeward 705.7 1975-80

Baomaxueshan Rizui 2080.0 Windward 425.0 1982-84mountain Benzilian 2025.3 Leeward 285,6 1982-84

Mountain-valley breeze and local circulation effect.. Hengduan Mts. regionhas preconditions in forming local arid environment due to the landform obturationand chasmal valley (U. Schweinfurth, 1981, 1992, Wangner, 1932).

Daily variation of temperature in valley causes day and night circulation ofmountain-valley breeze, which results in repeated and long-term effect of localcirculation, leads to the updraft of dry valley, resulting in the local arid phenomenain certain range. Coincidence between existence of montane forests and belt ofcloud and mist due to the valley air-stream rising to some extent elevation indicatesthe inconsistent phenomena of arid at valley bottom and relative humid at upside ofvalley slope.

Up to now, observable mountain-valley breeze on leeward slope of GaoligongMountains (FU Shaoming et.al.1983) was only reported due to lack of station datathere. The Comprehensive Scientific Investigation to the Hengduan Mts. region ofChinese Academy of Sciences attested that dry-hot wind blowing from down-riverto upriver went down to the wee hours of next day when it strongly appears in fine


summer day. In conclusion, the landscape of dry valley is a kind of typical localphenomenon.

Anthropogenic factors. Anthropogenic factors also play important role information of dry valley (Figure 14-4). Continual accretion of population pressure indry valley triggers people to cultivate virgin soil at steep slope, causingdeforestation and increasing soil erosion, especially in border of dry valley andmontane forests. Coupling with overpopulation, lack of fuel in living andproduction also arouses deforestation by clearing former arbores and shrubs,resulted in raising of lower limit of forest, and extending areas of dry valley.Furthermore, goat overgrazing (Figure 14-5) and frequent bush fire speed up thedeforestration. It is difficult to compare between former information from presentspecific places due to lack of specific data, however, some differences can bediscerned (Table 14-6, Figure 14-6). Some dry valleys belong to sub-humid climatictype by annual aridity index, whereas both sides of valley slope grow xeric-mesicshrub vegetation, which are inconsistent. It is thought that shrub in dry valley is theresult of long-term anthropogenic activities and it exhibits an increasing trend(ZHENG Du and YANG Qinye, 1985).

Cultivation onsteep slope

Structurereform

Proper increase ofpopulation

Road and ditchdilapidation

Overgrazing andexcessive cutting

Landslide andmud-rock flow

Vegetationrestoration

Monsoonrainstorm

Proper utilization ofresources

Figure 14-4 deteriorated factors of environment in dry valley

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Edaphicfunctiondegradation

Accretion ofedaphictemperatureswing

Advection rainfall reduction

Holding-waterperformance

Erosionintensification Road and

ditchcollapse

Figure 14-5 Influence of goat (ox) overgrazing and other factors on soil and vegetation, andvicious circle

Primary type

Yunnan pine forest(common slope)

River valleysclero-phyllousforest (to andnorthern rivervalley)

Subhumid evergreen broad-leafforest

Destruction intensification

Secondary type

Figure 14-6 Inverse succession of vegetation in dry-warm valley in middle Hengduan Mts.Region

Truncation ErosionBad land profile intensification Landslide, Road and

Accumulationmid-rock ditch

Bad soil cover flow collapseintensification

Surface grit l Cultivation on1Th>~nr~er effect Isteep slope

Surface firm andEdaphiccalcification ~Goat (ox) Overgrazing

function trampledegradation

Surface structure~Raindrop actiondestruction

litter layer Vegetation cover SelectiveEdaphic Eva.. attenuation reduction getting foodporation In- Biomasstensification Vegetation

decrease Seed and flowerdecreaseAccretion of wastage, fire

Communityedaphic Advection rain.. slope

temperature fall reduction component

swing simplification Excessi ve cuttingHolding..water Iand chopping_ Recruitmentperformance slowing down

Figure 14-5 Influence of goat (ox) overgrazing and other factors on soiI and vegetation, andvicious circle

Primary type

Yunnan pine forest(common slope)

River valleysclero-phyllousforest (to andnorthern river

I valley)

Subhumid ever..green broad ..leafforest

Destruction intensification

Secondary type

Contorted Yunnan,pine woodland

Sprouting scrub

Shrubgrassland

Grasslandslope

Barrenslope

Figure 14-6 Inverse succession of vegetation in dry-warm valley in middle Hengduan Mts.Region

294 YANGQ. Y.

14.3 Resources Utilization and Environment Management

Dry valleys with an area of 11,230 km2, accounts only 2.1 % of total area in the

Hengduan Mts. Agricultural population, arable land area, crop productivity, andlivestock in dry valleys range from 10% to 20% of the whole region, which is 5 to10 times the percentage in the area. Economic activities in dry valleys are moreintensive and human activities, in recent years, bring greater pressure to theenvironment. Environment management with resources utilization, is therefore ofgreat importance.

14.3.1 CURRENT SITUATION AND PROBLEM

Annual mean air temperature in dry valleys in the Hengduan Mts. Regionranges from 6°C to 20°C. The lowest monthly mean air temperature (January), O°Cto -12°C, is higher than that in east China with the same latitude. Further more, themountains around them make it impossible entry of cold air from north and keepthem warm in winter. The dry valleys are abundant in solar energy with averageannual solar radiation ranging from 502416 J/cm2 to 628020 J/cm2

, annual totalsunlight reach to 1600 h -2500 h. All those, coupled with large daily airtemperature range, and small annual air temperature range, are suitable for thedevelopment of agriculture. Some areas in the region, such as Batang County, arewell known for high productivity of food crops.

Although annual precipitation ranges in most regions from 500 mm to 800 mm,seasonal distribution of precipitation is varied greatly, dry winter and wet summer isapparent. From October to the next April in most part of the region, and fromOctober to the next May in northwest part of Yunnan Province and west part ofSichuan province, precipitation is only about 10 percent of the annual total.Precipitation during the summer, to the region as a whole, accounts more than 80percent of the whole year. According to Penman's formula, the drought index,which is the ratio of potential evapotranspiration to precipitation during rainyseasons, range from 0.60 to 2.40, which cover types of humid, subhumid, semiarid,and arid (YANG Qinye, et ai, 1987). The subhumid and semiarid regions are by farthe largest parts of all. If spring rain comes in time, and subhumid conditionsdominate the rainy season, productivity of crops are satisfying. Nonetheless, thecongenital feature of the Southwest Monsoon is contrast of humid and dry seasons,and the probability of spring drought is very large. To make things worse,sometimes drought may outbreak during intervals of rainy seasons, the watershortage is a common problem in arable land, especially in spring. Main Riverstreams in the Hengduan Mts. Region generally have large discharge rate. Butsteepness of topography makes in most regions the fields are very high above riverlevel. This makes channeling water to the field extremely difficult and pumpingwater inconvenient. Vast amounts of water flows away without being used forirrigation directly.

Cultivation index in dry valleys covers 16.4% of the total land. Plant culture is


the leading industry, which usually amount to more than 50 percent of all incomefrom agriculture. Food crops are the main crops cultivated there, usually amount to80 percent of the total area under cultivation. Forestry, animal husbandry are poorlydeveloped.

Productivity of each crop is rather low, in yielding of 1.5-3 tons per hectare. Inthe early 1990s, the arable land per capita is only 0.093 hectare, and the cereal percapita is less than 350 kg.

Coniferous forest of timber reserve is widely distributed on the high landsaround the dry valleys with 23x108m3

• Since 50s, trees were cut for commercial use,weighting utilization was being much more than renewal, in some main lumberingareas, deforestation rate outstrip natural growth rate by 2.3 to 4.0 times (ZHENGDu et ai, 1986). Now there are about 38.7 million hectares of deforested land, andsome 13.3million hectares of burned land need to be reforested. The coverage offorest has been decreasing rapidly. Some 700 years ago, forest coverage was mOrethan 50% along the upper reaches of Minjiang River in the 1950s, it dropped to30%, and now, only 18.8%. Timber falling, deforestation for arable land, slash andburn cultivation, and crop cultivation along steep slope etc. caused baseline offorest move upward, dry valleys enlarged. Dry valleys in the Aba Zang and QiangAutonomous State of west Sichuan province expanded 33.3 thousand hectares inthe last 30 years.

14.3.2 STRATEGY OF ENVIRONMENT MANAGEMENT

Environment management in dry valleys, in essential, is a problem ofecosystem management as a whole, including valleys and mountains. Which can bemanifested in rational relationship between various environmental conditions andresources utilization. However, this is only one aspect of integrated mountaindevelopment, achievement of which is depended upon all-aspect of economicdevelopment as a whole in the mountain areas, otherwise, environmentmanagement may be gone to failure.

Solving the drought problemWater shortage is an urgent problem in dry valleys. At present, irrigation

mainly depends upon digging of channel, leading water flow freely from tributaries.However, the following two problems must be considered: a) how to use availableirrigation works effectively; b) how to adjust the spatial patterns of water utility. Asto the first, emphasis should be laid upon renovation and construction ofsupplement works, in improving management on scientific use of water and tomake assurance of irrigation. As to the second, pumping and channeling systemsshould be developed, which foster full use of water resource from main streams.

Improvement ofarable landsEnvironment management in dry valleys should not merely be concentrated on

cultivated land, which is only of 197.2 thousand hectares. We must keep it in mind

296 YANGQ. Y.

that water shortage is an essential problem that caused environment degradation. So,adjustment of ratio among various types of land use and arrangement of land useadaptable to land type are necessary.

Arable land per capita has been decreasing steadily. For example, the arableland increased 4.53 thousand hectares, while the population increased 255 thousandfrom 1951 to 1981 in Ganzi Zang Autonomous Prefecture of west Sichuan province.The arable land per capita decreased from 0.17 hectares to 0.113 hectares.Population pressure forced local people to cultivate sloping land enlarge the area ofarable land. Now cultivated sloping land accounts for about 40% of all arable land,in case the sloping land even reaches 35°in dip, which resulted in accelerated soillose.

Forest is the safeguardfor the agriculture in the dry valleysIn recent years, due to excessive deforestation, environment deterioration went

rapidly in the dry valleys. Only by control of quantity on lumber and timberproduction environment quality can be ameliorated progressively. The temperatureand moisture conditions of ecotone in forest belt are better than that of dry valleys,thus the lower limit of forest on steep land usually becomes an exploitation zone ofcultivation. However, this belt is the most vulnerable one in the whole ecosystem,which is prone to be destroyed, and difficult to be restored. Consequently, specialprotection should be made to uncultivated land; as to the land already undercultivation, several steps may need to recede from cultivation to reforest.

Animal husbandry is an important sector ofeconomy in the mountain areasAnimal husbandry is a subordinate industrial sector although with very low

production. In which, goats account for 34.9%, sheep 7.9%; and cattle 7.5%.Overgrazing impairs the practice of soil conservation, so adjustment must be done.Feeding of pigs and cows instead of goats already showed in Maowen County,some economic and ecological advantages. Considering current vegetation cover indry valleys, animal husbandry should be under the guidance of low-density policy.Meanwhile, corral raising should take place instead of free grazing gradually. Inaddition, the pasture on high mountains and grasses under the trees should be fullyused under proper protection.

14.3.3 DIFFERENTIATION OF ENVIRONMENTAL MANAGEMENT

Figure 14-7 shows dry valley. According to the consistence of ends and meansof measurement of management, dry valleys in Hengduan Mts. can be divided intoseven regions.

(1) Dry-hot valley region in Nujiang River and Yuanjiang RiverThis region is located in the southmost portion, including dry-hot valleys in

middle sector ofYuanjiang River and Nujiangba ofNujiang River in total lengths ofdry valleys are 328km; and the area of 1990 km2

• Dry-hot valleys in middle sectorof Yuanjiang River are lower than 800-1000m in altitude; Nujiangba of Nujiang


River is a basin, where the vertical scopes of dry valleys are about 300m. Dry-hotvalleys in this region are usually bottomed on broad terraces, where are of the maincultivated land with majority of food production which accounts for 85% of totalagricultural income. The food productivity is relatively high. However, cultivatedland limited in, and irrigation makes difficult in expanding arable land for foodcrops. Appropriate proportions varieties and the improvement of productivity forhigh yielding are needed. Some tropical and subtropical economical forest shouldbe developed. Animal husbandry should be laid on cattle. Arable land 100m abovethe riverbed should be irrigated by pumping water.

Figure 14-7 Photo of dry valley

(2) Dry-hot valley region in lower section of Jinshajiang RiverThis region, with includes the section below Jinjiangjie along Jinshajiang

River, Binchuan and Yuanmou Basins in length of 998km with total area of4240km2 is heavy. Altitude of dry-warm valley ranges from 1400-2000m to 800900m in different sectors. Land is dwarfish compared with relative high density ofpopulation, and productivity is relatively low, only 2250 kg per hectare, and thefood production per capita is less than 250kg. Due to short in water resources forirrigation in basins, potential in expansion of arable land is limited. Croparrangement, therefore, should be adjusted decreasing rice field and increasing rainfed crops and cash crops in future. This region is not suitable for commercial foodproduction. Some cultivated land with low productivity should be reforested, and

298 YANGQ. Y.

irrational cultivation should be forbidden.(3) Dry-warm and dry-temperate valley region in Anninhe RiverThis region, in length of 283km and with total area of 1080km2, covers major

sector of Annihe River. Land in this region is quiet broad, and lands undercultivation are large, and the productivity is high. Food production is an importantpart of agriculture with about 90% of paddy fields. The current problems ofagriculture are maladjustment in structure and monotonousness of food production.Senseless expansion of arable land caused heavy soil and water erosion. Southsector of the region is suitable for the development of subtropical economical forestwhere may provide sugarcane, apple, pear, and walnut to the adjacent to industrialcity. Main water conservancy should also be considered on the main stream ofAnninghe River to satisfy the demand of water supply.

(4) Dry-warm and dry-temperate valleys of Daduhe River, Minjiang River andBailongjiang River

This region covers several parts along Daduhe River, Minjiang River andBailongjiang River with altitudes from 1500m to 2500m. Total length of dry valleysis about 434 km with total area of 630 km2

• Most of this region is in deep cut valleywith a few tabled terraces. At present, lower level farming is the main industry.Food crops accounts for more than 95% of total land under cultivation. Improvingfood productivity and developing diversification are needed. Special attentionshould be paid to fruit production like apple and pear to satisfy growing demand.

(5) Dry-warm and dry-temperate valleys region along Yalongjiang River,Jinshajiang River

This region covers lower sections of Jinshajiang River and mid-lower sector ofYalongjiang River in total length of 1014km and total area of 1600km2

• Most partsin this region are of canyons with only a few basins in some localities. Irrigation is amain problem because irrigation facilities are often damage by debris flows andlandslides. Productivity of cultivated land is low without irrigation. Emphasisshould be laid upon forestry and recovery of vegetation. Food production is barelyenough for the local people at present. Potential development of diversification is toplant nut that can make extra economic interests.

(6) Dry-temperate valleys region along upper sector of Jinshajiang River andLancangjiang River

This region covers upper sector of Jinshajiang River and Lancangjiang Riverbeyond Rizui in total length of 113lkm and total areas of 2430km2

• These valleysare mainly of gorges with few open terrains scattered in. The productivity of whichare only 1125 to 3000kg per hectare. Agriculture in this region is the leadingindustry with animal husbandry. However, with the cultivation of sloping land,water and soil erosion is extremely heavy. Emphasis should be put on adjustment ofagricultural structure and the improvement of productivity to minimize thedependence of food import. Climatic conditions in this region are suitable for fruitgrowing, such as, apple, pear, persimmon, and jujube, which should be developed.Nut, as a kind of woody oil crop, special stress should be laid on.

DRY VALLEYS IN HENGDUAN MTS REGION

14.4 Highland and Lowland Interaction

299

The regional relation between highland and lowland is a wide proposition .Transportation and exchange of energy flow and material flow run ever and againwhich result in significant differentiation and extensive relation in climatic ,vegetation, soil and whole physic-geographical environment. To discern mainfactors of montane environment are important for exploiting and managing montaneresources. Furthermore, it also is necessary to recognize main vertical zonations ofdry valley from ecosystem viewpoint.

(1) The community structure of alpine grassland (meadow, steppe) zone issimple, but a long-term developed soil has full-grown sod, which slows down thespeed of soil erosion. However, if the sod was destroyed, restore is difficult . Manykinds of micro-landforms such as mound are formed by trample of ungulate and digof rodent in a long period. Anthropogenic overgrazing easily causes degradationand desquamation of sod in decreasing of soil water and increasing of erosion, andconsequently influencing stability ofbiome around upper limit of forest.

(2) Subalpine and montane forest zones, as a 'holding (conserving) waterzone' in montane ecosystems, are most important. Those places are 'cold-dampsource ' of regulating valley climate due to abundance of atmospheric and advectionrainfall, stable runoff, less variation of temperature and humidity in air and soil.Although ecological functions of subalpine and montane forest zones are superior tothat of alpine and dry valley, their ecological equilibrium is still unstable . Recently,more attention has been paid to the vulnerability of ecological equilibrium intropical forest ecosystem, but the resistant vulnerability against external disturbancein subalpine and montane forest ecosystems in tropical and subtropical mounta ins isnot fully considered. It is difficult to renew after forests be cleared . In this case itcauses variation oflocal climatic, hydrological and ecological conditions along withloss of original regulation.

(3) Although, dry valley is regarded as an inconsistent ' reverse vertical zone'in phytogeography, its existence influences significant the whole montane verticalzones. Dry valley is a 'thermal (heat) source' oflocal mountain-valley breeze due toabundant heat quantity. It affects the intensity of valley breeze and its 'xerothermic'average status and then, influences combined feature of vertical zones everywhere.However, development process of dry valley itself depends on whole alpineecosystem. Hengduan Mountains, characteristics of natural condition are an influxof runoff, development of accumulation landform, flat terrace , and deeper soil. Thedominant communities here are mesic biomes with xeric features. However, owingto the differentiation of valley 's degree and aspect of slope, microlandform, andhydrological conditions, other biomes are inlaid , such as hygrophilous rainforest insouth branch valley and scattered pines and cypress on sunward slope in northregion. Dry valley is a center of agricultural activities in the Hengduan Mts. region .Due intensified to economic activities, severe erosion appeared, slope stability losttransfer of substance became active, and consequently ecological equilibrium is themost vulnerable.

300 YANGQ. Y.

Water and temperature conditions play an important role in evolution ofmontane natural environment. Property difference in each soil type reflectsdifferentiation and relation of environmental conditions between highland andlowland in many aspects and directly influences measures of soil amelioration andutilization. Physic-geographical features in periglacial and peak areas arecharacterized by cold climate, strong physical weathering, thin and discontinuoussoil horizon, and high-level solum rhogosol, low soil development. In montane darkconferious forest zone, features are shown by warm and humid climate, high soildevelopment, stronger weathering and various pedogenic processes includingallitization, humus accumulation and weak bleaching podzolization. Althoughclimate in river valley tends to aridity, intensive precipitation in summer,intensifying leach of carbonate in pedogenic processes. In general, along with therelief from high to low, natural environment generally exhibits spatial variation ofclimatic change, decreases of vegetation ingredients and lowering of soildevelopmental degree.

Interaction and reciprocity between highland and lowland is remarkable.Agricultural land use in the Hengduan Mts. region shows an obvious verticaldistribution and special pattern of 'stereo-agriculture' due to intensive impacts ofsocial and economic factors. Arable lands generally distribute both on riverbanksand basins. The forest, a green 'waistband' of mountainside, is the safeguard ofvalley agriculture. It not only supplies high quality timber and forestry byproducts,but also conserves soil and water. Forests, especially in vulnerable transition zoneof dry valley and woodland, will be replaced by shrubs and wasteland if be cleared.No or less vegetative cover is the main inducement of erosion intensification andmantle rock destruction. The pasturage is a key economic activity in Hengduan Mts.region. However, traditional pasturage has been impaired because of populationpressure and successive extension of cultivating area in recent years.

In order to regulate the interrelation between highland and lowland, and toestablish better agricultural ecosystem, it is necessary to couple with both sides andto make an adjustment based on structure of natural environment (Figure 14-8). Thepolicies, adjusting measures to local conditions and comprehensive exploitation,should be carried out in agricultural exploitation in the Hengduan Mts. Regiontomeet sustainable development. Measures are suggested as follows: (l) It shouldconserve forests, develop forestry and establish montane agricultural ecosystem; (2)It should fully employ existing arable land in valleys and intermontane basins todevelop plantation, properly control cropland area, strictly prohibit planting onsteep slope, strengthen scientific management, increase unit yield, appropriatelydeal with conflict between forestry and food production; (3) It should bringadvantages into play and keep away from disadvantages, enhance planting of forestfor no-timber, arrange parergon production; (4) It should potentate stockbreedingmanagement, adjust constitutive proportion of livestock, and advance corporatedevelopment of forestry, stockbreeding and agriculture.

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References

YANGQ. Y.

I. Koeppen W.Grundriss, 1931. der Klimakunde. Berlin:Walter de Gruyter.2. LI Bingyuan, 1983. Quaternary Geology in Xizang, Science Press, Beijing.3. LIU Dongsheng (ed.), 1981. Geological and Ecological Studies of Qinghai-xizang Plateau,

Vol. II, Science Press, Beijing.4. QIAN Jiliang and LIN Ziguang, 1965. A Preliminary Study on the Dry and Wet Climatic

Classification of China, Acta Geographica Sinica, 31 (I). (in Chinese)5. Schweinfurth, U.,1981. Plateau ,River Gorges, and Land Wind Phenomeny ,in Geo

logical and Ecological Studies of Qinghai-Xizang Plateau, vol. II, Science Press, Beijing,2005-2010.

6. Schweinfurth, U., 1992. The Eastern Marches of High Asia and the River Gorge Country,Geo-ecology ofthe High-mountain Regions of Eurasia (Carl Troll), Wiesbaden, 276-278.

7. SUN Honglie, ZHENG Du (Chief Editors), 1998. Formation,Evolution and Development ofQinghai-Xizang (Tibetan) Plateau, Guangdong Science and Technology Press, China(inChinese) The Map of the Arid Region Distribution of the World, UNESCO, 1977.

8. Tsui Youwen, 1958. A Phyto-geographical Survey of Northwest Szechuan and Regions ofChang-Tu District, Acta Geographica Sinica, 24(2). (in Chinese)

9. WANG Jinting, LI Yang, YAN Jianping, 1988. Some Suggestions on Utilization andAmelioration of the Arid Valley Vegetation in the Hengduan Mountains Region, MountainResearch, 6(1), 11-16. (in Chinese)

10. XU Jinzhi,1959. The Materials of Physical Geography, Science Press, Beijing. (in Chinese)II. YANG Qinye, ZHENG Du and LIU Yanhua, 1988. Natural features and Dllve!opment in

Dry valleys of Hengduan Mountains Region, Journal of Arid Land Resources and Envinonment, 2(2). (in Chinese)

12. YANG Qinye, ZHENG Du, 1987. Moisture Situation in the Hengduan Mountain Regionand Regionalization, Collected papers of Geography, 19,5cience Press. (in Chinese)

13. YANG Qinye, ZHENG Du, 1990. On Altidudinal Land Use Zonation of the HengduanMountains Region in Southwestern China, Geojournal, 20(4), 369-374.

14. ZHANG Rongzhu (ed.), 1992, The Dry Valleys of the Hengduan Mts. Region, SciencePress, Beijing. (in Chinese)

15. ZHANG Rongzhu, YANG Qinye, LI Mingsen and SUN Shangzhi, 1988. AgriculturalManagement Systems in the Arid Valley Areas of West Sichuan, Chinese Himalayas,Agricultural Development Experiences in West Sichuan and Xizang, China (WorkshopReport), ICIMOD, 67- 68.

16. ZHANG Rongzhu, ZHENG Du and YANG Qinye, 1982. The Physical Geography ofXizang (Tibet), Science Press, Beijing. (in Chinese)

17. ZHANG Rongzhu, ZHENG Du, YANG Qinye and LlU Yanhua, 1997. Physical Geographyof Hengduan Mountains, Science Press, Beijing, China. (in Chinese).

18. ZHENG Du, YANG Qinye, 1985. Some Problems on the Altitudinal Belts in the Southeastern Qinghai-Xizang Plateau, Acta Geographica Sinica, 40 (I). (in Chinese)

CHAPTER 15 HIGH-COLD SCRUBS AND MEADOW ZONE

WANG Xiuhong

Affected by atmospheric circulation and topographic configuration, differentregions have different combinations of temperature-moisture conditions, whichchange from warm-humid in the southeast to cold-arid in the northwest of theplateau. Along the above-mentioned direction, the natural landscapes occur in theorder of: montane forest / high clod meadow / high cold or montane steppe / highcold or montane desert. The high cold meadow is one of the four large naturallandscapes on the plateau.

Widely distributed in the middle east part of the plateau, the alpine meadow isan unique geoecological phenomenon on the Tibetan Plateau, which can not befound anywhere in the world (Figure 15-1). It covers an area of about 7.0x105 km2

,

accounting for nearly 50% of the total useable grassland area on the plateau(WANG Qiji et aI., 1995). The high cold meadow zone, which can be considered asthe connection or extension of altitudinally distributed alpine meadow, has an areaof 2.69x105 km2

, occupying 10.7% of total regional area of the plateau. Itspopulation density is 3.0 persons·km·2

, much higher than that on high cold steppeand high cold desert zones (SUN Honglie et aI., 1996). The zonation and rationaluse of the alpine meadow in some particular areas have received much attention,but the overall characteristics of the three-dimensional distribution, especially thespatial relationship between the horizontal zone and altitudinal belts, and therational development of the alpine meadow on the whole plateau remain as gaps inknowledge.

The author participated in the fieldwork related to the alpine meadow researchorganized by Chinese Academy of Sciences (CAS) in 1994, 1995, 1997, and 1998.There were two kinds of remarkable phenomena, one was the altitudinal belts ofalpine meadow on various mountains, which could form a "layer" with varyingthickness if "linked" together; the other was the seriously degraded or degradingalpine meadow, which was closely related to the rational use of alpine meadow onthe plateau.

Deeply enlightened by the figures of "Schematic vegetation profile of theworld from the Arctic to the Antarctic" by C. Troll (1961) and "Global cross-sectionofthe alpine region, showing the highest summits, snow lines and timberline" by J.D. Ives and R. G. Barry (1974), the author paid attention to studying the threedimensional distribution of the alpine meadow by using trend-surface analysis.Fortunately, all the data about the upper and lower limits of altitudinally distributed

303

ZHENG Du, ZHANG Qingsong and WU Shaohong (eds.), Mountain Geoecology and Sustainable Development oftheTibetan Plateau, 303-325.©2000 Kluwer Academic Publishers.

304 WANGX.H.

alpine meadow on the plateau in the previous studies were collected. The studyshows that the upper limit with changing longitude or latitude has the maximumvalue; while the lower limit generally increases from southeast to northwest of theplateau. The natural zone of the high cold meadow probably occurs within theboundary where the trend-surface of the lower limit distribution of alpine meadowintersects with the trend-surface of the plateau's base surface. Moreover, the abovementioned distributions are explained based on the related geoecologicalconditions.

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Figure 15-1 Position of the natural zone of high cold meadow on the Tibetan Plateau(after ZHENG Du, 1996a)

The alpine meadow is also important grassland, thus its rational use is closelyrelated to the survival and development of the herdsmen on the plateau. However,because of its fragile environment and malmanagement, the alpine meadow hasseriously degraded, likely becoming "the second loess plateau" in China in thefuture. The problems in the development of alpine meadow are identified, includingthe grassland degradation caused by both natural and artificial factors and thecontradiction between the limited grass production and the increasing livestocknumber. Some related countermeasures have been suggested, including the way ofrational use of natural grassland, construction of artificial and semi-artificialgrassland, rational protection of natural and artificial grasslands, enhancing theintegrated development, and strengthening capacity building.

HIGH-COLD SCRUBS AND MEADOW ZONE

15.1 Geoecological Features

305

Stretching in a direction of WSW to ENE, the natural zone is at an elevation of3500 m asl in Zoige and Aba of Sichuan in the east, 4000 m asl in Golog and Yushuof Qinghai in the upper reaches of the Tongtian River and the Yellow River, and4600 m asl in Nagqu of Xizang (Tibet) in the upper reaches ofNu Jiang in the west.The main divides, with broad valleys, basins and gentle hills in between, are BayanHar Mts. and the Tanggula Range.

15.1.1 PHYSICAL ENVIRONMENTS

Characterized by slight dissection, the natural zone is the transitional area ofhilly plateau landscapes. Fluvial dissections are strong with large differences of therelief in southeastern part of the natural zone, while the plateau surface maintainswell with obvious freezing weathering, periglacial landforms and permafrost innorthwestern part of the natural zone. Meanders develop on the erosion anddeposition surface of the zone. All kinds of profile curves, such as retreation ofslopelands and expansion of piedmont plains, reflect features of gentle and stable.

The natural zone, with a mean temperature of 6-10 (l2)OC in the warmestmonth and about 80-150 days of daily mean temperature above or equate 5°C, ischaracterized by low temperature in warm season. Westerlies prevail in winter halfyear, characterized by severe cold and drought with occasional snow in winter andspring; while the moisture-laden air masses coming from SE govern in summer halfyear. Thanks to the east-west orientation of the shear line, low baric systemspredominate in the warm season, with an annual precipitation of 400-800 mm,decreasing from SE to NW, and 80%-90% of it falls from May to September withincreasing rate from SE to NW. Hail shooting is frequent with 15-35 days in warmseason, increasing from east to west (ZHANG Rongzu et al., 1982; ZHENG Du,1996b). According to the combination of temperature-moisture regimes the naturalzone belongs to plateau subpolar humid / subhumid climate.

Most of the wetlands of the Tibetan Plateau are distributed in the natural zone,such as the swamp of Zoige in the east, the swamp and swampy meadow inheadwaters of the Tongtian River, Lancang Jiang and the Nu Jiang to the west. Thethickness of permafrost is 20-100 m, with frozen period of 4 months for the activesoil layer of 10-30cm (SUN Guangyou et al., 1995). The existing permafrost has aneffect on the percolation of surface water, promoting developments of the swamp.Being a relative subsidence area with Quaternary deposition at a thickness of morethan 100 m in valleys of the Yellow River and its tributaries, the plateau of Zoigeprovides favorable environmental conditions for development of swamps and peatbogs. The swamp is mainly distributed on terraces of the tributaries, with a swampratio of 21.2%-43.2% in Hei He basins (ZHENG Du et al., 1995).

306 WANGX.H.

Table 15-1 Temperature and precipitation of meteorological stations in the natural zone

MeanMean AnnualLatitude Longitude Altitude Temperature Accumulated

Location Temperature Temperature PrecipitationN E (m) (OC)

(OC) (July) (~5°C) (mm)(January)

Maqen 34°16' 99°12' 4211.1 -16.5 7.5 420.3 444.1

Zhiduo 33°51' 95°36' 4179.1 -12.6 8.8 664.2 387.0

Zoige 33°35' 103°58' 3446.7 -10.5 10.7 995.5 647.6

Jiuzhi 33°26' 101°29' 3628.5 -11.2 9.9 858.9 764.4

Serxu 32°59' 98°06' 4200.0 -12.7 8.4 543.1 569.0

Nagqu 31°29' 92°03' 4507.0 -13.8 8.8 792.9 406.9

15.1.2 VEGETATION TYPES

Predominated by frigid-resisting perennial mesophytes the alpine meadowbelongs to one of the zonal vegetation types on the Tibetan Plateau (ZHOUXingmin et a/., 1986; ZHANG Jingwei et a/., 1988). The alpine meadow consistschiefly of Kobresia plants of dense tussock, rhizome geophyte (cryptophyte), andother herbaceous plants of hemicryptophyte. As concerns floristic elements it iscomposed mainly of the Arctic-Alpine element, Sino-Himalayan element and theendemic element of Tibetan plateau. Among them the dominant species areKobresia pygmaea, Khumilis, Ksetehwanensis, Ktibetiea, K littledalei, Carexatrofusea, Po/ygonum s, Potentilla s, Leontopodium s, Poa s, Festuca s, etc. Therichness of species decreases with increasing elevation, reaching 25-30 species / m2

at lower altitude in SE, 10 species / m2 at high altitude in NW (ZHOU Xingmin etaI., 1994; WANG Jinting, 1992). Main types of alpine meadow include Kobresiameadow, herbaceous meadow and swampy meadow.

Kobresia meadows are characterized by low growth layer (3-5 cm in height),simplified structure with usually one herbaceous layer, dense population, largecoverage (70%-95%), short growing season and low production of biomass (7502250 kg / hm2), etc. According to studies on biomass of Kobresia humilis at HaibeiResearch Station of Alpine Meadow Ecosystem, photosynthetic production mainlyaccumulated in the belowground organs, the amounts of belowground biomass is 8times those of the aboveground biomass. (WANG Qiji et aI., 1989)

Herbaceous meadows, located in the southeastern part of the natural zone, arecharacterized by dense population, higher growth layer of 15-20 (25) cm in hight,with obvious seasonal aspects and colorful in blossom. The dominant species arePolygonum maerophyllum, Pviviparum, Anaphalis flavescens, Leontopodiumlongifolium, Speneeria ramalana, Anemones

Swampy meadows, due to gentle relief and impacts of permafrost and seasonal

HIGH-COLD SCRUBS AND MEADOW ZONE 307

frozen earth, with ground water level at 20-40 cm, occur in the lowland anddepression of broad valleys and basins or the rim of proluvial fans. It consistsmainly of Kobresia littledalei, K.tibetica, K.kansuensis, Carex muliensis, etc. andaccompanying species of hygro-mesophytes and hygrophytes, such as Blymussinocompressus., Carex moorcroftii., Juncus s, Trollius s, Primula pumila,Triglochin spp, etc. It is widely distributed with small areas, characterized by densepopulation and high biomass. Most of the swampy meadow are located in valleys,depressions and lakeside with climate of temperate and calm, suitable for grazingthe old, young, weak, and sick livestock and usually used as winter and springgrassland, playing an important role in animal husbandry of the plateau.

Alpine scrubs consist mainly of Rhododendron nivale, R. violaccum,R.capitatum, R.s, Salix oritrepha., Potentilla fruticosa, Caragana jubata, Spiraeacanescens Sibiraea angustata, etc. Most of them exist on the shady slopes, reachingupwards at elevations of 4600-4800 m as!. In addition to deciduous scrubs, scrubsof Sabina pingii var. wilsonii appear on the sunny slope too.

Montane coniferous forests occur in patches only at lower elevations inperipheries of the region. Forests of Picea balfouriana appear on shady slopes at anelevation of 3400-4000 m asl; forests of Picea crassifolia can be found at elevationsof below 3500 m asl on eastern flanks of Anyemaqen Mts.; while on the sunnyslopes exist open forests ofSabina tibetica, S.convallium and s.przewalskii.

15.1.3 ANIMAL GROUPS

As main bases of animal husbandry on the Tibetan Plateau the zone of alpinescrub and meadow is favorable for grazing yaks and sheep. A lot of wild animalsare important component of the natural ecosystem of alpine meadow and scrubs inthe zone. Among them, Ochotona of pika, characterized by large population, highdensity and widespread distribution, has its distribution center with 15 species onthe plateau. Ochotona curzoniae, Ohimalayana. Othibetana, Ocansa,etc. occurfrequently in the zone. In addition, Microtus oeconmus, Myospalax !antanieri,Myospalax bailey, Marmota himalayana and Procapra picticaudata, Lepusoiostolus, Cervus albirostris are commonly met with in the natural zone (SUNHonglie et al., 1996).

Main species of birds in the alpine meadow are Eremophila alpestris, Alaudagulgula, Melanocorypha maxima, Podoces humilis, etc. Wild animals of theswampy meadow are characterized with waterfowl, such as Anser indicus, Todorna!erruginea, Crus nigricollis, etc. Carnivorous animals of the zone are wolf (Canislupus), Mustela altaica, Meversmanni, red fox (Vulpes vulpes) and Aquilachrysactos, Falco tinnunculus, etc. They catch and feed on rodents and small birds,playing an important role in control grassland degradation caused by rodent damage.Insectivorous birds, such as Apus pacificus, Riparia riparia, Upupa epops, etc. arecommonly met with in the zone. Insects of the alpine meadow are simple,consisting chiefly of frigid resisting herbivorous insect of soil habitat or rock habitat(SUN Honglie et al., 1996).

308 WANGX.H.

The above-mentioned biotic composition of alpine meadow ecosystems and itsfood-chain structure show the closed relationship between various biotic groups andtheir interdependences.

15.1.4 ALPINE MEADOW SOILS

Alpine meadow soil (cryo-sod soil) usually belongs to AC type due to absenceof B horizon. The sod layer (As) with a thickness of 5-10 cm consists mainly ofliving roots and dead roots of Kobresia plants at soil surface layer. Beneath the sodlayer is the humus layer (A 1), then occurs a transitional layer of A liB or B/C due tothe B layer undeveloped. The C layer is obviously determined by properties ofbedrocks.

Alpine meadow can be regarded as the transitional landscape from montaneforest to alpine steppe. Compared with the chemical properties of alpine steppe soil,alpine meadow soil has a higher organic matter content, higher C/N value, andslight acidic or neutral reaction as shown in Table 15.2.

Owing to the long duration of low temperature conditions in dormant stage,the activities of microbes are restrained. With slow decomposition rate of plant deadbodies and remnants, enormous roots of Kobresia and other plants have intertwinedtogether, forming the sod layer. During growing season temperature conditions andmoisture regimes in the soils become more favorable for decomposition of plantdead bodies and remnants, accumulation of humus, and formation of fine soilstructure in the humus layer. Physical weathering dominates in soil-forming process.Because of low decomposition degree of mineral, clay mineral consists mainly ofhydromicas, with a low content and decreasing with soil depth. Therefore the alpinemeadow soils are characterized with shallow layer, light and coarse texture, as wellas weak differentiation of mineral composition in profiles (ZHANG Rongzu et al.,1982).

Table 15-2 Chemical properties of main layers for different alpine soils(GAO Yixin et aI., 1985)

Soil type Depth (cm) pH Organic Matter (%) CIN

Alpine meadow soil0-7 6.9 7.89 10.7

7-13 7.0 5.31 9.7

Alpine steppe soil0-5 8.7 2.73 10.1

5-11 8.6 1.34 7.9

Compared with other grassland soils on the plateau, e.g., alpine steppe soil, thehumic acid extracted from alpine meadow soil has a lower extinction coefficient inthe wavelength of 726-465 nm both in As (0.22-1.06) and Al (0.21-1.00) layers,which shows that humic acid from alpine soil has a lower humification degreemainly resulting from the lower temperature (ZUO Kecheng et al., 1980).

Freeze-thaw cracks develop in the surface layer of alpine meadow soils, soil


masses tum upwards along cracks on sunny slopes, forming sod layer mass.Because of differences of expansion and contract of various materials, as well asdistinction of thermal conductivity, herbaceous roots are cut off from the beneathsoil layer, and forming slip planes. Therefore the sod layer masses slip down veryoften, sod masses even break away from the soil surface, forming sod slip inpatches (ZHANG Rongzu et aI., 1982).

Because most of precipitation fell in summer, and the water-holding capacityof sod is high, the anaerobic condition of soil masses is unfavorable for intensedecomposition of organic matter. Corresponding with the decrease of water contentin soil layers, the aeration becomes better in dry season than that in rainy season.The mineralization of organic matter in soil layers is impeded due to decrease insoil temperature and long duration of soil frozen in winter half year. Characterizedby a large amount of organic matter and a high ratio of roots, the existing state oforganic matter of alpine meadow soils are quite different from the soils in lowlandareas at the same latitude (ZUO Kecheng et al., 1980; BAO Xinkui, 1992).

According to the investigation in the field of Haibei Research Station, the ratioof various organic matter and the amounts of organic matter in whole profile ofalpine meadow soil shows that the distribution of the organic matter is uneven andconcentrated in upper layers. The state and composition of organic matter varieswith the depth, the ratio of humus matter increases with depth (WANG Qiji et aI.,1989; BAO Xinkui, 1992).

Some studies show that the volume ratio of grass to soil in topsoil is closelyrelated to the formation and variation of sod layer. Sod layer does not form if thementioned ratio is too small; begins forming if the ratio is between 0.5 and 1.0;develops maturely and starts to degenerate if the ratio reaches 1.0-2.0. Highproportion of grass in topsoil greatly affects the release of effective nutrients, thuslimits the plant growth and development (BAO Xinkui, 1995).

15.2 The Three-Dimensional Distribution and Geo-Ecological Analysis

The three dimensional zonation of the plateau has received a good deal ofattention (ZHANG Xinshi, 1978). For better understanding of the mentioned abovezonation, some researchers insisted that horizontal zonation should be theconnection or extension of altitudinal zonation; others suggested that altitudinalzonation should be the miniature of horizontal zonation on the plateau. In this paper,the altitidinal distribution of alpine meadow was regarded as more universalphenomenon. By using the trend-surface analysis, the characteristics of upper andlower limit distributions and the spatial relationship between horizontal zone andaltitudinal belts of alpine meadow were studied based on its lower and upper limitdistributions and the plateau's base surface. The geoecological explanations for thetrend-surfaces were also offered.

310 WANGX.H.

15.2.1 TREND-SURFACE ANALYSIS OF THE UPPER AND LOWER LIMITDISTRIBUTIONS

All the data about altitudinal distribution of alpine meadow in the past studieswere obtained (WANG Xiuhong, 1996a), which was the satisfactory basis for thementioned trend-surface analysis. It is clear that the model is a simplified version ofan actual subject or environment used to study the regional nature and spatialrelationship based on the correlation among various indexes. At its most effective,the model is able to provide the basic tendencies and main characteristics of thestudied matter by synthesizing a great number of related data. For better analyzingthe altitudinal distribution of alpine meadow, two mathematical models wereestablished by stepwise regression.

Let H, x and y stand for upper (or lower) limit, geographic longitude andlatitude, respectively (omitting some limit values because of their unusualresponses), the model suitable for the upper limit distribution of alpine meadow is:

H=exp(2.46+0.0734x+O.203y-O.OOO448r-O.00331y l) (n=144, r=O. 895) (1)while the model for lower limit distribution is:

H=exp(-4.18+0.0923y-O.557y-O.OO351y l-O.00344xy) (n=135, r=0.833) (2)According to equation (1), the upper limit with changing longitude or latitude

has a maximum value. For the whole surface, the maximum value of H occurs at81.9°E, 30.6°N, which is located at the west of the boundary between North Tibetand South Tibet. According to equation (2), the lower limit is higher on thenorthwestern part, lower on the southern part, and much lower on the northeasternpart ofthe plateau. The trend-surface ofthe lower limit distribution has a northwestsoutheast trending shape of a saddle (Figure 15-2).

Figure 15-2 Trend-surfaces of the lower and upper limit distributions of alpine meadow(VV~GXiuhong, 1996b)


The range of altitudinally distributed alpine meadow can be approximatelyconsidered as the difference between its upper and lower limits. The characteristicsof the range distribution can be analyzed based on equations (1) and (2). Accordingto the trend-surface analyses, the range generally thins out northwestwards, alsoslightly reduces on the southeasternmost plateau. The differentiation of the rangedistribution is larger on the southeastern plateau. Deductively, the boundary wherethe upper limit is equal to the lower limit, i.e. the range becomes nothing, is theplace where the alpine meadow disappears.

15.2.2 GEOECOLOGICAL ANALYSIS OF THE TREND-SURFACES

As indicated by the stepwise regression analyses, both upper and lower limitsare significantly correlated with their fitted values. However, differences exist incorrelated coefficients and equation forms between upper and lower limits.Obviously, correlation for upper limit is higher than that for lower limit. This isbecause that the moisture and temperature conditions are stabler at higher elevationsthan those at lower elevations. In comparison, the climatic conditions at higherelevations have the similarities to those in marine areas, and the climatic conditionsat lower elevations have the similarities to those of continents. The upper limit ofalpine meadow belt corresponds to the lower limit of subnial belt, while the lowerlimit of alpine meadow belt corresponds to the upper limit of montane forest belt,montane steppe or alpine steppe belt. Each type of natural altitudinal belt probablyhas an upper limit distribution better fitting a model, yet, all the mentioned upperlimits, corresponding to. the lower limit of alpine meadow, can not fit a model verywell. With decreasing elevation, climatic conditions are becoming more complex,and vegetation is becoming more luxuriant.

It is one of the most important characteristics that the trend-surface for theupper limit has a maximum value. Climatically, the temperature generally decreaseswith increasing altitude, and both precipitation and temperature have the generaltendency of decrease from southeast to northwest on the plateau. For example, onthe southeastern part of the plateau, the number with mean daily temperature above5°C reaches 250 days, and the accumulated temperature (above 5°C) exceeds 3000°C, and an annual precipitation, 700 mm; while on the central-west section of theQilian Mountains, the number with mean daily temperature above 5°C ranges from80 to 150 days, accumulated temperature (above 5°C), 700 to 1500°C and an annualprecipitation, 300 mm. Thus it is easy to understand why the upper limit generallydecreases northwestwards. However, more precipitation (especially snowfalls witha lower snowline) has stronger function of lowering temperature on the upper partof the mountains located on the southeastern part of the plateau, which results in therelative cold-wet climatic conditions unfavorable to the increase of the upper limit.Accordingly, the upper limit is not very high on the southeastern part of the plateau.In addition, the plateau itself has the so-called heating function, which is suitablefor the increase of upper limit. Therefore, the upper limit has a maximum value incertain latitude and longitude.

312 WANGX.H.

The model (1) indicates that the latitudinal maximum value (y=30.6°N)appears in the transitional zone between subpolar and temperate belts in thesemiarid region and in the transitional zone between humid and subhumid regionsin the temperate belt on the plateau, which is also the boundary between SouthTibet and North Tibet and almost along the Gangdisi-Nyainqentanglha Range. Thelongitudinal maximum value (x=81.9°E) appears in the transitional zone betweensemiarid and arid regions. Mainly affected by the lowering temperature withincreasing altitude, subnival belt (with some mesophytes) occurs above alpinemeadow belt, therefore, the upper limit distribution of the alpine meadow belts, i.e.the lower limit distribution of subnival belts, is mainly determined by temperature.

The lower limit distribution of alpine meadow has a general tendency ofincrease with intensifying cold-arid climatic conditions northwestwards. In thesubpolar belt, the lower limit of alpine meadow, Le. the upper limit of alpine steppe,is usually higher because of the poor moisture condition at lower altitude. In thetemperature belt, the lower limit of alpine meadow, Le. the upper limit of montaneforest or montane steppe, is usually lower because the upper limit of montane forestor montane steppe is usually controlled by the temperature condition. Compared tothe upper limit of alpine meadow, its lower limit is less affected by the function oflowering temperature by more precipitation and the lower snowline in lowerlatitudes. It is clear that the climatic conditions on the northwest and thesoutheasternmost plateau are unfavorable to the range expansion of alpine meadowbelt. Large differentiation of the range distribution results from the complexclimatic conditions on the southeastern plateau.

15.2.3 SPATIAL RELATIONSHIP BETWEEN HORIZONTAL ZONE ANDALTITUDINAL BELTS

The spatial relationship between horizontal zone and altitudinal belts can bestudied in analyzing the relationship between the trend-surfaces of upper and lowerlimit distributions of alpine meadow and that of the base surface of the plateau.

The determination of the base surface of the plateau is helpful fordistinguishing the horizontally and altitudinally distributed alpine meadows. Sometypical base surfaces and their elevation ranges have been determined. For example,Qiangtang plateau, with representative lacustrine plain and piedmont plain, has anelevation range of 4500 m to 4800 m asl; while South Tibet has broad valley basinsas representative with an elevation range of 3500 m to 4500 m as!. In the middlenorthern part of the Hengduan Mountains, the typical base surface elevation rangesfrom 2500 to 3500 (4000) m as!. It is difficult to precisely determine the plateau'sbase trend-surface because of its complexity. According to the physicalregionalization for the plateau, the natural zone of the alpine meadow is distributedin the region of 30-35°N, 91-103°E. In this paper, the region of 89-103°E and 2937°N was selected from the topographic map, and the elevations of the net points(with unit change in longitude of lOin latitude of 0.5°) were used to roughlycalculate the trend-surface of the mentioned part of the plateau's base surface


(ZHENG Du, 1979).Let H, x and y represented elevation, geographic longitude and latitude of net

point, respectively, the model for the trend-surface of the mentioned part of theplateau's base surface was:

H=exp(-35.4+0.577X+l.09y-O.00318r-O.016'Zv2 (n=225, r=O.799) (3)

Figure 15-3 Two trend-surfaces intersect, showing the horizontally distributed region of alpinemeadow (WANG Xiuhong, 1996b)

Figure 15-3 shows that the trend-surface of lower limit distribution and that ofthe plateau's base surface intersect, and within the intersecting curve is thehorizontally distributed alpine meadow (the natural zone). The calculated curve isslightly distributed on the west, which is resulted from the fact that there are moremountains on the northwest and more gorges on the southeast of the plateau.However, this deviation does not affect the tentative idea to determine thehorizontal zone of alpine meadow.

The relationship among the three trend-surfaces is indicated in the sectionaldrawing (Figure 15-4). The horizontal zone and altitudinal belts of the alpinemeadow link up the montane forest zone (belts) and alpine steppe zone (belts), orthe monsoonal and continental climatic systems on the plateau.

Let L1 and L2 (surface becomes line in sectional drawing) represent the trendsurfaces of upper and limit lower distributions of alpine meadow, L3 the trendsurface of the plateau's base surface, MI, M2 and M3 stand for the mountains withthe base belts of montane forests, alpine meadows and alpine steppes, respectively.

314 WANGX.H.

It is clear that points A and B (line becomes point in sectional drawing) indicate aclosed curve where the trend-surface of the plateau's base surface intersects withthat of lower limit distribution of alpine meadow, i.e. representing the boundaryinside which alpine meadow is horizontally distributed (the zone); and point Cindicates the curve where the trend-surfaces of lower and upper limit distributionsof alpine meadow intersects, i.e. representing the boundary where the altitudiallydistributed alpine meadow disappears. Figure 15-4 can reflect the spatialrelationship between the horizontal zone and altitudinal belts. From the southeast tonorthwest of the plateau, alpine meadow starts its horizontal extension where itslower limit is equal to the elevation of the plateau's base surface (see point A), thenfinishes its horizontal extension where its increasing lower limit is equal to theelevation of the plateau's base surface (see point B). On region AB of the basesurface, the lower limit would be reflected if there were some gorges, and the upperlimit would be reflected if there were some mountains like M2. The so-called"layer" could be imaged between L1 and L2. and both the altitiudinally andhorizontally distributed alpine meadows could be regarded as the reflection of theprojection of the climatic "layer" on its underlaying surface.

c

M3 M2MI

NW .....I------i~. SE L3L2

Figure 15-4. Distribution model of alpine meadow on the Tibetan Plateau

Legend

L1, L2 and L3--

MI, M2 and M3-

A and B-

c--

Trend-surfaces of upper and lower limit distributions of alpine meadowand the plateau's base surface, respectively;

Mountains with base belts of montane forest, alpine meadow and alpinesteppe respectively;

Indicating the intersecting curve between L2 and L3;

Indicating the intersecting curve between LI and L2;


The climatic conditions within the so-called "layer" of alpine meadow arerelatively stable compared to those of alpine steppe or montane forest on large scale;however, they are distinguishable on small scale, mainly resulting from the spatialdifferentiation of alpine meadow distributed areas. From SE to NW in the naturalzone of alpine meadow, the regional differentiation is obvious. Its southeastboundary is also the northwest limit of montane forests, which is closely related tothe mean temperature of the warmest month and corresponding to the boundarybetween the plateau subpolar and the plateau temperate, while its northwestboundary is also the southeast boundary of the alpine steppe or alpine meadowsteppe zone, which is closely related to the moisture regimes from alpine subhumidto alpine semiarid. Having higher productivity than other types of alpine meadow,shrubby meadows are mainly distributed in the humid southeastern part with alpinescrubs on the shady slopes and alpine herbaceous meadows on the sunny slopes.Kobresia meadows are mainly distributed in the middle part with more gentle relief,with some wetlands of swampy meadow and swamp in depressions, flood lands andfluvial bogs. In the northwestern peripheries of the natural zone (the transitionalarea between subhumid and semiarid types), alpine steppe meadows withcarbonated alpine meadow Soils occur, because the Kobresia meadow chieflyconsists of Kobresia pygmaea, accompanied with Stipa s, Festuca s and other plantsof xerophytes (ZHENG Du, 1996a; WANG Xiuhong, 1996b).

Altitudinally distributed alpine meadows occur on larger region than thenatural zone of the alpine meadow on the plateau. Therefore, the spatialdifferentiation of alpine meadow can be shown with comparing various alpinemeadow plants on different altitudinal belts. On various altitudinal belts fromsoutheast to northwest of the plateau, alpine meadow gradually changes from (l)alpine scrub herbaceous meadow, to (2) alpine scrub meadow, (3) typical alpinemeadow mainly consisting of Kobresia pygmaea, (4) alpine steppe meadow chieflyconsisting of Kobresia pygmaea, Festuca s This spatial variation of the plantsreflects the para-horizontally climatic differentiation of alpine meadow distributivearea. Also, the variety of alpine meadow plants becomes fewer with increasingaltitude. Between the trend-surfaces of upper and lower limit distributions (or the"layer"), the grass yield decreases from the southeast to northwest, also decreaseswith increasing altitude.

15.3 Grassland Resources and Degradation Problems

The alpine meadow has satisfactory grazing conditions, e.g. large area andwide distribution, strong grazing-resistance and high storage rate in cold season,and high nutrient value and good palatability of grass, thus it is a type of grasslandessential to the Tibetan people; however it also has some deficiencies, e.g. shortgrowing season (90-150d), very low primary productivity, distinct seasonal changesof standing crop biomass and content of nutrient composition, very short plantheight impossible to reap for winter use, and fragile ecosystem easily influenced byvarious disasters, which likely cause some problems in its development. By rough

316 WANGX.H.

estimate, the total area of the natural zone of alpine scrub and meadow amounts to269,000 km2, making up 10.7% of the total area of the Tibetan plateau. Thepopulation density of the natural zone is 3.0 persons / km2, which is lower than theaverage of the plateau (ZHENG Du, 1996b).

The key problems existing in the sustainable use of alpine meadow grasslandresources include the contradiction between grass supply and livestock demand, andgrassland degradation. Grassland degradation is caused by integrated effect of bothnatural and artificial factors (Figure 15-5).

I degraded grasslands of alpine meadow on the plateau JI........ ,

physical factors \.. human impacts

I I Iimbalance grasslands low irrational

of grasslandsI-

destroyed by marketing - populationin time and insects, pikas ~I"" rate and structure of

space and rodents overgrazing livestock

Low productivity Forming Heitutan irrational cultivation& periodic (blackearth sand) and other activitiesdegradation

countermeasures for management of degraded grasslandsand development of animal husbandry

I Irestoration establishment demarcating

of natural of artificial grasslands for

l!:ra~slands l!:rasslands rational uti Iization

adjustment ofKilling rodents, management

population structureof livestock, raising pikas, and for

marketing rate insects Heitutan

Figure 15-5 Degraded grasslands and its management on the Tibetan Plateau


15.3.1 NATURAL DEGRADATION OF GRASSLAND

317

Periodical natural degradationThe results of spectrum analysis indicated that main abiotic factors in the

alpine meadow ecosystem, Le. rainfall and temperature, oscillate with cycles of 3-4years, and primary productivity oscillates with an average period 3-4 years underthe excitation of cyclic abiotic factors (ZHOU Li et al., 1995a). The formation andchange of sod layer of Kobresia meadow are closely related to the volume ratio ofgrass to soil in topsoil. The formation and destruction of the mentioned sod layerhas the periodic characteristics, with a period of 14-17 years, sometimes reachingmore than 30 years (BAa Xinkui, 1995). Based on these research results estimationcan be made that the alpine meadow ecosystem has its own characteristics ofchange on different time scales, which can not be changed by human beings withlarge scale.

Freeze-thaw stripping ofsod layerIn the area with larger slope where alpine meadow is distributed, soil-forming

conditions are not stable, and actions of daily and seasonal freeze-thaw andalternation of wetting and drying are very strong, which can easily result in thedestruction of sod layer. Generally, the difference in temperature between day andnight is great on the plateau. It has a lower temperature at night (below -10°C) andhigher temperature during the daytime (above 20°C), with diurnal temperaturedifference of II-17°C. According to statistical analysis, it has a long time forfreeze-thaw action on alpine meadow area in a year. Different swell-shrinkcharacteristics between organic matter and soil grain usually lead to the breakagebetween sod layer and its nether soil layer when freeze-thaw action occurs (Ll Xilaiet. al., 1995).

Impact ofwind and water erosionImpacts of regional strong wind and shower are very obvious. 60%-70% of

precipitation occurs in July and August, and it is dry in other months. In most ofplaces gale (~17m·s·l) usually takes place from December to next April, with anaccumulative total of more than 30 days. Integrated impacts of freeze-thawstripping of sod layer, more precipitation in summer, and strong wind in winter andspring create conditions for the increasing of bare land area and the formation of"Black Soil Patch" (LI Xilai et. al., 1995; ZHENG Yuanchang et al., 1995).

Harm ofrodent and insect pestIt has about 1.3xl07 hm2 of grassland seriously affected by rodent on the

plateau, in which Qinghai has about 5.3xl06 hm2, western Sichuan has about

1.3xl06 hm2, and southern Gansu and Tibet has about 6.7xl06 hm2. The plateau has

at least 6xl08 of pikas and lxl08 zokors, and 1.5xl0 lo kg of fresh grass is used bythem yearly, which can feed I.Ox 107 heads of sheep (ZHOU Xingmin et aI., 1995;ZHOU Xingmin, 1996). Rodent affected area generally has 2700 rodent holes per

318 WANGX.H.

hectare, with seriously affected area reaching 4500 rodent holes per hectare.Ochotona curzoniae and Mitrotus irene are the main rodents in "Black Soil Patch".Rodents eat the grass all the year round, and it is the time for rodents to need morenutrients when the grass begins growing. In the rodent seriously affected areausable grass has great difficulty to grow, but some poison grass has betterconditions to develop (LI Xilai et al., 1995).

Gynaephora s is one of the main insect pest types on the alpine grassland ofthe plateau. It is mainly distributed on the subpolar humid and subhumid grasslandwith an elevation of 3900-5000 m in Tibet. Administratively, Nagqu Prefecture isseriously affected by insect pests with an affected grassland area of 7.3 x105 hmz.The main insect pest harmful to grassland is Gynaephora qinghaiensis, sometimesincluding G. Aureata (Team of integrated scientific survey on the Qinghai-XizangPlateau, Chinese Academy of Sciences, 1992). Gynaephora spp usually occur onthe grassland with an elevation above 3700 m in Qinghai Province and affects anarea of 2.0x 105 hm2

. Insect pest density is usually 10-100 per square meter, whichhas weak impact; sometimes reaching more than 1000 per square meter, which hasstrong impact.

15.3.2 GRASSLAND DEGRADATION BY ARTIFICIAL FACTORS

OverstockingExcessive livestock capacity is usually the basic reason for grassland

degradation. This is because that overstocking generally results in more export ofsoil nutrients, which makes the topsoil lack more available nutrients and seriouslyinfluences the growth of grass. According to the recent statistics there are about6.0xl07-7.0xl07 heads of big and small livestock on the plateau, the amount oflivestock on hand increases 3 times than that in the 1950s. Excessive livestockcapacity usually leads to the decrease of unit yield of grass and plant species. Forexample, grassland of Kobresia pygmaea in Madoi County of Qinghai Provincenormally has a unit grass yield of 1500-2250 kg·hm-z; however, owing to thegrassland degradation caused by overstocking it has a unit grass yield of 300-450kg·hm-z, which decreases by 80% (ZHENG Yuanchang et al., 1995). However,poison grass off livestock's feed or not eaten by livestock can fully use variousresources to grow. Overstocking also accelerates the grassland degradation throughintensifying the rodent harm.

Unsuitable space-time matching between grass and livestockContradiction exists between grass supply and livestock need, i.e_ demand

exceeds supply in winter-spring season (withered grass period) but supply exceedsdemands in summer-autumn season (green grass period). In addition, the unsuitabledistribution of seasonal grassland, lack of rotating grassland for livestock onschedule and lower marketing rate of fattened livestock not only greatly affect thegrowth of grass in cold season, but also make most of livestock loss condition.Qinghai Province loses about 3.0x 107 kg of flesh yearly because of its lower


marketing rate. If one full-grown livestock needs 100 kg of green grass to increase Ikg of its flesh, Qinghai Province losses 3.0x109 kg of green grass yearly (HUANGWenxiu, 1996).

Satisfactory matching between certain grassland type and certain livestockspecies is essential to taking full advantage of grassland resources, as well askeeping high growth capacity of livestock and preventing livestock fromretrogressing. Unbalanced distribution of livestock species is the main reason forthat the local people cannot make full use of the grassland resources. For example,subpolar humid and subpolar subhumid area in Tibet is suitable for raising yaks andsheep. However, more sheep and goats have been fed than yaks in recent years,with a tendency of small livestock replacing big livestock, livestock with lowergrowth capacity replacing well-bred ones. In addition, irrational drove structure alsoleads to the decrease of livestock growth capacity. Some livestock are used forcarrying food and salt because of the poor traffic condition on the plateau. Theproportion of female livestock with fertility is small, while that of old livestock islarge.

Impact ofother activitiesBlindfold reclamation of grassland without considering its natural conditions

seriously affected both agriculture and animal husbandry. The grassland has not yetrecovered which once reclaimed in Qinghai Province in 1960. However, stockkeeping completely depending on natural conditions without technical and energyinput also affects the sustainable use of grassland. This is because that agriculture,industry and animal husbandry affect each other. For example, in the totalproduction value in Golog Prefecture in Qinghai Province in 1989, animalhusbandry accounted for 94.48%, agriculture 1.17%, forestry 0.2%, industry andsideline 3.73%1.

The dense establishment of settlements, implementation of contracting systemof grassland, little popularization of fenced grassland, over-large fenced grassland,different grazing conditions inside the fenced grassland, lack of drinking water, orinaccessibility of some grassland can reduce the total grazing area, which makessome grassland overused while others not developed. In particular, some herdsmenused the sod layers to build wall for fence and rotation grazing, which intensifiedthe wind erosion and rodent harm.

Mining, road construction, gold and sand collection etc made the grasslandloss protective layer, which, along with the strong wind, greatly accelerated thedegradation rate of grassland. However, lower opening degree of the grasslandsystem greatly affects the exchange of matter, energy and information between thesystem and its environment.

I Office for Integrated Regionalization of Agriculture in Golog Prefecture, 1991. IntegratedRegionalization of Agriculture in Golog Prefecture.

320 WANGX.H.

15.4 Countermeasures for Sustainable Use of Alpine Meadow Grassland

The sustainable development on the high-cold meadow zone directly dependson the sustainable use of the alpine meadow grassland resources. Preventinggrassland from degrading should be based on the rational matching between grasssupply and livestock demand both in time and space. Concerning the problems inthe sustainable use of alpine meadow grassland, some countermeasures are listed asfollows.

15.4.1 RATIONAL STRUCTURE OF LIVESTOCK SPECIES

Subjectively raising livestock without considering the large-scale matchingbetween grassland characteristics and livestock species is harmful to rationaldevelopment of the whole plateau. The alpine meadow occurs as alpine shrubmeadow, alpine meadow, and alpine steppe meadow from the southeast to thenorthwest of the plateau. According to its environmental conditions and grassproduction, big livestock (yak and common ox) should be mainly raised, and bothsheep and goats should be appropriately developed in alpine shrub meadow area;both cattle and sheep should be mainly raised, and horses should be appropriatelydeveloped in the alpine meadow area; and the proportion of small livestock shouldbe increased in the alpine steppe meadow. The study of optimized grazing plan inalpine meadow area of Qinghai Province shows that the ratio of sheep to yak shouldbe 3: 1. For better determining the structure, attention should be also paid toherdsman's experience, related scientific experiment, and local social economiccharacteristics.

15.4.2 RATIONAL STOCKING INTENSITY

Facing the situation of serious degradation of grassland, some researchersadvance that the grassland on the plateau should be completely fenced. However,some researches indicate that grazing with appropriate intensity can increase thegrass production rather than damage the grassland (WANG Qiji et al., 1995b).Further research indicates that 45%-54% of utilization rate of grass in each seasonis suitable for grassland and livestock production (ZHOU Li et al., 1995, 1996). Forkeeping this rate, some methods were listed as follows. (1) Separate establishmentof settlements should be encouraged to prevent livestock gathering and grazing insame place at night; (2) it is necessary to enlarge the contracted grassland in orderto cover the region with hard living conditions; (3) fence should be popularizedwith each fenced grassland having a area of 20-30 hm2 and having almost samegrazing conditions; (4) living conditions and transportation condition in the regionwith good grazing conditions but out-of-the-way location should be improved,small roads, small bridges and water supply should be constructed, which arehelpful to use the undeveloped grassland. Rational stocking intensity is more relatedto rational use of seasonal grassland.


15.4.3 RATIONAL USE OF SEASONAL GRASSLAND

321

Livestock demand is generally steady-going, however grass supply seasonallychanges. To be more exact, standing crop biomass reaches highest value in Augustand decreases to the lowest value in next April; moreover the crude protein contentof grass begins increasing in May, attaining maximum in the end of June, startsdecreasing from November to next April, reaching the minimum in April. Thegrazing period of winter-spring (cold season) grassland is longer than that ofsummer-autumn (warm season) grassland, also the former becomes longer while thelatter becomes shorter from southeast to northwest of the plateau. Therefore, thewarm season grassland is usually underused while the cold season grassland isusually overused and the situation becomes more serious towards the northwest ofthe plateau. In addition, the unsuitable distribution of seasonal grassland, lack ofrotating grassland for livestock on schedule and lower marketing rate of fattenedlivestock not only greatly influence the growth of grass in cold season, but alsomake most of livestock loss condition.

To prevent livestock becoming "the machine of burning grass", it is necessaryto implement seasonal livestock raising, i.e. sufficiently using the warm seasongrassland to raise the improved livestock, slaughtering them before winter andincreasing their marketing rate and commodity rate. In this way the cold seasongrassland can be effectively protected. Concerning the distribution of the seasonalgrassland, altitudinally distributed alpine meadow with high altitude is usually usedas warm season grassland; however, steep slopes (greater than 25 degrees) shouldnot be used because of their fragile environmental conditions. "Rationally fencing"is also a good way to protect grassland in cold season, but a much better way refersto the construction of artificial and semi-artificial grassland

15.4.4 CONSTRUCTION OF ARTIFICIAL AND SEMI-ARTIFICIALGRASSLAND

Construction of artificial and semi-artificial grassland can reduce the pressureon natural grassland, especially on the winter-spring grassland, and reduce theunbalance of grassland use in space and time. Concretely, it not only increases theusage of solar energy and percent conversion of matter, but also reduces the wasteof grassland resources. At present some countries with developed livestockhusbandry have paid a great attention to the construction of intensive grassland.However, the construction of artificial grassland on the plateau should be based onthe local environmental conditions and developing levels of economy, society andculture. It is clear that the environmental protection function of the alpine meadowis more important than its function as a type of resources; thus, it is shortsighted toconstruct overmuch artificial grassland, especially to construct grassland on the areawith strong wind and water erosions.

322 WANGX.H.

15.4.5 PROTECTION OF THE NATURAL GRASSLAND

There are various methods to prevent the grassland degrading, e.g. control ofrodent and insect pest harm, fencing, application of fertilizer, replanting,scarification, grass development by selection, marshaling of community optimizedstructure, and removal of poisonous weeds. Control of the rodent and insect pestharm is primary step to protect grassland. New idea should be used to control therodent and insect pest harm, i.e. positively limiting the disadvantageous aspect ofrodent and insect pest and exploiting their advantageous aspect by regarding themas resources. In recent years, the fur and bone of some rodents have been developedas ornament and medicine, which is helpful to reduce their harm on grassland.Chemical method is not suggested to use because it not only largely kills rodent'spredators but also seriously pollute the soil and water.The areas with steep slope and high altitude should be completely fenced becausestrong freeze-thaw action and wind and water erosion always occur there. Blindfoldreclamati9n of grassland located in flat and lower areas without considering itsnatural conditions should be avoided, because it can seriously influence bothagriculture and livestock husbandry. It is suggested to use concrete and wire nettingfor fencing, because fencing with the sod layer of alpine meadow, easily intensifiesthe wind and water erosion and rodent harm. Mining, gold and sand collectionshould be seriously controlled because these activities accelerate the degradationrate of grassland along with the strong wind erosion.

15.4.6 ENHANCING THE INTEGRATED DEVELOPMENT

Rational development of grassland is closely related to the regional integrateddevelopment, e.g. developments of agriculture, industry, transportation, commerceetc. Integrated development first increases the mechanization degree andtechnology content on grassland, which is important to release labor force andincrease working ability of labors; it secondly increases the integrated productivityof grassland, marketing rate and commodity rate of livestock, which can reduce thepressure of livestock on winter-spring grassland, intensifies the exchange of matter,energy and information between grassland system and its environment. With theintegrated development, a production basis of pollution-free meat can be establishedon the high-cold meadow zone, which will benefit the people all over the world.

15.4.7 STRENGTHENING THE CAPACITY BUILDING

The rational development of natural resources, in broad sense including theprotection of environment, is the basis for regional economic and socialdevelopments. However, rational economic and social developments have strongreaction on the former. Improving the educational level of herdsmen andstrengthening the capacity building are the basis for the three mentioneddevelopments. Capacity building includes training for scientific and technological


knowledge and intensifying law education. Capacity building can make the localpeople understand the basic characteristics of alpine meadow ecosystem, master thebasic skill of management and have consciousness of protecting ecologicalenvironment.

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39. ZUO Kecheng and LE Yanzhou, 1980. Formation and fertility of alpine meadow soil inQinghai, Province.Acta Pedologica Sinica. 17 (4): 308-317 (in Chinese with Englishabstract).

CHAPTER 16 HINTERLAND OF QIANGTANG PLATEAU

LI Bingyuan and ZHU Liping

• Qiangtang, which means 'Bare land in north' in Tibetan language, is situated inthe north of Tibet, and also called as North Tibetan Plateau. From 82.5°E to 90.7°Eand from 31°N to 36°N, this land extends 750-800 km along E-W direction andcrosses 450 kIn along SoN direction. It covers an area of over 400,000 km2 that isfrom the Kandese-Nyqintanggula Mountains in north to the Kunlun Mountains insouth and from Mt. Aludadang of the Karakorum Mountains in west to the Mt. GarKangri of Tanggula Mountains in east. Situated in hinterland ofthe Tibetan Plateau,Qiangtang is characterized with high altitude and extremely adverse climaticenvironment. Except for fewer herding activities, there is no permanent resident inthis area. Scientific survey in this area is very weak in researches of the totalTibetan Plateau due to difficult traffic conditions for entering this area. Under thiskind of background, this area is well conserved as its original situations and lessdisturbed by human activities (Figure 16-1).

Sketch map oi'ihe Qiangtang Plate.u

Figure 16-1 Sketch map of the Qiangtang Plateau

327

ZHENG Du, ZHANG Qingsong and WU Shaohong (eds.), Mountain Geoecology and Sustainable Development of theTibetan Plateau, 327-348.©2000 Kluwer Academic Publishers.

328

16.1 Natural Environment

LI B. Y. and ZHU L. P.

Qiangtang Plateau is mainly composed of wide valleys, lake basins, gentlyundulate platform and hills as well as middle-small undulate mountains which formthe typical plateau surface. Mountains are generally high above 5000-5500 m aslwhile the bottoms of lower basins fluctuate from 4400 to 5100 m as!. On someextremely high mountains with 6000-6500 m asl, the gentle landforms show thatgood planation surface is well preserved. Geomorphically described to QiangtangPlateau, snow peaks protrude on flat ridges of high mountains; undulate hills andmountains are nearly in the same plane; piedmont pluvial-fans incline to lake basins;lake platforms and a series of sand-gravel bars were left by lake retreating.Qiangtang Plateau, with average elevation of 5000 m, is the most gentle and thehighest area on the total Tibetan Plateau (YANG Yichou, et al., 1984).

Roughly bordered by 34.5°-34°N, Qiangtang Plateau may be divided as southQiangtang and north Qiangtang.

South Qiangtang is situated in extending areas of Karakorum and TanggulaMountains. Generally distributed along E-W direction, mountains and platforms inthis area were frequently disconnected by NE, NW or nearly S-N formations, whichformed a series of faulting mountains and basins. Many ice mountains and snowpeaks are high above 6000 m asl such as Chagdo Kangri (6148 m), Buruo Kangri(6436 m), Zangse Kangri (6580 m), Purag Kangri (6487 m), Dariyou (6282 m),Gomori (6058 m), Mayer Kangri (6286 m), Jangngaida Rinag (6098 m), MuggarKangri (6289 m). The widest site of basins reached 10 km. Lakes are generallydeveloped at the bottom of basins with average elevation of 4800-4500 m. Withelevation of 4400-4500 m, the lake level of Serling Co and Bangong Co is the lowest,in which landforms are largely undulated as relative height of 500 m, even 1000 m.

North Qiangtang is also called to be Hoh Xii because of the Hoh Xii Mountainsextending from east to west in this region. Except for Mt. Gangzari (6305 m),Songzhiling (6371 m) and other individual mountains, the elevation of Hoh XiiMountains are generally from 5300 to 5500 m as!. With elevation of lower than5300 m, most areas of north Qiangtang appeared as undulated surface which werecomposed of hills, platforms and plains. At the bottom of basins, there distributedlakes or dry lake beaches with elevation of 4750-5050 m and relative height of lessthan 200 m. The mountains' slope degrees are usually around 10° in this area sothat it is described "mountains in far, beaches in near." With the gentlest relief, thisarea was best conserved on the Tibetan Plateau, in which the Cenozoic volcanicactivities were very active and formed a series of lava mesa, lava cone, lava plain etc.

Historically, climatic data is short in Qiangtang except for that of Gerze climaticstation and Bangoin climatic station at southern border. Around this area, there aresome scattered climatic records or observed results such as that of Nagqu station andTuotuohe station in east and that of Tianshuihai area in west. The three times ofscientific surveys in 1976, 1987 and 1990 had reached the middle, northwest and eastpart respectively and collected systemic observed data during survey period.According to these climatic records and relative interpolation correction, thedistribution features of temperature and precipitation in this area had been obtained

HINTERLAND OF QIANGTANG PLATEAU 329

(GAO Youxi et al., 1984; 1999; LIN Zhenyao et aI., 1979). Both of latitude andaltitude are dominant factors to climate in this area. Temperature is obviouslydifferent in the basins along S-N direction. Data of Gerze and Bangoin stationshowed that, in the southern part of this area, mean temperatures of two sites in Julywere 12.1°C and 8.6°C while mean lowest temperatures were 4.6°C and 3.1°Crespectively. However, in central part of Qiangtang Plateau (near 87°E, 34°N),mean temperature in July decreased to 5.5°C while the lowest temperature was oftenlower than O°C. The difference of daily temperature even reached 15-20°C.Around Lexiewutan lake in the northeast part of Qiangtang, mean temperature andmean lowest temperature in July were only 1.7°C and -1.2°C respectively. In thenorth part of Qiangtang, mean temperature and mean highest temperature in Julywere 3-7°C and 7-lOoC respectively. In fact, the extremely lowest temperaturerecord from Tuotuohe climatic station even reached -45.2°C (January 5, 1986).Thus, it may be inferred that the extremely lowest temperature at higher altitude sitesin the inland of Qiangtang was lower than the value (Figure 16-2).

As this area is neighboring to the Central Asia dry area in the north, watermoisture that brings precipitation in Qiangtang is mainly from the east, south andwest direction. Among water moisture from the three directions, those from thewest and south have influenced smaller range and brought little precipitation whilethat from the east has only produced effect in the eastern part. This situation causesprecipitation in this area gradually decreases from southeast to northwest.Precipitation in the east-middle part is around 150 mm while it is lower than 50 mmin the north. This trend has also been reflected from observed data of three stationssuch as Bangoin (301.2 mm) in the southeast, Tuotuohe (277.2 mm) in the east andGerze (166.2 mm) in the south. However, precipitation in high mountains is higherthan that of plateau surface. For examples, the in site surveyed precipitation was200-250 mm at elevation of 5250 m on west Kunlun Mountains which is in thenorthwest part of this area while it is as high as 400-450 mm in accumulation area ofglaciers.

Due to extremely cold climate, most parts of this region are permafrost areas, inwhich periglacial process is very active except in lake basins and wide valleys whichare lower than 4700 m asl in its southern periphery. In the areas with much watercontent, pingos, ice wedges, stone-rings, stone-nets, stone-lines, frost-swellingstalagmites, stone-flow slopes, block cones, patterned grounds and rice grounds aredistributed elsewhere. However, snowlines are very high because of lessprecipitation. From 5500-5600 m asl in the east periphery, snowlines rise to 58006000 m asl in the west part. It is the highest snowline area on the Tibetan Plateau,in which modern glaciers only develop on mountains with elevation of more than6000 m. Flat surface of mountain tops avails to snow accumulation and providesproper landform conditions for glaciers development. Although precipitationconcentrate in summer, the nearly O°C of air temperature around snowlines make theform of precipitation mainly as snow or rain alternated with snow. The largest icecape in this area is situated in Purag Kangri, in which there are over 40 peaks withelevation of more than 6000 m and the highest one reaches 6482 m as\. This icecape, with a very flat top surface, covers an area of 420 km2 and extends out 65 ice

330 LI B. Y. and ZHU L. P.

tongues which reach to 5300-5600 m asl in surround valleys. It is called "IceFields" for the huge area and flat top surface. There are multi-kinds of glaciers inQiangtang such as valley glacier, cirque-valley glacier, cirque glacier, suspendingglacier, flat-top glacier and ice cape. The lowest position of modern glacier reaches5000 m asl while some glaciers extend to piedmont zone and form wide-tail glaciers.Under the extremely cold condition, both of accumulation and melting of glaciers inQiangtang area are all fewer. For an example, at the source of Yingxue River whichis situated to the southwest of Mt. Muztag, the end of glacier is 500 m wide and anice cliff is 20-30 m high. According to data surveyed on August 12, 1976, riverwater had been being broken off by frost action except that the 0.2 m3/s water currenthad only occurred during 11-15 o'clock. This reflected the water balance withlower level under continental climatic condition.

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Figure 16-2 Climatic data from weather stations in Qiangtang area


Except for Cona Lake drainage system at source of Nujiang in its southeastperiphery, all of drainage systems of Qiangtang belong to that of interior. It is thehighest interior drainage system area because terminal cutting base level of rivers isonly 4400-5000 m asl. With only tens of kilometers, most rivers of this area areshort in length. Big rivers are mainly distributed in the southern part, in whichZagya Zangbo, originating from southern piedmont of Tanggula Mountains andflowing into Serlin Co, is the longest one as the length of 480 km. Rivers aremainly supplied by thawy water of ice and snow, precipitation and groundwater.Although quantities of thawy water of ice and snow are more than that of the othertwos, the discharges are all small. For examples, the roughly surveyed dischargesof Zagya Zangbo and Jangngai Zangbo were 60 m3Is (May 27, 1976) and 1.4 m3Is(23 July, 1976) respectively. In Beilungqiangma that is situated at the east of ArmKangri and 10 km far to glaciers, the discharge was only 0.4 m3/s (July, 1976).Surface runoffs were fewer and most of them appeared during warm period (JulySeptember) of glacier melting or after rains. Even there existed groundwater supply,the water would be frozen on riverbed and formed huge ice-dress after it flowed outof ground surface. Rivers supplied by groundwater are very weak on the fluvialaction and often broken off in lower reaches.

With more than 500 lakes of over 1 km2 in each, Qiangtang is one of the mainlake distributive areas on the Tibetan Plateau (Ll Bingyuan, et aI., 1984). Most ofthese lakes are closed ones. Together with the lake zones on the northern flank ofKangdese Mountains, they form the north Tibetan lake areas. Qiangtang is also themost concentrated interior lake areas in China and the highest lake groups in altitudeon the earth. Lying at elevation of 4718 m asl, Nam Co is the second largest interiorlake in China with area of 1920 km2

• The lake water, with mineralized degree of1.7 gil, is supplied by thawy water from Nyainqentanglha Mountains. Lying atelevation of 4530 m asl, Serlin Co ranks the third largest interior lake as its area of1640 km2

• Lakes with the area of over 50 km2 are as more as 60 in numbers, ofwhich the distributed directions and lake shapes are coincided with the direction oftectonic lines. Some data documented that the formation of these lakes was relatedto tectonic movement. From less than 1 gil to 357.7 gil, there is big differentiationto lake water mineralized degree in some tested lakes. Generally, mineralizeddegree rises from the east and south to the west and north. Semi-saline lakes(mineralized degree at 1-35 gil) and saline lakes (mineralized degree at 35-50 gil)mainly exist in the southeastern part of Qiangtang. Some salt lakes (mineralizeddegree great than 50 gil) also distribute in the southeastern part, but most of them,with the saline lakes, mainly exist in the northwestern part of Qiangtang. Saltcontent is usually 10-30% high in salt lakes, in which some evolved to be dry saltlakes and contained plenty of salt mineral resources such as natrium, kalium, boron,magnesium, lithium, etc.

Restricted by water and heat condition, vegetation in Qiangtang is fewer in itskinds and sparse in its cover. With increasing of cold and dry degree from thesoutheast to the northwest, vegetation is gradually transferred from high-cold steppeto high-cold desert steppe and high-cold desert while soil types appeared thecorresponding changes.


Human activities are quite restricted by rigor natural condition in Qiangtang.There is no cultivation agriculture in this region while herd activities are mainlydistributed along Ngari-Nagqu highway. High-cold steppe grows well and has goodquality in some rangelands of southeastern part of Qiangtang where is lower inaltitude, but those in the middle and northern parts are difficult to satisfy pasturingneeds due to sparse cover and low grass yield. At present, rigor climatic conditionhas already made these areas as unpopulated areas. However, it is different in thepast according to survey results in 1970s. Stone implement relics left by ancienthuman activities were discovered in some 31 sites, in which two of them belonged tolate period of old stone age and distributed in southern periphery of Qiangtang. Theother 29 sites belonged to middle stone age and the subsequent fine stone age. 9 ofthem were in the middle and northern parts of Qiangtang where is unpopulated areaat present, in which the highest site was situated at west of Suishaola and reached5200 m as!. Their diagnostic analyses showed that they were similar in features tothe relics of late period of old stone age in north China, but evidently different withthose from south Asia. The fine stone implements also inherited that from northChina, but were different with that discovered in India. The distributive area forthese two kinds of stone implements is roughly demarcated by the HimalayaMountains. It not only provided an important base for deep research of culturalexchanging of ancient human in Stone Age, but also had important significance topast living environment of human beings in Qiangtang.

It is not discovered for co-existence of stone implements and wares at fine stoneimplement sites of Qiangtang. These fine stone implements, characterized by thatof middle stone age and new stone age (AN Zhimin et ai, 1979), may correspond to7500-5000 a BP compared with the dating data when it was the best climate period inHolocene Epoch. These situations reflected that Qiangtang had ever owned awarmer and more humid climatic environment than that of present so that it wasadequate for human beings living. Ranges of human beings activities were muchlarger than that at present, but they were kept being moved southward and to thelower sites due to climatic changes to cold and dry tendency. The best climateperiod in Holocene Epoch and subsequent climatic changing were also documentedby research results from evolutions of lakes, glaciers, permafrost and turves.

16.2 Ecosystem

Accompanied with development of the tendency towards to the cold and dry,biologic communities in Qiangtang were kept being changed. Thus, the largest scaleof high-cold ecosystem on the earth appeared in this area.

Limited by water and heat conditions, it is fewer to varieties of vegetation onthe Qiangtang Plateau, among which there are only 50 species of seed plants.Based upon multi-times field surveys by Chinese scientists, it is preliminarily to befound that there are about 250 species of advanced plants that are mainly cold-dryresistant alpine plants (LI Heng & WU Sugong, 1985). With increasing of cold anddry degree from southeast to northwest, vegetation zones show correspondingchanges from high-cold steppe, high-cold desert steppe to high-cold desert (ZHANG

HINTERLAND OF QIANGTANG PLATEAU

Jingwei et al., 1988).

16.2.1 HIGH-COLD STEPPE ECOSYSTEM

333

High-cold steppe ecosystem is the most unique ecosystem on the TibetanPlateau and dominates most areas of the Qiangtang, in which clustering Poa steppeand root-halm Carex steppe consist of 2 main steppe ecosystems that are distributedin the southern part and northern part respectively. Clustering Poa steppe, one of themain ecosystemic types on the Qiangtang Plateau, is mainly composed of Form.Stipa purpurea, Form. Stipa roborowskyi and Form. Stipa basiplumosa as well asForm. Stipa glareosa, among which, Form. Stipa purpurea is the most widelydistributed groups in the group-growing steppe.Mainly distributed in the Qiangtangand its adjacent river source areas, Form. Stipa purpurea is one of endemic contentsof the Tibetan Plateau (Figure 16-3).

Figure 16-3 High-cold steppe dominated by Form. Stipa pwpurea (near Co Ngoin in thesoutheast of the Qiangtang Plateau)

It is a kind of perennial clustering Poa, dominated by which the steppecommunities is main representative of steppe vegetation in Qiangtang, even on thewhole Tibetan Plateau (ZHANG Jingwei et al., 1988). Form. Stipa purpureawidely appears in south and middle part of Qiangtang and construct their mainlandscape types. From 4500 m asl to 5200 m asl (the highest site may reach 5400 masl), it is distributed on the gentle mountain slopes with good drainage system orlacustrine plains. Growing in the area with annual mean temperature of 0-3°C andannual precipitation of 150-300 mm as well as desert soil alternating with gravel, thisplant well suffers cold-dry conditions.


Under the rigorous environmental condition, Form. Stipa purpurea is short andsparse while its growing period is relatively short and late. In the southernQiangtang, it burgeons and grows out leaves in middle-late May, blooms andheadings from late July to August and then enters dormancy period in middle-lateSeptember due to dying of its above-surface parts by frost. The total growingperiod is only about 120 days. The appearance of Form. Stipa purpureacommunities are very humdrum as no obvious stratification occurring in summerexcept for a little differentiation of layers after August. Basically, the communitycomposition is very simple and species of vegetation are fewer in unit area.However, due to broad areas and big vertical amplitudes for Form. Stipa purpureadistribution, it usually constructs different communities with other plants such asArtemisia wellbyi, A. minor, Morina kokonorica, Caragana versicolor, Astragalusmonticolus, Carex montis-everestii, C. Moorcroftii, and is characterized with certainecosystemic distributive rules.

Stipa purpurea steppe is very significant to pasturing production. It is one ofthe main rangeland types in the Tibetan Plateau and is very adequate to herd Tibetsheep and other middle-small livestocks. Most species in the communities areexcellent or good herd grasses, in which Stipa purpurea is characterized by soft andfine quality, rich nutrition and good taste. However, due to short growing periodand sparse density as well as shortness of water in some areas, the yield of this kindof grasses is lower (150-600 kg/ha wet weight), which is an key limited factor tofurther development of pasturing production.

Stipa roborowskyi is similar to Stipa purpurea in shapes, especially in the periodwith rich nutrition except for its furling tassel flower, shorter arista and shorter plumein arista. Both of them are also similar in ecological propensity and usuallygrowing together. The former may be only distributed between 4300-5000 m asl(the highest reach 5150 m asl) in southern Qiangtang due to its narrow adaptedamplitudes to water and heat conditions. It is a perennial clustering Poa and haslittle dominant action in communities.

Stipa basiplumosa is the endemic clustering Poa under cold-dry condition onthe Tibetan Plateau, the steppes composed of which mainly appear in the QiangtangPlateau. They often occupy gravel terraces, pluvial fans, flat watershed of lakeshorelines and wide valleys in the out skirt of lakes without influence of groundwaterwhile some small patches may be seen on dry slopes. The vertical range fluctuateswidely from 4350 m asl to 5150 m asl while the surface of distributive area is usuallycovered by small gravels and composed of alpine steppe sandy soils. AlthoughStipa basiplumosa steppe appears rather widely on the Qiangtang Plateau, it isgenerally distributed sparsely and its area is much smaller than that of Stipa purpurea.In northern Qiangtang, Stipa purpurea communities are obviously decreased whileStipa basiplumosa steppes are relatively much. However, the latter is sparse ondensity with the cover degree of 15-30 (40)% and short on individual plant with theheight of 10-20 em. It is very simple to the composition of communities for only 3species of vegetation existing in per square meter in some places.

Less cold-resistant but better dry-resistant than Stipa purpurea, Stipa glareosa ismainly distributed in the west Qiangtang Plateau where it is less cold and much drier


as well as lower than 4750 m asl in elevation. Annual mean temperature is 0-3°ewhile annual precipitation is less than 150 mm, even less than 100 mm. The surfaceof this area is generally covered with gravels with cover degree of 45-70% while thesoil is mainly composed of sandy-soil or contains much sand. Stipa glareosa is akind of dry-resistant, short and clustering perennial grass.. Because of less than 10species of vegetation per square meter and only 10 cm of grass height, thecomposition of communities is also very simple. However, the growth anddevelopment of Stipa glareosa are still different with environmental changes. Theyare only 5-8 cm high above ground surface in west Qiangtang while half ofthem cannot heading and bloom.

Except for Form. Stipa purpurea as the absolutely dominant species, the warmliking white grasses and orinus thoroldi communities are also developed on thesouthern Qiangtang Plateau. In high-cold steppe zone, the altitudinal distribution ofmountain vegetation is relatively simple. For examples, high-cold meadow and itssimilar communities that are dominated by small Kobresia and Festuca ovina may bedistributed on Form. Stipa purpurea steppe zones, but they are only developed in thesouthern mountain areas which is divided by Naque-Arli highway in the southeasternQiangtang where the elevation fluctuates generally from 5100 to 5350 m asl whilethe grass layers are short and consecutive. In the northern mountain to the NaqueArli highway, high-cold meadow is weakly developed due to dry climate and onlypatchily distributed on humid shadow slopes. It gradually disappears northward andis replaced by steppe communities dominated by C. moorcroftii. Some patchyvegetation that are composed of snow-ice-suited Saussurea spp., Rhodiola rotundais,Kobresia, Saxifraga, Gentiana a/usca, etc. may be sparsely distributed in the areaabove elevation of 5300(5350) m. They may even grow above elevation from 5700to 5900 m asl which is near the permanent snowline (ZHANG Jingwei et al., 1988).

In addition, regionally non-dominant vegetation is also developed in high-coldsteppe zone of southern Qiangtang. For examples, the floodplain meadow that wascomposed of Trikeraia hookeri and C. moorcroftii frequently appeared in lakeshoresand wide valleys with sand-gravel land. Halophytic meadow that is composed ofLeymus secalinus and Polygonum sibiricum var. Thomsonii may be seen in lightsaline marsh of lakeshore. Swamp meadow or swamp which are composed ofKobresia littledalei, Blysmus compressus, etc. are widely developed in over-wetlands or seeper lands of lake shore and river bank.

Dominated by Carex moorcroftii, root-halm Carex steppe is one of the widelydistributive vegetation communities on the Qiangtang Plateau (Figure 16-4).

As an endemic species of the Tibetan Plateau, Carex moorcroftii is sand liking,cold resistant and widely adapted to range of water condition but not adapted to saltand alkali. In the northern part and high mountains of Qiangtang, it is dominantspecie of landscape vegetation with many biologic-morphologic features. On theone hand, it always appears thickly withered and yellow but not verdant colorcompared with that in humid environment of lake and river shores, most of leaves arestill half withered and yellow even in the warmest growing seasons of July-August.The leaves are kraurotic and short of water and chlorophyl content in their uppersection. It is obviously characterized with keratinization in the surface of leaves


and hardness and sharpness as needles at the tips. The root and halm are verydeveloped with underground halm of as long as several meters. These situationsshow that Carex moorcrofti has stronger growing and breeding as well as adaptedabilities to cold-dry environment. On the other hand, most of accompaniedvegetation is steppe species and less meadow contents due to very dry growingenvironment. Therefore, this kind of Carex moorcroftii is different from thatgrowing in humid environment on the ecological habits. Due to the strong drynessresistant ability, it should belong to medium dry ecological type, and thecommunities dominated by which have been listed into steppe vegetation.

Carex moorcroftii steppe is also the endemic steppe type on the Tibetan Plateau,which forms the main landscape vegetation in northern Qiangtang. It is mainlydistributed in lake terraces, gentle slopes and piedmont from 4900 (4800) m asl to5400 m asl, where the soil is thick and contains much sand. It is humid in lowersection of soil profiles while there is permanent permafrost soil in certain areas.The environment for vegetation growing is cold and little humid.

Generally, it is not complex to types of Carex moorcroftii communities, inwhich the important ones are uni-dominant Carex moorcroftii community and Carexmoorcroftii plus Ceratoides compacta dominant community. The former is widelydistributed in northern Qiangtang with the withered and yellow appearance, of whichgrass height is 10-15 em while the cover degree is 15-40% and gradually decreasedwith enhancing of cold and dry condition. In this kind of communities, the usuallyseen accompanied vegetation include Stipa basiplumosa, Stipa purpurea, Roegneriathoroldiana, Kobresia robusta, Astragalus henderson ii, A. heydei, Oxytropis tatarica,Hedinia tibetica, Saussurea gnaphalodes, S. humilis, Lepidium apetalum,Ptilotrichum canescens, Thylacospermum caespitosum and Ceratoides compacta(ZHANG Jingwei et al., 1988).

Carex moorcroftii steppe is the second important rangeland resource comparedwith Stipa purpurea steppe in the Qiangtang Plateau, and also in the high-coldsteppes of the Tibetan Plateau. From viewpoint of utilities, it is only the pastureground with medium-lower level due to coarse and hard grass quality, lower nutritionand bad taste. As the distributive area is remote and high in elevation, this kind ofsteppe is not fully utilized by human so that many gregarious wild Tibet antelopesand Bosmunus may exist in these areas.

As a vegetation type derived from the gradual transition of two species, thecommunities co-dominated by Stipa purpurea and Carex moorcroftii are mainlydistributed in middle Qiangtang. From 4900 (4800) m asl to 5200 (5400) m asl,their distributive elevation is higher than that of uni-dominant Stipa purpureacommunities. Appearance of the communities is yellow-green while the coverdegree is 20-35 (50)%. Grass height is 10-20 em and the composition is verysimple. The mainly accompanied vegetation are Stipa basiplumosa, Poa attenuata,P litwinowiana, Roegneria sp., R. Thoroldiana, Kobresia robusta, Carex montiseverestii, Potentilla bi/urca, Potentilla multiceps, Astragalus heydei, A. densiflorus, A.henderson ii, Oxytropis spp., Leontopodium pusillum, Saussurea spp., Artemisiawellbyi, A. minor, A. stracheyi, Hedinia tibetica, Arenaria edgeworthiana, Arcnariabryophylla.It is the transitional zones from high-cold steppe to high-cold desert in the


eastern and south-middle part of north Qiangtang and the western part of southQiangtang, where the climate is much colder and drier compared with high-coldsteppe in the southern part of Qiangtang. The main vegetation types are desertsteppe communities dominated by Carex moorcroftii, Ceratoides compacta, Stipaglareosa that have different ecological habit, especially in their adaptation totemperature. They are distributed in different areas and form the vegetation basezones of vertical distribution. For examples, Stipa glareosa is distributed in thewest of southern Qiangtang while Carex moorcroftii and Carex moorcroftii plusCeratoides compacta are distributed in south-middle part and eastern part of northernQiangtang respectively. The former widely appears in low mountains, hills and lakebasins below 5200 m asl while the latter is in lake periphery areas which are coveredby fine or clay sediments. High-cold meadow is less distributed in mountainvertical vegetation zones due to much more execrable ecological environment.Instead of it, desert steppe zone is directly connected to alpine periglacial vegetation.In addition, there are small patches of Hippophac tibetana, Potentilla fruticosa var.pumila, Kobresia littledalei communities in some local areas where a little more ofMyricaria prostrata communities are also distributed.

Figure 16-4 Steppe of Carex moorcroftii(near Shuangtoushan lava cone in the northeast of Qiangtang Plateau)

Soil types in high-cold steppe area are frost calcic soil and Saga soil. Humuslayer appears in top 10 cm section and contains about 1-2% of organic materials thatis obviously decreased with depth increasing. Due to weak eluviation, the contentof CaC03 is relatively high and reaches about 10%. It is illuviated in depth of 2040 cm where a weak calcic layer is formed. The iIIuvial CaC03 pellicle isfrequently seen at the bottom of gravels and stones. Although accumulation ofCaC03 is gradually reduced from north to south, all of the soil profiles are still

338 Ll B. Y. and ZHU L. P.

alkaline and the Ph values are great than 8.0. Mechanical composition is coarse inthe whole soil profiles except some particle structure appearing in surface layers.Gravel content is high above 10% while fine content is still dominated by sand. Itis characterized with sandy soil or light soil, which reflect the lower soil developeddegree. Because mechanic weathering is dominant in processes of soil formation,the content of sub-surface clay particles is relatively higher than that of surface soil.Ratio of Si/AI fluctuates between 2.8 and 3.7 and has no evidently change in sameprofile. Clay mineral is mainly composed of hydromica accompanied by chlorite,which indicates the initial stages of mineral weathering in dry climatic environment(GAO Yixin et al., 1985). In the northern and western par t of Qiangtang that aredominated by Carex moorcroft;; and Ceratoides compacta due to less precipitation,desert steppe soil is widely developed and become a sub-type of high-cold steppe soil.Because of much drier environment of development, the soil's humus is thin onthickness and light on color while content of organic materials is less than I% (GAOYixin et al., 1985).

The fauna is very poor in high-cold steppe ecosystem due to severe livingcondition. For an example, there are only 38 species of birds and 19 species ofmammals in the Hoh Xii region, Qinghai Province, the eastern part of Qiangtang.However, due to remote location and fewer herding activities in periphery ofsouthern Qiangtang, most of wild fields are free world to those animals which areadaptive to high-cold climate. The endemic animal types adapted to high-coldenvironment on the Tibetan Plateau are reptilia, aves and beast such as Tetraogallustibetan us, Columba leuconota, Grus nigricollis, Montifringilla, Bos munus,Pantholops hodgsoni, Procapra picticaudata, Equus kiang, Vulpes ferri/ata, Lepusoiostolus, Marmota himalayana, Alticola stoliczkanus, Patymys leucurus, etc. The

Figure 16-5 Group of wild yaks (Bas mutus)(near Memar Co in the west of the Qiangtang Plateau)


numbers of species are not more,but individual quantities in thecommunity are quiteconsiderable. For examples,based upon observationalstatistic to big herbivorousanimals in Qiangtang, there aretens of Pantholops hodgsoni,Equus kiang, Procaprapicticaudata, Bos mutus in eachcommunity respectively (Figure16-5, 16-6). The maximummay be over several hundreds inquantity. They mainly appearin the areas with good steppe inmiddle Qiangtang where thetotal amounts of them are over10,000. Rodents in this areaare mainly composed of Lepusoiostolus, Patymys leucurus andOchotona curzoniae whosedistribution is extremelyasymmetrical and closely related Figure 16-6 Wild animals in Qiangtang

to vegetation condition.Carnassial animals include Felis manui, Lynx, Meles and Vulpes ferrilata, but theamount is very few. The general species of aves are Pseudopodoces humilis,Kozlowia roborowskii, Montifringilla, Pyrrhocorax pyrrhocorax, etc. Upupa epopsare widely distributed and frequently seen on the Plateau while they usually inhabitin rat holes. In summer, some Larus brunnicephalus, Tadorna ferruginea, Anserindicus, Mergus merganser, Sterna hirundo, Ibidorhyncha struthersii may appear inlake areas where plateau Schizothoracinae are living while Grus nigricollis are alsoin local swamp environment (ZHANG Rongzu et aI., 1982).

16.2.2 HIGH-COLD DESERT

ECOSYSTEMHigh-cold desert system is distributed in Yang Lake and itsadjacent areas of northwestern Qiangtang where it is the most rigorous area in naturalconditions on the Tibetan Plateau for the high elevation, cold climate and brumallandscape (Figure 16-7). In this area, average elevation is over 5000 m asl, annualmean temperature is about -8°C while mean temperatures in the coldest and thewarmest month are -21°C and 5°C respectively. Annual precipitation is 20-40 mm.Non-frost days are fewer in total year and negative temperature may occur in themorning of any days. There are over one hundred days for big wind occurring.Permanent permafrost layer is widely distributed in soils while intensive frostweathering occurs on ground surface.


Figure 16-7 High-cold desert steppe in the west of the Qiangtang Plateau

High-cold desert ecosystem is dominated by Ceratoides compacta that is theendemic specie on the Tibetan Plateau. It is a kind of small procumbent shrub thatis cold and salt-alkali-resistant. The diameter of its cushion is 10-30 cm while theheight is 5-15 em. There are convex hillocks in its base. Vegetation growssparsely with only 5-10% of cover degree, but it may be 25% on the slopes withgood humid condition. The structure of community is very simple and there isfewer accompanied species. The usually-seen ones are Pegacephyton scapiflorum,Hedinia, Parrya exscapa, Braya oxycarpa, Oxytropis sp. etc. In addition, Arenariamonticola, Carex moorcroftii, Ajania scharnhorstii, Saussurea glandulifera, Stipasubsessiliflora var. Basiplumosa etc. may also be seen on the slopes of mountains (LIWenhua et al., 1998).

Because of high altitude and rigorous environment in the base belt, thevegetation structure is very simple on altitudinal distribution. Base belt is high-colddesert, and upward is from high-cold desert steppe (locally appears small piece ofhigh-cold steppe) to sub-snow ice belt, in which snow-ice belt exists on certain highmountains. For an example, the base belt which is dominated by Ceratoidescompacta is distributed on elevation of 4900-5100 m asl, and from 5100 to 5300 masl is high-cold steppe that is composed of Carex moorcroftii, Stipa basiplumosa,Stipa purpurea, etc. Sub-snow ice belt appears above 5300 m asl where sparse highmountain periglacial vegetation consists of Saussurea gnaphalodes, Hedinia tibetica.In some areas, high-cold desert is directly connected to sub-snow ice belt (ZHANGJingwei et al., 1988; ZHENG Du et aI., 1999)


Soil type of high-cold desert ecosystem is high-cold desert soil (cold-desert soil)that is the base belt soil in high-cold and dry area. Because of duplex effects of coldand dryness in the processes of soil formation, cold-desert soil is developed with verylow degree. Frost weathering is intensive so that gravels are obviously exposed onground surface due to blowing of strong wind. It is frequently observed that there iswhite salt-frost, cavelike crust and layer structure on gravel surface. Intensiveweathering and weak processes of soil formation result in less organic materialsaccumulation, of which the content is less than 0.5% and only concentrates in subsurface layers. The soil is as thin as less than 50 em in thickness and very coarse ingrain composition. Content of gravel reaches 400-600 glkg while most of finegrains falls in diameter range of 0.05-0.002 mm. Under the cold-dry conditions,soil is dry and eluviation is weak. It is usually observed to surface saltconcentrating, iron rusting and gypsum concentrating. For examples, salt content isas high as over 350 glkg in surface layer of dry basin of Yanghu. In the same soilprofile in Tianshuihai area, it appeared 3 layers of gypsum, in which one at 38-55 emdepth has the content of 200.2 glkg. According to contents of cold-desert soil, itmay be divided into cold-desert soil, gypsum cold-desert soil, salty cold-desert soil,chaps cold-desert soil, etc. (ZHENG Du et al., 1999; LI Bingyuan et al., 1996). Insome area with more water content, frost soil is developed due to influence offreezing-thaw action, in which hard-roelike structure with diameter of 0.5-1 mm isfrequently observed in soil profiles and distributed stratificatively.

Animals are poor in high-cold desert ecosystem and their activities are lessdiscovered. Only some individual Pantholops hodgsoni, Procapra picticaudata andEquus /dang are occasionally observed in periphery and well-vegetation areas ofhigh-cold desert region.

As the sum-up of mentioned above, the high-cold desert ecosystem of theQiangtang Plateau is characterized with small areas, less biological species,extremely low production and peculiar life activity. High-cold steppe ecosystemconsists of high-cold steppe and high-cold desert steppe. Although it is not rich onbiological species and not high on production, the total biological production is quitelarge due to much widely distributive area, in which the species are endemic onesevolved in high-cold and dry environment. Thus, high-cold steppe ecosystem is themost important and extremely valuable one in the ecosystems on the QiangtangPlateau.

16.3 Utilization and Protection

16.3.1 APPRAISEMENT OF ECOLOGICAL ENVIRONMENT

Representative 0/ high-cold steppe ecosystem~ Among mountain forests,high-cold meadow, high-cold steppe and high-cold desert ecosystems on the TibetanPlateau, high-cold steppe ecosystem is the most representative one in the totalplateau area and is dominant on the Qiangtang Plateau (LI Bosheng, 1989). Both ofthe flora such as Stipa purpurea, Stipa basiplumosa and Carex moorcroftii and thefauna such as Bos mutus, Pantholops hodgsoni, Equus /dang and Procapra


picticaudata are all endemic communities. They are typically representativespecies in high-cold steppe and in desert steppe, among which Bos mutus andPantholops hodgsoni are entirely distributed in the Qiangtang area. As of thehighest and largest highland eco-geographical area on the earth, the high-cold steppeecosystem of Qiangtang is not only the most representative in the Asia, but also inthe world, especially for its biological communities and multiple levels ofbiodiversity as well as inherited gene.

Despite of fewer biological species in this area, the rare and endemic species arerich while the quantities are large in their communities. The I class severelydangerous species which are listed in the CITES include Ursus arctos, Pantherauncia, Bos munus, Pantholops hodgsoni, Haliaeetus albicilla. Tetraogallus tibetanusprzeualskii. Grus nigricollis, etc. Those of the II class are more than 15 speciesinclude Canis lupus, Equus kiang etc. Animals on the protective lists of Chinesegovernment and ranked in the I, II classes are over 28 species. The endemic speciesof vegetation are also very rich. For an example, those in the Hoh XiI region of eastQinghai are more than 72 species and occupy 34.2% of the total according to thestatistic (WU Sugong et al., 1996).

Multiple types of abiological environment~ Qiangtang has not only ownedtypical high-cold ecosystem, but also shown out rich types of abiological and othernatural landscapes. Geomorphologically, modern glaciers and permanentpermafrost as well as the landforms corresponded with them are widely distributed inthis area. Different kinds of lakes are studded on the undulation surface of thePlateau, in which salt lakes are dominant while most of them preserved paleo-lakeshorelines induced by lakes retreating. It is occasionally seen to remnant hills andsand dunes that are formed by strong wind. Geologically, compared with hot springwith high temperature and different shapes of tufa occasionally observed in northQiangtang, the Cenozoic volcanic lava mesas and cones are widely distributed. Asevidences of plates collision and plateau uplifting, ophiolite belts and paleontologicalfossil sites are also widely exposed.

Fragility of ecological environment: Having experienced a long period ofevolution, high-cold steppe ecosystem is formed in the slow processes of materialcirculation and energy transformation under cold and dry condition. It is a fragilebalance that is constructed under the extremely rigorous natural conditions. Onceone of the links is damaged, it is difficult to be restored for whole ecosystem. Dueto the activities of over-grazing and gold-digging, the degradation and desertificationof rangelands had already occurred in the eastern and southern part of Qiangtang.

Well preserved original state of ecological environment: Except for grazingand mining as well as the subsequent disturbance of human activities in the southernpart, east and west periphery areas, most areas of the Qiangtang Plateau are nonresident areas until present. It may be one of the areas that are least disturbed byhuman activities on the earth. Vegetation succession and soil development is wellpreserved in their original state. Generally, wild animals are not influenced byhuman activities and live harmoniously with human beings. Under the backgroundof plateau uplifting, this area is still not influenced by river headward erosion andpreserves original plateau surface as well as the naturally evolved state of rivers and


lakes. Although characterized with simple ecological structure, low yields, rigorousenvironment and shortage of oxygen under high cold-dry condition, the high-coldsteppe ecosystem here, with enormous wild animal communities, had always keptrelatively ecological balance. It is very valuable to the study of zoology, botany andecology. Relics of paleo geography, paleontology, geological evolution andactivities of ancient human beings that are well preserved on the plateau aresignificantly important to the exploitation, utilization and protection of resources aswell as the sustainable development.

16.3.2 STATUS OF EXPLOITATION AND UTILIZATION

With small quantities and sparse distribution, the human activities in Qiangtangare only herding of Tibetan people in the southern periphery areas before 1950s.Most parts of middle and northern Qiangtang are unpopulated areas except forfootmarks of fewer expeditioners. Since 1960s, with improvement of materials andspirit life, construction of settlement sites, economic development and increasing ofpopulation, human activities in Qiangtang are ceaselessly strengthened on theintensity and enlarged on the range. At present, main activities such as grazing,exploiting of salt resources, illegal gold-digging and hunting are directly influencingthe well balance of ecological environment in this area. Over-grazing nearsettlement sites had already caused degradation of grassland and desertification incertain areas. Although local Tibetan people have the tradition for not harming wildanimals, some endemic ones in high-cold steppe such as Bosmunus, Pantholopshodgsoni, Equus kiang still had to move northward to desert steppe areas due to theincreased direct danger from human activities. The protection and management ofwild animals are enhanced and the relative laws and rules are promulgated byChinese government, but the effective practice is not carried out due to sparsepopulation and rigorous environment. Since 1980s, some benefits-chasers enteredthis area and made bad effects for their illegal hunting and gold-digging. Forexamples, the Pantholops hodgsoni are ceaselessly hunted and killed by illegalpersons who are chasing high benefits because the pashm on Pantholops hodgsoniare extremely valuable in the markets of south Asia and western countries. Due toimprovement of equipment for illegal hunting, the Pantholops hodgsoni are facingsevere dangers day by day. At least ten thousands of Pantholops hodgsoni areestimated to be killed until 1990s. Though quantities of Pantholops hodgsoni arelarge in its communities, the over-hunting and killing also made them facing thesituation of extermination. Another example is the ecosystemic damage induced byillegal gold-digging. The invading of hundreds and thousands of illegal golddiggers as well as their rude exploiting methods not only damaged mineral resources,but also destroyed surface vegetation and increased bare land. Thus, it has been theurgent issue for effectively protecting ecosystems and environment of the QiangtangPlateau.

Fortunately, different levels of governments in China have continuouslyenhanced the protection of wild animals and developed activities of anti-illegalhunting. National and provincial Qiangtang Natural Preservation Region and Hoh


Xii Natural Preservation Region are separately built by State Council, TibetAutonomous Region and Qinghai Province. They have covered over 90% of theQiangtang Plateau. However, the quite effective protection has not achieved due toshort time for the construction of these preservation regions.

16.3.3 UTILIZATION AND PROTECTION

With rare and representative high-cold steppe ecosystem, well preservedoriginal status, rich endemic species, fragile ecological environment, peculiar andmultiple landscapes, the Qiangtang Plateau has not only great value on scientificstudies and potential of practicality, but also the unique resource on tourism. TheTibetan nomadism style, relics of ancient human beings, even extremely rigorousenvironment are quite appealing to those who are interested in expeditions. Withimprovement of life levels, traffic and life equipment, tourists are graduallyincreasing year by year. In addition, the broad grassland, multiple resources of saltlakes and gold dust are also stimulating people's exploiting desire. These mustinduce increasing of population in this area and bring influence to the extremelyfragile ecological environment. Therefore, some basic principles must be insistedin the processes of utilization and protection.

(I) Making exploitation under the precondition of protection due to its peculiarstatus in the global ecological environment.

(2) Enhancing action of leading and coordinating among different levels ofgovernments. Seriously completing and carrying out the preservation regional plan.

(3) In terms of the preservation regional plan, taking absolutely protectivemeasures, such as no permission for tourists' entering and severe restriction forscientific surveys, in middle and northern Qiangtang, the core area of preservationregion, in which natural ecosystem, rare and endangered species are concentrated.Building cushioned area to keep core area from outside influence, in which thescientific researches, ecological tours and expeditions, grazing, man-madedomestication and breeding as well as utilization and exploitation of wild vegetationand animals should be carried out under the precondition of severe management.

(4) Constructing well coordination between protection of ecologicalenvironment and lives of local people. Under the support of governments, widelydeveloping scientific popularization and propagandist education among local peopleto obtain support from local people for protecting ecological environment in thisarea.

(5) Enhancing outward propaganda for designedly absorbing outside fund andscientific research power. Organizing limited tour and expedition activities forpromoting local economic development and supplementing shortage of managementfees.

(6) Taking effective measures for stoutly striking the activities of illegal huntingand mining.

16.4 Cold and dry core region


The cold and dry core region in Asia high land was thought to be situatedbetween the Kunlun and Karakorum Mountains (Wissmann, 1960/1961), but Troll(1972) thought that it was in the East Pamir and west Tibetan Plateau. Based uponrecent surveys on the Qiangtang Plateau, the Karakorum and west Kunlun Mountains,Chinese scientists thought that it should cover the area from Muztag in northwestQiangtang to Tianshuihai in northern flank of Karakorum Mountains. Its northernmargin should extend to the southern flank even interior of middle KunlunMountains (ZHENG Du et al., 1999). This region mainly exhibits the gentleplateau surface that is composed of wide valleys, basins, altitudinal hills andplatforms and is characterized with extremely cold and dry condition. For examples,mean temperature of January was -21.2°C, those of July and total year were 6.0°Cand -7.7°C respectively while annual precipitation was only 23.8 mm at Tianshuihai(4840 m as\) in the permafrost zone of this region. In Yanghu and white Gobi ofthe northwest Qiangtang (4800-5200 m asl), annual precipitation was 20-40 mmwhile it was only 3-6°C in the warmest month. Average elevation of snowline was5800 m, and some over 6100 m. It is the highest snowline distributive area in thewhole Tibetan Plateau, even in the north hemisphere. Thus, the cold and dryfeatures in this region may be inferred.

According to surface landscape survey, it is snow shadow area of theKarakorum Mountains in wide valleys from the northern flank of east KunlunMountains to the southern piedmont of Kunlun Mountains. Generally, precipitationis fewer in total area (such as in Tianshuihai), but it is a little more in certain placesbecause of the influence of extremely high fault mountains. The precipitation,together with thawy water of glaciers and accumulated snow, not only supplied lakesand kept their size in basins, but also made some area relatively wet and exhibiteddesert steppe landscape. However, due to gentle relief and shortage of extremelyhigh mountains for glaciers developing, there are fewer lakes in hundreds of squarekilometers from the east of Karakorum Mountains to the southern flank of middleKunlun Mountains. Except for Yanghu (36 km2

), each of the other lakes is less than10 km2

• It is the area with the lowest concentration of lake's distribution on theTibetan Plateau while the mineralized degrees of lake's water are higher and saltlakes keep to be formed accompanied with the drying and retreating of lakes. Theindex of river net density in this area is also the lowest on the total Tibetan Plateau aseven no surface runoff is existing in most parts of the area due to the drying ofriverbed. Vegetation is dominated by Ceratoides compacta, the representative ofhigh-cold desert. Due to severe wind erosion, vegetation dried and died in someareas, in which the vegetation cover degrees were only 1-5% while great pieces ofland were covered by bared desert. Soils mainly consisted of altitudinal desert soil,and even gypsum desert soil appeared. Under the cold and dry conditions, qualityof grassland was very bad, which even made it difficult to the living of Pantholopshodgsoni and Equus kiang that are adapted to Plateau environment. These animalsmay only appear in periphery of this region (ZHENG Du et aI, 1999).

The words "Cold and Dry Core" of Asia highland was initially raised by Troll(1972) when he was comparing the upper limit of dry areas between middle Asia andsouth America. It generally refers to the highland that is dry and completely short


of vegetation in middle Asia. Besides middle Asia, Troll thought that anotherextremely dry altitudinal region is situated in south America which includessouthwest Bolivia, north Chile and northwest Argentina. This is so-called "Puna deatacama", in most area of which annual precipitation is less than 50 mm.Vegetation is sparse between elevation of 3100-4800 m so that no soil may beformed. It is permafrost zone above 5600 m asl (Troll, 1972). Compared withPuna de atacama, the upper limit of dryness is also extremely high in the northwestQiangtang, the hinterland and southern flank of middle Kunlun Mountains. Dryclimate and its corresponding vegetation and soil made this area to be the "Cold andDry Core" on the Tibetan Plateau. However, it should to be pointed out thattemperatures are different in these two extremely dry altitudinal areas due to differentlatitudes and elevations. Puna de atacama is located at southern periphery oftropical zone and between 3600-4200 m asl, annual mean temperature is 6-9°C whilemonthly mean temperatures are 9-13°C and 2-7°C in the warmest and coldest monthrespectively. But in the southern flank of Kunlun Mountains and northwestQiangtang which is located at southern periphery of temperate zone, annual meantemperature is low to -7--11 °C while monthly mean temperatures are 3-6°C and lessthan -20°C in the warmest and coldest month respectively. Thus, it matches thename "Cold and Dry Core" on the Tibetan Plateau, and is also the only altitudinalcold and dry core region on the earth (ZHENG Du et ai, 1999) (Figure 16-8).

Figure 16-8 Landscape of high-cold desert steppe in the "Cold-dry core"of the northwest of the Qiangtang Plateau


From the view of macro scale, it is characterized by spatial differentiation fromthe warm-humid in the southeast to the cold-dry in the northwest on the TibetanPlateau. Horizontal zonation gradually changes from mountain forest, altitudinalmeadow, mountain/altitudinal steppe to mountain/altitudinal desert. On thecontrary, it is gradually drier and drier from the west to the east in the west Tibetanand east Pamir area. Although there distributed mountain dark coniferous forest orpatches of mountain coniferous forest in the northern flank of west Kunlun andsouthern flank of Karakorum Mountains due to local humid climate, it is extremelydry in wide valleys and basins between these two mountains. For examples, the EW direction valleys of Karakaxi River and Tianshuihai Basin are all dominated bydesert landscape. Influenced by climate and landform, present snowline distributionhas the same changing tendency with the rising of elevation on the Tibetan Plateau.From 4400 m asl in the southeast, snowline gradually rise to 6000-6100 m asl in thenorthwest Qiangtang and then decline to 5000-5100 m asl in the Pamir. It ischaracterized by the rising tendency from the outside to the interior of the Plateau.Besides effect of landform, this situation is closely related to the source of watermoisture on the Plateau.

The source of water moisture on the Tibetan Plateau mainly come from BengalBay, Arabian Sea of the Indian Ocean, and are transferred from the west, south andeast direction. Those from the west mainly influence the west Tibetan Plateau.Although a "wet tongue "may extends into the west part of the Plateau viaAfghanistan and Pakistan, most of the moisture are withheld by the west Himalaya,Karakorum and Kunlun Mountains in which grand glaciers group of middle-lowlatitude area were formed. Actually, there is little moisture entering into the Plateau.For an example, annual precipitation in Tianshuihai is only 23.8 mm during theperiod of 1989-1990. The moisture from the south way may transfer across theHimalaya Mountains, but no moisture rushes across the Kangdese Mountains to enterinto Qiangtang because of short transferring pathway and small influencing range.With shorter distance to the Plateau, the moisture of the east pathway come fromBengal Bay and smoothly enter into the Plateau along the valleys of YanglungZangbo River and Nujiang, Lancangjiang and Jinshajiang Rivers. Although most ofthe moisture is withheld when it passes the Nyainqentanglha Mountains where largescale of oceanic glaciers were also developed, some parts of moisture may still reachthe east Qiangtang. In fact, the so-called cold and dry core area which include thenorthwest Qiangtang, the west section and southern flank of middle KunlunMountains are just located in the area among these moisture transferring pathways.The formation of cold and dry core in Asia high land is related to its geographicalposition, landform and the moisture transferring pathways. However, anotheraltitudinal dry area - Puna de atacama is formed by the air current decline action ofanti-cyclone high pressure. Because of obvious blocking from the mountains whichrange along S-N direction, the little moisture plus the interaction of Hungburger coldand dry effect make it extremely dry in the west of middle Andes Mountains (Troll,1972).

Though these two dry core areas are similar in dryness degree, the causes oftheir formation are different while temperature conditions have great disparity. That


in the Asian highland should be the most representative altitudinal cold and dry corearea on the earth.

References

1. AN Zhimin, YIN Zesheng, LI Bingyuan, et ai, 1979. The paleolith and fine stone implementin Shuanghu, Xainza of north Tibet. Archaeology, 6: 481-491. (in Chinese)

2. GAO Yixin, CHEN Hongzhao, WU Zhidong, et al., 1985. Soils of Xizang (Tibet). Beijing:Science Press, 94-97; 300-310. (in Chinese)

3. GAO Youxi, JIANG Shiqui, SHEN Zhibao, et al., 1984. Climates of Xizang (Tibet). Beijing:Science Press, 102-121. (in Chinese)

4. LI Bingyuan, GU Guoan, LI Shude, et al., 1996. Physical environment of Hoh Xii Region,Qinghai. Beijing: Science Press, 1-248. (in Chinese)

5. L1 Bingyuan, WANG Fubao, ZHANG Qingsong, et al., 1983. Quaternary geology of Xizang(Tibet). Beijing: Science Press, 100-110. (in Chinese)

6. LI Bosheng, 1989. Preliminary evaluation of the Maimacuo Nature Reserve of the QiangtangPlateau in Tibet. Journal ofNatural Resources, 4(3): 281-288. (in Chinese)

7. LI Heng and WU Sugong, 1985. The subregion of vegetation on the Qinghai-Xizang (Tibetan)Plateau (Flora and fauna in Xizang). Geographical Sciences, 5( I): 1-10. (in Chinese)

8. LI Wenhua and ZHOU Xingmin, 1998. Ecosystem of Qinghai-Xizang (Tibetan) Plateau andapproach for their sustainable management. Guangzhou: Guangdong Science and TechnologyPress, 43-54. (in Chinese)

9. LIN Zhenyao and WU Xiangding, 1979. Preliminary study on the climatic features in thewarm season (June-August) of north Qiangtang. Acta geographica sinica, 34( I): 69-75. (inChinese)

10. Troll, c., 1972. The upper limit of aridity and the arid core of high Asia. In: Troll, C. (ed.):Landschafts (kologie der hochgebirge eurasiens. Erdwiss. Forschg, IV, Wiesbaden.

II. Wissmann, H. v., 1960/1961. Stufen and Gtirtel der vegetation und desklimas in Hochasienund seinen Randgebieten. Erdkunde XIV, Xv.

12. WU Sugong et al., 1996. Biodiversity ofHoh Xii Region, Qinghai. Beijing: Science Press. (inChinese)

13. YANG Yichou, LI Bingyuan, YIN Zesheng, et al., 1983. Geomorphology of Xizang (Tibet).Beijing: Science Press, 21-23; 115-126. (in Chinese)

14. ZHANG Jingwei, WANG Jinting, LI Bosheng, et al., 1988. Vegetation of Xizang (Tibet).Beijing: Science Press, 186-200; 318-330. (in Chinese)

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16. ZHENG Du et al., 1999. Physical-geography at the Karakorum-Kunlun Mountains. Beijing:Science Press, 37-42; 74-187. (in Chinese)

CHAPTER 17 KUNLUN MOUNTAINS REGION

ZHANG Baiping

17.1 Introduction

Towering in northwest boundary of the Tibetan Plateau and south of the Tarimand Qaidam basins, the Kunlun Mountain range extends from the Pamir Plateausoutheastward, and then nearly eastward, to northwestern Sichuan Province. Ittotals about 2,500 Ian, 100 Ian longer than the Himalayas, and is well known as the"Backbone of Asia". In terms of tectonic properties and landforms, the KunlunMountain range may be divided into three sections. To the west of Mt. QongMuztag is the West Kunlun; to the east of Kunlun Pass is the East Kunlun; andbetween them is the Middle Kunlun. This book involves only the West and MiddleKunlun Mountains (Figure 17-1).

'(

Figure 17-1 A sketch map of the Kunlun Mountains and their northern piedmont plains

"Kunlun" (meaning "south") is a word transliterated from the ancient languagespoken by the inhabitants of Hotan. Hotan is a famous oasis on the ancient SilkRoad on the southwestern margin of the immense Taklimakan Desert. As early asin the 10th century B.C., the Kunlun Mountain range was recorded in Chinesehistorical documents for their loftiness, beautiful jades, and majestic landscape.They were regarded as ''The Center of the Earth", ''The Father of All Mountains",and even "Mountains Leading to the Sky". They were added to many fairy tales and

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ZHENG Du, ZHANG Qingsong and WU Shaohong (eds.J, Mountain Geoecology and Sustainable Development o/theTibetan Plateau, 349-373.©2000 Kluwer Academic Publishers.

350 ZHANGB.P.

legends, as stated in the Emperor Mu, the Shan Hai ling, the Songs of Chu, theMaster Zhuang, the Huai Nan Zi, etc. The word "Kunlun" appeared in manyChinese poems, for it has been of symbolic significance of loftiness and majesty inChinese cultural history.

Yet, until the beginning of the 20th century, no scientific studies had beenconducted in this region. As late as the second half of the century an overall andsystematic scientific research on the Kunlun Mountains was carried out, organizedby the Chinese Academy of Sciences. The Kunlun Mountains are situated in thetransitional zone of China's two natural realms, Tibetan Frigid Plateau andNorthwest Arid China, being an important region for the study of physicalgeography of China; aridness and frigidity constitute two basic properties of thestudy region. The vertical variation of natural landscapes from the piedmont plainsto extremely high, ice-covered mountains might be compared with horizontaldifferentiation of natural landscapes from the Sahara Desert to North Pole.

The Kunlun Mountains and their northern piedmont plains are main habitats ofethnic minority peoples: Uygur, Tajik and Kirgiz (Khalkhas). Their distinctcultures, such as Uygur's graceful dance, Tajik's lively characters, and, especiallythe Islam culture, greatly enrich the study region. As is well known, the ancient"Silk Road" was significant communication line connecting ancient China andRoman Empires. Its southern branch, used from the very beginning and lasting forthe longest time, passed through this region. Hotan, Kashgar and Niya (Minfeng)were famous oases and towns on the "Silk Road". Many ancient castles, grottoes,posts, beacon towers, ruins of farmland opened up by station troops, graves, etc., alltell the glorious past of the region.

17.2 Physical Environment

As mentioned in Chapter 2 in this book, neotectonic movement has been beingvery active in the Kunlun Mountains and is a decisive factor in shaping landformsof the region. It has been pointed out (ZHANG Qingsong, et al., 1989) that violentuplift of the Kunlun Mountains region began from late Pliocene Epoch or in thebeginning of the Quaternary Period, just as the case of the Himalayas. Thanks toactive neotectonic movement, Kunlun Mountain region, situated in a criss-crossingzone of uplifting and relatively subsiding areas, makes a feature of obviouslydifferential movements of rising and falling of different structural units. Themountains and the Tarim Basin are sharply separated (Fig17-2); low-lying TarimBasin is at an elevation of only I,OOO-I,500m asl, generally 4,OOO-5,OOOm lowerthan the mountains. Considering that the mollasse deposits since the Pliocene agein northern front of West Kunlun and the Altun Mountains amount to over 5,000min thickness, a total relative movement in this region surpasses 10,OOO-12,OOOm(ZHANG Qingsong et al., 1989).

KUNLUN MOUNTAINS REGION 351

Mt.WuslengtagI

II

Ashikol BasinII

MI.LiUSlagII Tarim Basin

UoUu...L.L..L.LL..LI..L.L.L.Lu..u·o

If--PiedmOlIl plains----l

I•.-----Kunlun Mounlains-----~~~n

o 22 44 88 km...' __-"",__-".1....-_---',

-N masl5000

3000

Figure 17-2 Topographic features of Kunlun Mountains and their northern piedmont plains

17.2.1 DEEP INLAND GEOGRAPHIC LOCATION

The Kunlun Mountains are situated in the deep of the Eurasian continent-- thelargest continent in the world. Even the Indian Ocean, which is the nearest largebody of water is more than 2000 kIn away. What is more, around this region arehigh mountains and plateaus, such as the Tibetan Plateau to the south, the PamirPlateau on the west, and the Tianshan Mts. and Tarim Basin to the north. On aChinese map, the Xinjiang Uygur Autonomous Region is the most remoteprovince-level administrative unit; the study region is, in tum, the most remote areain Xinjiang. For example, the distance totals about 2000 kIn along the highwaybetween Hotan and Urumqi, the capital of Xinjiang.

17.2.2 HIGH MOUNTAINS CONTRASTING SHARPLY WITH DEEP GORGES.

In the geological evolution of the Kunlun Mountains, no expansive planationsurfaces have developed. In the process of uplifting, they have been tightly foldeddue to strong horizontal press, without evolving broad intermontane basins.Because the violent uplift of mountains is necessarily followed by intense downcutting of rivers, high mountains and deep river valleys are thus simultaneouslyproduced. As a result, in a relatively short horizontal distance from the river valleyto the mountain ridge, the relative relief may amount up to 3,000-4,ooOm.

17.2.3 EXTREMELY ARID MOUNTAIN CLIMATE

Because of its deep inland location and high surrounding mountains andplateaus, this region receives very few moist air currents, and most parts of the

352 ZHANGB.P.

region are characterized by climate with annual precipitation of less than 100 mmor even less than 50 mm.

Different parts of this region are exposed to different air currents, andprecipitation on them shows more or less differently (LIN Zhenyao, et ai., 1991).The extremely high mountains of West Kunlun are on the circulation track ofmoist-laden air masses from the Arabian Sea, and receive a considerable amount ofrainfall mainly in form of snow, generally over 600mm above snowline. Thisparticularly favors development of glaciers. Because the Arabian Sea air massescome from southwest, precipitation declines eastward in West Kunlun. The lowerparts of these mountains, however, differ completely from the upper parts. Dryvalleys, in particular, are both warm and dry, because they are locales to which theair currents subside. There rainfall is rare, often less than 100 mm or even 50 mm.For instance, Kangxiwar at an elevation of about 4000m asl has a precipitation ofonly 36.6 mm. Such sharp vertical differentiation of precipitation portrays principalnature of the Kunlun Mountains.

The southern flanks of eastern section of the West Kunlun Mountains are toofar both from the eastern moist-transporting route starting in the Bay of Bengle andfrom the western route rising in the Arabian Sea (LIN Zhenyao et ai., 1991) to beaffected by these air currents, so the climate is extremely arid with precipitationbelow 50 mm or even 25 mm. The annual mean precipitation is 23.8 mm atTianshuihai (4860 m asl), 46.7 mm at Tianwendian (5171.2 m); and 30.1 mm at theKongka Pass. It is in these areas that the so-called "frigid-arid core of the TibetanPlateau" is formed (ZHENG Du, 1992).

Air currents from the Bay of Bengle mainly affect the Middle Kunlun and HohXii Mountains, but very slightly, for these moist-laden air currents have come along way before reaching the Hoh Xii and Middle Kunlun. Consequently,precipitation here is scarce, and, because these air currents move northwestward,becomes even less in the same direction. For example, annual precipitation atTuotuo He and Wudaoliang that are all on the Qinghai-Tibet Highway is 282.6 mmand 262.2 mm respectively; while in the Kumkol Basin, it is only 150mm.

The low and middle mountains in northern flanks of the Kunlun range areexposed to the air currents circulating in and around the Tarim Basin. Controlled byMongolian-Siberian anticyclones, these currents come into the basin from itseastern entrance, and they are at once bifurcated into the northern and southernbranches. The former move westward along the southern flank of the TianshanMountains, and, after running into the Kunlun, changes its moving direction towardsoutheast, finally at Qira encountering the southern branch which comes along thenorthern flank of the Altun. Mainly in summer, these air currents are uplifted, andsometimes to such extent that orographic rain is formed in low and middle or evenhigh mountains. As a result, precipitation increases rapidly from piedmont plainsupwards to middle mountains where annual rainfall may be up to 300-400mm. Onthe other hand, the piedmont plains are suffering subsiding air masses, and, receivevery little precipitation, e.g., 61.3 mm in Kashi, 35.0 mm in Hotan, and 17.4 mm inRuoqiang.


The climate of the Kunlun Mountains is also characterized by vertical changeof air temperature (Table 17-1). Below elevation of 2000m asl, various temperatureindices change very little. But from this elevation upwards, they begin to declineconspicuously (ZHANG Baiping, 1991a). For example, the annual temperaturedecreases to O°C at approximately 3700m, and the accumulative temperature beginsto be less than 3000°C at elevation of 2300m. On the southern flank of the KunlunMountains at 4800-5200m asl, average temperature of warmest month (July) is only3-6°C, that of coldest month (January) low to -20°C, maximum temperature rangesbetween 16-20°C, and minimum is about -35°C. The vertical change of temperaturemay be generalized as follow:

a) Temperature decreases and its decreasing rate accelerated with height. Thiscan be explained by fact that near ground, air temperature is influenced bylandforms and exchanges of cold and warm air currents, but such an influenceweakens upwards.

b) Air temperature decreasing rate reaches the lowest point in winter and thepeak in summer, higher in spring than in autumn. In northern flank of the Kunlun,an inversion layer of air temperature often occurs in winter, at elevations of about3000m asl.

c) Decreasing rate of annual temperature range becomes smaller with height,but that of daily temperature range becomes larger.

Table 17-1 Vertical variation in temperature in the Kunlun Mountains (Northern flank)

Altitude Annual mean January mean July mean ~10°C accumulated

(m asl) temperature (0C) temperature (0C) temperature (0C) temperature (OC )

1,200 11.5 -6.4 25.4 4,100

1,500 11.2 -6.4 23,8 3,928

2,000 9.8 -6.8 21.0 3,510

2,500 7.4 -8.1 18.2 2,800

3,000 4.7 -9.8 15.34 1,517

3,500 1.7 -11.9 12.7

4,000 -1.5 -14.1 9.9

4,500 -4.9 -16.1 7.1

17.2.4 ASYMMETRICAL NORTHERN AND SOUTHERN FLANKS

Integral uplift of the mountains gives rise to not only their great difference inheight with the low-lying Tarim Basin, but also southward moving of watersheddivide as well as asymmetry of northern and southern flanks. The northern flank issteep and long, and, because of powerful erosion of running water, water systemsare well developed with quite dissected landforms. The southern flank is short andgentle, forming a relative relief of only 1,000-1 ,500m with the Qiangtang Plateau tothe south; and due to not well-developed water system and weak action of running

354

water, ground is open and round.

ZHANGB.P.

17.2.5 VERTICAL ZONATION OF LANDFORMS

Owing to great difference in elevation, vertical zonation of landforms is quiteconspicuous in the Kunlun Mountain region. According to operating exogenicforces and their landform features, six altitudinal landform-belts may bedistinguished.

a. Piedmont di1uvial and alluvial plains.b. Low-mountain weak weathering-denudation belt.c. Middle-high mountain intense weathering-denudation belt.d. Intermontane and plateau denudation-deposition belt.e. High-mountain freezing-and-thawing belt.f. Extremely high mountain nivation belt.

17.2.6 WIDESPREAD GLACIATION

It has been recognized that at least three glaciations have occurred inQuatornary times in the region. The first stage is estimated to be in middlePleistocene, characterized by marine types glacier, and its scope is the largest inthis region. After that, glaciers which became continental type, tended to retreat dueto environmental desiccation. But even now, the West Kunlun Mountains are still aglacier-developing center on the whole Tibetan Plateau, 8.2% of the West KunlunMts. are covered with glaciers. As a result, glacial and periglacial landforms arewidely distributed. Spatially, majority of existing glaciers are concentrated inseveral extremely high mountain regions, such as the Mt. Kun'gay glacial area, Mt.Kongur and Muztagata glacier areas, Mt. Yuruntag glacier area, Mt. Muztag glacierarea, Mt. Kangzhag Ri glacial area, etc. It is quite apparent that there are muchmore glaciers in the west than in the east. Around some 6000m high mountainpeaks are scattered a number of small glaciers.

These glaciers in continental type are characterized by low ice temperature (16.4°C has been recorded), low glacial runoff modulus, low accumulation andablation amounts, and relatively gentle ice surfaces with a wide and integral tongue.Glacial ice is clear, and there are few moraines of modern glaciers. Some ofglaciers are even now in process of moving forward, although very slowly (SinoJapan Joint West Kunlun Glacier Investigation Team, 1989)

17.2.7 INLAND RIVERS AND LAKES

All rivers in this region are inland, of which large rives pour northward intothe Tarim Basin, and small rivers terminate into closed Plateau lakes. The mainrivers empting into the Tarim Basin and their basic runoff characteristics are givenin Table 17-2. It is clear that major portion of runoff volume enters only a fewgreatrivers. The Yarkant River, the first great river in this region, originates in


northern flank of the Karakorum, collecting almost all meltwater released fromglaciers of northern Karakorum. When flowing out of the mountains with a largequantity of water, it has formed extensive Yarkant diluvial-a1luvial plains. TheYurunkax and Karakax rivers, the second and third largest rivers, rising in WestKunlun glacial areas and the eastern end of the Karakorum separately, combinetogether to give rise to famous Hotan Oasis. Out of glacial areas of Mt. Kongur, Mt.Muztagata and Mt. Kun'gay flow Kizilsu, Gez and Kushan rivers, which are jointly

Table 17-2 Main rivers and their runoff properties in the Kunlun Mountains

Annual runoff

Ratio with multi-yearAnnual runoff

River Ave. Spr. Sum. Aut. Win. averagedepth (mm)ve.

(108m3) (%) (%) (%) (%) high water low wateryear year

Kizilsu 19.76 18.40 55.26 18.15 8.19 0.11 1.19 0.73 171.8

Kalang- 1.05 23.55 39.08 25.41 11.96 0.35 2.85 0.67 51.6

Guluke

Gez 9.63 14.57 59.03 19.68 6.7 0.15 1.22 0.68 114.6

Weitake 1.74 14.16 63.67 15.84 5.53 0.11 1.19 0.85 369.0

Kushan 6.31 9.54 64.49 19.45 6.48 0.15 1.28 0.68 297.7

Yarkant 63.75 6.75 66.79 20.17 6.29 0.19 1.38 0.70 132.5

Tizna'p 7.64 7.56 75.82 12.66 3.96 0.17 1.16 0.76 142.5

Pishan 3.38 12.58 71.69 12.92 2.81 0.13 1.37 0.85 182.0

Sanju 2.53 11.95 75.14 10.13 2.78 0.12 1.22 0.75 276.2(Boska)

Karakax 21.46 8.67 74.49 13.56 3.28 0.21 1.48 0.57 138.0

Yurunkax 22.88 5.54 80.40 11.55 2.51 0.24 1.62 0.54 157.3

Qira 1.23 12.08 73.10 11.43 3.39 0.16 1.30 0.67 62.6

Nur 1.74 11.20 75.34 10.37 3.09 0.19 1.32 0.65 413.0

Keriya 7.13 11.31 66.98 14.75 6.96 0.19 1.50 0.76 110.1

Qiemo 5.33 28.67 48.66 15.16 7.51 0.26 1.57 0.58 29.5

responsible for the formation of Kashi oasis. Other rivers, middle or small,contribute to the formation and evolution of scattered oases on the piedmont plains,such as Pishan River and oasis, Niya River and Minfeng oasis, Keriya River andYutian oasis, Qiemo River and oasis, Ruoqiang River and oasis, etc. It is noticeablethat, as a whole, runoff volumes of rivers decrease from west to east, and the areaof oases also declines in the same direction, reflecting spatial distribution patternsof glaciers and precipitation. In addition, of the 9 large rivers whose annual runoffvolumes exceed 500 million m3

, 8 are in Wes.t Kunlun, 1 in western MiddleKunlun; while the 720 km long Altun do not nurse even one large river.

Multi-year cycle of runoff shows quite evenly for most of these rivers.

356 ZHANGB.P.

Variation coefficient generally ranges from 0.12-0.19, slightly higher for YurunkaxRiver (0.24) and Karakax River (0.21). The cases of the two rivers result fromstorm runoff occurring in the low mountains; rainstorm, which induces storm, doesnot occur every year. For most of the rivers, they are chiefly recharged withmeltwater that depends on summer temperature; summer temperature changes verylittle year in year out. Consequently, their multi-year runoff is portrayed by arelatively uniform cycle.

Along southern flanks of West Kunlun and in Middle Kunlun Mountains, anumber of inland lakes lie quietly, accepting meltwater from high-mountainglaciers surrounding them. Many of them are salt and saline lakes, such asAyakkum, Aqqikkol, Aksayqin, Gozha, Zonag, Hoh Sai, etc.; only one or two arefresh-water lakes, e.g., Lake Taiyang.

17.2.8 ALPINE VEGETATION AND WILD ANIMALS

By virtue of the extremely arid and frigid climate, as well as coarse groundsurface materials, plant growth is severely limited. The whole study region hasevolved only 243 genera and about 700 species of high plants (WU Sugong, et al.,1990). But the plant population is very large. An extensive area of plant communityis often composed of up to or slightly more than ten species of plant. Intensecompetition has enabled them to adapt to increasingly arid environment. Manyspecies have undergone processes of variation, differentiation and evenspecialization.

Phytogeographically, the study region is a transitional zone where differentfloristic elements of Iran-Turanean, Central Asiatic, Tibetan Plateau, TemperateAsian, North temperate, etc. have crossed paths. Since the beginning of QuaternaryPeriod, ice ages and interglacial periods have alternated, and the process ofdesiccation has developed continuously, resulting in mixing, pervasion andspecialization of different phytogeographical elements. The Kunlun Mts. are mainlyassociated with Central Asiatic elements; the western Karakorum, western WestKunlun, and East Pamir are influenced by Iran-Turanean elements; while the HohXiI and middle and eastern Karakorum, Middle Kunlun and northwesternQiangtang Plateau are characterized chiefly by Tibetan plateau elements,accompanied by some Central Asiatic elements.

The Sangju (Boska) River, in Pishan County, is an obvious floristicdemarcation line. Of the 243 genera of plants mentioned above, 72 have not beenfound in east of the river. West of the river, thanks to some relatively humidhabitats, montane needle-leaf forests appear, and Iran-Turanean elements dominate;to the east of the river, where no montane forests occur, Iran-Turanean elementsbecome less dominant with fewer plant species as a result of more arid climate.

The Iran-Turanean elements contain typical paleo-mediterranean element ormediterranean-W.Asia- Iran-Turanean element, such as Ceratoides latens andPeganum harmala. Eurytopic Iran-Turanean elements are Kalidium schrenkianumand Ephedra intermedia. The Central Asiatic element is apparently desiccated, its


representatives include Sympegma reglii, Nitraria sphaerocarpa, Ajaniafruticulose, Artemisia parvula, Stipa glareosa, S.gobica, S.breviflora, Festucaolgae, Sabina centrasiatica and Sabina pseudosabina var. turkestonica (endemic toWest Kunlun), Kobresia pamiroalaica, Carex stenocarpa, and Sibbaldia tetrandra.Of the Temperate-Asian elements, frequently met are Achnatherum Splendens andCaragana jubata. The North-temperate element are represented by Polygonumviviparum. The Tibetan Plateau elements mainly include Stipa purpurea, S.subsessilijlora var. basiplumosa, Carex moorcroftii, Ceratoides compacta, Ajaniatibetica, Thylacospermum caespitosum, Arenaria bryophylla, and Myricariaprostrata.

There is a wide range of vegetation types in the study region. They and theirmajor plant species include:

(1) Montane coniferous forest: Picea schrenkiana, Sabina centrasiatica, S.vulgaris var. jarkendensis, Sabina pseudosabina var. turkestanica.

(2) Alpine meadow: Kobresia pamiroalaica, Carex stenocarpa, etc.(3) Alpine steppe: Stipa purpurea, S. subsesslijlora var. basiplumosa, Carex

moorcroftii, etc.(4) Montane steppe: Stipa glareosa, S. gobica, S. brevijlora, Festuca algae,

etc.(5) Alpine desert-steppe: Carex moorcroftii, Stipa purpurea, Ceratoides

compacta, etc.(6) Montane desert-steppe: Stipa glareosa, S. gobica, Ajaniafruticulose,

Artemisia parvula, etc.(7) Alpine desert: Ceratoides compacta, Carex moorcroftii, Ajania tibetica,

etc.(8) Desert and montane desert: Ceratoides latens, Peganum harmala,

Kalidium schrenkianum, Sympegma regelii, Nitraria sphaerocarpa,Ajania fruticulose, Atemisia parvala, Capparis spinosa, etc.

(9) Alpine cushion plants: Saussurea gnaphalodes, Thylacospermumcaespitosum, Arenaria bryophylla, Rhodiola coccinea, etc.

A total of 21 species of wild animal resource are found in the study region(FENG Zuojian, 1990). They are made up of 5 orders, 10 families and 18 genera.

Zoogeographically, the study region may be divided into three parts:(1) The western parts of the Karakorum and West Kunlun Mountains are

populated mainly by wild animals of the Central Asian group, such as thesnow leopard (Panthera uncia), Goitered gazelle (Gazella subgutturosa),Ibex (Capra ibex), Argali sheep (Ovis ammon), Longtailed marmot(Marmota caudata), etc. Some northern Eurasian species or generalspecies, e.g., Red fox (Vulpes vulpes), Stone Marten (Martes foina) andCape hare (Lepus capensis), can also be found.

(2) From above-mentioned areas eastward to East Kunlun (including the Altunand Qimantag mountains) and Hoh XiI Mountains, endemic species of theQinghai-Tibetan Plateau are relatively common, with large ungulatesdominant. The representative species are Tibetan wild ass (Asinus kiang),

358 ZHANGB.P.

wild yak (Poephagus mutus), and Tibetan antelope (Pantholopshodgsoni). The Himalayan marmot (Marmota himalayana), highland hare(Lepus oiostolus), and Tibetan fox (Vulpes ferrilate) are also observed.

(3) On southern flanks of eastern section of western kunlun Mountains islocated the open northwestern Qiangtang Plateau, 4900-5100 m asl withnumerous lakes and lacustrine flats. Tibetan wild ass, wild yak, andTibetan antelope find excellent habitats in these areas, and theirpopulations are generally large.

17.2.9 POORLY DEVELOPED SOIL TYPES

Under foregoing conditions of climate and living things, the study region hasevolved varied types of natural soils, including Yermosols (brown desert soil,alpine desert soil, takyric soil, grey-brown desert soil, grey desert soil),Kastanozems (chestnut soil), Gleysols (bog soil, alpine meadow soil), Regosols(Alpine frozen soil, aeolian sandy soil, alpine steppe soil), Lithosols, Rankers(alpine meadow soil, subalpine meadow soil), Xerosols (semidesert brown soil),and Greyzems (grey forest soil).

Owing to intense mechanical weathering and weak chemical and biologicalweathering in soil-forming process, the soils are generally characterized by coarseparent materials, thin solum (30-50 mm or so), indistinct humus layer, and lowcontent of organic matter «1 % for most of the types). Even the most activecompounds of chloride and sulphate have migrated very little both vertically andhorizontally in the soils. The content of CaC03 remains constant or very slightlychanged in the whole profile of soils. In other words, soil profile is differentiatedsimply, with only 3-4 layers.

17.3 Altitudinal Zonation of Landscape

In the study region, mountains tower loftily, e.g., Mt. Kongur at 7649 m asl,which is the highest peak of the Kunlun Mountains, Mt. Muztagata at 7509 m asl,which is known as the "Father of Ice Mountains". But in the north, diluvial-alluvialplains descend to an elevation of only about 1200 m asl. In other words, a relativerelief of more than 5000 m exists in the study region. Such great difference inelevation necessarily brings about vertical variation of climate, vegetation, soil, andthe whole physical environment. This may be reflected by the vertical succession ofaltitudinal belts, which include, from piedmont plains to montane tops, warmtemperate desert, montane desert, montane desert-steppe, montane steppe, alpinesteppe, alpine meadow, sub-nival belt, and nival belt. Responding to such verticalchanges ·of physical environment, land use in the study region is also verticallyzoned: Oasis agriculture on the piedmont plains, farming-pastoral zone in themiddle and low mountains, and seasonal nomadism or transhumance on somemiddle and high mountains. The economy of the study region is virtually a verticalagricultural system centered on oasis agriculture.


The Kunlun Mountains are virtually extremely high mountains of arid land.Difference in elevation and in moisture conditions serves as the dominantdifferentiating factor, resulting in macroscopic, regular variation pattern of physicalenvironment of the study region. Other differentiating factors, such as mountainmass effect, slope direction, slope degree, surface ground material, ground-watercondition, etc, act only locally, embodying and complicating the macroscopicdifferential pattern.

By virtue of integrated action of various differentiating factors, the montaneenvironment is vertically zoned. In the study region, a total of 11 altitudinal beltsmay be distinguished (Table 17-3), 4 of which (warm-temperate desert, montanedesert, plateau desert, and plateau steppe) are or may serve as base belts. Eachaltitudinal belt is related to certain montane environment at certain elevations. In agiven mountain area, various kinds of altitudinal belts occurs in response tovertically varying environment, and they constitute a sequence--a spectrum ofaltitudinal belts.

17.3.1 SPECTRA OF ALTITUDINAL BELTS

In the study region, various spectra of altitudinal belts have developed indifferent sections and flanks of different mountains. They can be generalized intoseveral groups and subgroups. With respect to types of base belt which is ofdecisive significance in distinguishing vertical spectra, three groups of spectra areas follows: (l) The spectrum with warm-temperature desert as base belt; (2) Thespectrum with montane desert as base belt; and (3) The spectrum with alpine highcold desert or alpine high-cold steppe as base belt. In terms of types of dominantbelts, characteristic belts, and combination pattern of altitudinal belts, furthersubdivisions may be imposed on each of the four groups (Table 17-4).

Table 17-3 Altitudinal belts in the Kunlun Mountains

Altitudinal belt~levation

Soil type Vegetation type Plant cover (%)(m asl)

(A) Warm- Below Brown desert soil Desert <5.0%temperature desert 2400-3000(B)Montane desert- Piedmont line up cMontane brown Montane desert <10%-15%steppe to 3000-3300 k1esert soil(C)Montane desert- 2900-3100 ~rown soil and Montane desert- < 15%-20%steppe sierozem steppe(D) Montane steppe 300-3600 Chestnut Montane steppe 30%-40%(E) Alpine steppe 3600-4000 Alpine steppe soil Alpine steppe 30%-50%(F) Alpine meadow 4000-4500 Alpine meadow soil Alpine meadow 60%-90%(G) Sub-nival 5000(5300)- Frozen soil IExtremely sparse <5%

5600(5900) cushion vegetation(H) Nival > 5000-5800 - - -(I)Alpine(high-cold) 4500-5300 Alpine desert soil Alpine desert < 10%desert

360 ZHANGB.P.

(J)Alpine(high-cold) 4800-5300 Alpine desert- Alpine desert- 10%-25%desert-steppe steppe soil steppe(K)Alpine(high- 4500-5200 !Alpine steppe soil Alpine steppe 30%-50%cold) steppe

Table 17-4 Structural classification of spectra of altitudinal belts in the Kunlun Mountains

Note: D'--Montane steppe belt containing montane comferous forests; the meanings of othercharacters in Table 17-3.

Spectrum Spectrum type Sequence of Dominant Characteristictype (group) (subgroup) altitudinal belts belt belt

I.Warm 1 Moderate arid type A-B-C-D'-F-G-H B D'temperature 2 Arid type A-B-C-D--F-G-H D FDesert as base belt

3 Super-arid type A-B-C-D-E-G-H B,E D

4 Extremely arid type A-B-(-C-G-H) B B

II.Montane II I Arid type B-C-D-F-G-H D FDesert as Base belt ~12 Super-arid type B-C (-D)-G-H B B

13 Extremely arid type B-I-G-H B I

Ill.Alpine II I Alpine arid type I(J)-K-G-H I(J) K(high-cold)

112 Alpine extremely arid type I(J)-G-H 1(1) IDesert as base beltIV.Alpine(high-cold) V Alpine semiarid type K (-F)-G-H K (F)Steppe as base belt

..

I. Wann-temperature desert-based spectraThis group of spectra occurs in the northern flanks of Kunlun-Altun Mountains,facing the Tarim Basin. Altitudinal belts vary from spectrum to spectrum. Mainlybased on characteristic and dominant altitudinal belts, four types may be identifiedbelow.

11' Moderate arid type

The sequence of altitudinal belts is shown in Figure 17-3 and Table 17-4 Its mostoutstanding property is the existence of montane steppe belt containing montaneconiferous forests (D'). Consisting mainly of Picea schrenkiana and Sabinapseudosabina var. tuskestanica, the forst stands mostly on shady slopes at anelevation of 2800(2900)-3400(3600) m asl. In alpine meadow belt mayoccasionally be found deciduous shrub of Caragana jubata. It is evident that thebelt number of this type is relatively large, up to 7. Generally peaking, the verticallimit of the same kind of altitudinal belt lies relatively lower in this type ofspectrum than in other types. For example montane desert ascends only up to 2500m asl, compared with 3000m or even higher in other types of spectra. This type ofspectrum may be regarded as the basic spectrum of the study region, this means thatother types of spectrum appear to be formed through "degenerating" of the basicspectrum, whether through decreasing of belt number or through ascending of the


vertical limit or narrowing altitudinal belts. This type is typical of northern flank ofthe Kun'gay Mts.

1101

[!::!J Mo'tlanc conltelous IOlal

. ..

1111 A1plnc(hl."·WkJ) .tld

IIIJ A1plne(h1,h-cold) c:llIlCmcty .,td'v, AJplac(hi.".wkJ) "ml·.rkl

~ S",bnlval bell

ff:!] AlplM duct!

~ AlplftC dcKtI·Sh:Pp.:(U] MODIi1N: dUen-steppe

~ Moru... steppe

o Wum.,empculc ~fI

ff:!J MUftl.nc dclootJl

·t~/. :<,~.~~;....:,~:.!.'. '..:'~l/~.. ..';~"" .... .>k ...

.. .. ...... .. . .., .. . .... .. .. ... .. •• .. of II,

• II,.. ..II,

"'M1 Super·arid Ea"cm~ly arkS

· ·· ·" · ·. · ·. .. ·. ···.. ·.. . • .... .. .. •

of ~.. ~ ~.. .. .. .... .. ....

'.'

I, I,

"10110

c::::=:l Alpine Ilcppe

~ Alpine ntu\Ju....

~"'i lbo::ll

r-:sLl Sno line

Figure 17-3 Structural classification of the spectra of altitudinal belts in the Kulun Mountains12. Arid type

Its structure is shown in Figure 17-3 and Table 17-4. Compared with the basicspectrum, its montane steppe belt lacks montane coniferous forests, and all the beltsare slightly or fairly uplifted. Alpine meadow.belt acts as the characteristic belt, andmontane desert as the dominant belt; while montane steppe belt also occupies aconsiderable vertical span. The snowline lies at an elevation of over 5000-5500 mas!. This type of spectrum is typical of northern flank of the Kunlun between Boskaand Niya rivers.

13. Super-arid type

As illustrated in Figure 17-3 and Table 17-4, alpine meadow, as an integralaltitudinal belt, cannot be found in the spectrum, but is substituted by alpine steppe,only with patches of alpine meadow in some shady locales. Other belts areobviously raised. It seems that this type deviates further from the basic spectrum. Itis associated with the northern flanks of Kunlun and Altun from Niya rivereastward to Ruoqiang river.

14. Extremely arid type

In this type of spectrum, montane desert is not only the overwhelminglydominant belt but also the characteristic belt, with only certain degree ofdevelopment of montane desert-steppe. Montane steppe is often very poorlydeveloped. Owing to relatively low mountains, other altitudinal belts are scarcelyseen. This is the simpliest and most arid spectrum in the northern flank of the

362 ZHANGB.P.

Kunlun and Altun, appearing in the central part of eastern Altun Mountains.II. Montane desert-based spectraMainly developed in the interior of the study region's mountains, or in the

great river valleys between Western Kunlun and the Pamir Plateau-KarakorumMountains, this group of spectra has its various belts apparently higher than thoseof the first group. The base belt, montane desert, often ascends very high. Threetypes of spectra may be recognized as follows:

III . Arid typeThe base belt may climb up to 3900m asl. The alpine steppe belt is fairly

developed, but alpine meadow is in a poor development state. This type makes itsappearance in the western section of northern flank of the Karakorum Mts. andaround the Maryang Pass of the Kunlun Mts. In Karaqi Valley in western end of theKarakorum, there is the appearance of patches of coniferous shrub (Sabinacentrasiatica) in some shady locales of the alpine steppe belt.

112' Super-Arid typeAlpine meadow completely disappears, and the whole spectrum is obviously

simplified. Montane desert goes up to over 4000m asl, and alpine steppe is not welldeveloped. This type occurs in the central parts of northern flank of the Karakorumand their neighboring parts of southern flank of West Kunlun. In the vicinity of Mt.Qogir, a few plants of Ceratoides compacta can be found on some platforms,indicating the invasion of alpine desert element.

113' Extremely arid typeAbove the base belt (montane desert) are directly developed alpine desert, and

between alpine desert and subnival belts is a poorly developed alpine desert-steppebelt. This type of spectrum is simply a mirror of extremely arid montaneenvironment, standing in upper reaches of Yarkant and Karakax rivers. The verticalsequence of altitudinal belts around the Kek-art Pass is a good example.

III. Alpine desert-based spectraThis group of spectra is characterized by a simple structure, normally with

only 2 or 3 altitudinal belts above the base belt. Alpine desert-steppe belts shows noclear vertical limit with alpine desert; instead they together constitute a mosaic inspatial distribution. Subnival and nival belts are the only two visible altitudinalones. It spreads on the northwestern Qiangtang Plateau, namely, in southern flankof eastern portion of West Kunlun and in northwestern Tibetan Plateau proper.

IV. Alpine steppe-based spectraThe base belt (alpine steppe) is the result of semiarid environment, so this type

of spectrum is semiarid in nature. Above the base belt generally appear subnivalbelt, or exists a narrow alpine meadow "belt" but quite locally. This type is situatedin the eastern section of southern flank of Middle Kunlun and in the eastern HohXii Mountains. Figure17-3 gives spatial distribution of various types of spectra.

17.3.2 AREAL DIFFERENTIATION


Areal differentiation may be well illustrated by comparing spectrum structuresand altitudinal belts' distribution elevations in different areas both of the same flankand of the different flanks of mountains. In doing so, large-scale arealdifferentiation may be concretely and fully revealed.

The difference between the four groups of spectra reflects the largestdifferentiation of physical environment. Group one (I), with a complicated structureand a low-lying base belt, represents the vertical spectrum of high mountains inextremely arid land; group three and four (III and IV) are the typical spectra on thenorthern Tibetan Plateau, with a very simple structure and high-standing base belt.They illustrate the sharp contrast in physical environments of two natural realms inChina--Northwest Arid China and Tibetan Frigid Plateau. Group two (II) can beregarded as a transition both in structure and in distribution between group one andgroups three and four, appearing in the interior of mountains, or mainly along thegreat valleys between the Karakorum and West Kunlun Mountains and betweenEast Pamir Plateau and West Kunlun.

In each of the four groups, different types of spectra are distributed along thestrike of mountains generally from west to east. Invariably they follow an order ofdecreasing or increasing degree of aridity from east to west, so as to tell clearlyhow the mountain environment varies from east to west (Figiure 17-3).

Further areal differentiation occurs and shows quite differently in differentmountains.

17.3.3 WEST KUNLUN MOUNTAINS

(l) Northern flankThree types of spectra of group one, moderate arid, arid and super-arid, appear

successively from west to east. All altitudinal belts ascend to varying degreeseastward, with montane coniferous forests in the montane steppe belt graduallydiminishing and finally vanishing when approaching the Boska River in PishanCounty. The upper limit of montane desert ranges from 2400-2600 m asl in thewest to about 3000 m in the east, and the snowline arises from about 5000 m to5500 m or so along the same direction.

(2) Southern flankThe southern flank shows a high degree of desiccation and becomes more arid

from west to east. Spectra of group two are situated in the western and centralsections, with alpine desert-based spectrum in the eastern. Montane desert lies at anelevation of up to 3700 m in the west; but southeastward to Kek-art Pass, it ascendsup to 4400-4500 m, and still eastward, it tends to be substituted by alpine desertwhich is often on a maximum elevation of 5200-5300 m asl. The position ofsnowline changes slightly, averagely at 5500 m in the west and 5800 in the east.

In short, spectrum structure and types and the vertical limit of altitudinal beltsshow quite differently in northern and southern flanks of West Kunlun. In addition,some more complicated variation is imposed on the northern flank. Both at Oytagand at Xihexiu are there montane coniferous forest; but at Qarlung located between

364 ZHANGB.P.

Oytag and Xihexiu no montane forests can be seen. In other words, montaneconiferous forests spread intermittently from west to east in the northern flank.Many factors may be used to explain such phenomenon, such as different degreesof human disturbance, different landforms (gradient and slope direction) andresulting local climate, different conditions of ground surface material, etc.

17.3.4 MIDDLE KUNLUN MOUNTAINS

(1) Northern flankThe northern flank of Middle Kunlun may be divided into two sections.

Western section is this part between Niya and Qiemo (Qarqan) rivers, facing theTarim Basin to the north. It features super-arid spectrum of group one. From QiemoRiver to the Kunlun Pass lies the eastern section, with super-arid and extremely aridspectra of group two. Montane desert climbs from an elevation of 2900 m asl inwestern section to about 3800-3900 m in eastern section, rising nearly 1000 m. Thetrend toward a higher degree of aridity is quite obvious.

(2) Southern flankThe southern flank also falls into two sections. West of Mt. Muztagata prevails

alpine desert-based spectra, and to the east appears alpine steppe-based spectra.Meanwhile, and also naturally the vertical limits of altitudinal belts gradually lowerfrom west to east, demonstrating that the physical environment becomes moistereastward, or from extremely arid to semiarid.

17.3.5 INTERIOR OF THE MIDDLE KUNLUN MOUNTAINS

The spectrum in the interior of the Middle Kunlun is something like a mixtureof spectra of group two and group three. For example, in the Kurnkol Basin,montane desert, alpine desert and alpine (high-cold) steppe all appear as if they areall base belts, although montane desert and alpine desert are very limited in area.Montane desert is seen on the piedmont plains of southern flank of QimantagMountains, at an elevation of 3800-4000 m as!. Alpine desert can be found locallyin the southwestern comer of the basin, mainly on some river terraces.

At the eastern end of Middle Kunlun occurs a seemingly abnormalphenomenon, namely, mountain environment appears to be moister in the interiorthan in both flanks. It has been found that the upper limit of montane desert is lowerin the interior than in the northern flank, and alpine meadow occurs in the interiorbut not in both flanks. It is also obvious that the eastern end tends to be slightlymore humid than the Kurnkol Basin in the central section of Middle Kunlun.

Vertical and areal differentiation of the Kunlun Mountains may be brieflysummed up as follows:

(l) Great elevation of mountains and atmospheric circulation on a widerbackground are the two principal differentiating factors.

(2) Vertical differentiation shows quite conspicuously but differently fromarea to area. This is well embodied by recognization of different groups and types


of spectra of altitudinal belts.(3) The western parts of the study region tend to become more arid from west

to east; the eastern parts, however, have a trend toward higher degree of desiccationfrom east to west. The central parts, especially from Mt. Qong Muztag to theKararniran Pass, make the so-called "High-cold Arid Core" of the Tibetan Plateau(ZHENG Du, et aI, 1989)

17.4 Regional System

Regionalization "from bottom" is applied for the Kunlun Mountains. It needsfirst identification of the lowest-level region unit, and then combines them intohigher-level regions. The lowest-level regional unit, or called "natural area", refersto the smallest unit of physical regionalization. As a regional unit, it should involvethe comprehensiveness of physical features and the diversity of natural resources. Itis clear that any altitudinal belt or land type is only a section of land surface, or alocal portion of the complicated environment in mountain areas, far from thecriterion as a regional unit. If physical features and natural resources are fullyincluded, a natural area should at least include the whole spectrum from mountainpeaks or ridges to the local base level or the river valley. The similarity of landtypes structure pattern is taken the basic principle to delimit natural area. Again,some special topographic units, such as broad intermontane valleys or basins, maybe regarded as independent natural area, because they have their own naturallandscapes, land-type combination patterns and land use orientation. A total of 28lowest-level regions (natural areas) may be identified in the study region. Thosenatural areas with same group of spectra of altitudinal belts may be combined into anatural subregion with an exception that spectra of group one are divided into twosubgroups with respect to montane forests. Natural subregions with montane desertas the base belt are frigid and arid, but more frigid than arid in nature; thereforethey may be combined with subregions of alpine spectra into a natural region. Theregional system of the Kunlun Mountains is shown in Table 17-5.

Table 17-5 Physic-geographical regionalization system of the Kunlun Mountains

Natural NaturalNatural subregion Natural area

dividision re~ion

Tibetan Western part of 1. Kun'gay Mountain northern slopesFrigid Kunlun mountains 2. Mt. Kongur-QarlungPlateau Kunlun- northern slopes 3. Xihexiu-Kekyar

Altun4. Sangdu Pass and neighboring mountains

mountainsnorthern Eastern part of 5. Nur-pulu

slopes Kunlun Mountains 6. Aktag Mountain northern slopesnorthern slopes 7. Western Altun northern slopes

8. Eastern Altun Mountains

366 ZHANGB.P.

9. Muji Basin

Taxkorgan- 10. Taxkorgan-Waqia valleyKangxiwar valleys 11. Western section of Karakorum mountainsand mountains northern slopes

Southern12. Kangxiwar dry valley

Kunlun- Kunlun-Altun 13. Upper Qiemo River-

northern intermontane valley Yusupualek valleyKarakorum- 14. Eastern section of Karakorum MountainsHohXil Aksayqin Basin and northern slopesMountains surrounding 15. Aksayqin Basin

mountains 16. Mt. Yurungtag-Ashkol Basin17. Yanghu Lake-Huanl!:vanl!: Hill

Central and eastern 18. Kumkol BasinMiddle Kunlun 19. Eastern Middle Kunlun

17.5 Land Use and Sustainable Development

17.5.1 VERTICAL AGRICULTURAL SYSTEM

In the Kunlun Mountains region, air temperature strictly defines the growth ofcrops in certain ranges of elevation, e.g., cotton grows only up to 1500m, com to2400m, winter wheat and alfalfa to 2600m, spring wheat to 3000m, and highlandbarley to 3200m. Thus, farming, forestry, and animal husbandry are all verticallyzoned (ZHANG Baiping, 1991), as shown in Table 17-6. The four major verticalagricultural belts and the sub-belts reflect the general pattern of land use. They areinterrelated ecologically, economically, and administratively, and together theyform an integrated vertical agricultural system. It is significant that almost alladministrative counties contain all four agricultural belts. This kind of relationshipbetween physical features, land-use patterns, and administrative units is by nomeans accidental, but results from the long-term effect of natural features on humansociety and the progressive human adaptation in the process of using and reshapingthe physical environment.

Table 17-6 Vertical agriculture (VA) pattern in the Kunlun Mountains

VA zone VA subzone All. (m asl) Land type Problems

Water supply I.Water supply>4200

high and extremely -zone subzone high mountain

2. Alpine grazing4200-3400 high mountain

Low temperature,

subzone inaccessibilityGrazing zone

3. Montane grazing3400- 3000 middle mountain some over-grazed

subzone


Farming- 4. Grazing-farming

grazing subzone 2000- 3000midddle and low

overgrazing, degradationmixed zone

mountains, terrace

5. Oasis farming <1500 flat land, irrigated low content of organic

Oasis subzoneoasis, saline matter of soil, salinization

agricultural irrigated oasis and infertility of soil

zone 6. Forestry-grazing low wet land and salinization, sandification,subzone

<1400depression water shortage

17.5.2 HIGHLAND/LOWLAND INTERACTION

This vertical agricultural system is a typical highland/lowland interactionsystem. The large rivers connect glaciers on the extremely high mountains withoases downstream. The oases and the mountains are intimately interrelated throughinteraction and mutual dependence; an understanding of this linkage is of greatsignificance in the design of regional sustainable development. The oases have anextremely arid climate (mean annual rainfall only 30-60 mm); there would be nofarming without irrigation; the necessary water comes only from the mountains. Asa Uygur saying states, "Snow on the Kunlun Mountains is simply the blood of thehuman body downstream." The amount of water from the mountains determines thescale of oases, their economic production, and thus the quality of human life.Analysis indicates that the Yurungkax and Karakax rivers still have some potentialfor further exploitation, and the Hotan oases can be expected to expand the scale ofproduction. But the water of Yakant and Kez rivers has been almost completelyused, and little potential is left; therefore, the Kashi and Yakant oases have littleopportunity to expand production.

In the natural pasturelands, montane grassland is grazed mainly by livestockfrom the oases. Artificial forest in the oases and natural desert forest (Populudiversifolia) around the oases can provide a considerable amount of timber andfirewood for the oases settlements where live 96 percent of the. population of thestudy region. This restricts human damage to the montane forests.

Administratively, almost every county includes a complete spectrum ofaltitudinal belts. The administrative centers are situated in the oases, and themontane areas receive administrative management, new techniques and some lifenecessities from the oases. Sustainable development in the mountains is notpossible without the cooperation of the oases. There are also negative effects of theinteraction between the mountains and the oases. Summer torrent meltwater,especially when coupled with rainstorms in the middle mountains, often leads tocatastrophe in the oases, destroying irrigation channels, devouring farmlands, andeven damaging houses. As is well known, irrigation channels are the lifeline ofoases; without them, water can not be put to use, and oases will not survive. It isunderstandable that, throughout their history, the repair and maintenance ofirrigation channels almost every year had become a "forced labor" for the localpeople, and constitutes a large portion of human activities. "Haxia," a transliterated

368 ZHANGB.P.

tenn fro the Uygur language, is used to denote work of this sort. This is, of course,a heavy burden for the oasis people. Even today, the reinforcement andimprovement of irrigation facilities are still vitally necessary to ensure the full useof the limited water resources.

Moreover, overgrazing and degradation of pastures in the low and somemiddle mountain belts are chiefly caused by livestock from the oases. In addition,the development of oasis animal husbandry through the use of desert meadow,straw from the crops, and artificial grassland reduces the importance of mountainhusbandry. Farming on terraces and hills in the mountains cannot be compared withoasis farming, because of the very limited area and low productivity.

There is a sense of "distance" between mountains and oases. On the one hand,communication is very difficult owing to the long distance, and especially thewidespread gobi between them; as a result, the mountains developed a subsistenceagricultural economy. On the other hand, oases are the centers of regional politics,economy, and culture, while the mountains are the marginal areas with backwardeconomic and cultural development. Furthennore, the Uygur people and themountains by Khakhas, Tajik, Mongolian and other ethnic groups occupy the oases.

17.5.3 RATIONAL LAND USE

(l) Ratiotull use of montane forest: Montane forests are precious andecologically significant and should be placed under strict protection. The policy ofhands-off should be encouraged. It is suggested that nature reserves should bedefined for montane forests (Picea schrenkiana, Sabina vulgaris var jarkendensis)where they appear in large patches, such as at Oytag of Akto County and atSupikeya of Yecheng County. As for plain desert forests and shrubs, a certainamount of water must be ensured to the lower reaches of great rivers (Hotan,Yarkant, Keriya, Qarqan, and other rivers) so that natural forests and shrubs mayget necessary material in flood season for survival. Of course, reckless and unduedeforestation must be completely forbidden. Man-planted forests are far fromenough. Their expansion in area must first of all be considered, including furtherimprovement of shelter-forest network and enlargement of firewood and economicforests.

(2) Rational use of pastureland: Rational use of pastureland involves thefollowing aspects:

(2.1) Refonning grazing system. Over a long period of time, a backwardgrazing system, namely, grazing alternately on winter-spring pastureland and onsummer-autumn pastureland, has been pursued in the Kunlun Mountains. It givesrise to insufficient use of summer-autumn pastureland and over-use of winterspring pastureland, or waste of grassland resources on one hand, and grasslanddegradation on the other. In the recent years to come, a transitional grazing systemis encouraged, Le., the grassland is divided into three parts which are utilized indifferent seasons (winter, spring and summer-autumn). Winter pastureland has astrong pressure of stock, and forage stored for use in winter is necessary; trying


every means to make use of every usable patch of grassland is especially expected.With the development of man-improved grassland and soil-improving crops, a newgrazing system should be pursued (Table 17-7). It identifies three kinds ofseasonally used pastureland, winter, spring-autumn, and summer, of which springautumn pastureland is grazed twice in a year.

(2.2) Rational use of summer-autumn pastureland. In summer and autumn,natural grass resources are quite plentiful due to favorable moisture andtemperature conditions. They are often not fully used. Seasonal stock-raisingshould be encouraged and spread, it implies that sheep are scheduled to be born inearly spring and killed in late autumn. This, if done, may not only make full use ofsummer-autumn pastureland but also reduce stock pressure on winter and/or springpastureland.

Table 17-7 A new grazing system

Seasonal Winter Spring-autumn Summer Spring autumnpastureland pastureland pastureland pastureland pastureland

Time in use early November- Early April-early early June-early Early September -early April June September early November

Total days in use 151-155 60 90 60

Grassland type plain desert-- Montane semi- montane steppe- montane steppe-(in the order of montane desert-- desert- alpine steppe-- montane semi- desert-use) man-planted Montane steppe alpine meadow- montane desert

grassland -montane steppe

(2.3) Rational use of winter-spring pastureland. Winter-spring pasturelandfaces degradation, shortage of water for herdsmen and stock, and other problems.Its rational use consists in constructing small-scale water-conservancy works inorder to solve the problem of water shortage, enclosing some grassland so as toenhance their productivity, following rotation pasturing to get rid of over-grazing,and actively promoting grassland irrigation.

(2.4) Rational use of low-wet pastureland. Waste of grass resources isparticularly striking in low-wet pastureland. The ways for their rational use includegathering grass timely (from middle June to middle July), processing reaped grassesto increase their value as forage, fencing up saline meadow low wet land or shrubbymeadow low wet land to increase grass yield, etc.

(3) Rational use offarmland: low fertility and salinization have long exertedunfavorable influence on much of the farmland and grain production. Gradualsolution of the two problems is the central issue of rational use of farmland. Amongthe measures combating low fertility, such as application of chemical and organicfertilizers, rotation of cereal crops and grass (mainly alfalfa) has proved to be themost effective. Salinization is always related with high water table, some biologicaland engineering measures must be taken to lower water table. The salinizedfarmland may be ameliorated through washing out salt. In addition, intensive

370 ZHANG B. P.

agricultural production should be conducted on high-quality farmland so as to makefull use of plentiful solar radiation of the study region. The cropping system of twocrops a year should be spread if soil fertility may be maintained or even enhanced.

17.5.4 SUSTAINABLE DEVELOPMENT

In many aspects, the Kunlun Mountains range is more closely related with itsnorthern low-lying Tarim Basin than with other parts of the Tibetan Plateau.Administratively, it is mainly part of the Xinjiang Uygur Autonomous Region orparts of the Kashi, Hotan and Kizilsu Kirgiz(Khalkhas) Autonomous prefectures;ecologically, landscape changes in the mountains result mainly from the activitiesof the inhabitants in the southwestern Tarim Basin, and the existence of oases in theTarim Basin depends wholly on the water from the mountains. As a matter of fact,the Kunlun Mountains and the southwestern Tarim Basin combine together into aclosely interacting highland/lowland system and, therefore, an inseparable"sustainable development region". It is also interesting that many smalladministrative units, namely counties, contain part of the northwestern TibetanPlateau and part of the Tarim Basin and, therefore, are also highland/lowlandsystems. As a consequence, regional sustainable development must be based on therational coordination of the relationship of highland (the Kunlun Mountains) andlowland (the southwestern Tarim Basin).

Pastureland is widespread in the northwestern Tibetan Plateau; but themajority of the usable are distributed in the northern slopes of the Kunlun. They arethe most significant resource in the study region and their rational utilization iscentral to sustainable development of the study region. Over a long period, atraditional grazing system, namely grazing alternately on winter-spring grasslandand on summer-autumn grassland, has been pursued. As mentioned above,overgrazing and land degradation have been occurring on the winter-springgrassland due to low productivity and a long period of seasonal grazing (about 195days); while the summer-autumn grassland is insufficiently used. This situation isbeing displaced by a transitional grazing system: the grassland is divided into threeparts that are grazed in winter, spring, and summer-autumn, respectively. Thisshortens the period of grazing on the desert-steppe (spring grassland) from 195 to90 days, and thereby, restores to some extent its natural productivity and preventsfurther overgrazing; but it also imposes the problem that winter grassland sustainsan even strong pressure from livestock. This can be offset partly by dry grassstorage in summer and autumn. But the summer-autumn grassland still cannot befully used. With the development of managed grassland and soil-fertilizing crops,such as alfalfa, in the oases downstream, a completely new grazing system shouldbe pursued. Such a system identifies three types of seasonally used pastureland(winter, spring-autumn, and summer), of which the spring-autumn pastureland isgrazed twice (spring and autumn) in a year (Table 17-7).

This system can prevent not only overuse and under-use of pastureland, butcan also increase the yields of animal husbandry and bring montane steppe and


desert ecosystems into an integral economic system (CUI and WANG, 1990).However, as have been shown, this can be attained only through cooperation withoases downstream, where necessary amount of artificial forage for winter andspring use can be produced. In other words, cooperation between the northwesternTibetan Plateau and the southwestern Tarim Basin is a requisite for theirsustainable development.

To achieve full use of summer-autumn pastureland, one of the effective stepsis to promote the development of seasonal livestock rising, namely, to breed oneyear sheep which are scheduled to be born in spring and killed in late autumn. Thi~practice would also prevent overuse of the present winter-spring pastureland. Inaddition, some summer-autumn pastures are difficult to use because of extremeinaccessibility; it is therefore necessary to construct small roads and simple bridges.It is also necessary to control and reduce the population of mannots to protectgrassland from damage. The present winter-spring pastureland faces degradation,shortage of water for herdsmen and livestock, and other problems. The solutionhere is the construction of small-scale water-conservancy works, enclosure of somegrasslands to enhance productivity, the practice of rotation grazing to eliminateovergrazing, and active promotion of grassland irrigation.

Owing to harsh environment conditions, the northwestern Tibetan Plateau hasvery limited habits for the growth of natural forests. They are ecologically veryfragile, grow very slowly, and, once destroyed, are very difficult to restore. Theseforests and the surrounding alpine meadow, montane steppe and even glaciersconstitute a cool and comfortable summer site for tourism, set against the generalaridity of the northwestern Tibetan Plateau and the sandy desert in the Tarim Basin.It is safe to argue that, with the development of the economy and an increase in theliving standards of the local people, the montane forests are bound to become asummer resort in the near future. Some planning and measures should beundertaken in advance. It will be too late to restore such forests after they havebeen heavily damaged. Great attention should be paid to the regeneration of theseforests and, where possible, their extension. A nature reserve have been suggestedfor the Oytag area, so that the largest patch of such forest in the northwesternTibetan Plateau can be well protected and sustainably used (ZHANG Baiping,1995).

In recent years, some nature reserves have been established in the studyregion, including the Altun Nature Reserve, the Taxkorgan Nature Reserve and theNorthern Qiangtang Plateau Nature Reserve. They play an active role in theprotection of rare wide animals and their environment and in promoting regionalsustainable development. On the other hand, tourism has developed quickly insome locales of the Kunlun Mountains, e.g., at the Kara Kol Lake and at the Oytagarea. Many tourists come for sight-seeing. At the same time, the landscapes arenecessarily damaged to some extend. So, more strict management should beimplemented to reduce or avoid environmental disturbance.

372

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ACKNOWLEDGEMENTS

We would like here to express our hearty thanks to the contributors of the rep0l1,as well as all the people who have helped us selflessly.

Particularly, we would like to take this opportunity to pay our deep appreciationto the project Comprehensive Scientific Expedition to the Karakorum and KunlunMountains (l987~1992) supported by the National Natural Science Foundation ofChina (NNSFC) and the Chinese Academy of Sciences (CAS), the projectEnvironmental Changes and Regional Sustainable Development of the TibetanPlateau (K.Z951-Al-204; KZ95-T6) supported by CAS, the National ClimbingProject of China Formation, Evolution, Environmental Changes and Ecosystems ofthe Tibetan Plateau (1992~1997), and the State Key Project for Basic ResearchDevelopment Planning Formation and Evolution of Tibetan Plateau with ItsEnvironment and Resource Effects (G1998040800) supported by SMST.

We are also grateful to the hard and careful compilation of Petra D. VanSteenbergen, the publishing editor for the Geosciences programme of KluwerAcademic Publishers. It is just through the warm and friend cooperation between usthat guarantee the smooth publication of the book Mountain Geoecology andSustainable Development ofthe Tibetan Plateau.

ZHENG Du, ZHANG Qingsong, and WU Shaohong

373

CONTRIBUTORS

BAO Haosheng

CHEN Guichen

CHENG Guodong

FU Xiaofeng

LI Bingyuan

LI Bosheng

LI Ribang

LI Shuxun

LIN Zhenyao

LIUYi

PENGBuzhuo

PU Lijie

TAN Jian/An

WANG Jinting

WANGWuyi

WANG Xiuhong

WUShaohong

YANG Qinye

YIN Zhiyong

Geography Department, Nanjing University, Nanjing

Northwest Institute of Plateau Biology, Chinese Academy of Sciences,Xining

Institute of Environment and Engineering in Cold-Dry Regions, ChineseAcademy of Sciences, Lanzhou

Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences, Beijing

Institute of Geographical.Sciences and Natural Resources Research,Chinese Academy of Sciences, Beijing

Institute of Botany, Chinese Academy of Sciences, Beijing








Institute of Botany, Chinese Academy of Sciences, Beijing


Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences, Beij ing



Georgia State University, USA, Atlanta

375

ZHANG Baiping

ZHANG Qingsong

ZHANG Xueqin

ZHAO Lin

ZHENGDu

ZHU Liping

ZHUWenyu








376

SUBJECT INDEX

A

Aba, 342accompanying plants, 125, 126, 149active landform processes, 203active layer, 116,117,121,122,128,129,130,131,132,133,137,217administrative regionalization, 71agricultural surplus labors, 87alkaline soil, 48, 63alpine belt, 49, 52, 64, 150, 151, 152, 154, 279alpine cushion vegetation, 154,232alpine desert, 6,48,49,50,55,57,60,61,357,358,360,362,363,364,365alpine desert-steppe 49, 50, 108, 109, 152, 153, 154, 168, 183, 191, 357, 360, 362,

363alpine gypsiferous desert soils, 55, 109alpine meadow, 6,12,48,49,50,54,57,58,59,61,108,125,137,150, 151,154,

168, 176, 186, 191,222,228,229,231,236,233,269,270,271,272,274,277,303,304,306,307,308,309,310,311,312,313,314,315,316, 317, 318, 319,320,321,322,323,324,325

alpine meadow soil (cryo-sod soil), 48, 125, 151, 168, 186,270271,272,308,309,325,358,360

alpine periglacial vegetation, 127,337,alpine scrub and meadow belt, 48, 54alpine sparse vegetation, 154, 155alpine steppe, 6,41,48,49,50,57,60,61,108, 109,152,154,176, 183, 186,308,

311,312,313,314,315,320,334,357,358,359,360,362,363,364,370,altitudinal belts, 5,6, 12, 14,49,57,58,61,62,64,68,69,303,309,312,313,314,

315,359,360,361,362,363,364,3635,366,367,368altitudinal distribution, 310, 335, 340altocryic isohumisols, 48Altun Nature Reserve, 226,272animal husbandry, 13, 54, 105, 176, 246, 247, 248, 249, 250, 256, 257, 258, 262,

278,280,281,295,296,298,303,319,316,366,368,371appraisement of ecological environment, 341Arabian Sea, 28,90, 107, 109,347,352arable land, 79,80,276,277,278,279,294,295,296,297,298,310areal differentiation, 363, 365, 372aridisol, 53aridity index, 53,62,291Asian monsoons, 19,47atmospheric circulation, 6, 12,53,59,61,64,90,303,365atmospheric oxygen pressure, 14azonal factors, 58, 369

377

378 INDEX

B

backbone of Asia, 349Bangoin, 328, 329Bangong Lake, 109,209base belt, 48,49, 109,267,268,269,287,313,314,340,341,359,360,361,362,

363,364,365,366Batang, 207,241,281,294Bay ofBengal, 30, 104, 106, 107Bayan Har Mountains, 30, 31Beijing, 9,98,99, 101, 102, 162Bhutan, 235, 250, 283Biocoenose, 14, 139, 146, 147, 151, 152, 155Biodiversity, 139,223,226,235,342bio-geographical region, 140biologic-morphologic features, 335biosphere, 223,225biota, 12, 14,52139, 140, 143, 144, 145bird island, 223Black-Necked Crane, 227,237,238,241boundarylaye~ 109,274Brahmaputra, 106, 246, 247, 262, 266broad-leaved forest, 48,50,57,229,270,273,275broad-leaved mixed forest, 50, 145, 147, 148,229,287Buddhism, 245,261Burang, 169, 191,227,250

c

carbonate cinnamon soils, 48cell membrane, 167, 172Cenozoic Era, 1, 10, 14, 19,20,22,24,25,33, 139, 140Central Asia, 5,7,57,61, 110, 141, 144,329,356,357central government, 8, 15, 87, 182, 245, 247, 248, 249, 250, 251, 252, 253, 254,

255,256,257Changdu, 287Chen Co, 41Chengdu, 251China, 1,4, 7,8,9, 19,20,21,23,25,26,27,47,59,71,72, 74, 76, 78, 79, 84, 85,

86,87,90,91,96,98,99, 101, 105, 109, 110, 113, 122, 139, 142, 145, 153, 161,163,164,165,167,168,172,173,174,176,182,183,184, 186, 193, 195, 197,198,210,213,223,224,225,227,230,234,235,236,237,238,243,244,245,250,251,256,257,258,259,260,261,267,268,284,294

Chinese Academy of Sciences (CAS), 8, 19,235,290, 303, 318, 350

GEOECOLOGY & SUSTAINABLE DEVELOPMENT OF TIBETAN PLATEAU 379

Chongqing, 240, 251chronic mountain sickness, 161Chumbi station, 102Classification, 13,47,60,62,64, 122, 123, 184,225,283,284,285,360,361climate change, 14, 101, 131climatic regionalization, 284Climbing Projects, 9cloud masses, 107cold and dry core region, 344, 345, 346cold-front cloud system, 103community structure, 125, 126, 148, 149,299coniferous forest, 48,49, 50, 55, 57, 65, 108, 109, 147, 148, 149, 150, 227, 229,

269,270,271,272,273,274,287,295,307,347,357,360,361,364continental frigid-desiccation, 48continental glacier, 5, 32, 64, 228continental systems, 6,47,48,49,58continuous permafrost, 119, 120, 130convective cloud masses, 107cool-dry, 48, 53cormophyte, 139, 140coverage, 53,55,125,126,127,129,132,150,151,152,154,192,196, 215,231,

276,278,281,295,306,cryosphere, 27,90, 109, 110cryostructure, 119cryptophyte, 54, 306cultivated land, 53,79,80,81, 184, 185,277,279,295,296,297,298cultivation index, 294cultivation system, 276,277,278

D

Dalai Lama, 93Danba, 240, 286Dan'niang, 267,268debris flows, 13, 14,52,208,209,211,212,216,220,275,278,298deciduous scrubs, 48, 54, 150, 307deforestation, 279,291,295,296,269degradation, 13, 14,41,55, 129, 131, 132, 133, 134, 194,214,215,216,217,220,

248,277,278,296,299,293,304,307, 315, 316,317,318,319,320, 322, 342,343,367,368,369,371

democracy reform, 85density of population, 6, 297dental fluorosis, 167, 170, 171denudation, 3, 55, 354desertification, 14, 132, 216, 217, 220, 342, 343

380 INDEX

desiccation, 32,48, 55, 234, 354, 356, 364, 365development of agriculture, 80, 183, 294development policy, 245, 248discQntinuous permafrost, 130distribution pattern, 28,49, 109, 140, 150, 155,356dominant belt, 6, 12,47,58,61,359,360,361,362dominant species, 125, 126, 127, 151, 153, 154,215, 273, 306, 335drainage system, 4, 331, 333driving forces, 87dry land cropping, 189dry valleys, 12, 15,48,51,52,53, 191,203,283,284,285,286,287,290,291,294,

295,296,297,298,352dry-hot, 284, 285, 286, 290, 296, 297dry-warm, 284,285,286,293,297,298Dujiangyan, 210, 240Dunde ice core, 38,39,40dwarf cushion suffrutice , 55dynamic mechanism, 87dynamic threshold height, 90

E

early Pleistocene, 11, 19,20,22,23,25,26,27,30,34,35,38East Asia monsoon, 90, 105, 109eco-geographical regional system, 14,47ecological habits, 336ecological type, 58, 336economic condition reconstruction, 244economic crops, 276, 280, 281economic strength, 81, 246, 251, 260,ecosystemsl,9, 10, 14,20,35,53, 124, 129, 134,223,225,226,229,235,238,268,

269,276,299,308,333,341,343,371,educational level, 83, 322eluviation, 53, 273, 273, 337, 341endemic animal types, 338endemic communities, 342endemic cretinism, 163endemic diseases, 14, 173endemic goiter, 163endemic natural hazards, 208endemic species,S, 55, 142, 144, 145, 149,230,235,236,335,342,344,358environment management, 294, 295environmental changes, 7, 8, 9, 10, II, 13, 14, 19, 27, 38, 89, 93,96, 335environmental deterioration, 6epidemiological study, 160


Euphoria royleana, 283Eurasia, 19,24,58,61,109evapo-transpiration potential, 63evergreen broadleaf forest, 287exploitation and utilization, 343extinction coefficient, 308

F

farming and animal husbandry, 246,247,248,250,257,262,280fault zones, 2, 203, 204, 206faulting mountains and basins, 328fauna, 5, 19,25,26,27,34, 108, 139, 140, 141, 142, 145, 154, 183,229,270,272,

338,341ferrallitic soils, 48financial investment, 251fisflora, 5,7, 12, 108, 124, 139, 140, 144, 183,229,231,268,341fluorapatite, 167fluoride, 162,167,168,169,170,171fluvial erosion process, 4food support, 79forest resources, 195, 197, 198,276,279,280forestry, 13,64,83,230,235,276,278,280,281,295,298,300,319,366forest-tundra, 54fragile environment, 194,203,214,219,304,321freeze-thaw stripping of sod layer, 317freezing-thawing action, 4frigidization, 65frost action, 121frost calcic soil and Saga soil, 337frost cracking, 121, 122, 129frost heaving, 121, 122, 129, 133frost mounds, 123frost scars, 122frost sorting, 121, 122, 129frost weathering, 121, 122, 129,339,341frost-sod soils (alpine meadow soils), 48fuel wood, 198, 291

G

GaSha, 93Gandise-Nyainqentanglha Range, 7Gangise River, 23Gangrigabo Ridge, 274

382 INDEX

Gansu Corridor, 24, 25GDP per capita, 251, 252general circulation, 105, 287general malaise, 160genetic engineering organisms, 223genetic mutant organisms, 223geo-ecological features, 3,273geo-ecological phenomena, 14,47,51,52geoecology, 159geoecosystem, 159, 162, 173, 174geographical element, 3,64, 140, 141, 144geographical environment, 159Gerze, 11 0, 241, 328, 329glacial sequences, 31, 32glaciation, 3,5, 11, 14,28,30,31,32,36,39,40,41,51,52,55,354glacier lakes, 209,210global change, 10, 11, 14,60, Ill, 129global radiation, 4global warming, 101, 110, 130gold-digging, 342, 343Golmud, 96Gongga Shan Nature Reserve, 226, 227Gonghe Basin, 217Gorge Country, 56grain production, 80, 81, 82gravity anomaly, 2grazing conditions, 315, 319, 320grazing land, 14, 181, 184, 185, 191, 192, 193grazing yaks and sheep, 307ground ice, 119,120,121,122,124,130,131,133Guangxi, 251Guizhou238, 244, 251Gulia ice core, 41

H

heart rate and energy metabolism, 160heat and cold sources, 14heat transportation, 104heating effect, 4,50Heilongjiang Province, 173Hemicryptophyte, 54, 306Hengduan Mountains, 2,9, 17,30,47,62,67,68, 107, 157,200,204,205,207,

209,211,212,219,221,283,284,286,299,302,312herbaceous meadow, 54, 306, 315


Hexi corridor, 57,207high altitude asthenia, 161high altitude encephaledema, 161high altitude heart disease, 161high altitude polycythemia, 161high altitude pulmonary edema, 161high altitude respons, 161High Asia, 55,67,302,48high clod meadow, 303high-cold desert, 55, 154, 214, 231, 232, 331, 332, 336, 339, 340, 341, 345, 346,

359high-cold desert steppe, 331, 332, 340, 341, 346high-cold ecosystem, 332, 342high-cold scrubs and meadow zone, 12, 15,303high-cold steppe, 54,65, 150, 152, 154, 156,214,331, 332, 333, 335, 336, 337,

338,340,341,342,343,344,359highland, 2, 12,52,53,63, Ill, 145, 173, 176, 186, 188, 189, 190,200,201,228,

299,342,345,348,358,366,367,370,371highland barley, 63, 173,201,366Himalaya Mountains, 205,206,208,209,211,332,347Himalayan Main Boundary Thrust, 203Himalayan movement, 19,22,23Hinterland, 31,32, 184,236,266,290,327,346Hipparion fauna, 19,25,26,27,42,44Hoh Xii Natural Preservation Region, 344Holarctic kingdom, 5, 140Holocene, 14,23,36,38,42,44,51,92,332horizontal zone, 6,58,59,61,225,303,309,312,313,314huanglong Si Nature Reserve, 227human activities, 1, 6, 8, 10, 13, 40, 52, 53, 54, 72, 79, 101, 183, 184, 203, 209,

214,216,217,220,223,294,327,33,342,343,368human health, 159, 162, 172, 175humic acid, 308humification, 308humus layer, 308,337,358Hunza valley, 53Hydroxyapatite, 167Hypoxia, 159, 160, 161, 162, 180

I

ice cape, 329ice tongue, 330ice wedges, 329income and expenditure, 251, 252

384 INDEX

index of flood/drought, 95Indian Ocean, 52, 105, 183,229,266,347,351Indian Shield, 25Indian Subcontinent, 5,22,43, 107Indo-Malaysian Subkingdom, 5Indus, 7,9, 13, 15,20,21,75,76,78,87,223industrial structure, 248,256,257,259,260inhalation, 159Inner Mongolia, 186, 251instrumental observation, 89intensive tectonic movement, 203inter-annual variability of temperature, 96iodine deficiency, 163, 164, 165iodine metabolism, 163, 165island permafrost, 216

J

jet stream cloud system, 106Jiangxi Province, 267Jinshajiang, 191,204,207,211,212,287,290,292,297,298,347Jiujiang County, 267

K

Karakorum Mountains, 9,23,35, 36, 67, 191,209, 211, 327, 345, 347, 362, 366,372

karst landforms, 19, 227Kashin-Beckdisease, 173,174,175,178,179,180Kashmir, 7, 57Keshan County, 173Keshan disease, 173, 174, 175, 179knick points, 4Kobresia meadow, 54, 151,306,315,317,325,Konger Mountain, 208Kunlun Mountains, 2,5,9, 11, 16, 17,23,26,29,43,44,45,67,68,69,91,96, 107,

108, 109, 156,201,206,211,212,349,350,351,352,353,354,355, 356, 357,358,359,360,363,364,365,366,367,369,370,371,372,373

Kunlun Pass, 32

L

labor forces, 85land degradation, 13,14,216,304,307,316,318,369,371land reclamation, 76,216,217,277


land sandification, 216, 217, 218, 220land utilization and conservation, 16,275landslide, 13,14,19,52,203,205,206,208,210,211,212,216,219, 220, 245,

298,293,land-use, 14, 19, 161, 181, 182, 183, 184, 185, 190, 199,200,367last interglacial age, 92late Cenozoic, 1,10,14,16,17,19,20,25,33,42,43,44,45,111,112,139,373late Paleolithic Period, 72late Pleistocene, 30, 31, 32, 38, 51late Pliocene, 21,22,23,350late Teritary, 92latitudinal zones, 58leeward slope, 290Lhasa, 8,9,22,78,86,88,91,92,93,94,98,99, 101, 102, 103, 100, 110, Ill, 162,

164,167,169, 174, 172, 183, 184, 185, 186, 187, 190, 191, 196,216,246,247,260,262,263

Liaoning, 251life elements, 162, 167, 179life process, 162Lithosphere, 15Little Ice Age, 93livestock farming, 191, 194livestock husbandry, 14,83,182,184, 185, 186, 187, 190, 193, 194, 195, 199,200,

201,321,322livestock quality, 194, 281local interest, 248Longmenshan earthquake zone, 204, 205loss of water and soil, 215,216,220lower limit, 50,64, 154,217,291,296,303,304,309,310,311,312,313,314,315lower oxygen environment, 160lower Siwalik group, 22, 23lowland, 4, 5, 12,47, 52, 53, 54, 55, 61, 145, 161, 183, 186, 228, 299, 300, 307,

309,367,370,371

M

Mann-Kendall algorithm, 98maritime glacier, 4,32, 106MarmotaHimalayan, 14,142,151,153,154,338,358Marsh, 192,335mean air temperature, 294mean precipitation, 112, 266, 267, 352Medieval Warm Period, 93mental disorientation, 160meso-xeromorphic, 53

386 INDEX

microphyllous, 53mid-Pleistocene, 90, 92mineral weathering, 338Ming Dynasty, 71Minority, 78,243,244,245,251,257,277,350modern education, 82, 83, 85moisture channel, 52,moisture regime, 4, 12,47,48,49,50,54,57,58,59,60,61,62,63, 109,279,287,

305,308,315moisture transportation, 14, 55, 66, 105, 106, 107, 108, 109, 111, 112, 266moisture-bearing air mass, 55, 108, 109moisture-laden air-mass, 52Molasse deposits, 21, 22, 23Mongolian high, 31,91,92monk population, 84monsoon passage, 290monsoon system, 6, 14,27,89,90monsoonal rainforest, 48montane belt, 49, 145, 147, 152, 153montane brown soils, 48montane cinnamon soils, 48montane coniferous forest belt, 48montane dark coniferous forest, 287montane desert belt, 48, 49montane drab soil, 53montane evergreen broad-leaved forest, 48,50,57,65montane forest, 11,47,48,50,57,58,59,61,63,64,108, 109, 150,229,273,290,

291,299,303,308,311,312,313,314,315,357,364,366,368,369,372montane resources, 299montane sclerophyllous, 57, 109,287montane sclerophyllous forests, 57montane shrubby steppe, 49, 57montane steppe belt, 48, 49, 360, 361, 364montane warm coniferous forest, 287morbidity, 166morphological adaptation, 161mountain geo-ecology, 13mountain sickness, 160, 161mountain vertical vegetation zones, 337mountain wind, 53mountain-valley breeze, 290, 299multiple climatic types, 203

N


}Jagqu, 48,57,65,103,155,169,187,191, 196, 197,213,214,260,261,305,306,318,328

}Jaque-Arli highway, 335national parks, 227, 228nationality structure, 77, 78, 79natural and social conditions, 245, 278natural ecosystem, 54,225,226,268,269,307,344natural environment, 3,6, 7, 9, 12, 19,52,67,79, 176, 188,221,223,225,245,

300,323,328natural hazards, 7,9,203,208,218,219,220,221,,222natural historical remains, 227natural landscapes, 5, 7, 59,60, 149,272,303,342,350,366natural resources, 1,6,8,9, 12, 13, 16,60,68,69, 176, 184, 197,201,214,223,

225,245,264,275,281,282,322,348,365,372,373natural zone, 6, 12, 53, 54, 57, 58, 59, 62, 63, 64, 65, 69, 282, 287, 304, 305, 306,

307,312,313,315,316nature conservation, 14, 156, 157, 223}Jeogene lacustrine deposits, 19}Jeoglaciation, 40, 41neo-tectonic movement, 11, 19,35}Jepal, 23,210,229,230,235,250,283}Jgari areas, 107}Jieniexiongla glaciation, 30}Jingxia, 251nival belts, 48, 312, 362, 363nivation process, 5nomadism style, 344non-agricultural land, 181, 199non-dominant vegetation, 335}Jorth China, 19,27,332}Jorth Hemisphere, 98, 105, 109, 110,265,345}Jujiang }Jature Reserve, 226}Jyainqentanglha Mountains, 5, 106, 108, 176, 192,207,208,212,213,331,347}Jyingchi, 78,103,43, 145, 159, 169, 175, 176, 187, 190, 196, 197,206,260,261,

276,279,280,281

o

Ochotona of pika, 307Oligocene age, 22,33omnivorous Ursus arctos, 151, 153onghe-Jinshajiang-Hoh XiI fault, 204orchard, 181, 182, 184, 185, 195oriental region, 140, 270Oriental species, 5, 148, 149

388

over-grazing, 342, 343, 369oxygen pressure, 14, 159, 160, 162oxygen-saturated degree, 160

INDEX

p

palaeoarctic region, 272Palaeo-tropical Kingdom, 5Pamirs, 1,2,7, 107Pandemics, 176Pantholops Hodgsoni, 142, 146, 153, 154,232,236,338,342,343,345,358peaceful liberation, 72, 81, 83, 86, 87peneplanation, 11, 89perennial mesophytes, 54, 306periglacial landforms, 5, 15,305,354periodical natural degradation, 317permafrost, 4, 5, 14, 16,40,53, 54, 183,203,216,217,220, 305, 306, 329, 332,

336,339,342,345physical environments, 1, 13,53,54,57, 139, 146,305,363physical regionalization of China, 267, 268, 281physical weathering, 48, 274, 300, 308physic-geographical conditions, 6, 284physic-geographical region, 47,56,60,61,62,64,65,66,67,68,366physic-regional system, 62piedmont zone, 327pillar industries, 250, 258, 260, 261Pingos, 329planation surface, 6, 24, 25, 26, 31, 42, 48, 89, 90, 328, 351planetary winds, 90plant ecotype, 283plateau high-cold areas, 223plateau monsoon system, 14,89,90plateau surface, 2,4, 11, 12,26,40, 54,60,90,92, 109,209,217,219,220,229,

305,328,329,342,345Plateau's base surface, 304,309,312,313,314Pleistocene conglomerates, 19Pliocene, 2, II, 19320, 21, 22, 23, 24, 25, 26, 27, 34, 35, 42, 45, 90, 350podzolic soils, 149,272population censuses, 77population density, 54, 184, 275, 283, 303, 316population migration, 76population pressure, 291, 296, 300population quality, 82potential evaporation, 60poultry, 183, 193


poverty alleviation, 251, 256, 257poverty relief, 256principal of exploitation, 248proxy materials, 89Qaidarn Basin, 2, 13, 92, 108, 153, 188, 191, 192, 201, 202, 206, 216, 217, 230,

246,247,261,263,349Qiangtang plateau, 4, 15, 23, 26, 31, 56, 57, 58, 62, 65, 151, 152, 154, 156, 168,

200,201,312,327,328,329,333,334,335,336,337,338, 340, 341, 342, 343,344,345,346,349,354,356,358,363,372

Qilian Mountains, 19, 22, 23, 26, 31, 38, 44, 110, 176, 177, 200, 201, 206, 207, 211,311

Qing Dynasty, 71, 72, 84, 85, 93Qinghai - Tibetan Plateau, 15, 66, 89, 90, 92, 93, 94, 96, 104, 105, 109, 110, Ill,

112,156,220,222,323,324,358

Qinghai Lake, 32,39,40,41,44,65, 166,201,216,217,218,220,223327,233,234,235

Qinghai Province, 1,9, 15, 16, 17,71,72,73,74,76,77,78,80,86,87,88, 149,160,164,166,167,168,169,170,172,174,182,186,187, 188, 190, 192, 193,195,196,197,201,213,214,221,235,242,246,247,250, 251, 254, 257, 261,263,264,318,319,320,323,324,325,338,344

Qingzang Movement, 23, 26, 27Qinling Mts, 1Qomolangma glaciation, 30quasi-tropical monsoon forest, 269,270,271Quaternary glaciation, 5, 14,29

R

radiation balance, 58,radiation index, 54rational stocking intensity, 320regional differentiation, 6, 12, 14,47,48,51,54,55,56,57,58,61,61,64,68,98,

103,139,144,201,265,272,281,282,286,287,315Rejuvenation, 4Relict, 142religion force and influence, 85religion privilege, 85residential land, 184resources utilization, 294, 295rhizome geophyte, 54, 306rigorous environment, 334, 340, 343, 344rock fall, 52, 274

390 INDEX

s

satellite images, 106, 107scientific expedition, 6,7,8,9, 16, 19,44,124,126, 169segregated ice, 119selenium, 162,171,172,173,174,175,178,179selenoenzyme, 172selenoproreins, ,172semiarid, 39,48,50,53,54,58,60,63,145,150,151,152, 155,283,284,285,287,

294,312,315,360, 363,364sensitive regions for climatic changes, 109serf and temple system, 85SFG (Seasonally frozen ground), 116, 119, 132Shanghai, 98,99,101,102Shelter, 142,197,269,274,369shrub belt, 287siallisols, 48Siberian-Mongolian high, 91,92Sichuan, 1,7,8,9,57,65,69,71,96,97,103,123,143,149, lSI, ISS, 166, 167, 171,

174,176,193,199,200,207,209,210,223,224,226,227, 240, 283,294,295,296

Sino-Himalayan floristic elements, 269Siwaliks, 25skeletal fluorosis, 170slash-and-burn cultivation, 182snow accumulation, 14, 41, 329snow hazards, 93, 213Snow Leopard, 227,230,235,357Snowline, 31, 32, 50, 51, 58, 64, 183, 231, 311, 312, 329, 335, 345, 347, 352, 361,

364sod layer, 308,309,317,319,322soil conservation, 216, 280, 296soil erosion, 248,275,278,284,291,298,299soil formation, 274,338,341solar radiation, 4, 58,93, 110, 183, 191,279,294, 370solifluction, 64,119,121,122,123sorghum, 184, 188sorted polygons122, 123spatio-temporal characteristics, 96speciation, 5, 52, 235, 269, 274species genetic diversity, 223spectrum-structure, 6, 12,47,48,49spermatophyte, 124, 140, 141, 142, 144stratification stability, 109structural landform unit, 1


sub-alpine meadow soils, 48sub-humid, 6,40,48,49,52, 53,54,55,57,58,60,63,91,279,283,284,285,287,

291subnial belt, 311sub-polar zone, 54subsidiary criterion, 62subtropical evergreen broad-leafforest268, 269, 270subtropical vegetation, 19summit surface, 2super-arid types, 6super-xerophytic, 48surface albedo, 105, 133sustainable development, 13, 14, 15, 83, 223, 225, 245, 248, 249, 251, 252, 263,

264,300,320,343,366,367,368,380,371,372sustainable strategic objects, 243swampy meadow, 41,53,54,155,305,306,307,315

T

Tanggula, 32,56,108,120,122,127,130,131,212,327,328,331Tarim Basin, 55,57,106,107,350,351,352,355,364,370,371,372Taxkorgan, 227235,242,366,372tectonic landform, 2tectonic mechanism, 20tectonic uplifting, 89temperate desert, 57, 153, 183,359temperate-dry, 53temperature anomaly, 98,99, 101, 104temperature belt, 47,62,63,64,65,312temperature inversion, 273,274temperature pattern, 91temperature-moisture conditions, 6, 57, 59, 61,303Tertiary, 24,53,89,90,91,92thermal forcing, 90, 105thermokarst, 121, 123, 124, 128, 129thorny scrubs, 53three dimensional differentiation, 13,47three dimensional zonation, 309thyroxine, 163Tibet Autonomous Region, 72, 73, 74, 75, 76, 77, 78, 81, 82, 84, 85, 86, 97, 185,

186,187,188,189,190, 191,193,194,195,196,197,198,200,344Tibetan Buddhism, 84, 245Tibetan Wild Ass, 55,226,237Tien shan Mountains, 203time-series, 98

392

topographic configuration, 59, 303topographic-climatic factors, 53traditional plan-economy, 245trend-surface analysis, 303,309,310tropical element, 61, 229, 268tropical rainforest, 48,49,52, 147Tufan Dynasty, 71Tundra, 54, 228, 229type classification, 225, 283

INDEX

u

un-developed land, 184undulate platform, 328uneven spatial-temporal distribution, 89unsorted polygons, 122, 123upheaving stones, 122uplifting process, 2, 11, 14upper limit, 58,64, 148,274,275,287,299,304,309,310,311, 312,314, 364, 365urban development, 71urbanization, 85, 86, 87,248useable grassland, 186, 303

v

valley wind systems, 53vascular plant, 52, 139, 142, 144, 229, 231, 234vegetation type, 57,65,108,109,283,306,357,360vertical distribution, 269,274,287,300vertical natural belts, 265, 269vicarious species, 149volume ratio of grass to soil, 309, 317vortex cloud systems, 107

w

Ward, F. K., 7warm-dry, 53warm-temperate zone, 55water shortage, 294,295,296,367,370water vapor, 106weather hazards, 203,212westerly, 56, 91, 105, 106, 107White Gobi, 55, 109wild animals, 55,152,154,226,237,342,343,356,358


Wild Yak, 55,236,237,338,358Wolong-Wanglang, 224World Conservation Union OUCN), 223, 225World Wildlife Fund (WWF), 223

x

Xerophyte, 53, 283, 315Xigaze, 187,190,191,196,260,261,263Xinjiang Uygur Autonomous Region, 1,96,110,168,242,351,371Xixiabangma mountains, 30, 32Xiyue and Yumen conglomerate, 26Xizang Autonomous Region, 1, 9, 241

y

Yak, 55,151,152,154,155,183,186,192,193,201,236,237, 281, 307, 319, 320,338,358,368

Yangtze River, 31, 108, 164, 166, 195, 245, 283Yangzoyum Co, 41Yarlung Zangbo Grand Canyon Nature Reserve, 226Yarlung Zangbo-Lhasa-Niyang River, 103Yellow River, 4,27,31,32,65,166,195,216,223,245,246,251,305You Tai Lhasa Weather Diary, 93Yuan Dynasty, 71, 85Yueyang, 267Yulong Xueshan Nature Reserve, 226Yunnan, 1,7,8,9,71,74, 143, 147, 148, 166, 191,200,207,212,224,227,229,

238,241,251,283,292,294

z

zero-mesophilous deciduous scrubs, 46Zoige Basin, 39, 40zonal differentiation, 38,90zonal moisture regime, 47,62zonal vegetation, 54, 61, 62, 64, 65, 306zone of high-cold scrub and meadow53, 54


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Policies. 1998 ISBN 0-7923-4854-044. B.K. Maloney (ed.): Human Activities and the Tropical Rainforest. Past, Present and

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