Study on Sustainable Nutrient Supply in Fast- Growing ......Rp Rupiah, Indonesia's currency TPTI Tebang Pilih Tanam Indonesia – selective timber harvesting method in Indonesia. According

Tropical Forest Research

Study on SustainableNutrient Supply in Fast-Growing Plantations

Ecological and Economic Implicationsin East Kalimantan, Indonesia

Dr. Jens MackensenProf. Dr. Horst Fölster

Eschborn, 1999

TÖB publication number: TÖB FTWF-II/11e

Published by: Deutsche Gesellschaft fürTechnische Zusammenarbeit (GTZ) GmbHPostfach 5180D-65726 Eschborn

Responsible: Tropenökologisches Begleitprogramm (TÖB)Dr. Claus Baetke

Authors: Dr. Jens Mackensen, Büsgenweg 2, D-37077Göttingen,Tel.: 0551-399529, Fax: 00551-393310email: [email protected]

Prof. Dr. Horst Fölster, Büsgenweg 2, D-37077Göttingen,Tel.: 0551-399529, Fax: 00551-393310

Local Partners: Sustainable Forestry Management Project(SFMP), Dr. Huljus, Kotak Pos 10 97, Samarinda75001, East Kalimantan, Indonesien,Tel.: 0062-541-33434, Fax: 0062-541-33437email: [email protected]

Layout: Michaela Hammer

ISBN: 3-9806467

Nominal fee: 10,-DM

Produced by: TZ Verlagsgesellschaft mbH, D-64380 Rossdorf

© 1999 All rights reserved

PrefaceAdopted at the 1992 United Nations Conference on Environment andDevelopment, at which 178 countries were represented, Agenda 21 includes asection devoted to forests. Together with the UNCED Forests Statement, Agenda21 forms a basis for international cooperation on the management, conservationand sustainable development of all types of forests. The Rio resolutions alsoserve as the foundation for a process of national-policy modification designed tostimulate environmentally compatible sustainable development in bothindustrialized and emerging countries.Ideally, sustainable development builds on three primary guiding principles for allpolicy-related activities: economic efficiency, social equity and ecologicalsustainability. With regard to the management of natural resources, this meansthat their global utilization must not impair future generations' developmentalopportunities. With their myriad functions, forests in all climate zones not onlyprovide one of humankind's most vital needs but also help preserve biologicaldiversity around the world. Forest resources and wooded areas must therefore besustainably managed, preserved and developed. Otherwise, it would neither bepossible to ensure the long-term generation of timber, fodder, food, medicine,fuels and other forest-based products, nor sustainably and appropriately topreserve such other important functions of forests as the prevention of erosion,the conservation of biotopes, and the collection and storage of the greenhouse gasCO2.Implemented by the Deutsche Gesellschaft für Technische Zusammenarbeit(GTZ) GmbH on behalf of the German Federal Ministry for EconomicCooperation and Development (BMZ), the "Tropical Forest Research" projectaims to improve the scientific basis of sustainable forest development and, hence,to help implement the Rio resolutions within the context of developmentcooperation.Application-oriented research serves to improve our understanding of tropicalforest ecosystems and their reciprocity with the economic and social dimensionsof human development. The project also serves to promote and encouragepractice-oriented young German and local researchers as the basis fordevelopment and dissemination of ecologically, economically and sociallyappropriate forestry production systems.Through a series of publications, the "Tropical Forest Research" project makesthe studies' results and recommendations for action available in a form that isgenerally comprehensible both to organizations and institutions active in the fieldof development cooperation and to a public interested in environmental anddevelopment-policy affairs.

Dr. H.-P. Schipulle Dr. D. BurgerHead of Division:Environmental Policy, Protection of NaturalResources, Forestry; CSD, GDF

German Federal Ministry for EconomicCooperation and Development (BMZ)

Head of Division:Forest Resources Management, LivestockFarming, Fisheries, Nature Conservation

Deutsche Gesellschaft fürTechnische Zusammenarbeit (GTZ) GmbH

Table of contents

I

Table of contents

LIST OF FIGURES ......................................................................... III

LIST OF TABLES...........................................................................IV

GLOSSARY ..................................................................................VI

SUMMARY................................................................................ VIII

1 INTRODUCTION ......................................................................1

1.1 Problem Analysis and General Objectives .................................. 1

1.2 Terms of Reference .................................................................... 2

1.3 Cooperation Partners .................................................................. 3

2 RESULTS ................................................................................5

2.1 Plantation Policy in Indonesia .................................................... 5

2.2 Types of Sites and Nutrient Pools............................................... 7

2.2.1 Types of Sites ................................................................. 7

2.2.2 Nutrient Pools in the Soil................................................ 9

2.3 Plantation Productivity ............................................................. 10

2.3.1 Inventory of stands ....................................................... 11

2.3.2 Nutrient Pools in the Stand ........................................... 13

2.4 Nutrient Budgets....................................................................... 15

2.4.1 Nutrient Budgets and Plantation Management .............. 15

2.4.2 Quantifying Nutrient Fluxes ......................................... 20

2.4.3 Harvest Balance............................................................ 23

2.4.4 Overall Balance ............................................................ 26

2.5 Replacement of Nutrients ......................................................... 28

2.6 Plantation Economics ............................................................... 30

2.6.1 Costs of Fertilization to Replace Nutrient Losses ......... 30

Sustainable Nutrient Supply in Fast-Growing Plantations

II

2.6.2 Investment Analysis ......................................................34

2.6.3 Sensitivity Analysis .......................................................35

3 PRACTICAL RELEVANCE ......................................................39

3.1 Opportunities and Limitations of Timber Plantations ................39

3.2 Regional Development and Land-Use Planning.........................39

3.2.1 Further Need for Research .............................................41

4 RECOMMENDATIONS FOR ACTION .......................................43

4.1 Plantation Enterprises................................................................43

4.2 Land-Use Policy ........................................................................44

4.3 DC Institutions ..........................................................................44

4.3.1 Information Policy.........................................................45

4.3.2 Concepts for Action.......................................................46

5 REFERENCES ........................................................................47

6 APPENDIX ............................................................................51

List of figures

III

List of Figures

Fig 1: Nutrient concentrations in stemwood (H) and -bark (R)

of Eucalyptus deglupta (Ed), Acacia mangium (Am)

and Paraserianthes falcataria (Pf)........................................................ 13

Fig. 2: Plantation stand in the closed stand phase. ........................................ 15

Fig. 3: Plantation in the clear-cutting phase.................................................. 16

Fig. 4: Clear-cutting and land preparation phase........................................... 17

Fig. 5: Growing plantation forest in the open (1) and

closed stand phase (2)......................................................................... 18

Fig. 6: Time course of site productivity ........................................................ 19

Fig. 7: Estimation of the different fluxes of Nt within

one rotation period ............................................................................. 21

Fig. 8: Estimation of the different fluxes of Pt within

one rotation period ............................................................................. 21

Fig. 9: Proportion of K export [%] in relation to pools in

soil and harvest [m3] for Acacia mangium ......................................... 25

Fig. 10: Proportion of Ca export [%] in relation to pools in

soil and harvest [m3] for Acacia mangium ......................................... 25

Fig. 11: The internal rate of return as a function of changes

in the PT.IHM's costs or revenue........................................................ 35


IV

List of tables

Tab. 1: Pools of C, Nt , Pt and exchangeable cations

in 0-100 cm soil depth ........................................................................ 10

Tab. 2: Stand parameter for Acacia mangium (Am) and

Eucalyptus deglupta (Ed) ................................................................... 12

Tab. 3: Comparison of relative nutrient exports for Acacia mangium .......... 24

Tab. 4: Comparison of current costs for fertilizaion with the costs

of compensation of nutrients removed with the harvest ..................... 31

Tab. 5: Costs of fertilization in case of compensation of

total nutrient losses............................................................................. 32

Tab. 6: Parameter of the soil types in different soil depth............................. 52

Tab. 7: Export of nutrients with stemwood and -bark for

Acacia mangium................................................................................. 53

Tab. 8: Export of nutrients with stemwood and -bark for

Eucalyptus deglupta ........................................................................... 54

Tab. 9: Management-dependent export fluxes for N and P

in relation [%] to the exports by harvest ............................................. 55

Tab. 10: Management-dependent export fluxes for K, Ca and

Mg in relation [%] to the exports by harvest....................................... 56

Tab. 11: Sum of management-dependent nutrient export fluxes ................... 57

Tab. 12: Estimation of the amount of fertilizers necessary to

compensate management-dependent export fluxes of N ..................... 58

List of tables

V


compensate management-dependent export fluxes of P...................... 59


compensate management-dependent export fluxes of K ..................... 60

Tab. 15: Comparison of the current amount of fertilizers with the amount

of fertilizers necessary to compensate harvest export ......................... 61

Tab. 16: Costs of fertilization necessary to compensate total

nutrient losses with management variants .......................................... 62


VI

Glossary

Al Chemical symbol for aluminium

Al saturation Proportion of aluminium as a percentage of the ECEC

MAI Average total increment at the reference age (8 yrs) in m3/ha per

annum

Ca Chemical symbol for calcium

ECEC Effective cation exchange capacity. Ability, in particular of clay

minerals and organic substances, to adsorp and exchange cations at

their surface. Related to the pH range concerned

Degradation Deterioration in the quality, e.g. of a soil site, e.g as a result of

inappropriate use

GH5 Greatest height (at the reference age of 5 yrs), i.e. the height of a

stipulated number of tallest trees per unit area

INHUTANI Public forestry companies in Indonesia (outside Java)

K Chemical symbol for potassium

Mb cations Cations whose hydroxides are strong bases: Na, K, Ca, Mg

Melioration Soil-improving measures (liming, drainage, etc.)

Mg Unit of weight: megagram (106 g), formerly "ton"

Mg Chemical symbol for magnesium

N Chemical symbol for nitrogen

Nt Total N pool in the soil

Navail N fraction easily available to plants

NPK fertilizer Type of fertilizer containing nitrogen, phosphate and potassium

P Chemical symbol for phosphorus

Pt Total P pool in the soil

Pavail P fraction easily available to plants

Glossary

VII

Production forest According to the Indonesian classification system, an area of natural

forest intended for permanent use

Rotation period length of a management cycle

Rp Rupiah, Indonesia's currency

TPTI Tebang Pilih Tanam Indonesia – selective timber harvesting method

in Indonesia. According to this method, only trees with a diameter at

breast height (DBH) of more than 50 cm may be felled. Forest

manipulations are carried out every 35 years at the most, and stand

rejuvenation has to be ensured


VIII

Summary

Industrial fast-growing plantations in the tropics are acquiring increasing

significance for various reasons. Taking a plantation concession in East

Kalimantan (Indonesia) as an example, the present study shows that the

conversion of large areas of land into one-species plantations presents a

threat to the ecological and economic sustainability of various types of

sites.

Over 90% of the land used to cultivate plantations has highly weathered

soils with a moderate to poor supply of nutrients (Alisols, Acrisols,

Ferralsols and Arenosols). In contrast, azonal soil types such as Fluvisols

and Calcisols have a good to excellent supply of nutrients, but only very

small areas of these soils are found. The distribution of nutrients depends

inter alia on the relief. On lower parts of slope and in valleys, the supply of

nutrients is greater by a factor of 2-10 than on the corresponding upper

parts of slopes or ridges.

With a stand rotation cycle of 8 years, the average yield expected by

plantation concessions is 200 m3/ha or 25 m3/ha per annum. In the first

rotation cycle, the actual yield of Acacia mangium stands was higher and

that of Eucalyptus deglupta stands considerably lower than this expected

growth. As a pioneer species, Acacia mangium can show high rates of

growth in the first rotation cycle even on soils with a poor supply of

nutrients. In contrast, Eucalyptus deglupta requires a site with deep soil and

a good water supply (e.g. Fluvisols and Alisols/Acrisols on lower parts of

slopes). Moreover, this tree species requires intensive maintenance work, in

particular to monitor the accessory vegetation.

Summary

IX

Harvesting of stemwood and bark results in the removal of nutrients. The

extent of this loss depends on the volume of harvest and the species-

specific level of nutrients in the wood and bark. The removal of nutrients

with the harvest has a significant impact on the nutrient cycle of fast-

growing plantations.

Preparing nutrient budgets serves to compare the input and output of

nutrients in an ecosystem (in this case a fast-growing plantation). The

results of these balances allow conclusions to be drawn about the stability

of the system concerned. If the balance is negative, a plantation cannot be

managed sustainably. The input and output of nutrients (or nutrient fluxes)

taken into account in the balance include both the management-

independent and the management-dependent parameters. The management-

independent parameters include nutrient input by precipitation, silicate

weathering and biological N fixation and nutrient output by leaching (so-

called base fluxes). The management-dependent parameters include

nutrient output by harvesting (removal with the harvest), net leaching due

to management, erosion, and output as a result of burning due to

volatilization and ash loss (burning losses). In assessing the macronutrient

status (N, P, K, Ca, Mg), output is generally found to be higher than input,

resulting in a negative nutrient balance.

The management-dependent nutrient fluxes that occur in addition to the

base fluxes (the management-independent fluxes) are sometimes

considerably higher than the nutrients removed with the harvest alone.

Depending on the management intensity and the tree species, the

additional, management-dependent nutrient losses amount to 80-170% for

N, 80-250% for P, 50-280% for K, 30-190% for Ca and 70-450% for Mg

(as a percentage of the corresponding removal of nutrients with the

harvest).


X

By comparing the amount of nutrients removed with the harvest and the

site-specific nutrient pools in the soil (so-called harvest balance), it can be

seen that considerable amounts of base cations (K, Ca, Mg) are removed

from the plantation system during harvesting. The harvest balance depends

on the input variables volume of harvest and nutrient pools in the stand and

soil. On poor Alisols/Acrisols or Ferralsols, for example, if we assume a

volume of harvest of 200 m3/ha, 18-30% of the available Ca and K supplies

are lost in Acacia mangium stands after one rotation. Assuming linear stand

productivity, an average loss of 20% means that the available supplies of

the elements will be exhausted after five rotations. The continuous output

of nutrients leads to degradation of the site, resulting in decreased

productivity.

In addition to the nutrients removed with the harvest that are taken into

account in the harvest balance, the overall balance also includes all the

other management-dependent and management-independent nutrient fluxes

and compares these with the system's pools. The system's pools comprise

the nutrient pools in the soil (to a depth of 1 m), in the trees, in the forest

understorey and in the organic O-horizon. Assuming that the area is

managed conventionally (using tractors, harvesters, etc. and burning the

logging debris), the total loss of nutrients on typical sites (Alisols/Acrisols)

after one rotation amounts to 21-62% of the system's pools of K, 9-32% of

Ca and 5-20% of Mg, depending on the tree species. The losses of P

amount to a maximum of 17% and of N (for Eucalyptus deglupta only) to a

maximum of 53%. Using a form of management that preserves the land by

not burning the felling waste (slash) and by using methods that preserve the

soil (light-weight machines, high-lead cable car systems), the nutrient

losses that occur within one rotation can be reduced by approximately 50%.

Summary

XI

Generally speaking, plantation management is associated with significant

nutrient losses.

The estimated nutrient losses highlight the need for sustainable nutrient

supply, particularly on sites with poor nutrient stocks. Measures should be

taken to reduce and replace nutrient losses. The most direct method to

replace nutrient losses is to use mineral fertilizers.

Fertilization management has to fulfil various criteria on the sites studied.

Due to the acidic to highly acidic soil conditions, only fertilizer types that

cause no or little soil acidification may be used. The element-specific

utilization levels need to be estimated realistically. The utilization rate for P

fertilizers is 10-40%, but in highly acidic soils utilization is less than 10%

due to the P immobilization caused by aluminium. A utilization rate of 50-

70% can be assumed for N and K fertilizers. Species-specific differences

should also be taken into account when applying fertilizer, e.g. Acacia

mangium requires less K fertilization than Eucalyptus deglupta and no or

only very little N fertilization. Fertilization should also be adapted to suit

the particular site. On Alisols/Acrisols, the upper parts of slopes and ridges,

in particular, require fertilization, while on Fluvisols no fertilization is

needed and on Calcisols essentially only K fertilization is necessary. Due to

the high degree of P immobilization on acid soils, liming is recommended

on Alisols/Acrisols with pH values of less than 4.5.

The amounts of fertilizer currently used in plantation management are not

sufficient to replace the nutrient losses that occur, particularly if fertilizers

with a standard composition (e.g. NPK) are used.

Assuming an optimal composition of fertilizers, the costs of fertilizing to

replace total losses in plantation management are conservatively estimated

(see Min200) as 3.5-fold higher for Acacia mangium and 5.7-fold higher for


XII

Eucalyptus deglupta than the fertilizer costs actually estimated by the

concession.

While fertilization management currently accounts for an average of 4% of

the plantation's total costs, the costs of the fertilizer actually required to

replace losses range from 9% to 40% of the plantation's total costs,

depending on the tree species, management type and fertilizer used. In

intensively managed plantations, the measures required to replace nutrient

losses in order to ensure a sustainable nutrient supply thus constitute a

significant cost factor.

The internal rate of return on equity calculated by the company in

accordance with government stipulations is 17.7% (1991/92 conditions). If

fertilization management is geared towards replacing nutrient losses and

the plantation's costs therefore increase by 13% (replacing nutrients

removed with the harvest), the internal rate of return on equity drops to

11%. Investment calculations for plantations therefore need to take account

of the site-specific results of nutrient budgets. Establishing large, uniform

areas and managing them conventionally is economically inefficient in

comparison.

The results of the present study show that the technical and financial inputs

required to manage a plantation on the given sites on a permanent basis, i.e.

over the course of many rotation cycles with a constant level of

productivity, have to be considerably higher than the current expenditure in

conventional plantations. Under the given conditions, plantation

management cannot be carried out in accordance with the classical models

of extensive forestry.

Under the current conditions, the sustainability potential of intensively

cultivated fast-growing plantations in the region is regarded as being low.

Summary

XIII

In the interest of regional development policy, the following conclusion can

be drawn: If sustainable regional development and forest management

planning are to be achieved, attention needs to be paid to the ecological and

economic stability of industrial timber plantations.

Introduction

1

1 Introduction

1.1 Problem Analysis and General Objectives

According to the FAO (1995), after China and India, Indonesia already

showed the largest increase in plantation areas between 1980 and 1990 (cf.

Winjum and Schroeder 1997). In the current decade, in view of the

decreasing timber supply from natural forests, the Indonesian Government

has further intensified efforts to establish plantations. The creation of over

10 million ha of fast-growing plantations by the year 2010 has been

planned or already initiated.

The ecological and economic implications associated with this

development were studied using a concession in East Kalimantan as an

example. With decreasing areas of natural forest and rising costs for their

exploitation, large areas of overexploited natural forests in littoral regions

have been converted into fast-growing plantations since the beginning of

the 1990s. The average size of these plantation concessions is 100,000-

200,000 ha. On the same scale, 10,000-15,000 ha of contiguous land are

converted into plantations every year regardless of the site conditions. The

entire area is established as a unit regardless of whether the individual areas

are at all suitable for the intended use, thus consciously running the risk

that this conversion may be partially unsuccessful, with all the ecological

and economic losses this entails.

As part of the research project, the significance of site heterogeneity in

plantation management and the impact of management on the quality of the

site were studied with the aim of establishing the basis for site-specific

planning in the creation of plantations. In this context, the potential of

various sites was assessed using nutrient budgets on the basis of different


2

levels of productivity and different forms of management. In order to

clarify the importance of the nutrient pools and fluxes in plantation

management, the costs associated with the various management options

were investigated and assessed in terms of investment analysis. This

resulted in a site-specific assessment of the ecological and economic

sustainability of plantation management in the region.

1.2 Terms of Reference

Result A: Characterization of the predominant types of site.

Activities: Selection of suitable study areas within a plantation concession.

Differentiation of sites at the level of a reconnaissance survey

on the basis of relief differentiation of the soil cover.

Result B: A set of expectations for various potential management

concepts have been identified for the types of site characterized.

Activities: Use-related characterization of the types of site, including soil

analysis and calculation of the soil-borne nutrient pools,

assessment of the suitability of each type of site for particular

tree species, yield, expected use of natural forest on the basis of

regional experience and assessment of the expected

development of nutrient pools and the necessary fertilization to

replace losses according to the type of site and its management.

Result C: Various alternative management plans have been drawn up to

be assessed in terms of their silvicultural and ecological

prospects, measures and risks.

Activities: Selection of site-specific alternative management options taking

account of ecological sustainability criteria to different degrees.

Introduction

3

Development of alternative planning concepts for the site types

depending on the type of use.

Result D: The price-cost relations for various management concepts have

been clarified.

Activities: Calculation of expected profits and costs associated with the

various alternative management concepts on the basis of

previous operating figures. Evaluation of the alternatives from

an economic point of view, taking into account the changes to

be expected over longer periods.

1.3 Cooperation Partners

The project was conducted in close cooperation with the Institute of Soil

Science at the Forestry Faculty of Mulawarman University, Samarinda,

Indonesia, supervised by the dean Dr. Daddy Ruhiyat. In connection with

the cooperation between Mulawarman University and the PT.ITCI

concession, the fieldwork was actively promoted by the PT.ITCI/PT.IHM.

Logistic support for the present study was provided by the Indonesian-

German Forestry Project (IGFP) and later by the Deutsche Gesellschaft für

technische Zusammenarbeit (GTZ) GmbH's Sustainable Forestry

Management Project (SFMP) and Mulawarman University.

Results

15

2.4 Nutrient Budgets

2.4.1 Nutrient Budgets and Plantation Management

Figures 2-5 show the most important system parameters of plantation

management. These parameters are used as input and output variables in

nutrient budgets.

Fig. 2: Plantation stand in the closed stand phase. Three possible

undergrowth variants are shown: organic O-horizon only (1),

herbaceous understorey, often Imperata cylindrica or Chromolaena

odorata (2) and understorey with pioneer species (often Macaranga

spp.) or valuable timber species (e.g. Eusideroxylin zwaageri) (3).

Various nutirent fluxes are taken into account: precipitation

deposition (a), leaching (b), nutrient uptake (c), weathering of the

bedrock (d) and N-fixation (e).

a

2

3

b

c

de

1


16

Nutrient budgets serve to assess the stability of ecosystems (Ulrich 1993).

If there is an imbalance between the input and output of nutrients in a

system, it has to be assumed that, in the long term, the features of this

system will change and as far as the nutrient status is concerned will shift

to a lower or higher level. On the basis of nutrient budgets, the

sustainability of a particular form of management can be evaluated and the

need for and extent of nutrient replacement can be assessed (Ulrich 1993).

Fig 3: Plantation in the clear-cutting phase. A distinction is made

between the use of heavy machinery causing severe erosion and soil

compaction (1) and the use of high-lead cable yarding systems that

minimise erosion and soil compaction (2). The following processes

are outlined: timber harvest (a), residual phytomass (slash) remaining

on the site (b), soil compaction and destruction of the topsoil (c),

gully and sheet erosion (d).

1 2

a

b

c

c

d

d

Results

17

In estimating nutrient budgets, a distinction is generally made between

pools and fluxes, and the latter can be further divided into those within a

system and those between systems. Fluxes within a system are those

parameters that essentially lead to changes in the compartments of the

system (litter fall, canopy leaching, etc.). Fluxes between systems are those

parameters that cross the boundaries of an individual system (precipitation,

leaching, etc.).

Fig. 4: Clear-cutting and land preparation phase. A distinction is made

between land preparation by burning the residual phytomass (1) and

leaving the residual phytomass unburnt (2). If option 2 is chosen,

planting spots or lines have to be created before the seedlings can be

planted. The following processes are outlined: nutrient losses by

volatilization and in ash particle transport (a), ash beds and

unprotected mineral soil (b), gully and sheet erosion (c) and

herbaceous secondary vegetation (d).

1 2

c

c

b

b

a

d


18

Fig. 5: Growing plantation forest in the open (1) and closed stand

phase (2). The competition between trees and understorey in the

open stand phase (a) and land maintenance by monitoring and

controlling understorey (b) are outlined.

Various phases are distinguished. The clear-cutting phase is the period after

the land has been converted or after the harvesting of the previous stand

before the new stand is planted. The open stand phase is the period between

the establishment of the stand and canopy closure, a transitional period

leading up to the closed stand phase. The latter phase covers the period

between canopy closure and stand maturity and shows the greatest

differences from the subsequent clear-cutting phase.

A distinction is made between harvest and total nutrient balance

approaches (see Sects. 2.4.3, 2.4.4). If they are used as a frame of reference

for a rotation phase, both approaches are purely static in nature. To

determine the balance continuously , i.e. covering several rotation cycles,

12

a

b

Results

19

assumptions about the dynamic nature of the individual site parameters

have to be made. There are

basically three scenarios for the

time course of site productivity as

a function of the physical and

chemical properties of the soil

(Fig. 6): productivity that remains

constant over time (a), productivity

that increases in successive rotations (b) and decreasing productivity (c,d).

The first scenario (a) is feasible on sites with optimal supply if tree species

that suit the site are chosen. The second (b) may occur on sites which have

been improved by a pioneer forest stage, for example. Site degradation

(scenario c or d) may be caused by choosing an unsuitable tree species or

by inappropriate management.

Despite the rapid increase in area, particularly in South-East Asia (cf.

Sect. 1.1), few studies have been documented on forest productivity in

tropical plantations over the course of several rotation cycles. Declining

productivity in the second and third rotation has been reported in the SSSB

concession in Sabah, Malaysia (main tree species Acacia sp. and

Eucalyptus sp.) (Chia, personal communication) and in Paraserianthes

plantations on Java, Indonesia (Fakuara, personal communication).

Exceptions to this rule can only be expected on soils with very good

nutrient supply, such as those of volcanic origin, or in subtropical areas

under certain conditions (cf. Evans 1982, 1988). For the majority of the

tropical plantation sites, a decline in productivity is more likely in the

future (cf. Mackensen 1998).

Fig. 6: Time course of site productivity

time course of site productivity

(a)

(b)

(c)(d)

prod

uctiv

ity


20

2.4.2 Quantifying Nutrient Fluxes

2.4.2.1 Management-Independent Flux Parameters

In this context, management-independent flux parameters are those flux

variables within a system that occur as so-called base fluxes, regardless of

the type and intensity of management. The most important base fluxes for

nutrients are atmospheric deposition, rock weathering, biological N fixation

and leaching.

2.4.2.2 Management-Dependent Flux Parameters

The conversion of natural forest into other land use forms and the rotation

change on plantation sites result in changes in the hydrological,

microclimatic and physical-chemical soil parameters of the system. These

changes lead to nutrient losses (output fluxes). The output fluxes taken into

account in nutrient budgets include nutrients removed with the harvest,

management-dependent net leaching, erosion, and volatilization and loss of

ash particles caused by burning (burning losses).

In order to allow the flux parameters to be applied to specific plantation

conditions, parameters are expressed as a function of a variable that is

relevant within plantation management and assigned to the relevant stand

phase or management stage (cf. Mackensen 1998). Thus, nutrient export

with the harvest is a function of the species-specific nutrient concentrations

in the exported compartments (stemwood and -bark, see Sect. 2.3.2) and

the harvest volume. Management-dependent net leaching and the losses

caused by burning are a function of the nutrient pools in the residual

phytomass (including the understorey and the organic O-horizon). The

nutrient losses caused by the net leaching are modified by precipitation and

the buffering capacity of soil. The losses due to burning depend on the

Results

21

extent of burning and the intensity of the fire. The losses due to erosion in

this context are a function of the nutrient levels in the topsoil.

Fig. 7: Estimation of the different fluxes of Nt within one rotation

period

Fig. 8: Estimation of the different fluxes of Pt within one rotation

period

In Figs. 7 and 8 (and in the Appendix, Table 9), the range of N and P-losses

in the clear-cutting phase as a result of management-dependent leaching

(mAw), erosion (Ero) and burning (Br) are quantified and correlated with

the nutrients removed with the harvest (E), assuming a volume of harvest

0

10

20

30

40

P[k

gha

]t

-1

E Am E Ed E Pf Nie Aw mAw Ero Br

E Am, Ed, Pf

Br

= element export with harvest for Acacia mangium, Eucalyptus deglupta and Paraserianthes falcataria with a harvest volume of 100, 200 and 300 m ha .

= losses by burning ( with a residual vegetation of 200 m ha ).

3 -1

3 -1

Nie

Aw

mAw

Ero

= input via precipitation (data from literature).

= output via leaching (data from literature for primary tropical forests).

= management-dependent leaching in case of conversion of stands

= management depending leaching in case of conversion of stands.

1

0

100

200

300

400

500

N[k

gha

]t

-

E Am E Ed E Pf Nie Aw mAw Ero Br

E Am, Ed, Pf

Br

= element export with harvest for Acacia mangium, Eucalyptus deglupta and Paraserianthes falcataria with a harvest volume of 100, 200 and 300 m ha .

= losses by burning ( with a residual vegetation of 200 m ha ).

3 -1

3 -1

Nie

Aw

mAw

Ero

= input via precipitation (data from literature).

= output via leaching (data from literature for primary tropical forests).

= management-dependent leaching in case of conversion of stands

= management depending leaching in case of conversion of stands.


22

of 100, 200 or 300 m3/ha. The base fluxes precipitation (Nie) and runoff

(Aw) are also given. These variables have been extrapolated for a rotation

period of 8 years.

If we compare the nutrient input by precipitation (Nie) and the nutrient

output by management-independent leaching (Aw), there is a higher input

than output of Nt and Pt (cf. Figs. 7, 8), while the output of K, Ca and Mg is

higher than the input (cf. Appendix, Table 10). Ideally, however, the base

fluxes precipitation and leaching are assumed to be balanced in the long

term (cf. Bruijnzeel 1990; Lesack and Melack 1996; Mackensen 1998).

In summary: Taking into account the major nutrient fluxes, input is

considerably lower than output for all the elements considered. The

plantation system has a negative nutrient balance.

According to a very conservative estimate, if we assume a volume of

harvest of 200 m3/ha, the sum of all management-dependent N-losses

(above and beyond the nutrients removed with the harvest) range from 80%

to 170% of the nutrients removed with the harvest alone, depending on the

tree species. Management-dependent P-losses have been estimated at 80-

250% under the same conditions (cf. Appendix, Table 9). This means that,

depending on the management system, nutrient losses due to burning,

leaching and erosion are at least as high as, and often considerably higher

than, the nutrient losses caused by timber harvesting alone.

In the Appendix (Table 10), the management-dependent losses of the

nutrients K, Ca and Mg are compared. In comparison to the nutrients

removed with the harvest, the additional losses to be anticipated as a result

of plantation management range from 40% to 280% for K, depending on

the tree species. The Ca-losses caused by harvesting are very high, which is

why the additional management-dependent losses are relatively low,

Results

23

ranging from 16% to 190%. Additional management-dependent Mg-losses

are very high, amounting to 70-450% of the nutrients removed with the

harvest.

In summary: In addition to the nutrient losses caused by stand harvesting

(nutrients removed with the harvest), considerable additional nutrient losses

(losses caused by management) per unit area are to be expected in

plantation management as a result of management measures.

2.4.3 Harvest Balance

The harvest balance only takes into account those amounts of nutrients

removed from the area with the harvest (cf. Sect. 2.3.2) and compares these

losses with the corresponding pools in the soil (cf. Sect. 2.2.2). The relative

export value (in %) refers to the pool of elements in the harvested

compartments (stemwood and -bark) and the soil (cf. Table 3).

The nutrient pools in the phytomass compartments that are not exported,

such as the crown, the roots and the understorey, are not taken into account

in this balance. For the purposes of drawing up the balance, it is assumed

that the level of nutrients stored in these compartments remains constant in

quantitative terms in the development of the second and successive stand

generations (constant productivity, cf. Fig. 6).

The results of the harvest balance are summarized in Table 3 for Acacia

mangium. As Acacia trees are able to take up N from the atmosphere via

symbionts, the N status can be ignored for this species. If Ca and K pools in

the soil are low (cf. sandy Alisols, Ferralsols/Arenosols), 18-30% of the

nutrients available in the system are depleted in the first rotation (cf.

Table 3). Even in soils with average nutrient supply, the nutrients removed


24

with the harvest amount to approximately 10% of the pools taken into

account.

Tab. 3: Comparison of relative nutrient exports for Acacia mangium in case ofstemwood harvest only (H) with harvest of stemwood and -bark (HR)related to the nutrient pools in soil (0-100 cm) and in stem timber andstem bark

Navail Pavail K Ca Mg Mndata in [%] H HR H HR H HR H HR H HR H HRmedium. Alisol 12,6 24,0 1,3 3,1 3,7 8,8 3,2 9,9 0,9 1,6 0,0 0,5rich Alisol 6,8 13,9 0,6 1,4 2,2 5,5 1,1 3,7 0,3 0,5 0,0 0,2poor Alisol 20,4 36,0 3,4 8,0 7,7 17,5 11,3 30,0 4,3 7,5 0,1 2,3Acrisol 15,3 28,4 1,8 4,3 4,0 9,5 4,2 12,8 1,7 3,0 0,1 0,9Ferral-/Arenosol 22,4 38,7 2,9 6,9 10,9 23,6 7,8 22,1 2,1 3,8 0,1 2,0Calcisol 12,9 24,5 1,0 2,5 5,3 12,3 0,1 0,3 0,7 1,2 0,0 0,5Share of bark inexport

54,4 59,5 60,3 70,3 44,8 94,2

a Navail and. Pavail are N and P fraction easily available to plants. All data are related to a stand harvest of 200 m3 ha-1.

In summary: According to the results of the harvest balance, the proportion

of nutrients removed with the bark is 45-94%. If the bark were to remain on

the site, nutrient export by stem harvest would be considerably lower.

Figures 9 and 10 show the losses for different harvest volumes depending

on the nutrient pools concerned (cf. Table 1).

Results

25

Fig. 9: Proportion of K export [%] in relation to pools in soil and

harvest [m3] for Acacia mangium.

Fig. 10: Proportion of Ca export [%] in relation to pools in soil and

harvest [m3] for Acacia mangium.

0

10

20

30

40

50

60

70

80

100 300 500 700 900 1100 1300 1500

400 m3

300 m3

200 m3

100 m3

R 400 m3

R 200 m3

Pools of exchangeable K [kg ha ] in the soil-1

Expo

rt [%

of p

ools

in so

il an

d ha

rves

t]

R = Export by harvesting calculated with data of element concentration from Ruhiyat (1989)

0

10

20

30

40

50

60

70

80

100 300 600 900 1200 1500 1800 2100 2400 2700

100 m3

200 m3

300 m3

400 m3

Pools of exchangeable Ca [kg ha ] in the soil-1

Expo

rt [%

of p

ools

in s

oil a

nd h

arve

st]


26

If the volume of harvest is greater or the soil less deep, the amount of

nutrients removed with the harvest increases accordingly (see Figs. 9, 10;

Appendix, Tables 7, 8; cf. Mackensen 1998).

In summary: Losses due to harvesting amounting to 20% of the pools

concerned, for example, mean that, the nutrient pools will be exhausted

after five rotations at the latest (assuming constant productivity levels over

this time). The site is then deficient in nutrients or degraded.

2.4.4 Overall Balance

In addition to the variables included in the harvest balance, the overall

balance also takes into account all management-dependent fluxes discussed

in Sect. 2.4.2. The sum of all losses is correlated to the system's nutrient

pools that are taken into account. The system's pools include the nutrient

pools in the soil (0-100 cm), the trees, the organic O-horizon and the

understorey. The nutrient pools in the roots are here snot taken into

account.

Overall balances were drawn up both for conventional and for an

alternative form of plantation management (cf. Mackensen 1998). In this

context, conventional land management is understood as the use of

machines (tractors, harvesters and/or forwarders) and slash burning. In this

approach, a maximal and a minimal variant (Max200 and Min200) have been

distinguished. Alternative land management is defined in this context as

minimized soil destruction by using harvesting methods that preserve the

soil (e.g. high-lead cable yarding systems) and no slash burning (Alt200).

All variants assume a volume of harvest of 200 m3/ha (cf. Sect. 2.3). If

volumes of harvest are greater than this (cf. Table 2), the pools are

exhausted more rapidly (cf. Sect. 2.4.3).

Results

27

After one rotation of conventional management, depending on the site

quality, management intensity and tree species, K losses range from 7% to

65% of the system's pools, for example. For Ca, the figure can be as high as

approximately 50%. For P and Mg, the figures can be as high as 35%,

particularly on nutrient-poor soils (cf. Appendix, Table 11). Even on soils

with a good supply of nutrients (Fluvisols, Calcisols and loamy Alisols on

lower slope positions), pools of K and N in conventionally managed areas

are already exhausted after two to three rotations.

Declining productivity rates and soil degradation will be observed on the

ridges and upper parts of slopes first due to their poor nutrient statement. In

addition, these locations are particularly susceptible to erosion.

Alternative plantation management (Alt200) in which the residual

phytomass is not burned and soil-preserving measures (light machinery,

etc.) are taken, can reduce nutrient losses that occur within one rotation by

approximately 50% (cf. Appendix, Table 11).

In summary: Alternative management measures reduce nutrient losses in

fast-growing plantations by half.

Especially measures under the conventional management scheme lead to a

deterioration in the site quality. In this context, the organic O-horizon is

particularly significant. A loss of organic matter results in a reduction in the

cation exchange capacity and the water storage capacity of the topsoil. The

soil is no longer protected by an O-horizon and is thus more susceptible to

erosion, is compacted to a greater extent by the use of machines and dries

out more quickly; in addition, the existing N and P pools are mineralised

and depleted more rapidly (cf. detailed discussion in Mackensen 1998;

Klinge 1998; Malmer and Grip 1994).


28

The estimated total nutrient losses in conventional plantation management

highlight the need to take measures aimed at replacing and reducing

management-dependent nutrient losses and thus to improve the nutrient

status and to increase stand productivity as part of sustainable plantation

management.

In summary: A reduction of nutrient losses and the replacement of nutrients

is vital in order to achieve sustainable management of fast-growing

plantations on the given sites.

Results

5

2 Results

2.1 Plantation Policy in Indonesia

The annual rate of deforestation in Indonesia ranges from 0.9% to 1.2%

(Opitz 1995; WALHI 1992; Fearnside 1997). East Kalimantan's

deforestation rate is 1.6% and is thus higher than the national average

(WALHI 1992). Based on an estimated timber increment of 0.8 m3/ha per

annum the average annual cutting has been 24.5 million m3 since 1992,

while the Indonesian timber industry requires 52 million m3 per annum

(FAO 1990; WALHI 1992). A timber shortage already began to be forecast

as early as the mid-1980s as a result of the deforestation rate and stand

overexploitation (FAO 1990; Hamilton 1997).

Back in 1980, the Indonesian Government introduced a so-called

Reforestation Fund (Dana Jaminah Reboisasi, DR), into which taxes were

paid for timber felled in natural forests in order to finance the reforestation

of deforested areas. Once reforestation had taken place, money was to be

repaid to the concessionaires. However, in conjunction with the fact that

rights of use were limited to 20 years, many concessionaires regarded these

taxes as a payment to exempt them from their obligations, and the

reforestation objective largely failed to be achieved.

In 1984, in connection with the anticipated timber shortage and the need to

reforest unproductive areas of land, the Indonesian Government began an

Industrial Timber Plantation Programme (Hutan Tanaman Industri, HTI).

As part of this programme, the 1.6 million ha of plantation area that already

existed were to be supplemented by an additional 4.6 million ha of

plantation area for timber production by the year 2000, mainly on Sumatra,

Kalimantan, Sulawesi and Irian Jaya (FAO 1990).


6

Since 1990, the Government has been granting concession rights for

plantations (HPHTI) that give private investors special conditions. The

concession rights run for 35 years, and there is an extension option; the

rights apply to up to 300,000 ha and include an explicit guarantee for the

use of all areas that are established. Links between private enterprises and

the state-owned INHUTANI concession companies are particularly

promoted. In accordance with the guidelines for approving these plantation

concessions, the plantations are to be established primarily on grassland

and in unprofitable production forests (see glossary). Special approval is

required for the conversion of production forests.

The private sector's interest in establishing plantations has grown

considerably since the beginning of the 1990s, the reasons for this being

seen as the far-reaching concession rights that guarantee investments (see

above), the Government's subsidization policy and the so-called clear-

cutting profits (see below).

The state subsidy for a joint venture between a public company and a

private enterprise consists in an interest-free loan limited to the first

rotation, amounting to 32.5% of the costs of establishing the plantation

(Biaya pembanguan HTI), and exemption from land tax (PBB). The loan is

financed from the Reforestation Fund (DR), and the costs that can be

claimed for establishing a plantation are determined by region by the

Ministry of Forestry (Groome-Pöyry 1993). An additional 14% of the costs

are also paid out of the Reforestation Fund as the capital share of the public

company; 21% of the costs are borne by the private investor, and the

remaining 32.5% are financed by a bank loan at normal interest rates. The

costs of clearing the land and all subsequent reforestation activities (Biaya

pengusahaan HTI) are no longer financed by DR loans.

Results

7

According to WALHI (1992), many plantations are established on forest

land and fewer on grassland or scrubland. TPTI guidelines usually ban the

use of certain valuable timber species if their diameter is too small;

however, when plantations are established on production forest land, these

guidelines do not apply and concessionaires are able to use these species in

the conversion process. A greater harvesting efficiency is thus achieved at

minimal costs, as the entire infrastructure, in particular the road network,

already exists ("clear-cutting profits").

In summary: The Indonesian Government promotes fast-growing

plantations to a large extent. In order to ensure the nation's timber supplies

and to help set up a pulp industry, plantations are given a high priority on a

political level and in the private sector.

2.2 Types of Sites and Nutrient Pools

2.2.1 Types of Sites

In the study area, the predominant soil types are Alisols and Acrisols (FAO

Soil Classification, cf. WRB 1994). These soil types account for more than

80% of the total area. Alisols and Acrisols are old, highly weathered soils

that mainly develop on sedimentary rock. In the part of the soil profile

investigated (0-100 cm), the average ECEC values were 25-26 cmolc/kg

clay. The aluminium saturation is very high, averaging 85%. In general,

using the PPT (1983) guidelines, the nutrient status can be classified as

moderate to poor (cf. Appendix, Table 6). The specific physical and

chemical values of the soil are presented and discussed by Mackensen

(1998) and Ohta et al. (1992).

The spatial distribution of the Alisols/Acrisols depends on the soil texture.

If the substratum is sandy, the poorer Acrisols prevail, while Alisols


8

predominate on more loamy soils. Due to the similarity of their definitions

in the classification system used, it is not possible to make a clear

distinction between these two soil types in the field and by area. The soil

types vary greatly within small areas. In general, the nutrient status varies

depending on the position on the slope. On midslopes and lower parts of

slopes, the nutrient pools, particularly that of Mb cations, are a factor of 2-

10 higher than on the corresponding upper parts of slopes or ridges. On

account of the short slope lengths (50-200 m) in the study area, it is,

however, not feasible for the plantation mangement to differentiate

between types of sites on the basis of their relief. In order to assess the

quality of a site, it can be assumed in practical terms that loamy sites have a

better nutrient status than sandy ones.

Ferralsols and Arenosols account for only a relatively small share of the

study area. Ferralsols are very highly weathered soils and differ from

Alisols/Acrisols in that they have even lower ECEC values (<12 cmolc/kg

clay). Arenosols also have a very low ECEC, as they have a high sand

content. They account for 10-15% of the area.

Both types of soil are usually found on gentler slopes and are easy to

distinguish in the field due to their high sand content. In the part of the soil

profile investigated, their clay fraction is less than 20%. In contrast to the

other soil types, these soil types are generally poor in nutrients (cf.

Appendix, Table 6) due to their high kaolinite content and the concomitant

low ECEC (2.5 cmolc/kg soil). Their pH values are slightly higher than

those of the Alisols/Acrisols, and the aluminium saturation in these soils

averages 70-80%.

Azonal soils, such as the Calcisols that develop on limestone or the

Fluvisols found in valleys, were treated separately. These two soil types

each account for less than 5% of the area. Calcisol sites are found to be

Results

9

extended enough to be managed separately. In contrast, Fluvisols are only

found in valleys, and these are often narrow; a separate treatment of this

soil type would thus not appear to be economically feasible.

Fluvisols and Calcisols are soils with a very good nutrient supply.

However, using the criteria of the PPT (1983), the K supply in Calcisols is

low and is comparable to the corresponding values for Alisols/Acrisols (cf.

Appendix, Table 6). The ECEC of the Calcisols, in particular, is extremely

high (>85 cmolc/kg clay). The pH values range from 5 to 7.

In summary: More than 90% of the land used for plantations has highly

weathered soils with moderate to poor nutrient supply.

2.2.2 Nutrient Pools in the Soil

The nutrient pools in the soil that are available for plant nutrition

(exchangeable nutrients) are mainly a function of the nutrient

concentration, content of remaining stones and the soil density. Soil density

averages 1.2 cm3/g in the topsoil and 1.5 cm3/g in the subsoil. The

differences between sandy and loamy soils are relatively small in this

respect. The amount of stones is low, except for in Calcisol sites. The

average nutrient pools in the soil are lowest in Ferralsols/Arenols, higher in

Acrisols and highest in Alisols. Calcisols have higher levels of C, Pt, Ca

and Mg than the main soil types (Ali-/Acrisols). Fluvisols have above-

average levels of C, Nt, Pt and Mb cations (cf. Table 1). In the main soil

group of Alisols/Acrisols, higher nutrient pools are found in the loamy soils

than in the sandy ones (cf. Mackensen 1998).


10

Tab. 1: Pools of C, Nt , Pt and exchangeable cations in 0-100 cm soil depth.

Soil typ C N P Na K Ca Mg Fe Mn Al[Mg ha-1] [kg ha-1]

Alisol X 93,0 11,4 1691,0 345,4 756,6 1454,6 617,7 99,8 124,0 8454,7(n=29) Med 89,9 11,1 1606,3 393,4 769,9 1185,9 396,5 81,3 115,8 8212,6

Stdabw 19,4 3,2 641,4 158,7 252,7 936,0 517,0 93,8 64,7 2649,1Max 148,2 22,4 3742,5 552,8 1255,2 4188,7 1876,7 321,3 271,4 14925,7Min 59,7 6,4 616,9 95,9 343,7 374,9 120,8 0,0 27,2 4570,5

Acrisol X 83,3 9,1 1186,7 276,6 693,4 1091,7 311,3 87,0 67,1 6468,4(n=7) Med 86,1 9,1 1189,3 163,5 702,7 961,4 271,6 57,0 73,6 6384,6

Stdabw 18,6 1,6 231,6 147,5 163,2 626,5 126,0 67,7 35,8 1134,7Max 108,2 12,2 1621,7 450,9 947,2 2101,2 501,9 215,5 104,9 8551,2Min 49,2 6,8 917,6 152,6 454,5 504,7 198,4 23,5 12,6 4844,8

Ferralsol- X 78,8 5,7 721,4 372,2 236,0 565,5 246,6 89,5 31,2 2423,1Arenosol Med 75,4 5,4 740,7 445,2 226,9 547,0 278,3 85,1 31,8 1905,8(n=4) Stdabw 17,4 1,2 57,0 153,4 22,9 145,0 92,6 37,7 10,4 1194,1

Max 102,8 7,2 766,4 455,9 269,6 749,2 318,7 134,1 41,1 4199,4Min 61,4 4,5 637,9 142,4 220,5 418,9 111,1 53,7 20,3 1681,4

Calcisol X 111,4 11,1 2100,8 218,9 516,7 51012,7 824,1 0,0 123,5 486,7(n=2)Fluvisol (n=1) 130,3 19,0 4176,6 649,1 1314,5 12537,9 7681,3 0,0 383,4 2263,9x=mean, med=median, Stdabw=standard deviation, max/min=maximum/minimum.

2.3 Plantation Productivity

Acacia mangium, Eucalyptus deglupta and Paraserianthes falcataria (syn.

Albizzia falcataria) are the tree species mainly used in the PT.IHM

plantation concession. The primary aim is the production of pulpwood. Up

to 1996, 80% of the land was planted with Eucalyptus deglupta. As the

yield of this tree species did not match expectations, 70-80% of the land

has been planted with Acacia mangium since 1996/97. Acacia mangium is

by far the most common tree species planted in the pulp plantations in

Indonesia and Malaysia.

Regardless of the tree species planted, the planting space used by PT.IHM

was 3×3 m. A stand rotation period of 8 years is planned for the stands.

Thinning is not carried out. The anticipated yield (MAI) is 25 m3/ha per

annum, corresponding to a harvesting efficiency of 200 m3/ha after 8 years.

Results

11

2.3.1 Inventory of stands

In connection with the soil profile analyses (see Sect. 2.2.1), a total of 42

stands were investigated. On study plots of 0.05 ha Eucalyptus deglupta

and Acacia mangium stands of different ages, the diameter at breast height

(DBH) and tree height were recorded. The values are summarized in

Table 2. The yield on which the concession based its investment

calculations is usually exceeded in the Acacia stands and not attained in the

Eucalyptus stands.

The high volume output of the Acacia stands in the first rotation is due,

among others, to the high stand density and the large number of stems per

tree of the provenance used ("Queensland"). On the basis of the yield

classification criteria (GH5) given by Forss (1994), the productivity of the

Acacia stands investigated in this study can be classified as moderate to

low. Acacia mangium is a relatively undemanding pioneer tree species and

is thus able to achieve high yield in the first rotation even on comparatively

poor sites (Ferralsols/Arenosols, cf. Sect. 2.2.1).

The growth of Eucalyptus deglupta is considerably lower than the values

originally assumed by the management (cf. Sect. 2.3). The low yield of

Eucalyptus deglupta is due to the unsuitable choice of site and insufficient

maintenance work on the stands. The species requires deep soil and a good

water supply (e.g. Fluvisols) for optimal growth rates. During the early

growth phase, Eucalyptus deglupta is not able to compete very successfully

with accessory vegetation, and the mortality rate is correspondingly high,

especially if adequate tending of stands is not carried out (cf. Table 2, cf.

Mackensen 1998).


12

Tab. 2: Stand parameter for Acacia mangium (Am) and Eucalyptus deglupta (Ed).

spec. age [a] n mean range of values stand density [%]a

ATG [m3 ha-1] Ed 7,5 6 14,3 6,3-17,7 51 (24-78)Am 7,5 4 50,5 43,4-59,2 100 (62-169)Ed 8,5 15 16,1 5,2-23,2 71 (42-89)Am 8,5 2 47,4 36,2-58,8 84 (53-115)Ed 9,5 4 27,1 22,8-33,1 69 (55-78)Ed 9,5 2 17,0 52Am 9,5 3 42,1 34,9-53,8 100 (75-118)Ed 14,5 6 20,3 13,8-28,3 36 (24-44)

Vol [m3 ha-1] Ed 7,5 6 97 46,9-132,5Am 7,5 4 379 325,4-444Ed 8,5 15 136 44,4-196,9Am 8,5 2 404 307,8-500Ed 9,5 4 257 216,8-314,6Ed 9,5 2 161 149,8-172,7Am 9,5 3 400 331,8-510,9Ed 14,5 6 295 200,4-410,3

GH [m] Ed 7,5 6 19,7 14,2-24,2Am 7,5 4 27,5 25,5-29,2Ed 8,5 15 20,6 15,4-25,9Am 8,5 2 27,5 27-28Ed 9,5 4 26,1 24,2-27,6Ed 9,5 2 24,2 23,7-24,6Am 9,5 3 29,0 26,4-31,6Ed 14,5 6 31,6 27,9-37,5

ATG = average total increment for listed age, Vol = volume of stem timber, GH= height of the 5 tallesttrees per area (0,05 ha), stand density = amount of still growing trees in relation to number of plantedtrees (n=1111 ha-1), n = number of research plots; a :values >100% caused by trees with several stems.For basics of calculation cf. Mackensen (1998)

A relatively clear correlation between relief and stand productivity can be

observed. Stands on lower parts of slopes and in valleys are taller than

those with comparable forest cover on ridges and upper parts of slopes.

However, as changes in the topography occur within very small areas

(short slope lengths, etc., cf. Sect. 2.2.1), these relationships are of only

secondary practical relevance for the plantation management in the study

area.

Results

13

2.3.2 Nutrient Pools in the Stand

The nutrient pools in the stand depend on the stand volume and the element

concentration in the individual stand compartments. The stand

compartments considered include the stemwood, -bark, branches and

leaves. The stemwood and -bark are removed from the site in the course of

harvesting (exported compartments). The branches and leaves remain on

the site as residual phytomass (slash). Other compartments assessed include

the forest understorey (accessory vegetation) and the organic O-horizon.

Fig. 1: Nutrient concentrations in stemwood (H) and bark (R) of

Eucalyptus deglupta (Ed), Acacia mangium (Am) and

Paraserianthes falcataria (Pf).

N = 15 in each case.

N [%]

0,0

0,5

1,0

1,5P [mg g ]-1

0

10

20

30K [mg g ]-1

0

5

10

15

20Ca [mg g ]-1

0

1

2

3

Ed-H

Ed-

R

Am

-H

Am

-R

Pf-H

Pf-R

Mg [mg g ]-1

0,0

0,2

0,4

0,6

Ed-H

Ed-R

Am

-H

Am

-R

Pf-H

Pf-R

Mn [mg g ]-1

0,0

0,5

1,0

1,5

2,0


14

The stand nutrient pools vary depending on the species. Figure 1 shows the

concentration of elements in the compartments stemwood and -bark for the

main tree species. The nutrient levels in the bark are particularly high. On

the basis of available data (Ruhiyat 1989; Mackensen 1998), a correlation

between the tree and stand volume and the dry weight of the compartments

stemwood, -bark, branches and leaves can be made for the main tree

species. Using the concentration data, the nutrient supply can thus be

estimated for given stand supply levels (cf. Appendix, Tables 7, 8).

Assuming a volume of harvest of 350 m3/ha, for example, the amounts of

nutrients removed with the stemwood and -bark of Acacia mangium stands

are 266-332 kg N/ha, 3.4-4.3 kg P/ha, 34-36 kg Na/ha, 93-119 kg K/ha,

192-259 kg Ca/ha and 14-16 kg Mg/ha (cf. Appendix, Tables 7, 8).

Detailed data on the pools of nutrients in the residual phytomass, the

understorey and the organic O-horizon can be found in Ruhiyat (1989) and

Mackensen (1998).

In summary: Harvesting of the stand entails nutrient losses (nutrients

removed with the harvest). The extent of nutrient loss depends on the

volume of the harvest and the species-specific nutrient levels in stemwood

and -bark.


28

2.5 Replacement of Nutrients

The most direct method to replace nutrient losses is to use mineral

fertilizers or organic manure. This can be referred to as fertilization to

restore nutrient levels. In contrast to soil-enhancing fertilization, in which

additional amounts of nutrients are used in order to increase the level of

productivity, fertilization to restore nutrient levels is primarily designed to

maintain the level of productivity. However, a clear distinction between

these two forms cannot be made. The fertilizer-specific uptake efficiency

by plants (utilization rate) and the interaction with the soil chemistry have

to be taken into account in fertilization.

The use of fertilizer in conventional plantation management is usually

regarded by the plantation concessions as soil-enhancing fertilization. The

amount of fertilizer used is primarily based on the results of experiments

carried out in young stands or on data given in the literature. Standard

fertilizers are generally used, and fertilizers are usually applied without

taking into account the tree species or the conditions of the site.

As the soil conditions are already acidic to highly acidic (cf. Table 6), only

fertilizers that cause no or little soil acidification should be used. In order to

Results

29

calculate the amount of fertilizer necessary to replace nutrient losses, the

following utilization rates are assumed: N and K fertilizers 50-70%, P

fertilizers 10-40%. For P fertilizers, in particular, a high level of P fixation

(immobilization) is assumed for the soils that were studied (cf. Grüneberg

1983; Voss et al. 1977). Despite a high level of P fertilization, only a very

low level of uptake by the plant can therefore be expected.

By comparing the amount of fertilizer actually used and the amount

necessary to replace the nutrients removed with the harvest (cf. Sect. 2.4.3),

it can be seen that there is a considerably greater need for fertilizers.

Depending on the tree species, fertilizer type and utilization rate, the

amount of N fertilizer used needs to be increased by a factor of 8-22. For P,

assuming a utilization rate of 40%, the amount currently used is sufficient.

In order to replace the K pools lost during harvesting, the amount of

fertilizer used has to be increased six- to 17-fold. The amount of fertilizer

required to replace the total losses (cf. Sect. 2.4.4) is considerably higher

(cf. Appendix, Tables 12-14).

Fertilization management needs to be varied according to the species

concerned. In Eucalyptus deglupta, for example, a much greater need for K

fertilization should be reckoned with to replace losses than in Acacia

mangium. The nutrient composition of standard fertilizers (e.g. NPK

fertilizers) is poorly suited to replace the nutrient losses (cf. Mackensen

1998).

In summary: The amount of fertilizer currently used in plantation

management is not sufficient to replace nutrient losses. Species- and site-

specific fertilization management is necessary to replace the nutrient losses

occurring in plantation management.


30

In addition to fertilization, general soil melioration by liming is necessary

on many sites. On sites with a high level of aluminium saturation in the

topsoil, in particular, liming is required to reduce the aluminium levels in

the soil solution and to decrease P fixation. For sites with a pH value of

≤4.7, liming with 2.5 Mg dolomitic limestone per ha is thus recommended.

On sites with an aluminium saturation of more than 80% in the topsoil, 4-

8 Mg limestone per ha is necessary to offset soil acidity (cf. Mackensen

1998). In the PT.IHM plantation management, less than 1 Mg limestone

per ha is currently applied.

In summary: The measures currently used to improve soil quality are not

adequate to ensure the long-term availability of nutrients.

2.6 Plantation Economics

2.6.1 Costs of Fertilization to Replace Nutrient Losses

The amount of fertilization to replace nutrient losses that is deemed

necessary to achieve a sustainable nutrient balance (cf. Sect. 2.5) entails

additional costs. Table 4 compares the PT.IHM's costs for fertilization

management with the costs of replacing nutrients removed with the harvest

(costs 1996/97, cf. Mackensen 1998). PT.IHM's fertilization management

costs Rp 193,680 per ha for each rotation (based on official market prices,

not including labor). This calculation is based on the use of 100 g NPK,

40 g TSP and 840 g dolomitic limestone per plant, with a stand density of

800 trees per ha.

If the same fertilizer types as used by the company were applied to replace

the nutrients removed with the harvest (cf. Sect. 2.4.3), the expenditure on

fertilizer would increase by 13.7- or 10.7-fold (cf. Table 4). If no N

fertilizer is used for N-fixing tree species (Acacia mangium), the costs still

Results

31

rise by a factor of 5.2 (Table 4, see Appendix, Table 15). This demonstrates

both, the huge quantity needed for a minimum nutrient replenishment and

the inefficiency of standard fertilizer combinations.

Tab. 4: Comparison of current costs for fertilization with the costs of

compensation of nutrients removed with the harvest (200m3 ha-1)

variant costs for fertilizationPT.IHM Am Ed[Rp ha-1] [%] [Rp ha-1] [%] [Rp ha-1] [%]

current costs (PT.IHM, 1996) including NPK, TSPand dolomite 193.680

100

Compensation of harvest exports by standardfertilizers (NPK, TSP, dolomite)

2.654.475 1371 2.076.880 1072

Compensation of harvest exports (NPK, TSP,dolomite), but without NPK-N for Acacia mangium

1.007.005 520

Compensation of harvest exports by alternativefertilizers (Urea, TSP, potash, dolomite)

783.838 405 820.039 423

Compensation of harvest exports by alternativefertilizers (TSP, potash, dolomite),no N-fertilization for Acacia mangium

505.990 261

(Am) Acacia mangium, (Ed) Eucalyptus deglupta . Harvest volume for each stand: 200m3 ha-1

costs related to 1996/97 (1 US$ =. 2200 Rp.)

If more effective types of fertilizer are used (Urea, CIRP, K2SO4, dolomitic

limestone), the costs of fertilizers to replace nutrients removed with the

harvest are lower, but still 2.6-fold (Acacia mangium, without using Urea)

and 4.2-fold (Eucalyptus deglupta) higher than the costs of the company's

current use of fertilizers (cf. Table 4).

Compared with the data for Acacia mangium, the fertilization programme

for Eucalyptus deglupta stands is approximately 60% more expensive. As

the nutrient costs for Eucalyptus deglupta are generally higher, this species

is only profitable on sites with natural good nutrient supply (Fluvisols and

Calcisols, Alisols with above-average nutrient pools, cf. Sect. 2.2) on

which fertilization to replace nutrient losses is not necessary or is only


32

necessary to a limited degree in later rotations (e.g. K fertilization on

Calcisols) (cf. Mackensen 1998).

Replacing total management-dependent losses (cf. Sect. 2.4.4) entails

higher expenditure on fertilizer (Tab. 5; cf. Mackensen 1998). At a

conservative estimate (cf. minimal variant Min200, cf. Sect. 2.4.4.),

compared with the company's current expenditure on fertilizer, the costs of

fertilizer to replace the total losses are 350-570% higher, if alternative

fertilizers are used (Tab. 5, cf. Appendix, Tab. 16).

Tab. 5: Costs of fertilization in case of compensation of total nutrient losses for themanagement variants Min200 and Alt200 (cf. Appendix Tab.12-14).

Acacia mangium Eucalyptus degluptaVariant Min200

a Alt200b Min200

a Alt200b

[Rp ha-1] [%]c [Rp ha-1] [%]c [Rp ha-1] [%]c [Rp ha-1] [%]c

standard (NPK, TSP, dolomite) 4.317.620 2229 2.561.622 1323 2.431.655 1256 1.232.945 637

standard (NPK, TSP, dolomite),without NPK-N

1.904.665 983 1.197.550 618

alternative fertilizers (Urea, TSP,potash, dolomite)

1.166.719 602 810.021 418 1.099.578 568 841.318 434

alternative fertilizers (TSP,potash, dolomite), without N-fertilizers

685.210 354 543.275 281

a harvest volume: 200 m3,minimal losses by leaching, burning and erosion.b harvest volume: 200 m3, minimal losses by leaching and erosion. Without burning.c related to the costs of fertilization management of PT.IHM (100% = 193.680 Rp ha-1; Tab.4).

Assuming very low total losses by alternative plantation management

(Alt200, cf. Sect. 2.4.4), the costs of replacing the total losses are

comparable to the costs of replacing the nutrients removed with the harvest

(cf. Table 4, cf. Mackensen 1998).

In summary: The costs of replacing the total nutrient losses are at least

three- to sixfold higher than the current expenditure on fertilizer.

Results

33

While the PT.IHM's current fertilization management accounts for an

average of 4% of the plantation's total costs, the costs of the fertilizer

necessary to replace nutrient losses range from 9% to 40% of the

plantation's total costs, depending on the tree species, type of management

and fertilizer (cf. Mackensen 1998).

In summary: The replacement of nutrients that is necessary to ensure

sustainable nutrient pools in intensively managed timber plantations

constitutes a major operating cost factor.

To obtain a conservative estimate of the fertilizer costs, it is assumed that

only the nutrients removed with the harvest or small total losses (variants

Min200 or Alt200, cf. Sect. 2.4.4) are replaced. Variant Max200 is not

considered. In the assumptions made, it is also assumed that all the types of

fertilizer are available. If, for example, raw phosphate fertilizer is not

available in the region, either acquisition costs will be higher or more

expensive alternatives (e.g. TSP) will have to be used. It is also assumed

that fertilization does not entail any additional costs in other cost groups

apart from operating costs. Thus this simplified assumption does not take

account of any further cost changes in planning, infrastructure, research or

training. Possible increases in the costs of labour or fertilizer as a result of a

greater demand and a lower supply are also not taken into account.

In summary: On the basis of the above-mentioned assumptions for the

economic evaluation of nutrient losses, it should be assumed that the

estimates presented here are minimum values.


34

2.6.2 Investment Analysis

The internal rate of return is used to examine the profitability of

investments. The internal rate of return is the effective return on an

investment. It is defined as the interest rate at which the net present value

of an investment would be zero (Heinrichsmeyer et al. 1988). An

investment can be regarded as lucrative if the internal rate of return is

higher than the rate of return from other investment options would be.

Calculated over a period of 44 years (rights of use for 35 years plus a

further rotation, cf. Sect. 2.1), the internal rate of return on establishing and

managing HTI-plantations is 14.0% (basis of calculation according to

PT.IHM 1991). The financial expenses of the private loans and

reinvestment profits are not taken into account. All the figures are adjusted

for inflation as specified by the Indonesian Ministry of Forestry (MoF

1994).

As no interest has to be paid on the government loan of 32.5% from the

Reforestation Fund (DR), while interest is charged on the bank loan (32.5%

of the total capital) at a rate of 24%, the internal rate of return on the

company's equity capital (totalling 35%, cf. Sect. 2.1) increases to 17.7%

(cf. PT.IHM 1991; Mackensen 1998). Data presented by the FAO (1990),

Groome-Pöyry (1993) and the MoF (1995) are comparable with these

results.

A comparison with risk-free bank deposits (the interest on principal for

bank deposits was over 18% up to the middle of 1997) shows that the

classical plantation model has a below-average rate of return on equity

combined with risks that are difficult to calculate as a result of productivity

losses due to pests or fire, for instance. It therefore seems reasonable to

suppose that a plantation is not established merely to engage in profitable

Results

35

timber production. The "clear-cutting profits" obtained when converting

land (cf. Sect. 2.1), internal processing to obtain more profitable end-

products such as paper and cardboard and political considerations all play

an important role in the establishment of plantation concessions (cf.

Groome Pöyry 1993).

2.6.3 Sensitivity Analysis

Figure 11 shows the changes in the internal rate of return under the

PT.IHM's investment conditions (1991) for an increase or decrease in costs

or revenue.

Fig. 11: The internal rate of return as a function of changes in the

PT.IHM's costs or revenue.

If costs rise or revenue decreases, the internal rate of return drops. If the

total costs increase by 9-40% (cf. Sect. 2.6.1) and revenue remains

constant, the internal rate of return drops to approximately 8-12% (cf.

Fig. 11). The return on equity then amounts to 12.9% to -0.3%.

If the costs were to increase by 13% to replace the nutrients removed with

the harvest using alternative types of fertilizer, the internal rate of return

0

5

10

15

20

25

30

35

-60 -40 -20 0 20 40 60

Inte

rnal

rate

of r

etur

n [%

]

Changes in costs and revenue

costsrevenue


36

would drop to 11.8%, and the internal rate of return on equity would drop

to 11.1% due to the high bank interest (see above).

In summary: An increase in costs due to the need to use fertilizer to replace

nutrient losses reduces the internal rate of return significantly in some

cases. The poorer the quality of the site, the lower the internal rate of

return.

If both costs and revenue change, the internal rate of return changes as

follows: For a volume of harvest of 300 m3 in Acacia mangium stands (cf.

Sect. 2.3.1), revenue increases by 50% compared with the initial situation if

the other conditions remain the same; at the same time, the costs of

replacing the nutrients removed with the harvest rise by 19% (optimized

fertilization, including N fertilization). The overall internal rate of return

increases to 18.0%, and the return on equity increases accordingly to

29.3%. For an average volume of harvest in Eucalyptus deglupta stands of

150 m3, revenue decreases by 25% and costs increase by 15% due to the

amount of fertilizer required to replace the nutrients removed with the

harvest (cf. Mackensen 1998). The internal rate of return then drops to

5.8%, and the return on equity is therefore -5.7%. However, the additional

expenditure on felling and transport, for example, cannot be taken into

account in these estimates, and this calculation is therefore of limited use.

The biggest problem in calculating the internal rate of return is estimating

the development of timber prices. The revenue from timber assumed in the

investment analysis is merely a price estimate (cf. Mackensen 1998).

However, many companies are able to set their prices internally if timber is

purchased by a pulp factory owned by the company itself; under certain

circumstances, price are thus set solely to cover the costs of timber

production. The costs of timber harvesting also constitute a variable that is

Results

37

difficult to calculate, as no data are available in Indonesia yet for this area

(cf. Mackensen 1998). The economic significance of nutrient losses can

therefore only be shown to a limited extent using the internal rate of return

method.

Sites with low nutrient pools that already have to be fertilized in the second

rotation (Ferralsols/Arenosols, sandy Alisols/Acrisols; cf. Sects. 2.2 and

2.5) have a particularly low rate of return and are unprofitable in the long

run. According to the results of this study, even average sites with

Alisols/Acrisols requiring an increasingly intensive use of fertilizers as

productivity declines have a below-average rate of return and profitability

(cf. Mackensen 1998). The form of management has a decisive impact on

the profitability of the land. A form of "gentle" management in which the

slash is not burned and losses due to erosion and leaching are minimized by

optimizing harvesting techniques leads to lower nutrient costs than

conventional methods.

In summary: Investment calculations for plantation projects need to take

account of the site-specific results of nutrient budgets. Setting up large

areas of uniform fast-growing plantations and managing them

conventionally is economically inefficient and ecologically unsound.

Practical Relevance

39

3 Practical Relevance

3.1 Opportunities and Limitations of Timber Plantations

Fast-growing tropical plantations are regarded as very productive and easy

to manage. The present results provide a range of instruments that can be

used to assess the ecological feasibility and economic efficiency of fast-

growing plantations. It can thus be shown that a high level of productivity

and an intensive form of management place a very great strain on the sites.

It is incorrect to assume that plantations intrinsically have a constant level

of productivity and do not require a great amount of management

resources.

On the basis of the results of this study, the amount of technical and

financial resources required to manage a plantation on the given sites and

to maintain a constant level of productivity on a long-term basis, i.e. over

many rotation cycles, needs to be considerably greater than it is at present

in conventionally managed plantations. Thus, under the given conditions,

plantation management cannot be carried out in accordance with the

classical models of extensive forestry.

The results of nutrient budgets highlight the fact that alternative, resource-

saving management concepts need to be developed (cf. Sect. 4.1) in order

to guarantee the intensive use of sites on a long-term basis.

3.2 Regional Development and Land-Use Planning

The results obtained by drawing up nutrient budgets show the need to

improve land-use planning for intensively managed fast-growing

plantations. It would seem sensible to draw up nutrient budgets along the


40

lines specified as part of the environmental-impact assessments (EIAs) of

the preliminary planning phase. Establishing plantations on unsuitable sites

can thus be avoided.

It is often claimed that timber production in plantations is able to reduce the

pressure on natural forests (Nambiar and Brown 1997). This assumption

only appears to be justified if plantations can be stably managed on a long-

term basis. Plantations that have to be abandoned after only a few rotation

cycles due to the wrong site having been chosen, inappropriate

management methods being used or profitability being too low represent a

threat to development aimed at stabilizing the region.

Plantation concessions that become unprofitable for the above-mentioned

reasons also jeopardize the livelihood of the people who have been brought

there to settle as part of transmigration projects. In this respect, inadequate

land-use policies have a specific impact on the socio-economic conditions

of a region.

A capital-intensive pulp-processing industry is currently being established

in Indonesia, particularly in Kalimantan (cf. WALHI 1992). This industry

has to rely on the input of raw materials from intensively managed fast-

growing plantations. Plantation sites that are becoming degraded will cause

plantation companies to extend their plantation areas in order to ensure that

the felling volume remains constant, largely at the expense of areas of

natural forest. This development is not compatible with long-term land-use

planning.

Plantation sites that have to be abandoned as a result of inappropriate

management or an unsuitable choice of site increase the proportion of

unproductive land. This runs counter to the aim of putting degraded land to

use again by establishing plantations (cf. FAO 1990; WALHI 1992).

Practical Relevance

41

3.2.1 Further Need for Research

In the near future, plantations will play an increasingly important role in

forestry, particularly in the tropics. This development should be

accompanied by scientific research. On the one hand, research in this area

enables the use of the various resources to be improved and is thus

important for the economic success of such enterprises. On the other hand,

independent research on various aspects of plantations provides

information about the need for accompanying measures for nature

conservation and landscape protection.

The site-specific results of this study need to be applied to higher planning

levels. How much intensively managed fast-growing plantation can a

region tolerate and how high is the potential? In the long run, a

diversification of land use in forestry needs to be developed, involving fast-

growing plantations in combination with valuable timber plantations and

semi-natural commercial forests in small areas.

Considerable research is required to stabilize plantation systems in order to

create a sustainable form of management, including the associated potential

for development. Studies on the relationship between management

intensity, nutrient fluxes, type of soil and fertilization management are

urgently needed. On the basis of such studies, criteria can be developed for

a stabilizing land-use policy at various levels.

The plantation management studied is limited to a very few species and

follows a standard pattern. Research is required to study and introduce new,

native species in plantations. Methods need to be further developed to

allow work on hilly terrain without damaging the land (small high-lead

systems, etc.).

Recommendations for Action

43

4 Recommendations for Action

4.1 Plantation Estates

The following recommendations are made for plantation management with

fast-growing tree species on the sites that were studied:

Soil mapping on the basis of the soil type (sandy, loamy, clayey) and the

pH value. Nutrient analyses of samples. Additional recording of important

site parameters (inclination and length of slopes, etc.). Information of this

kind is entered in a Geographical Information System (GIS). Identification

of site units.

No uniform conversion of Ferralsol/Arenosol and sandy Alisol/Acrisol

sites into fast-growing plantations. Similar to sites on steep slopes and at

riverbanks, retaining the natural forest cover is also recommended for these

sites.

Minimization of nutrient losses by appropriate plantation management, in

particular by not burning residual phytomass (slash) to prepare land and by

using technologies to harvest timber that avoid soil damage.

Site-specific calculation of nutrient fluxes and, on the basis of these

calculations, optimized fertilization management, i.e. taking into account

the soil type, tree species and management form.

Development of alternative management concepts: change of tree species,

use of alternative species, mixed-species stands, use of green manure,

understorey management, spreading ash, etc.

Inclusion of nutrient budgets in business costing processes.


44

4.2 Land-Use Policy

The following general recommendations can be made for land-use policy,

regional planning and forest management planning:

Stricter requirements for establishing fast-growing plantations. As part of

an environmental-impact assessment, enterprises have to show that the site

is suitable for intensive management by providing nutrient budgets and

taking account of fertilizer costs. Management concepts addressing the

issue of the species planned to be used, the fertilization management and

the harvesting methods should also be presented or demonstrated.

Promotion of small units. Greater stratification of land-use units, i.e. higher

density of various management concepts within a single planning unit.

Support programmes for the actual use of degraded land as plantations.

Stricter ban on the conversion of natural forest and more thorough

implementation of existing guidelines.

4.3 DC Institutions

In future, plantations will acquire increasing economic and political

significance in Indonesia, in particular, but also in the tropics and

subtropics as a whole. This development is based on the need to offset the

declining timber yields from natural forests by fast-growing timber species

in plantations and, at the same time, to establish a processing industry and

to use unproductive areas of land to contribute to further regional and

national economic development. This will have impacts on the ecological,

socio-economic, technological and political development of a region. It is

thus the task of development cooperation (DC) to exert a positive influence

on the potential and steering of such processes in the interests of a

sustainable use of resources.

Recommendations for Action

45

In addition to the specific recommendations for action mentioned above,

we regard the following aspects as particularly important in the context of

international development work:

4.3.1 Information Policy

A crucial criterion for all the measures for planning and action that are to

be derived is that there should be a transparent flux of information. In this

context, it is important that an information policy such as this does not only

emphasize the plantation aspect or is restricted to this aspect, but also

highlights and discusses the links with neighbouring disciplines and areas

of life. Taking the specific example of East Kalimantan, even a partial

failure of plantation projects results in soil degradation, the destruction of

natural forests and timber shortages and jeopardizes economic development

and the source of income associated with it for the population. The need for

action and information is thus correspondingly large.

It would appear to be particularly useful in this context to cooperate with

specialist institutions at an international level (e.g. CIFOR) with the aim of

passing on knowledge acquired in connection with the results to the

national decision-makers.

The key role in sustainable development that the GTZ (1993) has ascribed

to forests also applies to the same extent to plantations. In the view of the

authors, plantation management only plays a very minor role in German

DC compared with the management of natural forests. This does not do

justice to regional conditions, and in our opinion, the positive and negative

potential of the plantation sector in terms of regional development merits

greater attention.


46

4.3.2 Concepts for Action

Concepts for the protection and sustainable management of natural tropical

forests need to include criteria for the stabilization of areas at the forest

margins. The results presented above highlight the fact that inadequate

plantation policy and management can play a significant role in

destabilizing natural and production forests.

We thus regard it as important that development programmes to stabilize

areas at forest margins should include industrial plantations and other non-

traditional forms of management. The range of levels affected by

inappropriate regional development indicates that the stabilization

programmes need to be correspondingly broad. The accompanying research

necessary in this context is outlined in Sect. 3.3.

The German Federal Government's Advisory Council on Global Change

(Wissenschaftlicher Beirat Globale Umweltveränderungen; WBGU 1996)

has classified the area of non-sustainable industrial land and water

management, the so-called "dust-bowl syndrome", as belonging to the

highest priority category. Intensive plantation management on unsuitable

sites is explicitly mentioned in this context. The syndromes defined by the

WBGU (1996) are characterized by their trans-sectoral and global nature,

and strategies to solve these problems should thus be developed regionally

and put in a global context.

References

47

5 References

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EVANS J., 1982. Plantation forestry in the tropics. Clarendon, Oxford. 472S.

EVANS J., 1988. The Usutu forest: 20 years later. Unasylva 159 (40):19-29.

FAO, 1990. Situation and outlook of the forestry sector in Indonesia. Vol.2: Forest Resource Base. FAO and Ministry of Forestry, Indonesia.Forestry Studies Technical Report No.1. 265 S.

FAO, 1995. Forest resources assessment 1990. Global synthesis. FAO,Rome. FAO Forestry Paper 124. 89 S.

FEARNSIDE P.M., 1997. Transmigration in Indonesia: Lessons from itsenvironmental and social impacts. Environmental Management21(4): 553-570.

FORSS E., 1994. Zur Modellierung des Wachstums der Baumart Acaciamangium Willd. in Südkalimantan, Indonesien. Magister-Arbeit amForstwissenschaftlichen Fachbereich, Universität Göttingen. 83 S.

GROOME-PÖYRY Consulting, 1993. Institutional strengthening for timberplantation development. Asian Development Bank AdvisoryTechnical Assistance 1244-INO, Ministry of Forestry, Directorate ofIndustrial Timber Estates. Jakarta, Indonesia. 99 S.

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HEINRICHSMEYER W., Gans O. & Evers I., 1988. Einführung in dieVolkswirtschaftslehre. UTB, Stuttgart. 600 S.

KLINGE R., 1998. Wasser- und Nährstoffdynamik im Boden und Bestandbeim Aufbau einer Holzplantage im östlichen Amazonasgebiet.Göttinger Beiträge zur Land- und Forstwirtschaftin den Tropen undSubtropen, 122:1-260.

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MACKENSEN J. 1998. Untersuchung zur nachhaltigen Nährstoffversorgungin schnellwachsenden Plantagensystemen in Ost-Kalimantan,Indonesien - ökologische und ökonomische Implikationen. GöttingerBeiträge zur Land- und Forstwirtschaftin den Tropen und Subtropen,127:1-209.

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OHTA S., EFFENDI S., TANAKA N. & MIURA S., 1992. Characteristics ofmajor soils under lowland Dipterocarp forest in East Kalimantan,Indonesia. PUSREHUT Special Publication No. 2. 72 S.

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PPT (Pusat Penelitian Tanah), 1983. Terms of reference klassifikasi lahan.Dept. Pertanian Rap. No. 59B/1983. P3MT, Soil Research Institute,Bogor, Indonesia.

PT.IHM, 1991. Unpublished study on project planning and environmental-impact assessment of PT.IHM, Kenangan, Kalimamtan Timur,Indonesia.

RUHIYAT D., 1989. Die Entwicklung der standörtlichen Nährstoffvorrätebei naturnaher Waldbewirtschaftung und im Plantagenbetrieb,Ostkalimantan, Indonesien. Göttinger Beiträge zur Land- undForstwirtschaft in den Tropen und Subtropen, Heft 35. 206 S.

ULRICH B., 1993. 25 Jahre Forstökosystem- und Waldschadensforschungim Solling. Forstarchiv 64:147-152.

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WALHI (Wahana Lingkungan Hidup Indonesia - The Indonesia Forum forthe Environment), 1992. Mistaking plantations for the Indonesiantropical forest. 1-70.


50

WINJUM J.K. & Schroeder P.E., 1997. Forest plantations of the world: theirextent, ecological atttributes, and carbon storage. Agriculturla andForest Meteorology 84:153-167.

WISSENSCHAFTLICHER BEIRAT DER BUNDESREGIERUNG: GlobaleUmweltveränderung (WBGU), 1996. Welt im Wandel -Herausforderung für die deutsche Wissenschaft. Jahresgutachten1996. Springer Verlag Berlin. 200 S.

WORLD REFERENCE BASE FOR SOIL RESOURCES (WRB), 1994. 1. Draft.International Society of Soil Science (ISSS), International SoilReference and Information Centre (ISRIC) and FAO. Wageningen,Rome. 161 S.

Appendix

6 Appendix

Tab. 6: Parameter of the soil types in different soil depth. Data for total soil profile (0-100 cm) calculated from means of single soil depth

considering different thickness of layers. BS= base saturation, Al-S.= Aluminum saturation

n depth C Nt C/N Pt C/P P/N pH K Ca Mg Na Fe Mn Al H KAKe CECeclay BS Al-S.[cm] [%] [%] (H2O) (KCl) [µmol+ g-1] [cmol+ kg-1] [%]

Alisol 29 0-100 0,74 0,09 8,5 0,0136 61,8 0,15 4,6 3,5 1,52 5,67 4,12 1,17 0,41 0,35 73,1 0,07 86,4 25,7 14 850-10 2,27 0,17 13,6 0,0176 139,4 0,10 4,6 3,6 2,21 22,75 9,29 1,19 1,03 1,27 46,8 0,49 85,1 25,5 41 56

10-30 0,89 0,1 9,07 0,0139 71,2 0,14 4,5 3,5 1,55 7,37 4,48 1,15 0,68 0,40 65,5 0,06 81,2 26,1 18 8130-50 0,61 0,08 7,9 0,0129 54,0 0,16 4,6 3,5 1,44 3,70 3,20 1,15 0,38 0,25 74,9 0,02 85,0 25,2 11 88

50-100 0,43 0,08 6,2 0,0131 38,4 0,17 4,7 3,5 1,40 2,36 3,31 1,18 0,19 0,19 80,6 0,01 89,2 26,1 9 90Acrisol 7 0-100 0,64 0,07 9,3 0,0089 73,2 0,13 4,7 3,7 1,32 4,1 1,91 0,90 0,35 0,18 53,2 0,04 62,0 18,3 14 85

0-10 1,91 0,14 13,5 0,0119 159,5 0,09 4,8 3,7 2,13 16,84 5,91 0,94 1,27 0,74 38,7 0,23 66,7 18,1 40 5610-30 0,75 0,08 9,5 0,0091 83,0 0,12 4,6 3,6 1,31 4,23 1,93 0,88 0,61 0,16 51,2 0,03 60,4 18,9 15 8430-50 0,53 0,06 8,6 0,0087 63,3 0,14 4,7 3,6 1,25 2,6 1,36 0,94 0,31 0,14 53,6 0,02 60,2 18,5 11 88

50-100 0,39 0,05 7,4 0,0083 48,63 0,15 4,8 3,6 1,19 2,0 1,32 0,88 0,08 0,10 56,8 0,01 62,5 17,6 9 91Ferral- 4 0-100 0,60 0,04 14,0 0,0053 112,7 0,13 4,7 3,9 0,43 2,04 1,46 1,13 0,36 0,08 19,0 0,06 24,6 9,1 21 77Arenosol 0-10 1,80 0,11 15,9 0,0081 220,5 0,07 4,6 3,8 0,97 4,91 3,29 1,22 1,28 0,25 27,5 0,56 40,0 8,7 27 68

10-30 0,85 0,06 14,0 0,0061 137,2 0,10 4,7 3,9 0,50 2,40 1,82 1,15 0,60 0,09 21,5 0,01 28,1 10,2 22 7630-50 0,48 0,04 13,5 0,0052 91,6 0,15 4,8 3,9 0,39 2,02 1,54 1,12 0,27 0,07 17,5 0,00 22,9 8,8 23 75

50-100 0,30 0,02 12,6 0,0044 69,0 0,19 4,7 3,9 0,32 1,33 0,92 1,12 0,11 0,05 16,9 0,00 20,8 8,5 20 80Calcisol 2 0-100 2,00 0,19 10,0 0,0350 53,1 0,19 7,6 6,5 2,04 416,3 10,76 1,48 0,00 0,53 8,8 0,08 440,0 97,2 89 11

0-10 3,99 0,33 12,1 0,0392 98,4 0,12 7,1 6,2 3,39 358,2 21,62 1,45 0,00 1,17 0,0 0,00 385,8 96,3 99 010-30 1,79 0,20 8,7 0,0349 49,1 0,18 7,5 6,5 2,27 392,1 12,09 1,44 0,00 0,45 3,3 0,00 411,6 103,8 94 530-50 1,46 0,18 8,0 0,0371 37,0 0,22 7,6 6,6 1,81 434,5 9,72 1,41 0,00 0,44 7,0 0,00 454,8 101,3 90 10

50-100 1,91 0,16 10,7 0,0334 51,3 0,21 7,8 6,6 1,78 430,3 8,48 1,53 0,00 0,46 13,6 0,15 456,3 87,4 84 15Fluvisol 0-100 0,95 0,14 6,9 0,0299 31,8 0,218 5,6 4,2 2,41 45,82 45,18 2,01 0,00 1,0 17,6 0,00 114,0 20,2 82 17

0-10 2,45 0,240 10,2 0,0342 71,6 0,143 6,2 5,3 2,75 120,16

49,54 1,53 0,00 0,9 0,0 0,00 174,9 20,2 100 0

10-30 1,01 0,150 6,7 0,0298 33,9 0,199 5,6 3,9 2,26 56,89 45,49 1,86 0,00 0,9 10,2 0,00 117,6 21,7 91 930-50 0,89 0,140 6,4 0,0291 30,6 0,208 5,6 4,2 2,30 57,69 36,80 1,81 0,00 0,7 4,4 0,00 103,8 18,5 95 4

50-100 0,65 0,110 5,9 0,0294 22,1 0,267 5,5 3,8 2,43 21,78 47,53 2,24 0,00 1,2 29,4 0,00 104,5 20,6 71 28

52

Sustainable Nutrient Supply in Fast-G

rowing Plantations

Appendix

Tab. 7: Export of nutrients with stemwood and -bark for Acacia mangium.

N P Na K Ca Mg S Mn[m3] [n ha-1] [m3 Vx] [kg ha-1]100 700 0,143 117,7 1,6 11,0 43,1 97,6 5,6 8,0 0,4100 800 0,125 122,5 1,6 11,1 45,0 102,5 5,8 8,3 0,4100 900 0,111 126,9 1,7 11,2 46,8 107,1 5,9 8,6 0,5100 1000 0,100 131,1 1,7 11,3 48,5 111,4 6,1 8,8 0,5100 1100 0,091 135,1 1,8 11,5 50,1 115,5 6,3 9,1 0,5150 700 0,214 157,6 2,1 15,9 57,1 126,9 7,6 10,8 0,5150 800 0,188 163,5 2,1 16,0 59,4 132,9 7,8 11,2 0,5150 900 0,167 168,9 2,2 16,2 61,6 138,6 8,0 11,5 0,6150 1000 0,150 174,1 2,3 16,4 63,7 143,9 8,2 11,8 0,6150 1100 0,136 179,0 2,4 16,5 65,7 149,0 8,4 12,1 0,6200 700 0,286 194,9 2,5 20,7 70,0 153,5 9,5 13,5 0,6200 800 0,250 201,7 2,6 20,9 72,8 160,5 9,8 14,0 0,6200 900 0,222 208,1 2,7 21,1 75,3 167,1 10,0 14,3 0,7200 1000 0,200 214,1 2,8 21,3 77,7 173,3 10,3 14,7 0,7200 1100 0,182 219,8 2,9 21,5 80,0 179,2 10,5 15,0 0,7250 700 0,357 230,6 3,0 25,5 82,3 178,5 11,4 16,1 0,7250 800 0,313 238,2 3,1 25,8 85,4 186,4 11,7 16,6 0,7250 900 0,278 245,4 3,2 26,0 88,3 193,7 12,0 17,0 0,8250 1000 0,250 252,1 3,3 26,2 91,0 200,7 12,2 17,4 0,8250 1100 0,227 258,5 3,4 26,4 93,5 207,3 12,5 17,8 0,8300 700 0,429 265,1 3,4 30,3 94,1 202,3 13,2 18,7 0,8300 800 0,375 273,5 3,5 30,6 97,5 210,9 13,5 19,2 0,8300 900 0,333 281,3 3,7 30,8 100,7 219,0 13,8 19,6 0,8300 1000 0,300 288,8 3,8 31,0 103,6 226,6 14,1 20,1 0,9300 1100 0,273 295,8 3,9 31,2 106,5 233,9 14,4 20,5 0,9350 700 0,500 298,7 3,8 35,1 105,6 225,1 14,9 21,1 0,8350 800 0,438 307,8 4,0 35,3 109,3 234,5 15,3 21,7 0,9350 900 0,389 316,3 4,1 35,6 112,7 243,2 15,6 22,2 0,9350 1000 0,350 324,4 4,2 35,8 115,9 251,5 16,0 22,7 1,0350 1100 0,318 332,0 4,3 36,0 119,0 259,4 16,3 23,1 1,0400 700 0,571 331,6 4,2 39,8 116,8 247,2 16,7 23,6 0,9400 800 0,500 341,3 4,4 40,1 120,7 257,3 17,1 24,1 0,9400 900 0,444 350,5 4,5 40,3 124,4 266,7 17,4 24,7 1,0400 1000 0,400 359,1 4,6 40,6 127,8 275,5 17,8 25,2 1,0400 1100 0,364 367,3 4,8 40,8 131,1 284,0 18,1 25,7 1,1450 700 0,643 363,9 4,6 44,5 127,7 268,7 18,4 25,9 0,9450 800 0,563 374,3 4,8 44,8 131,9 279,4 18,8 26,6 1,0450 900 0,500 384,0 4,9 45,1 135,8 289,4 19,2 27,2 1,1450 1000 0,450 393,2 5,1 45,4 139,5 298,9 19,6 27,7 1,1450 1100 0,409 401,9 5,2 45,6 142,9 307,8 19,9 28,2 1,1500 600 0,833 383,9 4,9 48,9 133,8 277,6 19,6 27,6 0,9500 800 0,625 406,7 5,2 49,5 142,9 301,0 20,6 29,0 1,1500 900 0,556 417,0 5,3 49,8 147,0 311,6 21,0 29,6 1,1500 1000 0,500 426,7 5,5 50,1 150,9 321,6 21,3 30,2 1,2[m3]=volume of harvest, [n ha-1]=number of trees, [m3 Vx]=volume of stem of medium volume

54

Tab. 8: Export of nutrients with stemwood and -bark for Eucalyptus deglupta.

N P Na K Ca Mg S Mn[m3] [n ha-1] [m3 V

x] [kg ha-1]

100 500 0,200 38,9 2,0 0,3 107,3 44,3 10,9 4,9 1,5100 600 0,167 40,1 2,0 0,4 111,2 45,9 11,2 5,1 1,5100 700 0,143 41,2 2,1 0,4 114,7 47,4 11,5 5,2 1,6100 800 0,125 42,1 2,1 0,4 117,8 48,7 11,7 5,3 1,6100 900 0,111 42,9 2,2 0,4 120,6 50,0 12,0 5,4 1,7100 1000 0,100 43,7 2,2 0,4 123,2 51,1 12,2 5,5 1,7100 1100 0,091 44,4 2,3 0,4 125,7 52,1 12,4 5,6 1,7150 500 0,300 54,7 2,7 0,5 149,0 61,3 15,3 6,9 2,1150 600 0,250 56,3 2,8 0,5 154,2 63,5 15,7 7,1 2,1150 700 0,214 57,7 2,9 0,5 158,8 65,5 16,1 7,3 2,2150 800 0,188 59,0 3,0 0,5 163,0 67,3 16,5 7,5 2,3150 900 0,167 60,2 3,0 0,5 166,8 68,9 16,8 7,6 2,3150 1000 0,150 61,2 3,1 0,5 170,3 70,4 17,1 7,7 2,3150 1100 0,136 62,2 3,1 0,6 173,6 71,8 17,3 7,9 2,4200 500 0,400 69,8 3,4 0,6 188,3 77,3 19,5 8,9 2,6200 600 0,333 71,8 3,6 0,6 194,8 80,0 20,0 9,1 2,7200 700 0,286 73,5 3,7 0,6 200,5 82,5 20,5 9,3 2,8200 800 0,250 75,1 3,7 0,7 205,6 84,7 21,0 9,5 2,8200 900 0,222 76,5 3,8 0,7 210,3 86,7 21,4 9,7 2,9200 1000 0,200 77,9 3,9 0,7 214,6 88,5 21,7 9,9 3,0200 1100 0,182 79,1 4,0 0,7 218,7 90,2 22,1 10,0 3,0250 500 0,500 84,3 4,1 0,7 226,0 92,6 23,5 10,7 3,2250 600 0,417 86,7 4,3 0,7 233,6 95,8 24,2 11,0 3,3250 700 0,357 88,8 4,4 0,8 240,4 98,7 24,8 11,3 3,3250 800 0,313 90,6 4,5 0,8 246,4 101,3 25,3 11,5 3,4250 900 0,278 92,3 4,6 0,8 251,9 103,6 25,8 11,7 3,5250 1000 0,250 93,9 4,7 0,8 257,0 105,8 26,2 11,9 3,6250 1100 0,227 95,3 4,8 0,8 261,8 107,8 26,6 12,1 3,6300 500 0,600 98,5 4,8 0,8 262,5 107,4 27,5 12,5 3,7300 600 0,500 101,2 5,0 0,9 271,2 111,1 28,2 12,9 3,8300 700 0,429 103,6 5,1 0,9 278,9 114,4 28,9 13,2 3,9300 800 0,375 105,7 5,2 0,9 285,8 117,3 29,5 13,4 4,0300 900 0,333 107,7 5,3 0,9 292,1 120,0 30,0 13,7 4,1300 1000 0,300 109,5 5,4 0,9 298,0 122,5 30,5 13,9 4,1300 1100 0,273 111,1 5,5 1,0 303,4 124,8 31,0 14,1 4,2350 500 0,700 112,3 5,5 0,9 298,1 121,8 31,4 14,3 4,2350 600 0,583 115,4 5,7 1,0 307,8 125,9 32,2 14,7 4,3350 700 0,500 118,1 5,8 1,0 316,4 129,6 33,0 15,0 4,4350 800 0,438 120,5 5,9 1,0 324,2 132,9 33,6 15,3 4,5350 900 0,389 122,7 6,1 1,0 331,2 135,9 34,2 15,6 4,6350 1000 0,350 124,7 6,2 1,1 337,8 138,7 34,8 15,8 4,7350 1100 0,318 126,5 6,3 1,1 343,8 141,3 35,3 16,1 4,8[m3]=volume of harvest, [n ha-1]=number of trees, [m3 Vx]=volume of stem of medium volume

Tab. 9: Management-dependent export fluxes (B-D) for N and P in relation [%] to the exports by harvest (A) for Acacia mangium (Am), Eucalyptus deglupta (Ed)

and Paraserianthes falcataria (Pf). The net leaching losses and the losses into atmosphere by burning are related to the residual phytomass (crown,

understorey and org. O-horizon) of stands with a harvest volume of 200 m3. For E1 values of median order are listed, not the mean, and for E2 minimum

values are listed. IL: losses independent of tree species

Nt Pt

iL Am Ed Pf iL Am Ed Pf[kg] [kg] [%] [kg] [%] [kg] [%] [kg] [kg] [%] [kg] [%] [kg] [%]

A export with harvest [kg ha-1] 202 100 75 100 133 100 2,6 100 3,8 100 9,5 100stem timber and bark, 200 m3

B management-dependent leachingB1 net losses (KLINGE, 1997; A2, 9 MON.) 144 71 192 144 0,0 0 0 0B2 net losses (KLINGE, 1997; A3, 9 MON.) 180 89 239 179 0,0 0 0 0B3 net losses (MALMER ET AL,, 1994; W5, 9 MON.) 13 6 17 13 0,9 34 24 9B4 25% of K-, 5% of Ca and 10% of Mg-pools in 16 8 11 15 10 7 0,3 11 0,1 3 0,5 5

crowns, understorey, org. O-horizons 80 40 53 71 48 36C losses into atmosphere by burningC1 average losses by burning 318 158 212 282 335 251 2,5 95 1,1 29 4,3 45C2 maximum losses by burning 393 195 262 349 413 310 3 114 1,4 37 5,3 56C3 minimum losses by burning 92 46 61 81 97 73 1,6 61 0,7 19 2,8 29D ErosionD1 50 Mg ha-1 loss of top soil, medium Alisol 84,5 42 75 56 8,8 333 235 93D2 50 Mg ha-1 loss of top soil, rich Alisol 140 69 112 84 16,95 642 452 178D3 50 Mg ha-1 loss of top soil, poor Alisol 56,7 28 186 139 4,95 188 132 52D4 200 Mg ha-1 loss of top soil, medium Alisol 338 168 450 337 35,2 1333 939 371E1 Sum of and amount of average losses (B4/5 and B3+C1+D1), respec. 483 239 350 465 468 351 12 439 10 267 13 139E2 Sum of and amount of minimum losses (B3/4 and B1+C3+D3), respec. 162 80 129 171 164 123 7 248 6 151 8 82

55

56

Tab. 10: Management-dependent export fluxes (B-D) for K, Ca and Mg in relation [%] to the exports by harvest (A) for Acacia mangium (Am), Eucalyptus

deglupta (Ed) and Paraserianthes falcataria (Pf). The net leaching losses and the losses into atmosphere by burning are related to the residual phytomass

(crown, understorey and org. O-horizon) of stands with a harvest volume of 200 m 3. For E1 values of median order are listed, not the mean, and for E 2

minimum values are listed. IL: losses independent of tree species

K Ca MgiL Am Ed Pf iL Am Ed Pf uV Am Ed Pf

[kg] [kg] [%] [kg] [%] [kg] [%] [kg] [kg] [%] [kg] [%] [kg] [%] [kg] [kg] [%] [kg] [%] [kg] [%]A export with harvest [kg ha -1] 73 100 206 100 208 100 161 100 85 100 157 100 9,8 100 21,0 100 11,6 100

stem timber and bark, 200 m3

B management-dependent leachingB1 net losses (KLINGE, 1997; A2, 9 MON.) 38 52 18 18 49 31 58 31 20 207 96 174B2 net losses (KLINGE, 1997; A3, 9 MON.) 88 121 43 42 79 49 93 50 20 200 94 169B3 net losses (MALMER ET AL,, 1994; W5, 9 MON.) 102 140 50 49 12 7 14 8 8 82 38 69B4 25% of K-, 5% of Ca and 10% of Mg-pools in 62 85 49 24 62 30 8 5 9 11 16 10 5 51 5 24 6 52

crowns, understorey, org. O-horizonsC losses into atmosphere by burningC1 average losses by burning 112 154 90 44 114 55 63 39 65 77 121 77 20 204 30 95 24 207C2 maximum losses by burning 194 267 156 76 197 95 127 79 133 157 246 156 30 307 31 148 36 311C3 minimum losses by burning 39 54 32 16 40 19 15 9 15 18 28 18 9 92 9 43 10 86D erosionD1 50 Mg ha-1 loss of top soil, medium Alisol 4,3 6 2 2 19,9 12 23 13 4,6 14 22 40D2 50 Mg ha-1 loss of top soil, rich Alisol 6,7 9 3 3 83,6 52 99 53 13,7 140 65 118D3 50 Mg ha-1 loss of top soil, poor Alisol 2,1 3 1 1 4,5 3 5 3 1,4 14 7 12D4 200 Mg ha-1 loss of top soil, medium Alisol 17,2 24 8 8 79,4 49 94 50 18,4 188 88 159E1 Sum / amount of average losses (B1/2 +C1+D1), 204 280 182 89 206 99 155 97 157 186 213 135 44 449 54 257 48 414E2 Sum / amount of average losses (B4 +C3+D3), 103 142 83 40 104 50 25 16 26 31 46 29 15 157 15 73 17 150

Tab. 11: Sum of management-dependent nutrient export fluxes (harvest, management-dependent leaching, burning and erosion) in relation [%] to the total

stand pools (nutrient pools of Navail, Pavail and exchangeable cations K, Ca and Mg in the soil from 0-100 cm, stand, understorey and org. O-

horizon) of different soil types

N P K Ca MgMax200

a Min200b Alt200 Max200 Min200 Alt200 Max200 Min200 Alt200 Max200 Min200 Alt200 Max200 Min200 Alt200

Acacia mangiumAli-/Acrisol, medium nutrient supply 50 38 25 8 5 4 28 21 12 20 14 10 9 5 2Ali-/Acrisol, high nutrient supply 34 24 14 5 3 2 20 14 8 13 6 4 5 2 1Ali-/Acrisol, low nutrient supply 63 51 37 17 12 9 46 36 23 42 36 31 28 18 9Ferral-/Arenosol 67 55 40 15 10 7 55 45 31 32 27 23 17 10 5Calcisol 52 39 25 9 5 3 38 28 17 3 1 0 11 4 2Fluvisol 17 13 7 2 2 1 1 0 0Eucalyptus degluptaAli-/Acrisol, medium nutrient supply 37 24 11 8 5 4 34 29 23 16 9 6 11 6 4Ali-/Acrisol, high nutrient supply 23 14 6 4 3 2 24 20 16 12 5 2 6 3 1Ali-/Acrisol, low nutrient supply 50 35 18 16 13 11 53 47 40 34 26 19 33 24 16Ferral-/Arenosol 53 38 20 14 11 10 62 56 49 26 19 14 20 14 9Calcisol 39 25 12 8 5 4 44 38 31 3 1 0 12 6 3Fluvisol 22 19 15 1 1 1 1 0 0Paraserianthes falcatariaAli-/Acrisol, medium nutrient supply 39 28 18 16 13 10 37 31 24 23 15 10 11 5 2Ali-/Acrisol, high nutrient supply 25 16 10 9 6 5 26 21 16 14 7 4 5 2 1Ali-/Acrisol, low nutrient supply 52 40 28 34 28 24 55 49 41 48 39 31 32 21 11Ferral-/Arenosol 56 43 30 30 25 21 65 58 50 38 30 23 19 11 6Calcisol 41 29 18 15 11 9 47 40 32 3 1 0 11 5 2Fluvisol 24 20 15 2 2 1 1 0 0a Maximum variant: harvest of 200 m3, max. losses by leaching, burning and erosion.b Minimum variant: harvest of 200 m3, min. losses by leaching and burning; medium losses of erosion..c Variant with alternative management: harvest of 200 m 3, min. losses by leaching, burning and erosion.Relative losses of 50% means that the stand can grow for 2 rotation periods (100/50)

57


58

Tab. 12: Estimation of the amount of fertilizers necessary to compensate management-

dependent export fluxes of N, depending on N content and utilization efficiency

type of fertilizer losses NPK (13% N) Urea (46% N) Ammonium-Nitrate (35% N)

Nitrate fertilizer(16% N)

utilization efficiency [kg ha-1] 50% 60% 70% 50% 60% 70% 50% 60% 70% 50% 60% 70%Eucalyptus degl., soil type: medium Ali-/Acrisolharvest of 200 m3 75 1155 960 825 323 270 233 428 360 308 938 780 668amount of bark withexport

23 354 294 253 99 83 71 131 110 94 288 239 205

max. leaching 53 816 678 583 228 191 164 302 254 217 663 551 472min. leaching 11 169 141 121 47 40 34 63 53 45 138 114 98burning (100% of area) 211 3249 2701 2321 907 760 654 1203 1013 865 2638 2194 1878burning (50% of area) 106 1632 1357 1166 456 382 329 604 509 435 1325 1102 943erosion (200 Mg ha-1) 18,9 291 242 208 81 68 59 108 91 77 236 197 168erosion (50 Mg ha-1) 4,7 72 60 52 20 17 15 27 23 19 59 49 42erosion (10 Mg ha-1) 0,9 14 12 10 4 3 3 5 4 4 11 9 8sum Max200a 358 5513 4582 3938 1539 1289 1110 2041 1718 1468 4475 3723 3186sum Min200b 197 3034 2522 2167 847 709 611 1123 946 808 2463 2049 1753sum Alt200a 81 1247 1037 891 348 292 251 462 389 332 1013 842 721a Maximum variant: harvest of 200 m3, max. losses by leaching, burning and erosion.b Minimum variant: harvest of 200 m3, min. losses by leaching and burning; medium losses of erosion..c Variant with alternative management: harvest of 200 m3, min. losses by leaching, burning and erosion.

Appendix


dependent export fluxes of P, depending on P content and utilization efficiency

type of fertilizer losses NPK (5,7% P) TSP (22% P) CIRP (15,8% P) SP (8% P)utilization efficiency [kg ha-1] 10% 15% 40% 10% 15% 40% 10% 15% 40% 10% 15% 40%Acacia mangium, soil type: medium Ali-/Acrisolharvest of 200 m3 2,6 466 311 116 118 79 30 165 110 41 325 217 81amount of bark withexport

1,6 287 191 72 73 48 18 101 68 25 200 133 50

max. leaching 0,3 54 36 13 14 9 3 19 13 5 38 25 9min. leachingburning (100% of area) 2,4 430 287 108 109 73 27 152 101 38 300 200 75burning (50% of area) 1,2 215 143 54 55 36 14 76 51 19 150 100 38erosion (200 Mg ha-1) 1,7 305 203 76 77 52 19 108 72 27 213 142 53erosion (50 Mg ha-1) 0,4 72 48 18 18 12 5 25 17 6 50 33 13erosion (10 Mg ha-1) 0,1 18 12 4 5 3 1 6 4 2 13 8 3sum Max200a 7 1254 837 314 319 212 80 443 295 111 875 583 219sum Min200b 4,2 753 502 188 191 127 48 266 177 66 525 350 131sum Alt200a 2,7 484 323 121 123 82 31 171 114 43 338 225 85Eucalyptus degl., soil type: medium Ali-/Acrisolharvest of 200 m3 3,8 681 454 170 173 115 43 241 160 60 475 317 119amount of bark withexport

1,5 269 179 67 68 45 17 95 63 24 188 125 47

max. leaching 0,1 18 12 4 5 3 1 6 4 2 13 8 3min. leachingburning (100% of area) 1,1 197 131 49 50 33 13 70 46 17 138 92 34burning (50% of area) 0,5 90 60 22 23 15 6 32 21 8 63 42 16erosion (200 Mg ha-1) 1,7 305 203 76 77 52 19 108 72 27 213 142 53erosion (50 Mg ha-1) 0,4 72 48 18 18 12 5 25 17 6 50 33 13erosion (10 Mg ha-1) 0,1 18 12 4 5 3 1 6 4 2 13 8 3sum Max200a 6,7 1201 801 300 305 203 76 424 283 106 838 558 210sum Min200b 4,7 842 562 211 214 142 54 298 198 74 588 392 147sum Alt200a 3,9 699 466 175 177 118 44 247 165 62 488 325 122a Maximum variant: harvest of 200 m3, max. losses by leaching, burning and erosion.b Minimum variant: harvest of 200 m3, min. losses by leaching and burning; medium losses of erosion..c Variant with alternative management: harvest of 200 m3, min. losses by leaching, burning and erosion.


60


dependent export fluxes of K, depending on K content and utilization efficiency

type of fertilizer losses NPK (17,4% K) 42 potash (42% K) 50 potash (50% K)utilization efficiency [kg ha-1] 50% 60% 70% 50% 60% 70% 50% 60% 70%Acacia mangium, soil type: medium Ali-/Acrisolharvest of 200 m3 73 840 701 599 350 292 248 292 241 212amount of bark withexport

44 506 422 361 211 176 150 176 145 128

max. leaching 86 989 826 705 413 344 292 344 284 249min. leaching 62 713 595 508 298 248 211 248 205 180burning (100% of area) 113 1300 1085 927 542 452 384 452 373 328burning (50% of area) 57 656 547 467 274 228 194 228 188 165erosion (200 Mg ha-1) 17 196 163 139 82 68 58 68 56 49erosion (50 Mg ha-1) 4,3 49 41 35 21 17 15 17 14 12erosion (10 Mg ha-1) 0,9 10 9 7 4 4 3 4 3 3sum Max200a 289 3324 2774 2370 1387 1156 983 1156 954 838sum Min200b 196 2254 1882 1607 941 784 666 784 647 568sum Alt200a 105 1208 1008 861 504 420 357 420 347 305Eucalyptus degl., soil type: medium Ali-/Acrisolharvest of 200 m3 206 2369 1978 1689 989 824 700 824 680 597amount of bark withexport

88 1012 845 722 422 352 299 352 290 255

max. leaching 69 794 662 566 331 276 235 276 228 200min. leaching 49 564 470 402 235 196 167 196 162 142burning (100% of area) 91 1047 874 746 437 364 309 364 300 264burning (50% of area) 45 518 432 369 216 180 153 180 149 131erosion (200 Mg ha-1) 17 196 163 139 82 68 58 68 56 49erosion (50 Mg ha-1) 4,3 49 41 35 21 17 15 17 14 12erosion (10 Mg ha-1) 0,9 10 9 7 4 4 3 4 3 3sum Max200a 383 4405 3677 3141 1838 1532 1302 1532 1264 1111sum Min200b 304 3496 2918 2493 1459 1216 1034 1216 1003 882sum Alt200a 232 2668 2227 1902 1114 928 789 928 766 673a Maximum variant: harvest of 200 m3, max. losses by leaching, burning and erosion.b Minimum variant: harvest of 200 m3, min. losses by leaching and burning; medium losses of erosion..c Variant with alternative management: harvest of 200 m3, min. losses by leaching, burning and erosion.

Appendix

Tab. 15: Comparison of the current amount of fertilizers (PT.IHM) with the amount of

fertilizers necessary to compensate harvest export (200m3 ha-1), including costs of

fertilizers. Acacia mangium (Am), Eucalyptus deglupta (Ed).

Nutrients and fertilizers Amount of fertilizer Costs of fertilizationfertilizer conc. UE PT.IHM Am Ed PT.IHM Am Ed

[%] [%] [kg ha-1] [Rp ha-1] [%] [Rp ha-1] [%] [Rp ha-1] [%]A1 N NPK 13 70 80 2418 879 74.800 2.260.830 821.865A2 Urea 46 70 681 248 277.848 101.184B1 P NPK 5,7 40 80 129 178 74.800 120.615 166.430B2 TSP 22 40 32 33 45 18.080 18.645 25.425B3 CIRP 15,8 40 46 63 10.350 14.175C1 K NPK 17,4 70 80 656 1793 74.800 613.360 1.676.455C2 potash 50 70 232 634 120.640 329.680D1 Ca TSP 100D2 dolomite 100 672 2500 2500 100.800 375.000 375.000D2 Mg dolomite 100 672 2500 2500 100.800 375.000 375.000conventional fertilization (A1+B2+D2): 193.680 100 2.654.475 1371 2.076.880 1072conventional fertilization (without costs for NPK-N) 1.007.005 520alternative fertilization (A2+B2+C2+D2) 783.838 405 820.039 423alternative fertilization (without N-fertilizer for Am) 505.990 261conc. = concentration of nutrient in fertilizer, UE = estimated utilization efficiency.


62

Tab. 16: Costs of fertilization necessary to compensate total nutrient losses with management

variants Min200 and Alt200 (cf. Appendix Tab.12-14).

Nutrients and fertilizers Acacia mangium Eucalyptus degluptafertilizer conc UE Min200

a Alt200b Min200

a Alt200b

[%] [%] [Rp ha-1] [%]c [Rp ha-1] [%]c [Rp ha-1] [%]c [Rp ha-1] [%]c

A1 N NPK 13 70 3.915.500 2.169.107 2.026.145 833.085A2 Urea 46 70 481.509 266.746 249.288 102.408B1 P NPK 5,7 40 175.780 113.135 197.285 163.625B2 TSP 22 40 27.120 17.515 30.510 24.860B3 CIRP 15,8 40 14.850 9.675 16.650 13.950C1 K NPK 17,4 70 1.502.545 805.035 2.330.955 1.778.370C2 potash 50 70 295.360 158.600 458.640 349.960D1 Ca TSP 100D2 dolomite 100 375.000 375.000 375.000 375.000D2 Mg dolomite 100 375.000 375.000 375.000 375.000conv. fertilization (A1+B2+D2): 4.317.620 2229 2.561.622 1323 2.431.655 1256 1.232.945 637conv. fertilization (without A1) 1.904.665 983 1.197.550 618altern. fertilization (A2+B2+C2+D2) 1.166.719 602 810.021 418 1.099.578 568 841.318 434altern. fertilization (without A2) 685.210 354 543.275 281a maximum variant: harvest of 200 m3, max. losses by leaching, burning and erosion.b alternative management: harvest of 200 m3, min. losses by leaching, burning and erosionc.relative to costs for fertilization management at PT.IHM (100% = 193.680 Rp ha-1; s. Tab. 15)conc. = concentration of nutrient in fertilizer, UE = estimated utilization efficiency.

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