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International Poplar Commission

COUNTRY REPORTS

P. R. China

Activities Related to Poplar and Willow Cultivation and Utilization 2012-2015

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Electronic versions of national reports (including the questionnaire) should be sent to the IPC-Secretariat, E-mail

IPC-Secretariat@fao.org no later than 30th April 2016.

The reporting period is 2012 to 2015 (4 years).

I. POLICY AND LEGAL FRAMEWORK

In October 2015, the proposed 13th “Five-Year plan” for economic and social development in China included

various new policies aimed for natural forest protection mainly focused on banning commercial harvest of natural

forest and increasing forest area and stock. The State Forestry Administration adopted this proposal and started a

pilot project in Heilongjiang province..By the end of 2015, commercial timber harvests of state-owned natural

forest areas in north-eastern Inner Mongolia has been banned. Furthermore, we are glad to witness the nation-wide

implementation of this policy by the end of 2017.The new policies call for higher standards in plantation

development and management in order to meet the increased domestic consumptions on forestry products.

In December 2014, the State Council passed the ‘State Owned Forestry Farm Reform Plan’ and the ‘Guide on State

Owned Forestry Farm Reform’. According to the documents, state-owned forestry farms will focus on ecological

protection and guarantee staff‘s livehood through innovations in management and monitoring system in future.

According to the guideline, state-owned forestry farms should undergo a role-switch from timber production

machinery to the role of ecological reparation units. There is also the need to setup new mechanisms to foster forest

resources and support ecological system conservation.

In 2013, the State Council released documents on speeding up modern agriculture development and supporting

rural area development, in which the concept of strengthening national timber strategic reserve base was mentioned.

According to the State Council’s requirements on developing the timber security system, the State Forestry

Administration developed the ‘Outline of national timber strategic reserve base (2013-2020)’, which planned to

develop 18 bases in 6 regions involving 25 provinces, with a total base area reacheing 14 million ha in year 2020.

Among the 95 tree species selected for national timber strategic reserve base construction, poplar was included.

‘The national forest nursery and seeding plan (2011-2015)’ required adoption of research results based on forest

nursery and seeding and set up of bases with quality-improved seedlings. The plan was aimed on improvements in

variety selection methods of over 70 main afforestation species, using genetical technologies to improve breeding

techniques, which also included researches on transgenic poplars.

II. TECHNICAL INFORMATION

1．Identification, registration and varietal control

1.1 Test and examination of new varieties

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In 2000, the Protection Office of New Plant Variety in the State Forestry Administration (SFA) listed poplar and willow

in the second directory of tree species, which was for protection of new varieties. According to the announcements of

SFA during the last four years, 38 poplar clones and 9 willow clones were registered and defined as new varieties

according to national Guidelines for the conduct of tests for DUS –willow (GB/T 26910-2011) and -poplar (GB/T

32344-2015).

1.2 Authorization of improved varieties

Poplar and willow clones must be tested and authorized on the provincial and national level before their cultivation

and plantation in China. According to the announcements of SFA during the last four years, 14 poplar varieties

were approved and added to the national list of genetically improved tree varieties issued by the National Review

Committee on Improved Tree Species/Varieties, SFA. In addition, some poplar varieties and willow varieties were

approved as improved varieties by the seedling stations in each province.

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Table 1 – Clones under examination by the Bureau of National Forestry for registration as commercial cultivars in 2012-2015

Latin Name Source Gende

r

Breeder Characteristics Usage Suitable Areas for Planting

P. deltoides

‘Nanyang’

P. deltoides

‘Danhongyang’

P. deltoides ‘Bartr’ x P.

deltoides ‘2KEN8’

Male Research Institute of

Forestry(RIF) of the

Chinese Academy of

Forestry

Fast growing, high survival rate,

straight trunk, narrow crown,

excellent wood property, suitable for

industrial timber.

timber

forest

Shandong, Henan, Hunan and

Hubei Province, etc.

P. euramericana

‘2012’

Introduced from Italy female Research Institute of

Forestry(RIF) of the

Chinese Academy of

Forestry

Fast growing, high survival rate,

straight trunk, narrow crown,

excellent wood property, suitable for

industrial timber.

timber

forest

Beijing, Hebei, Shangdong

and Henan Province, etc.

P. ‘Sanmaoyang7’

P. ‘Sanmaoyang 8’

Hybrid of P. tomentosa female

male

Beijing Forestry

University (BFU)

Fast growing, high survival rate,

straight trunk, narrow crown,

excellent wood property, suitable for

industrial timber.

timber

forest

Beijing, Hebei, Shanxi and

Shandong and Henan

Province, etc.

P. deltoides cv.

“Huanghuai3’

P. deltoides ‘Bartar’ x

P. deltoids cl. ‘10/17’

Femal

e

Research Institute of

Forestry(RIF) of the

Chinese Academy of

Forestry

For pulp- and fiber-timber

plantation.

timber

forest

Henan and Shangdong

Province, etc.

P.× ‘Yiyang 1’,

P. × ‘Yiyang 2’,

P. × ‘Yiyang 3’

(P. tomentasa x P. alba

var. pyramidalis) x P.

tomentosa var. truncata

Male

female

male

Beijing Forestry

University (BFU)

For fast-growing and high-yield

plantation, shelter forest and urban

greening.

timber

forest

Hebei, Shangdong Province,

etc.

P. deltoides cv.

Chuangxin’

P. deltoides cv.

‘Beiyang’

P. deltoides cl.

‘Nankang1A’ ×P.

deltoides cl. ‘D175’

P. deltoides cl.

‘Nankang1B’ ×P.

deltoides cl. ‘Imperieal’

Male Research Institute of

Forestry(RIF) of the

Chinese Academy of

Forestry

Resistance to Cerambycidae and

without Anoplophora glabripennis.

For fast-growing and high-yield

plantation, shelter forest and urban

greening.

timber

forest

Beijing, Inner-Mongolia,

Shanxi, Henan Province, etc.

P. ‘Beilinxiongzhu 1’

P. ‘Beilinxiongzhu 2’

(P. tomentasa x P. alba

var. pyramidalis) x P.

tomentosa var. truncata

Male

Male

Beijing Forestry

University (BFU)

For fast-growing and high-yield

plantation, shelter forest and urban

greening.

timber

forest Hebei, Shangdong and Henan

Province, etc.

P. deltoides×P.nigra

‘Southern Sijiyang’

Introduced from

Pakistan

Male Forestry Academy of

Sichuan Forestry

Academy of Province,

Chongqing, Fotrestry

Bureau of Xichang

City, Xichang

High-yield plantation, semi-ever and

ever green for urban greening.

timber

forest Sichuan, Chongqing,

Yunan,Zhejiang Province,

etc.

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2．Production Systems and Cultivation

（a）Nursery practices and propagation techniques including applications of biotechnology - particularly plant propagation,

reproductive materials, use of GMOs etc.

（b）Planted Forests with emphasis on the choice of cultivars, type of plants, spacing and layout of plantations; planting and

tending (fertilization, irrigation, weeding, pruning, thinning etc.); management (growth, rotation according to yields

and industrial requirements).

（c）Indigenous Forests, with emphasis on experiences and experiments concerning silvicultural treatments, harvesting,

management, protection and regeneration.

（d）Agroforestry and Trees outside Forests with emphasis on their effects on forest and agricultural crops or livestock and

diversification of the landscape.

2.1 Northeast Area In the past four years (2012-2015), the researches and technical improvements in the cultivation systems of poplar

plantations in Northern China have mainly been concentrated on increasing stand productivity and economic benefits

through variety selection, planting density control, site preparation, fertilization, irrigation, thinning and pruning so as to

develop optimum cultivation models for diversified purposes. However, more attentions have also been paid to researches

on the ecological roles of poplar plantations and the maintenance of their long-term productivity, such as successive

rotation and soil management, soil and environment remediation, carbon storage and fixation, etc. More than 15 research

institutions have been involved in researches related to the cultivation of poplar plantations in Northern China, and the

most important institutions are Chinese Academy of Forestry，Beijing Forestry University，Northeast Forestry University,

Shandong Academy of Forestry, Shandong Agricultural University, Agricultural University of Hebei, Heilongjiang

Province Forest and Environment Scientific Academies, Liaoning Provincial Research Institute of Poplar and Northwest

A&F University.

2.1.1 Nursery practices and propagation techniques Due to advantageous characteristics such as good wood quality, high-growth rate and easy propagation, poplar plays an

irreplaceable role in the establishment of ecological and industrial forests in Northern China. To develop the optimum

methods for high-quality planting seedlings production in different regions, a large number of studies and experiments

have been conducted. They are mainly focused on the effects on seedling quality and field performance of various factors

such as cutting density, quality, length, age, positioning, container nursery, fertilization, grafting techniques, coupling

effects of water and fertilizer, seedbed seedling and pest control. To propagate Populus × euramercana ‘Neva’ in Hebei

province of China, for instance, 1-year-old stem cuttings were better than branch cuttings of mature trees, and the

optimum planting space in Hebei province was 60 cm × 90 cm, while the optimal planting density of P. beijingensis was

30 cm × 30 cm in Tibet (China). Considering seedling traits such as root length, root fresh weight, rooting activity,

survival rate, etc, P. deltoids cv.’Zhonghuahongye’ and I-214 were the most suitable clones for container propagation.

There are many researches focused on the cultivation of poplar seedlings for specific sites (e.g. salted soils, drought and

cold region) and environmental applications. These researches have investigated the effects of container type and

cultivation medium on fibrous roots growth and root architecture of poplar cuttings. 22 poplar clones, including P. simonii

× P. nigra, (P. psudosimonii × P. nigra) × P. nigra CL ‘A5’ and P. ussuriensis were collected in Heilongjiang province.

Through comparative analysis of seedling height and diameter, 5 poplar clones suitable for the Sanjiang Plain Area and 4

poplar clones suitable for the Songnen Plain Area were selected. Generally, poplar clones cannot live on sites with soil salt

content above 0.2%. However, the results of hydroponics and pot experiments using 30 Aigeiros clones showed that 3

clones had high salt tolerance, and could be planted in fields with soil salt content as high as 0.5%. In addition, 6 clones

could be planted in fields with 0.4%soil salt content.

Moreover, nitrogen use efficiency, water evaporation in transportation and the coupling effects of water and fertilizer have

also been studied. Results showed that an increase in irrigation and nitrogen application could increase the aboveground

biomass of P. × euramericana ’74/76’, and nitrogen fertilizer exhibited major effect on aboveground biomass. The

optimal combination of irrigation amount and nitrogen rate was 35.14-41.35 kg water and 9.18-11.68 g nitrogen per tree.

And other results showed that the biomass of the cuttings significantly increased after application of nitrogen and

phosphorus, and the main reasons for this biomass difference were that phosphorus application markedly increased the

leaf net photosynthetic rate, while nitrogen remarkably increased the total leaf area of P. × euramericana cv. "74/76"

cuttings.

2.1.2 Silviculture of poplar plantations

2.1.2.1 Planting density and rotation control

Planting density and rotation control are two important cultivation parameters for plantations. Generally, planting density

could pose significant impacts on tree DBH (diameter at breast height) and crown size. With the decrease in planting

density, the DBH and crown size significantly increased, thus the low plantation density contributes to the fast

growing-rate of poplar trees. The response to weak light varied among genotypes. A plot survey was conducted in a

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5-year-old poplar plantation with four different planting spacings (spacing of 2 m × 3 m, 2 m × 4 m, 2 m × 5 m, and 2 m ×

6 m）to study the influence of initial spacing on tree growth and biomass accumulation. Initial planting spacing showed

significant effects on DBH and single tree volume, but had no effects on tree height and stand biomass. With the increase

of planting density, there was a drop in DBH, volume, crown and aboveground biomass of individual trees , while there

was are rise in stand biomass. DBH and tree height were positively correlated to stem, branch and leaf biomass. Planting

density of 2 × 3 m turns out to be the best choice in western areas of Shandong Province.

The effects of spacing between rows and spacing between trees in a row on growth and photosynthetic characteristics in

poplar plantations were investigated in a field experiment. The experiment consisted of 3 planting patterns of 4 poplar

clones (L35, I-107, W-141, zhonghe-1) under similar densities (about 417 trees hm-2

), and the planting spacings were 3

× 8 m, 4 × 6 m, and 5 m × 5 m, respectively. The results indicated that height and crown size of trees showed no

significant correlation with planting patterns. DBH, form and individual tree volume under 5 m × 5 m planting scheme

were significantly higher than that under the other schemes. Eccentricity of cross section of 5 m × 5 m allocation was

lower than that in the other allocations. Pn, Tr and WUE of poplar trees increased, when planting spacing decreased. In the

case of similar densities, poplars which were square planted with narrowing row spacing and poplars with increased plant

spacing were more conducive to make full use of space.

2.1.2.2 Choice of poplar clones

In order to find poplar clones suitable for specific sites, a lot of studies have been conducted to select clones for major

plantation in Northern China. In order to select excellent afforestation poplar species for forest systems in the oasis region of

Ulan Buh sandy land, initial growth and adaptability of poplar varieties in this area were evaluated. Multi-regional trials with

60 hybrid clones of Section Airgeiros have been carried out in different ecological areas, such as Linghai of Liaoning Province,

Zhucheng, Juancheng, Ninyang and Juxian of Shandong Province, and two new pulpwood varieties (P. × euramericana

cl.‘Bofeng 1’and ‘Bofeng 2’) were selected. The mean individual volumes of clones ‘Bofeng 1’ and ‘Bofeng 2’ were 0. 3487

and 0.3239 m3, respectively, at the age of 6 years in Linghai of Liaoning province, which were 23.52% and 14.73% higher

than that of CK (I-108, 0.2823 m3) , respectively. The new selected varieties were especially suitable for the region around the

Bohai Bay in the Northeast China. About 20 poplar clones including Beikang, 08 and Zhonglin series were used as candidates

and the Xinjiang Populus, which is the current main afforestation species, wastaken as a reference in the researches in Ulan

Buh sandy land. Among the 20 varieties, ten varieties (08-01, etc.) were able to grow vigorously and could serve as alternative

tree species for afforestation and wood resources reserves in this area.

In addition, many researches also focused on the selection of clones for disease-resistance, targeted cultivation and pulp

plantation. Two clones were suitable for the Yili River Valley and could be used as the raw materials for pencil

industry. Similarly, the F1 generation (P. euramericana "N3016" × P. ussuriensis) was tested in Qiqihar region of Helongjiang

province. The hybrids grew fast and had strong resistance against major diseases and stem-borers (e.g. grey leaf-spot, rust

disease, Saperda populnea, Cryptorrhynchus lapathi). The hybrids were tree species suitable for the use as pulpwood,

industrial timbers, shelterbelts and afforestation in the Northeast China.

2.1.2.3 Fertilization and irrigation

Many studies were focused on the effects of fertilization on physiological and biochemical properties, cold resistance, and

water-fertilizer coupling in poplar plantations. When using the same inorganic fertilizer, application of humic acid with

inorganic fertilizers could significantly increase root activity and chlorophyll content, enhance photosynthesis and water

utilization efficiency, increase the contents of IAA, GA and ZT, and biomass of root, stem and leaf. According to a study on

the growth of poplar in different soil conditions in Hejing County of Xinjiang, growth on sandy loam was found to be best,

followed by gobi gravel soil and aeolian sandy soil. Under the same fertilization condition, adding 100 g compound fertilizer to

each tree could bring the maximum growth rate. 7 kinds of different fertilizer types and 3 fertilization periods were used for P.

× canadensis ‘Sacran-79’. Results showed that 200 g compound P-K fertilizer per tree could improve the cold resistance of

poplar in its early stage (fast growing period). For P. tomentosa clone S86, compound N-P-K fertilizer had significant effect on

promoting seedling growth, and the optimal application rates of nitrogen, phosphorus and potassium were 326.55~367.24,

175.20~201.90 and 39.24~45.81 kg/hm2, respectively. The results of other researches conducted on two-year-old poplar

plantations showed that after two years of fertilization, the average tree height and DBH of the experimental group were 22%

and 19% higher than that of the control group, respectively. As a fertilizer-saving and high-efficiency fertilization technique,

drip fertigation has been applied in poplar plantations. A nitrogen fertigation research was conducted by Beijing Forestry

University in a P. tomentosa plantation located in Gaotang county of Shandong province. Results showed that nitrogen

fertigation could significantly increased tree diameter and nitrogen uptake. Furthermore, application frequency was an

important management parameter of nitrogen fertigation, and 115 kg N ha-1

yr-1

with 4 application times per year was

recommended show best results for P. tomentosa in this area.

Due to seasonal drought and low precipitation, water is the main limiting factor of poplar plantations in Northern China. There

are many studies focused on irrigation techniques to increase water-use efficiency, enhance environment protection and

increase potential productivity of poplar plantation. These researches covered areas such as irrigation method, irrigation

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regimes, water and nitrogen dynamics within root zone and efficiency of irrigation and fertilization, etc. To develop

irrigation modes that are more effective, a field experiment comparing FI (flood irrigation) and BI (border irrigation) was

conducted. Results showed that compared with FI, BI showed a decreased in root biomass in the 0-20 cm soil layer by 8.28%,

but in the 20-80 cm layer there was an increased of 35.87%. To evaluate the coupling effect of water and nitrogen on growth of

P. × euramericana ‘Guariento’, an experiment including nine different treatments (a combination of three irrigation treatments

with three fertilization treatments) were implemented. A control plot (CK) with non-irrigation and non-fertilization treatment

was also included. Results showed that fine root rates in the D2F3 and D3F3 treatments were significantly higher than that in

the other treatments. Compared with CK, fine roots biomass density in the six soil layers were significantly enhanced by 359%,

388%, 328%, 3823%, 4774% and 2866%, respectively, in the treatment with high water and high nitrogen levels. For poplar

plantations cultivated under drip irrigation, soil water potential could be used to indicate the timing of irrigation according to

the research results of Beijing Forestry University. When planting P. tomentosa in sites with silt soil in the North China plain,

subsurface drip irrigation should be promoted in the cultivation of P. tomentosa to improve tree growth; a range of -50 to -75

kPa at a depth of 20 cm and 10 cm distant from a drip emitter was recommended as the irrigation threshold for scheduling drip

irrigation. Furthermore, irrigation should be applied between April and July, while drainage should be implemented between

August and October.

2.1.2.4 Thinning and pruning

Thinning and pruning have been the important intensive cultivation techniques used to increase the productivity, wood

quality, stem shape, and health level of poplar plantations. Current researches related to thinning mainly focused on the

effects of thinning intensity and period on tree growth and ecophysiological characteristics, and the subsequent

economic benefits. A field experiment in P. ussuriensis plantations with four different treatments (CK: unthinned; M1:

remaining tree number of 1100/hm2; M2: remaining tree number of 1600/hm

2; M3: remaining tree number of 2500/hm

2)

was conducted to assess the impacts of thinning regimes on tree height and stock volume per unit stand area. After 3 years

of thinning, compared with the CK, stock volume of M3 were significantly increased by 15.86%, while the rise of tree

height was not obvious. As for P. × Liaoningensis, a field experiment with three different treatments (CK: unthinned and

remaining tree number of 556/hm2; T1: remaining tree number of 370/hm

2; T2: remaining tree number of 278/hm

2) was

conducted. 3 years after thinning, in comparison to CK, the individual tree volume of T1 and T2 were significantly

increased by 27.5% and 22.67%, respectively, while stock volume showed a slight decrease. Furthermore, an experiment

was conducted to study the regulation effects of root pruning on growth of P. × euramericana cv. Neva. Results showed that

the root pruning at 8 times DBH distance significantly increased the DBH and height increments of poplar trees. The contents

of N, P, K and IAA in poplar leaves as well as photosynthetic rate showed a significantly drop on the 35th day after root

pruning, but increased significantly on the 161st day in comparison with the control.

The pruning researches focused on the conditions of pruned poplar stands, age, season, period and intensity, etc. The

effects of different pruning intensities on growth of P. deltoides × P. cathayana were investigated. Results showed that

using moderate intensity pruning improved DBH growth and growing stock. Compared with moderate pruning intensity,

tree height and DBH in treatments under weak and severe pruning all reduced. Crown area decreased with the increase of

pruning intensity. Therefore, optimal pruning intensity could not only improve the trunk crown, but also increase stand

volume and improve wood quality. Using 5-year-old P. × euramericana cv.‘Neva’ as experimental material, the effects of

different pruning seasons and intensities on the sapling growth was studied. Results showed that the treatments in which

pruning the base first canopy before spring budding exhibited the best effects among all combinations. The tree height and

DBH were 17.2 m and 15.2 cm, which were 24.6% and 9.4% higher than the control, respectively.

2.1.2.5. Poplar in agroforestry

Agroforestry system, in which trees and crops can make best use of environmental resources, e.g. water, nutrient, irradiance,

etc, are considered to be an alternative land-use system. Poplar trees are usually planted on plat lands, which makes them the

main tree species used in agroforestry systems in China. The aim of researches and practices is to establish high-efficiency

agroforestry systems, which are not only focus on the utilization efficiency of resources (land, water, nutrient, irradiance,

etc.), but are also interested in the economic benefits. The water use of 2-, 6-, and 15-years-old poplar-wheat intercropping

systems at four growth periods of winter wheat in Yudong Plain area of Henan Province was studied by using stable carbon

isotope technique. The water use efficiency (WUE） and water use quantity (WU） were calculated by using the stable carbon

isotope ratio δ^13

C , biomass and meteorological data. The results showed that the δ^13

C and WUE of both poplar and wheat

from all the systems showed the highest values at the jointing stages of wheat. Two-year-old poplar had the highest δ^13

C and

WUE values among the three intercropping systems. The water usage of sole wheat was 25.71% less than that of 2-year-old

poplar intercropped with wheat, but it was 2.78 and 1.88 times of that of 6- and 15-year-old poplar intercropped with wheat,

respectively. 2-year-old poplar-wheat intercropping system had the greatest yield and highest land use efficiency.

In order to efficiently apply alfalfa in the cultivation of P. tomentosa pulpwood plantations under the wide-and-narrow planting

scheme, a field experiment was conducted to investigate the effects of mode M1 (intercropped with alfalfa), M2 (intercropped

with cotton and wheat) and M3 (pure plantation) on growth and soil nutrients of P. tomentosa pulpwood plantations in the

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period of 4 years. Results showed that under M1, DBH, height, individual volume and stand volume increased on average by

6.04%, 2.53%, 13.33% and 12.07%, respectively in comparison to M2, while the same parameters increased on average by

28.18%, 26.47%, 70.00% and 10.27% , respectively, in comparison to M3. The contents of soil organic, total N and available

N under M1, M2 and M3 increased to some extent in the 0-60 cm soil layer.The contents of these nutrient indicators were the

least under M3. Considering the economic benefits, the total net income of M1 was the highest, which reached 78043.56

yuan/hm2, which was respectively 3.97% and 38.73% higher than that of M2 and M3.

2.1.2.1.6 Successive rotation and soil management

As the land resource is scarce, poplar plantations can only be cultivated with successive rotation on the limited forestlands in

China. The productivity of plantations follows a declining course, making the long-term soil productivity maintaince

technology for plantations a hot research topic. The variety of soil nutrient environment, microbial community, fine roots

structure and leaf nutrient have been the key research domains in studies focusing on the declination of forest land productivity

on successive rotation plantation. Based on the Ion Exchange Resin Membranes (IERMs) and PCR-DGGE technology, the

dynamics of soil nutrient pool and flux, soil microbial community were studied in poplar plantations. The results showed that

the content of soil nutrient decreased over generations of poplar plantation, and the content of available nitrogen and potassium

in both rhziosphere soil and bulk soil also decreased significantly. Soil nutrient deficiency was obvious in poplar plantations.

The canonical correlation analysis showed that the soil nutrient availability of poplar plantation was significantly correlated to

the succession of soil bacterial community. The bacterial community succession might play an important role in soil

nitrification and nitrogen availability. To explore the structure and diversity of soil bacterial community, 454 pyrosequencings

were applied to investigate the bacterial diversity of soil samples from rhizosphere (RS) and non-rhizosphere (NRS) in a

continuous cropping poplar plantation (P. × euramericana‘Neva’) in Shandong Province. The results indicated that continuous

cropping reduced the population diversities and bacteria varieties in soil samples from both RS and NRS, with RS showing a

significantly bigger drop. With the increase of generation number, the SOCD and STND decreased gradually. Therefore,

continuous planting for various generations should be avoided during poplar plantation management. It is recommended to

take a rotation or replace tree species to avoid multiple generation effect caused by continuous cropping.

2.1.2.7 Short rotation coppice system

In a short period, short rotation poplar with high density can provide a large number of raw materials for multiple usage such

as fiberboard, biomass energy, feed production and paper industry. Relevant studies about short rotation coppice systems

included selection of optimal varieties, density determination, spacing configuration, biomass, chemical characteristics, forest

microenvironments and photosynthetic characteristics. To select the optimal varieties for short rotation in Shandong province,

a plot survey was conducted using one-year-old seeding of five poplar clones for short-rotation management. The results

showed that poplar clones were a major factor influencing the biomass of one-year-old plantations, and there was a

significant biomass difference among the five clones. The individual tree biomass ranged from 93.7 to 432.8 g for the five

clones, among which P. × euramericana cv.‘79-35’ had the highest biomass, followed by P. × euramericana cv.‘74/76’,

P.× euramericana cv.‘Zhonglin46’, P. deltoites cv.‘Zhonghe-1’and P.בBalizhuangyang’. And in Yili district of Xinjiang

province, an experiment was conducted by the Forest Tree Breeding Experiment Center of Yili Prefecture in 2013. 13

varieties of poplar in local areas were used in experiments under three planting densities (2 m × 0.5 m, 3 m × 0.5 m and 2

m × 1 m). Results showed that planting density of 3 m × 0.5 m was more suitable for increasing poplar forest energy,

while P. balsamifera, I-467 and I-262 were more suitable for developing forestry biomass energy.

Moreover, an experiment with six planting spacings (30 cm × 30 cm, 30 cm × 40 cm, 30 cm × 50 cm, 50 cm × 40 cm, 50

cm × 50 cm, 50 cm × 80 cm) was conducted to detect the effects of initial planting spacing on growth of short-rotation

poplar plantations. The results indicated that the diameter and individual biomass of P. × euramericana cv. ‘79-35’

decreased with increasing planting spacing, while the aboveground biomass increased with decreasing spacing. There was

no intimate relation between the height and planting composition. Compared with the growth indexes of one-year-old

poplar trees, the two-year-old poplar trees had higher levels of increase in diameter, height and individual biomass. The

three-year-old poplar trees showed slighter increase in growth indexes than that of the two-year-old poplar trees.

2.2 Southern Area In the recent four years (from 2012 to 2015), the researches and technical extensions on production systems and

cultivation of poplar plantations in southern China have generally been focused on how to further improve stand

productivity and increase economic benefits of the plantations through clone selection, planting density control, site

preparation, fertilizing, weed control, thinning and pruning so as to develop cultivation patterns that satisfy diversified

purposes. However, more attentions are paid to researches on the environmental roles of poplar plantations and

maintenance of its long-term site productivity, such as the role of short rotation plantation in immobilizing CO2 and

preventing greenhouse effect, and the relationships between diversity and productivity in poplar plantations, in order to

meet the requirements of social and economic development and environment protection. Approximately 10 institutions

have been involved in the researches and technical extensions of poplar plantation silviculture in southern China, among

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which Nanjing Forestry University, Hunan Academy of Forestry, Hubei Academy of Forestry, Anhui Academy of

Forestry and Jiangsu Academy of Forestry were the most important institutions.

2.2.1 Nursery practices and propagation techniques

One advantage of poplar is that superior material is quickly available for use, because Aigeiros species used in China are

easy to propagate through asexual means, usually by vegetative propagation of unrooted dormant stem cuttings. However,

bareroot dormant cuttings are used to establish widely spaced plantations for agroforestry systems and plywood

plantations in Southern China. In order to identify the optimum cultural practices for producing the largest number of

planting seedlings of new poplar clones at each region, lots of cultural practices and studies aimed to improve seedling

quality have been conducted in order to enable better matching of seedlings to forest sites and merchantable utilization,

reducing the chance of regeneration delay and improving future growth of poplar plantation. Most of the researches were

focused on effects of cutting density, cutting quality, hormone concentration (IAA etc.), fertilization, weed and pest

control on bareroot seedling quality (morphology and physiology) and field performance(growth and survival). However,

attentions were also paid to culture of poplar container seedlings for specific sites (such as salted or drought soils) and

environmental application, which focused on how container type and cultivation medium affect fibrous root growth and

root architecture of poplar cutting, as well as field performance in growth and survival.

Moreover, effect of mycorrhiza helper Bacillus sp. on the growth of poplar seedlings was studied and the results showed

that Bacillus DZ18 coinoculated with Pisolithus tinctorius or Lactarius insulsus significantly improved mycorrhizal

formation rate and growth of poplar seedlings. Therefore, strain DZ18 had potential value to become an excellent

bio-fertilizer strain resource.

2.2.2 Silviculture of poplar plantations

2.2.2.1 Planting density and rotation control

In order to improve the productivity of poplar plantation, some researches on planting density and rotation control were

conducted. For instance, an experimental treatment applied in a split-plot design with four planting spacings (3×8 m, 5×5

m, 4.5×8 m and 6×6 m) and three poplar clones (Nanlin-95, Nanlin-895 and Nanlin-797) was established and effects of

four planting spacings on stand canopy structure characteristics, understorey vegetation diversity and biomass production,

and tree growth in the poplar plantations were evaluated over 8 years. The obtained results suggest that planting spacing

not only significantly affect canopy structure characteristics of the plantation but also poplar plantation and understory

vegetation productivity. The best option for poplar timber production at a similar site is to choose square spacing of 5×5 m.

In general, the optimum harvesting period of poplar plantations in southern China within planting densities of 208-833

plant ha-1

is 12-13 years．

Nutrient availability and mineralization are key parameters and transformation processes that influence plant growth and

forest productivity. Using ion-exchange resin method, the soil inorganic N pool (0-20 cm) was investigated in poplar

plantations with different planting spacings. The external inorganic N input had a seasonal variation pattern, and the gross

input of inorganic N in high density plantation was higher than that in low density during the growing season. In general,

planting spacing affected nitrogen (N) availability in soil by altering N mineralization rates, while high annual N

mineralization was found in soils of low density plantations, with higher rates in square spacing than rectangular spacing.

Poplar plantations with different stand densities and spacing were also investigated to study the effects of stand structure

on understory characteristics, and the results showed that the Shannon index of the understory was higher under the low

density stands than under the high density ones, while the distribution of understory was much homogeneous under high

density stands. At specific sites, choosing suitable planting spacing and poplar clone could lead to higher growth and

enhanced N mineralization, but seasonal variation of soil N mineralization may not only be directly related to

plantationproductivity but also to understory vegetation productivity.

2.2.2.2 Choice of poplar clones and mixed tree species

According to the principle of “matching clones to right sites”, how to make full use of the achievements of poplar breeding in

China and select the right clones in major poplar plantation areas is still the main task, and lots of field studies were conducted

focusing on this topic. In southern China, in order to select the poplar clones most suitable to be planted on the beach land

of Yangtse River, twenty clones of poplar were evaluated by improved Analytic Hierarchy Process, and clonesNanlin-895,

Nanlin-324 and Nanlin-1388 were selected to plant on the beach land of Yangtse River. Microbial activity of the tree

rhizosphere provides important information related to the selection of tree species for afforestation of the degraded land. Using

an in situ rhizobox approach aimed to establishing a viable technique for sampling desired rhizosphere soil and assessing the

feasibility of rhizosphere soil using microbial index as an indicator to screen tree species suitable for the seasonal flood land of

Yantse River, China. Influences of waterlogging stress on cell structure of primary roots were also investigated to elucidate

flood-tolerance mechanism of poplars, and the results indicated that normal hypertrophied lenticels, fine aerenchyma, as

well as numerous structural stable mitochondria played a vital role in poplar under water logging stress.

Using a rhizobox approach, a greenhouse experiment was conducted to evaluate effects of monoculture and mixed planting of

three tree species on enzyme activities, microbial biomass, microbial diversity and nitrogen availability in rhizosphere and bulk

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soils. Six treatments with poplar, willow, and alder mono- or mixed seedlings grown in the rhizoboxes and both rhizosphere

and bulk soils were sampled and analysed after eight-month growth. Alder addition significantly improved genotypic richness,

microbial diversity index and nitrogen availability in the rhizosphere soils, suggesting that adding N-fixing alder into poplar

plantations may be a good option in the practice. Compared to poplar clone monoculture, addition of other tree species

obviously increased rhizosphere urease activity, but greatly reduced rhizosphere L-asparaginase activity. Poplar growth was

enhanced only when coexisted with alder. These results suggested that a highly productive or keystone plant species in a

community had greater influence on soil functions than the contribution of diversity. Furthermore, an incubation test was

conducted to study the effects of the decomposition of poplar and alder leaf litters with different mixed ratios and under

different application ways on soil microbial biomass carbon (MBC) and nitrogen (MBN). Alder leaf litter addition significantly

enhanced MBC and MBN, but did not modify the ratio of MBC to MBN. Moreover, the addition of the litters did not affect

soil microflora.

2.2.2.3 Fertilization and irrigation Based on the site conditions and poplar clones, many studies have been conducted to improve poplar growth and site

productivity through soil testing and formulated fertilization. Furthermore, studies are also focused on organic fertilizer

application in poplar plantations. A fertilization trial on 7-year-old poplar plantation indicated that the single tree volume

growth and the stand volume growth were the greatest when applying 1 kg organic fertilizer per plant, which increased

42％ and 42％ respectively compared with that of the contrast. Biogas slurry is a kind of high quality organic fertilizer

which is rich in N，P，K, and other nutrients，the effects of pig manure biogas slurry on soil properties, soil microbial

biomass carbon and nitrogen as well as growth of a poplar plantation were studied, and the results suggest that biogas

slurry fertilization below 450 m3 ha

-1 could promote poplar growth.

Fertilization affected not only poplar growth, but also the effects on soil fauna, soil respiration, and carbon metabolism.

Nitrogen（N）addition significantly affected soil fauna through altering soil nutrition condition. Moderate N（10-15 g N m-2

yr-1）addition had a promoting effect on soil fauna community, while high N (30 g N m

-2 yr

-1) addition posed negative

influence. N application influenced microbial community structure, increasing the amount of bacterial and grampositive

bacterial PLFAs and decreasing the amount of arbuscular mycorrhizal fugal and protistic PLFAs. However, the annual

amount of CO2 released from the plantations of low N, moderate N and high N addition reduced by 30.3, 23.8 and 31.1%

respectively. Moreover, biogas slurry application increased the concentrations of dissolved organic carbon and NO3--N,

while decreasing soil microbial biomass carbon and soil pH value, indicating that biochar improved the population of

microbe that was in favor of polymer utilization and thus has the potential to modify soil microbial functional diversity.

2.2.2.4 Thinning and pruning

Thinning is one of the intensive forest management techniques commonly applied to increase the merchantable timber

volume and improve the quality of the poplar plantations. Some field experiments with four or five treatments (CK:

unthinned, MB: medium intensity thinning from below, HB: high intensity thinning from below, and HI: high intensity

thinning by remove every alternative row of trees) was conducted to assess the impact of thinning regimes on soil

available nitrogen supply, including inorganic nitrogen, DON(soil dissolved organic nitrogen)and SMBN(soil microbial

biomass nitrogen), as well as restitution of litter and nutrient in Southern China. Soil available nitrogen was significantly

affected by thinning treatments, and the contents of available nitrogen, DON and SMBN were the highest when treated

with 50％ thinning intensities. The contents of inorganic nitrogen, DON and SMBN showed a seasonal change. These

results could provide a theoretical basis for the cultivation oflarge-diameter poplar timber. A pruning trial of Populus deltoides ‘Lux’ was established and influence of initial pruning age and pruning season on

wound coalescence was investigated．The full-coalescence rate of pruning wound whose width was less than 4 am was

much higher than that of pruning wound whose width was more than 4 am. Pruning wound coalescence was influenced by

initial pruning age, while the pruning wound's size was affected by branch ages. A larger number of large branches and

dead branches as well as a lower rate of full-coalescence were observed as initial pruning age increased. Pruning wound

coalescence was also influenced by pruning season. When branches were pruned in spring，the rate of full-coalescence and

the rate of coalescence growth of pruning wound were much higher than in winter or summer. Considering the influence

of pruning on DBH growth，it is suggested that the suitable initial pruning age for poplar plantation is 4 years old，and the

suitable pruning season is spring(from later March to early April).

2.2.2.5 Poplar in agroforestry

Agroforestry systems are considered an alternative land-use system that increases land-use intensity and diversifies the

farm economy. Agroforestry systems are widely practiced in the temperate region of China and in northern Jiangsu

province, with poplar as the main tree species in this system. Researches and practices on the structural design of poplar-crop

intercropping systems and its design principle for establishing high-efficiency agroforestry system were conducted. The

intercropping spacing, potential productivity, resource utilization, stability and economic benefits of existing major

poplar-crop intercropping patterns were summarized in various regions. Generally, the impact of different intercropping

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patterns on the yield and quality of crops had strong connections with the age of poplar plantations. In order to reduce the

impact of shading from the crown of poplar tree, wide spacing should be applied. Most recently, more attentions are paid

to poplar-medical plant intercropping, such as poplar- dandelion (Taraxacum mongolicum) intercropping, to increase

economic benefits.

Agricultural non-point pollution caused by the overuse of fertilizer in farmland has become one of the main causes for

water quality deterioration and eutrophication. In order to select suitable agroforestry intercropping systems to control soil

nitrogen loss, different poplar-crop intercropping systems (such as poplar-wheat intercropping, poplar-amaranth

intercropping etc.) were evaluated by the Nanjing Forestry University. Overall, poplar-crop intercropping systems with

closer spacing (2×5 m) could significantly reduced surface runoff,1eaching and nitrogen loss, while the accumulation of

ammonia volatilization in the poplar-wheat intercropping systems of 2×5 m and 2×15 m spacings were 0.76-4.23 kg ha-1

and 2.13-4.23 kg ha-1

respectively, which were obviously less than that of wheat mono-cropping system．Meanwhile, the

allelochemical effects of poplar root exudates on Lactuca sativa, Triticum aestivum, and Zea mays were also explored.

Litter decomposition is a critical step linking ecosystem processes with plant productivity, and the effect of mixing either

litter material with high N and phosphorus (P) concentrations or those with low N and P concentrations on litter

decomposition and nutrient release were investigated in the context of agroforestry systems. Non-additive effects were

clearly demonstrated in decomposition rates and nutrient release, when different types of litter were mixed, and such

effects were moderated by site differences. Mixed species agroforestry systems can be used to enhance nutrient cycling,

soil fertility, and site productivity in land-use systems.

2.2.2.6 Cropping system and soil management

The productivity of poplar plantation with successive rotations depleted seriously. Based on morphological and anatomical

properties of the fine roots，the inter-rotation difference of fine root growth and its relation to the depletion of plantation

productivity were studied to reveal mechanisms of the productivity depletion of plantation with successive rotations.

Successive rotations led to significant changes of fine root morphology and significant increases of fine roots biomass，indicating that the biomass allocation to underground part was increased in poplar plantation with successive rotations.

This conclusion was consistent with the theory of optimal allocation of photosynthetic products under nutrient deficiency

conditions. With fine roots mortality and turnover，the allocation pattern of fine root biomass of poplar plantation with

successive rotations could have a negative effect on aboveground productivity.

Polar plantation sites with different stand ages and rotations were selected to study the dynamics and the distribution

characteristics of soil microbial biomass phosphorus (SMBP) and soil microbial biomass nitrogen (SMBN). The contents

of SMBP and SMBN decreased with the increase of stand ages and rotations of poplar plantation. The correlation analysis

indicated that there were significant correlations between SMBN and soil total nitrogen and organic matter, as well as

between SMBP and the content of soil organic matter，total nitrogen and total phosphorus，but not with the soil available

phosphorus. Generally, successive rotations planting of poplars should be avoided and the replacement of varieties of

poplar or species could be used to alleviate the negative influence of successive planting. Meanwhile, maintaining the

level of soil enzyme and microorganisms should be paid attention to, and measures should be applied to decrease the soil

acidification at the same time.

2.7. Management modeling system and its application

Given the fact that the mixed clone afforestation mostly occurred in main planting area of southern China, a research on

southern type poplar plantation management model system was carried out．By means of quantitative model method and

regression technique, site quality evaluation models were established both for forested land and non-forested land, while

growth and yield models for southern type poplar, including models of stand basal area at breast height, diameter

distribution, diameter-height curve, stem taper, stand timber volume, stand merchantable volume and stand biomass, were

developed. Meanwhile, the quantitative effect models of primary cultivation measures, database of experts' knowledge as

well as the dynamic economic benefit evaluation model were also established for southern type poplar plantations.

Moreover, the relationships between optimum cultivation patterns and stand maturity ages (quantitative maturity age、technical maturity age and financial maturity age) were analyzed and described, andthe model which can give optimum

cultivation patterns were developed for southern type poplar plantations.

Taking the Microsoft Windows XP as an operational environment and Visual C++

as tools, a computer management

modeling system for southern type poplar plantations was developed. The establishment of the model system would not

only provide a reliable tool for implementing the theory of modeling directive cultivation of southern type poplar，but also

guide the practice of cultivation of southern type poplar plantations.

3．Genetics, Conservation and Improvement

3.1 Biotechnology Progress in Poplar and Willow

3.1.1 Genetics

3.1.1.1 Application of molecular markers

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In the last five years, SSRs and SNPs from candidate genes related to abiotic stress and wood properties have been

developed in Populus tomentosa and P. euphratica. Also, using SRAP, AFLP, SSR, cpDNA and rDNA ITS markers, we

identified genetic relationships and phylogeny of poplar clones and germplasm resources. Especially, evaluation of some

population genetic structure were conducted in the native population of Tibetan poplar, P. simonii, P. laurifoli, P. nigra, P.

tomentosa, P. tremuloides, P. tremulaand P. davidiana.Using the linkage and association mapping approaches, the

theories of molecular marker-assisted selection breeding were discovered in several important poplar species. New

progresses include:(1) QTL analysis and dissection of SNP/SSR effects within candidate genes invoved in wood formation

and abiotic stress; (2) identification of additive, dominant, and epistatic variation of quantitative traits, and (3) detection of

the interactions among miRNA, transcription factor and their target genes using association mapping.

3.1.1.2 Cytogenetics By using the model system of Populus, a new strategy for characterizing hDNAs in higher plants was proposed (Dong et

al, 2014a). First-division restitution (FDR), second-division restitution (SDR), and postmeiotic restitution (PMR) 2n eggs

were found to be transmitted different parental heterozygosities in Populus using120 triploid hybrids and 30 SSR markers.

Higher poplar ploidy level can generate extensive transcriptomic diversity compared with its parents. Furthermore, recent

study revealed that hybridization and polyploidization have immediate and distinct effects on the large-scale patterns of

gene expression. Syntenic analysis also revealed substantial chromosome rearrangements between willow's alternate sex

chromatids.

3.1.1.3 Epigenetics By using MSAP markers analysis, the associations between photosynthetic, growth traits and epigenetic diversity were

examined in natural populations of P. tomentosa. Studies of variation in genomic methylation in natural populations of P. simonii revealed that epigenetics bridges environmental and genetic factors. The methylation has diverse negative

regulatory roles on gene expression in poplar. Furthermore, DNA methylation also plays important roles in response to

abiotic stress, such as cold and osmotic. The methylation patterns of the parents were verified to be both partially and

dynamically passed onto their hybrids in P.deltoides and P.tomentosa.

3.1.1.4 Genomics

Subcellular relocalization and positive selection play key roles in the retention of duplicate genes of Populus class III

peroxidase family. As our ongoing effort to understandpoplar’s adaptation to salt stress, the genome sequencing of desert

poplar, P. euphratica, has been finished and the salinity tolerant poplar database (STPD) has been established. Also, the

genome of a shrub willow S. suchowensis has been sequenced by the Naijing Forestry University. Sequencing of the M.

brunnea genome provided evidence for genome-genome interactions that play an important role in poplar-pathogen

co-evolution.

3.1.2 Genetic engineering

3.1.2.1Flowering development Overexpression of AP1M3 regulates flowering time and floral development in Arabidopsis; two FT orthologs PsFT1 and

PsFT2 from P. simonii can induce early flowering in Arabidopsis and poplar (Shenet al, 2012; Chenet al, 2015).

3.1.2.2 Poplar growth and wood formation Comparative genomics, transcriptome and proteomics analysis of a TaLEA-introduced transgenic P. simonii× P. nigra

dwarf mutant reveals numerous differentially expressed genes related to salt tolerance. Using transgenic operation

mothods, a series of studies revealed that NACs, FLA6, Cel9A6, KOR1,PtrHB7 MAN6, REM, and R2R3-MYBs can

regulate cell wall thickening during fiber development in Populus species. Overexpresson of some WUSCHEL-related

homeobox genes are involved in adventitious root formation of poplar.

3.1.2.3 Poplar abiotic and biotic stress resistance

Resistance to drought: Overexpression of the poplar transcription factors NF-YB7 and bHLH35 can confer drought

tolerance and improve water-use efficiency in Arabidopsis; similarly, CPK10 and HAB1 were validated to affect

drought-tolerance in Populus.

Resistance to salt or cold: Genetic operations of XTH, CBL6, CBL10, NHX1, VP1.1, and DREB1 can enhance

salinity-tolerance of transgenic poplar. As for studies focused on cold-tolerance, we observed that Populus G6PDH and

APYRASE2 can contribut to cold tolerance in model plants.

Resistance to pest and fungal: Bt ‘Nanlin895’ poplar and double-Bts P. tomentosa were used to examine effects of

Btprotein on the metabolic enzymes of pest, results showed that the activities of esterase and carboxylesterase were

inhibited byBt protein. Constitutive expression of PtrLAR3 enhances fungal resistance in transgenic plants。

Also, some studies showed that (1) efficient CRISPR/Cas9-mediated targeted mutagenesis in Populus; (2) two

different transformation vectors can provide differential expression of dual Bt genes in transgene poplar; (3)a transient

gene expression system in Populus was prepared from suspension cultured cells.

3.1.3 Molecular biology in poplar

3.1.3.1 Wood formation mechanism

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Using RNA-seq, we performed transcriptome-sequencing for wood tissues in P. tomentosa, and identified wood-related

key genes and long non-coding RNAs. Furthermore, an integrated database (WFRGdb,

http://me.lzu.edu.cn/woodformation/) forwood-formation related genes was reported. The PopulusTIR1 and DUF579

families revealed differential expression patterns in vascular cambium proliferation during secondary growth.

3.1.3.2Flowering mechanism Identification and expression analysis of APETALA1 homologues and SUPERMAN family reveals sex-specific differences

in Populus floral development. Transcriptome-analysis of seed hair growth in Populus and in the male and female shrub

willows was performed and the differentially expressed genes were checked.

3.1.3.3 Poplar stresses resistance

Differentially expressed non-conding RNAs and target genes: Identification and expression analysis of different abiotic

stresses-responsive and novel microRNAs were perform in Populus tomentosa by high-throughput sequencing. In other

Populus species, drought-responsive lincRNAs, microRNAs and targets were detected by high-throughput sequencing and

their targets were detected using degradome analysis. We obtained many DE genes of several poplar and willow speices

under various abiotic tolerating conditions. Some comparative transcriptiom analysis were conducted among different

species, different stresses and different ploidies clones and so on.

Key gene families affecting abiotic stresses: Characterization, expression and molecular evolution of AP2/EREBP genes

in poplar have been reported. Genome-wide analysis of the Hsf and Hsp families in Poplar and Salix suchowensis reveals

differential expression patterns, localization, and heat stress responses during development and abiotic stresses. In addition,

several studies focused on identification and characterization of the Populus WRKY family and analysis of their expression

in response to salt stress was conducted.

Recently, genome-wide identification and characterization of the Populus C3HC4, CCCH, SPLs, HD-ZIP, PIN, FLAS,

PP2C, 4CL, LEA, AREB/ABF, and ERF gene families related to growth and development were also reported.

3.2 Improvement and breeding of poplar

3.2.1 Aigeiros section Construction of the core gemplasma of section Aigeiros: the collection was set up on about 30 hm and the growth, wood

property, utilization effiency of water and nutritions were accessed.

Breeding and selection of the new varieties of section Aigeiros: under the concept of ecological adaptation, 9 breeding

regions were targeted based on their climate and the biology of poplar species, to develop new varieties for these regions. So far,

more than 30 such varieties were applied for 6 regions. For instances, the new hybrid “Huanghuai 3”, “chuangxin” and

“Beiyang” were used in the region along the Yangtze River. Changjiang river.

3.2.2 Hybridization, polyploidy breeding and genetic engineering of Section Leuce The Beijing Forestry University (BFU) produced more than 4500 hybrids from some cross combinations, including (P. alba L. ×

P. glandulosa) × (P. tomentosa × P. bolleana), (P. alba L. × P. glandulosa) ×P. tomentosa Carr., and (P. hopeiensis Hu et Chow) ×

P. bolleana Lauche. Ploidy levels of 469 clones of P. tomentosa from a gene pool located at Guan County of Shandong Province

were analyzed by flow cytometry. A total of 28 spontaneous triploid clones (24 female and 4 male) were found, including 2 from

Beijing, 12 from Hebei, 1 from Shandong, 2 from Shanxi and 11 from Shaanxi. More than 10000 seedlings from 74 half-sib families

from the gene pool were collected to analyze the seed-set of different female clones. Using P. tomentosa clones 3119, 3532, 8212 and

P. alba L. × P. glandulosa as female parent, P. alba L. × P. glandulosa, P. tomentosa ‘Shandong male’ or P. tomentosa ‘Baotoubai’

as male parent, a total of 746 triploid hybrids were induced by treating the pollinated female catkins in high temperature. Female

gametic and zygotic chromosome doubling of P. adenopoda Maxim was studied and 63 triploids and 32 tetraploids were induced.

In addition, the BFU selected a series of new P. tomentosa hybrid ‘Yiyang’ varieties, which are characterized by fast growth,

straight stem and canker-resistance. They could be both used for landscaping and industrial plantation. Among the three selected

clones, P. × tomentosa ‘Yiyang 1’ and P. × tomentosa ‘Yiyang 2’ were from control pollination between P. tomentosa

‘Truncata’ (female parent) and P. tomentosa × P. bolleana (male parent). P. × tomentosa ‘Yiyang 3’ is a hybrid between P.

tomentosa ‘LM50’ (female parent) and P. tomentosa × P. bolleana (male parent). P. × tomentosa ‘Yiyang 4’ is a hybrid between

P. tomentosa × P. bolleana (female parent) and P. alba × P. glandulosa ‘84K’ (male parent). Some triploid varieties of white

poplar were selected. Populus ‘Sanmaoyang 7’ and Populus ‘Sanmaoyang 8’ derived from pollination with natural 2n pollen of

P. tomentosa, and both grow fast. Populus ‘Beilinxiongzhu 1’ and Populus ‘Beilinxiongzhu 2’ derived from P. tomentosa × P.

bolleana with 60

Co-γ ray radiated artificial 2n pollen of P. alba L. × P. glandulosa. They have good traits in growth and could be

used as pulpwood. When reaching the age of five, stem volume, fiber length, and holocellulose content of these triploid clones

were 79.6%, 20.7% and 1.3% higher respectively than that of the diploid control (P. tomentosa ‘1319’), the lignin content was

21.7% lower than that of the diploid control. In order to achieve vegetative propagation, leaf-explant regeneration system in vitro

of the triploid hybrids was established.

The Hebei Agricultural University (HAU) transformed 741 poplars with double Bt genes and obtained 9 regenerated lines with

hygromycin resistance. Toxicity evaluation on Plagiodera versicolora (Coleoptera) and Hyphantria cunea (Lepidoptera) by

feeding fresh detached leaves showed double resistance. The Northwest Agriculture and Forestry University (NAFU) established

fingerprinting by SSR molecular marker of 4 new hybrids of white poplar (03-4-9, 03-4-22, 03-5-17 and 03-6-11), their parents

and 3 related varieties, providing the technical basis for identification of these hybrids and varieties in commercial applications.

13

Northwest A & F University finished interspecific cross-breeding of Populus in Leuce in 2002-2008. Nearly all native

species in Leuce section in China were involved in cross-breeding. These are P. alba L., P. alba L. var. pyramidalis Bge., P. canescens (Ait.) Smith., P. tomentosa Carr. , P. davidiana Dode, P. hopeiensis Hu et Chow, P. adenopoda Maxim, and

one introduced clone named 84K (P. alba xP.glandulosa) from Korea. Manipulated crosses between the above-mentioned

individual species in Leuce section were conducted. There are 34 hybridized combinations conducted and 28,000

hybrid-seedlings obtained. Seeds were sowed in container for growing at the first two months and then transplanted to

nursery for growing. Selection of superior hybridized combinations and clones were carried out according to growth rate,

rooting capacity and form of the one year seedlings. The nursery test showed that the hybridized combinations of P. alba L.

x (P. alba x P. glandulosa), P. alba L. x P. tomentosa Carr., P. alba L. x P. davidiana Dode, P. adenopoda Maxim. x (P.

alba x P. glandulosa), P. hopeiensis Hu et Chow x (P. alba x P. glandulosa), P. tomentosa Carr. x (P. alba x P. glandulosa), and P. davidiana Dode x ( P. alba x P. glandulosa) had a high growth-rate(one-year seedling reaching 3m

height). Rooting-capacity by stem cutting of the combinations with P. alba L. as female parent were above 80%. Through

further field trials and regional tests, three superior clones named as Qinbaiyang NO.1, Qinbaiyang NO.2, and Qinbaiyang

NO.3 were selected from the hybridized combinations of P. alba L. x (P. alba x P. glandulosa),which were characterized

by fast growing rate and good rooting capacity (by stem cutting in 2015). The increase in volume of 10-year old trees was

about 120-138% higher than that of P. tomentosa Carr. (a very famous variety for commercial use), and rooting capacity

by stem cutting was about 80% higher. Now, the 3 clones of Qinbaiyang have been extended for commercial use in

Northwestern regions of China. So far, some hybrids are still on the way for regional tests, we hope that 2-3 new super

clones will be selected from the hybridized combinations of P. alba L. x P. tomentosa Carr. ,which are suitable for

commercial usage in next 2-3 years.

3.2.3 Hybridization, polyploidy breeding and genetic engineering of Section Tacamahaca The BFU produced 6317 hybrids from 117 cross combinations including P. simonii, P. pseudo-simonii, P. nigra, P. deltoides

and P. × euramericana clones. After phenotypic investigation, general combining ability (GCA) of parents and special

combining ability (SCA) of combinations were studied preliminarily. For polyploid breeding of section Tacamahaca, colchicine

or high temperature were used to induce megaspore, embryo sac and zygotic chromosome doubling of P. pseudo-simonii × P.

nigra ‘Zheyin3#’, producing 222 polyploids. Some elite triploid clones were selected to clonal test in Tongliao City (Inner

Mongolia), Wuwei City (Gansu Province) and Weixian County (Hebei Province). Tetraploids were produced by anther-derived

callus culture of P. × beijingensis W. Y. Hsu. Additionally, haploids were produced by anther culture, the frequency of haploids

reached 10.3%.

Additionally, cross combination P. deltoides × P. ussuriensis produced 6 good varieties with excellent cold tolerance. Populus

‘Yiyang 5’ and Populus ‘Yiyang 6’ were produced by crossing P. deltoides cv. ‘Lux’ and P. ussuriensis cl. ‘U3’. Populus

‘Yiyang 7’ was obtained by pollinating P. ussuriensis cl. ‘U4’ with P. deltoides cv. ‘T66’. Populus ‘Yiyang 8’, Populus ‘Yiyang

9’ and Populus ‘Yiyang 10’ were all derived from P. ussuriensis cl. ‘U4’ ×P. deltoides cv. ‘T26’.

The Northeast Forestry University investigated variations of growth and stress-resistance traits of transgenic Populus simonii ×

P. nigra clones carrying TaLEA gene. ANOVA analyses showed that growth traits, shape of stem, leaf traits, and lenticel traits

between the transgenic and control poplar clones were all significantly different. Clones XL9, XL1 and XL14 were selected as

suitable clones for applications owing to their high biomass and strong stability. Moreover, clone XL11 was found as a dwarf

mutant characterized by small leaf, low stomatal density and leaf thickness, and thick epidermis, large palisade and spongy

tissue ratios and big stomatal size. The change of growth and anatomical structure of leaf traits of the dwarf mutant may be

related to the up-regulation of AP2/PthRAV genes. Overexpression of TaLEA gene in the transgenic poplar clones improved salt

and drought tolerance, especially for the XL11 dwarf mutant, which performed the best in stress-resistance tests.

The Northwest Agriculture and Forestry University (NAFU) collected 10 clones of P. cathayana Rehd., P. pseudo-simonii and

P. przewalskii Maxim. The cold- and drought-tolerance of several hybrids of P. deltoids × Section Tacamahaca were analyzed.

The order of cold tolerance of these hybrids was 07-69 × P. cathayana 1 > 06-57 × P. szechuanica 1 > 06-69 × P. purdomii 1 >

07-west da-zhai × P. purdomii 1 > 09-69 × P. cathayana 2 > 08-69 × P. cathayana 4 > E24-01; the order for drought tolerance

was 07-69 × P. cathayana 1 > 06-57 × P. szechuanica 1 > 07-west da-zhai × P. purdomii 1 > 06-69 × P. szechuanica 1 > 06-69

× P. purdomii 1 > 06-69 × P. cathayana 1.

The Inner Mongolia Forestry Science Institute of Tongliao City selected 3 good hybrid varieties, including P. × simonii cl

‘Huilin88’, P. simonii × P. nigra cl. ‘Tonglin 7’ and P. pseudo-cathayana × P. deltoides. P. × simonii cl ‘Huilin88’ is a natural

hybrid using P. simonii as female parent, with good properties including fast growth, cold- and drought-tolerance, and suitable to

be planted in barren land. P. simonii × P. nigra cl. ‘Tonglin 7’ derived from control pollination of P. simonii with pollen of P.

nigra L., which is characterized by easy cutting, fast growth, good cold- and drought-tolerance. P. pseudo-cathayana × P.

deltoides also has some excellent traits, such as straight stem, cold- and drought-tolerance, pest- and salt-resistance.

3.2.4 Distant hybridization of P. euphratica Olive

The Liaoning Poplar Institution produced 50 distant hybrids by crossing P. deltoides and P. euphratica Olive. Variation of leaf

morphology was analyzed.

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The Inner Mongolia Forestry Science Institute of Tongliao City produced a good distant hybrid P. simonii × P. euphratica,

which has some good properties such as easy to cutting, salt-resistance and fast-growth, which makes it suitable for landscaping

and planting in saline-alkali soil.

3.3 Willows 3.1 Collection, Conservation and Utilization of Willow Germplasm Resources

The Jiangsu academy of forestry brought in the germplasm resources of Salix alba, Salix nigra, Salix eriocephala, Salix

purpurea and Salix, miyabeana in March 2013 from the Cornell University, the State University of New York and the

United States Double A Willow company. Totally, 5 clones of Salix alba, 27 clones of Salix nigra, 20 clones of Salix eriocephala, 20 clones of Salix purpurea, 9 clones of Salix miyabeana and 3 clones of S. alba x Salix matsudana, 8 clones

of “Fish Creek” were collected from united states. Now 0.6 ha nursery of willow germplasm resources from the United

States were established in the Dafeng base of the Jiangsu academy of forestry. The survival rate and morphological

parameters were recorded in November 2013.

The Jiangsu academy of forestry investigated and collected willow germplasm resources from Gansu province, Ningxia

Hui Autonomous Region and the three northeasern provinces from 2012 to 2015. In Gansu province, 161 species seed

reproduction lines were collected, among which 59 lines were artificial cultivated, mainly Salix matsudana, Salix

babylonica; 102 lines were naturaly distributed, mainly shrub willows. There were more than 15 collected species,

including Salix matsudana, Salix babylonica, Salix matsudana, Salix paraplesia Schneid, Salix magnifica, Salix jishiensis,

etc. In Ningxia Hui Autonomous Region, 8 species were collected including Salix cheilophila, Salix gordejevii, Salix

permollis, Salix viminalis, Salix matsudana and Salix alba. In the three northeastern provinces, 176 species seed

reproduction lines were collected, among which 5 lines were artificialy cultivated, mainly tree willows. More than 25

varieties were collected, including Salix fragilis, Salix eriocephala, Salix koreensis Anderss., Salix viminalis, Salix pyrolifolia, Salix myrtilloides and Salix pierotii Miq..

3.2 The measuring, selection and breeding of Salix clones

3.2.1 Measuring of metal-contamination tolerance of Salix clones

3.2.1.1 Measuring of Pb-contamination tolerance of Salix clones

To evaluate the potential adaptation and remediation of Salix against heavy metal contaminations, six tree species,

including S.integra were used in a field experiment on vegetation restoration in the abandoned lead-zinc tailings for 2

years by Zhejiang University. Plant species showed different tolerance to the tailings. Most species showed heavy

metal-induced etiolation, defoliation, or growth-inhibition. There were significant differences in the increasing rates in

height and base diameter, root growth, and biomass among the species. According to the evaluation, S. integra would be

more suitable for the remediation of Pb/Zn tailings.

The Tianjin Normal University studied the effects of lead (Pb) stress on some physiological indicators of five fast-growing

willow clones (Salix ‘Zhuliu’, Salix jiangsuensis CL J-172, Salix jiangsuensis CL J-795, Salix matsudana

var.anshanenensis and Salix matsudana Kidz) in a pot experiment. The

results showed that with the increase of lead concentrations, the POD, SOD and CAT activities of the Salix ‘Zhuliu’ was

the best, MDA content and chlorophyll content decreased the least, and the root activity was the strongest. It indicated that

the accumulation to Pb2+ of five willows was different under the same lead concentration, and the Salix ‘Zhuliu’ was

better than others. Comprehensive evaluation of each physiological parameter indicated that the lead ions tolerance order

was: S. ‘Zhuliu’>S. matsudana var. anshanenensis>S. matsudana Koid>S. jiangsuensis CL J-795>S. jiangsuensis CL

J-172.

3.2.1.2 Measuring of Cd-contamination tolerance of Salix clones

The Chinese Academy of Forestry studied the effects of Cd2+ solution on morphology of the root of S. matsudana, S. integra, S. leucopithecia under sand culture condition. The results showed that, under Cd2+ stress, Salix matsudana root

accelerated the absorption of calcium, and its transport to shoot. The distribution ratio of magnesium in Salix matsudana

root significantly increased. The capacities of magnesium transport and potassium absorbtion of stem and leaf of Salix matsudana was suppressed by Cd

2+ stress. Capacities of potassium absorbtion and potassium aboveground transport in

root of Salix matsudana were suppressed by Cd2+

stress. The effects of Cd2+ stress on rapid light-response curves of

photochemical and non-photochemical chlorophyll fluorescence quenching parameters were nvestigated by

Mini-Imaging-PAM Chlorophyll Fluorometer. The results indicate that S. leucopithecia has strong tolerance to Cd2+

stress

by irreversible inactivation of PSⅡreaction centers. However, under high concentration of Cd2+

solution for prolonged

stress, PSⅡ reaction centers were closed or irreversible inactivated, showing photoinhibition. Therefore, S. matsudana, S.

integra, S. leucopithecia have strong tolerance to high concentration Cd2+

stress. They can be used for phytoremediation of

severe cadmium polluted area, and they are good materials for breeding of willow varieties for heavy metal

phytoremediation.

3.2.1.3 Measuring of eutrophication polluting

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In order to analyze the tolerance of willows to eutrophication pollutions, six willow clones were irrigated by four solutions

with different levels of nitrogen and phosphorous content. The results showed that there were significant differences

between the growth and biomass among the different clones or TN/TP content. The sequence of the survival rate under

different irrigated solution was CK＞the grade of the national grade Ⅱ water quality＞the grade of the surface water

quality of V class＞the grade of the rural domestic sewage. And the sequence of the height and total dry biomass of the

potted seedlings were the grade of the national grade Ⅱ water quality＞the grade of the surface water quality of V class＞

CK≈the grade of the rural domestic sewage. Under the conditions of national grade Ⅱ water quality, 2487 had the

lowestsurvival rate, P63 was the lowest in height and biomass. The highest survival rate was P63 (96.97%), while P879

and 2 487 had the highest height and the total dry biomass with is 105.23 cm and 10.20 g/plant, respectively. Under the

condition of rural domestic sewage, the ratio of above-ground /below-ground dry biomass of the potted-seedlings was 7.61,

which was significantly higher than others.

3.2.2 Measuring of salt tolerance of Salix clones

The Jiangsu Academy of Forestry studied 310 shrub willow hybrid clones and 32 shrub willow stock clones under 85mM

NaCl stress, 6 salt-tolerant shrub willow clones were selected, including 5 shrub willow hybrid clones (2555, 2610, 35-10,

2667, 3636) and 1 shrub willow stock clone (P1024). Principal component analysis and subordinate function method were

used to evaluate the salt-tolerance of shrub willow clones (2555, 2610, 35-10, 2667, 3636, P1024), the D value of 6 shrub

willow clones was 0.0705, 0.1045, 0.0945, 0.0630, 0.0780, 0.0855. As a result, the order of salt-tolerance was

2610>35-10>P1024>3636>2555>2667.

3.3 Study on Molecular biology of Salix

3.3.1 The study on gene expression profiling and transcriptome

3.3.1.1 Gene expression profile in the male and female shrub willows

To gain a global view of the genes differentially expressed in the male and female shrub willows and to develop a

database for further studies, the Nanjing Forestry University performed a large-scale transcriptome sequencing of flower

buds which were separately collected from the two sexes. Totally, 1,201,931 high quality reads were obtained, with an

average length of 389 bp and a total length of 467.96 Mb. The ESTs were assembled into 29,048 contigs, and 132,709

singletons. These unigenes were further functionally annotated by comparing their sequences to different protein- and

functional-domain-databases and assigned with Gene Ontology (GO) terms. A biochemical pathway database containing

291 predicted pathways was also created based on the annotations of the unigenes. Digital expression analysis identified

806 differentially expressed genes between the male and female flower buds. And 33 of them were located on the incipient

sex chromosome of Salicaceae, among which, 12 genes might be involved in plant sex determination empirically. This

work provides valuable information and sequence resources for uncovering the sex determining genes andfuture functional

genomics analysis of Salicaceae spp.

3.3.1.2 Gene expression profile of willows under Cd-stress

Using illumine paired-end sequencing, the Zhejiang University obstained approximately 60.05 million high-quality reads

of willows under Cd-stress. De novo assembly yielded 80,105 unigenes with an average length of 703 bp. A total of

50,221 (63%) unigenes were further functionally annotated by comparing their sequences to different protein- and

functional domain databases. Totally 13,973 unigenes were annoted in Plant Cyc database, including 607 pathways, of

which 287 unigenes were related to metal transportation and cellular detoxification, playing roles in Ascorbate-glutathione

cycle, degradation of superoxide ion pathway and GSH mediated detoxification process II, etc. Based on the digital gene

expression profiling sequencing, we discovered 896 differentially expressed genes in leaves of S.integra with cadmium

and without cadmium, of which 293 IV were significantly up-regulated, and 603 were down-regulated under cadmium

stress. Among the 293 up-regulated genes, most were annotated the hypothetical protein of Populus trichocarpa, which

means that the response processes to cadmium in S. integra were controlled by many genes with unknown function. We

also found several genes related to stress responses, like metallothionein (M7), metal tolerant proteins (M7P7), Zrt/Irt-like

protein (ZIP), heavy metal ATPase (HAM) and phytochelatin syntheses (PC5). This work lays the foundation for further

discovery of the functions of these genes under cadmium stress.

3.3.1.3 The transcriptome research of Salix

The Jiangsu Academy of Forestry used 454 GS FLX platform and Titanium reagent to produce EST of the leaves of S. babylonica and S. suchowensis. A total of 547104 ESTs (280074 in S. babylonica, 267030 in S. suchowensis) with an

average read length of 415 bp were generated. The ESTs of S. babylonica were assembled into 40271 Unigenes

(4701Contig and 35570 Singlet), while the ESTs of S. suchowensis were assembled into 55083 Unigenes (7793Contig and

47290 Singlet). All unigenes were functionally categorized into GO (Gene Ontology) categories and metabolic pathways

were analyzed into KEGG respectively. 550 differentially expressed genes were found in S. babylonica and S. suchowensis, these genes were functionally categorized into GO (Gene Ontology) categories.

3.3.2 Development of molecular markers

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RNA-seq was carried out to produce substantial expressed sequence tags (ESTs) using leaves of S. babylonica and S.

suchowensis through 454 GS FLX platform by the Jiangsu Academy of Forestry. On the basis of databases, a set of SSR

markers were developed, and the transferability of SSR markers of salix was analyzed between different species and

hybrids. Based on transcriptome sequencing EST data resource, 4521 SSR were found in all Unigenes of salix using

MISA software (1752 SSR in S. babylonica and 2949 SSR in S. suchowensis). Use the software Primer 5 , a total of 1288

pairs of primers were designed (459 in S. babylonica and 729 in S. suchowensis). 1082 SSRs were successful amplified by

PCR and verified by agarose gel electrophoresis (424 pairs in S. babylonica and 658 pairs in S. suchowensis).

This research built a linkage map based on amplified fragment length polymorphism and simple sequence repeat using

280 F1 individuals derived from crossing of S. erioclada ‘P718’ and ‘P718’. Fifty-four pairs of AFLP primers and 36 pairs

of SSR primers were selected and used toconstruct the genetic map of S.erioclada ‘P718’ × ‘P718’. 3386 makers were

generated from 54 pairs of AFLP primers, including 1027 polymorphic makers. 885 makers were in accordance with

Mendel's law of segregation, and 142 makers followed partial separation. In 36 pairs of SSR primers, 17 pairs were in

accordance with Mendel's law of segregation, and 18 pairs followed partial separation.

3.3.3 Genetic map construction and marker-assisted breeding of willows

The Nanjing Forestry University successfully designed 106 and 90 pairs of SSR primers for chromosome XIX and XV,

respectively. MAPMAKER (version 3.0) following the two-way pseudo-test cross mapping strategy was employed to

perform the genetic linkage analysis, using SSR loci amplified in the present study together with 749 AFLP loci (420 were

maternally informative; 329were paternally informative).

The Chinese Academy of Forestry used 280 F1 individuals derived from a cross between S. erioclada ‘P718’ and ‘P718’

as materials. 902 markers in accordance with Mendel's law were generated for construction of genetic linkage map using

JoinMap4.0 software. 19 major linkage groups, 2 small linkage group, 7 triplets and 16 doublets were obtained. 609 AFLP

markers and 8 SSR markers were ordered tothe 19 major linkage groups. The distance of linkage groups was between

47.32 cM and 225.30 cM. The total distance of linkage groups was 2481.75 cM, and the average distance was 4.07 cM.

Estimated length of genetic map was 2208.35 cM. Map coverage rate was calculated according to the method of Lange

(1982) and Bishop (1983), which was 99.29% and 99.98%, respectively.

3.3.4 Cloning and expression of salt-tolerant genes The Jiangsu Academy of Agricultural Sciences cloned salt tolerant genes from salix using the primers designed according

to the genes of P. trchocarpa. The complete open reading frames of betaine aldehyde dehydrogenase (BADH) gene and

VHA-B gene were cloned from salt tolerant Salix cultivar L0911. Their length were 1539 bp and 1566bp, respectively,

and coding 512 and 518 amino acids (aa), respectively. Real-time fluorescence quantitative PCR revealed that gene

expression of Salix cultivar L0911 could be induced by NaCl stress, indicating that BADH VHA-B genes were related to

salt stress.

3.3.5 Research of Salix diseases and pests The Jiangsu Academy of Forestry released Dastarcus helophoroides on willow trees in some parks of Nanjing City in

order to to parasitize on and control Anoplophora glabripennis, whichseverely harmed the willow trees. The parasitic rate

and control effect were periodically determined. The results showed that the release of Dastarcus helophoroides could

effectively control Anoplophora glabripennis both in the first and second year. The corrected parasitic rate of Dastarcus

helophoroides could reach 35% one month after releasing, and the corrected decline rate of Anoplophora glabripennis pest

population was about 45%. The average parasitic rate of Dastarcus helophoroides on Anoplophora glabripennis was

around 37% in the second year. The study showed that Dastarcus helophoroides could parasitize on pupa of both

Anoplophora glabripennis (with a parasitic rate of 67%) and Zophobas morio (with a parasitic rate of 85%), while it

could not parasitize on Bombyx mori pupa．

4．Forest Protection

4.1 Poplar Insect Pests

Generally speaking, , the situation of insect pests damage of poplar and willow species during the past five years tends to

be steady. However the following states could be summarized: (1) In the three northern regions, especially in Gan-su and

Shan-xi Province, the Asian Longhorned Beetle (Anoplophora glabripennis (Motschulsky)) has reprevailed, damaging

ecological protection forests since its last severe outbreak almost 30 years ago. (2) Saperda populnea L. was found to

destructively harm poplar trees in cultivation lands in Tibet, some 2-year-old seedlings were completely destroyed. (3)

Local defoliator pests seriously occurred in some regions, such as He-nan, Shan-dong and Jiang-su Province. Invasive

defoliator pest-Hyphantria cune (Drury) is rapidly spreading to new regions, bringing severe damages. Jiang-su and

An-hui Province have become its new colonization. (4) The spreading risk of Xylotrechus rusticus L. was analyzed and

predicted as follow: the high-adaptive area is northern, northwestern, southwestern China, and most parts of northeastern China; the moderately adaptive area is Fujian, Zhejiang and Jiangxi province, most part of Jiangsu, Anhui, Hubei and

Guangdong province, the northern part of northeastern China, the southeastern part of Henan province, and the central part

of Ejina County.

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4.1.1 Basic Researches on Insect Pests

During the past 5 years, insect pests damaging poplar and willow trees mainly included Coleoptera, Lepidoptera,

Hymenoptera, Homoptera, Hemiptera and Orthoptera. Among them, the most widely studied defoliators are including:

Apocheima cinerarius Erschoff, Clostera anachoreta Fabricius, Micromelalopha troglodyte Graeser, Leucoptera susinella

Herrich-Schaffer, Hyphantria cunea Drary and Stilpnotia candida Staudinger etc.. The bio-ecology characteristics and

occurrence pattern of A. cinerarius were detailedly investigated, providing essential information to monitor and control

this pest. The bio-ecology characteristics, especially the life history, growth period and copulation behaviors of C. anachoreta, M. troglodyte and Chrysomela populi L. were investigated. Host preferences of L. susinella were studied;

results showed a decrease in host preference in the following order: P. beijingensis W. Y. Hsu, P. alba var. pyramidalis

Bunge, P. nigra var. italica (Moench) Koehne. Host preferences, starving tolerance, cold tolerance of H. cunea (Drary)

fed on poplar trees were also investigated.

Researches showed that woodborers damaging poplar trees mainly included: Anoplophora glabripennis (Motschulsky),

Xylotrechus rusticus (Linnaeus), Saperda carcharias (Linnaeus), Saperda populnea (Linnaeus), Apriona germari (Hope),

Batocera horsfieldi (Hope), Cryptorrhynchus lapathi (Linnaeus), Melanophilapicta Pallas, Poecilonota variolosa

(Paykull), belonging to Coleoptera; and Paranthrene tabaniformis (Rottenberg), Cossuscossus orientalis Gaede belonging

to Lepidoptera. Most of the studies focused on the outbreaks of the pests, pest occurrence pattern, damage characteristics

and bio-ecology characteristics such as host preferences, flight ability, sensilla morphology characteristics etc.. X. rusticus

was one of the most widely studied pests. Long Pan et al. (2015) measured the frequency distribution of the head capsule

and the pronotum width, and determined that each larva has 13 instars. Jue-Wen Li et al. (2013) re-constructed three

dimensional gallery features to illustrate different damage stages of X. rusticus, in order to provide guidance in monitoring

and detection of this pest. Ling Li et al. (2014) investigated the associated fungi-Fusariumsolani (Mart.) Sacc. of X.

rusticus. Ling Li et al. (2013) studied the influence of electroantennogram and behavior of X. rusticus from the bark

essential oils of its hosts, and found that it attracted benzothiazole. Besides, host preference and breed resistance of poplar

were also investigated, for example, resistance of different poplar strains against C. lapathi were tested. Furthermore,

relationships between the resistance level of poplar strains to C. lapathi and the physical properties of poplar trunks were

studied. In the breeding of highly resistant strains to C. lapathi, it is recommendable to choose P. pseudo-simonii, P. cathayana or P. suaveolens as parents, while P. deltoides or P. nigra should not be chosen as parents.

On the plant-insect community aspect, Zhang (2012) investigated the resources of moths in three poplar samples in

Nanjing Xiaozhuang College, the results showed 69 species belonging to 62 genera, 13 families, and the diversity of moth

in different seasons showed that the main factor was obviously seasonal variation. Yan (2013) investigated underground

pests in Anhui Province, the results showed that the grubs were composed of 9 species in 3 families, and the dominant

species were Holotrichiapa rallela, Maladera ovatula and Serica orientalis. Wu (2014) investigated the community

structure of pure poplar- and mixed forests in Jinshatan. The number of families, species and individuals of insect

community was the following oreder: poplar pure forest < poplar and scotch pine mixed forest<poplar, scotch pine and

buckthorn mixed forest< Poplar, scotchpine, buckthorn, and caragana mixed forest.

4.1.2 Induced Resistance and Physiological Changes by Insect Pests Induced resistance is a defense system within plants which allows them to resist pest attacks. The defense system reacts to

the external attacks with physiological changes, triggered by the generation of proteins and chemicals that lead to activation

of the plant's immune system. Understanding this physiological proces will lead to improvements in eco-friendly pest

control methods.

Wen Zhang (2006) studied the role of hydrogen peroxide (HP) in interplant wounding signal transduction of P. simonii x P. pyramidalis ‘opera 8277’. The contents of HP appeared to increase in the Clostera anachoreta herbivore-infested leaves and

undamaged parts of herbivore-infested leaves, but also increased in the neighbouring healthy plants. The antioxidant

enzymes were also activated; and Jasmonate-signal transduction pathway was also involved in the induction of plant defense.

Besides, the differential expressions of defense-related genes and oxidative burst were induced by C. anachoreta wounding.

The functions of H2O2, Jasmonic acid and abscisic acid in defense respond, the emission of aldehydes induced by

mechanical damage, the effective airborne signal molecules between poplar plantswere also investigated. Yan Wang (2009)

investigated the variation of foliar phenolic compounds in P. euphratica under environmental damage in Ejina Oasi.

Furthermore, the chemical structure and their important roles in defense against insect damage and

environmental-stress-resistance were summarized. The defense responses of poplar strains induced byS. populnea were

studied to select the more insect-resistant poplar strains. The nutrition and secondary metabolites were compared before and

after damage caused by S. populnea. Hui-Fang Yue (2013), Yu-Tong Wang (2015) investigated the resistance induced by

exogenous jasmonic acid in P. cathayana and the effects of the gypsy moth, Lymantriadispar on development.Contents of

peroxidase (POD), polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL), chymotrypsin inhibitor (CI) and

trypsin inhibitor (TI) increased accordingly. The weight of L. dispar decreased, while the developmental duration

increased after feeding with treated poplar leaves. The roots of most land vascular plants can form a symbiotic association

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(mycorrhiza) with special fungi. The development and growth of C. anachoreta mediated by ectomycorrhizal fungus

Paxillusinvolutus inoculated on P. ×canescens was investigated to support the hypothesis. The results showed that the

inoculated P. ×canescens with P. involutus could reduce the development of C. anachoreta larvae by changing the total

nitrogen, phosphorus, soluble sugar, protein, starch, and hormones contents.

In the recent 5 years, the physiological indexe changes of poplar damaged by pests have been only occasionally reported.

Liang (2012) investigated the characteristics of photosynthesis of damaged poplar leaves and discussed the photosynthesis

compensation of poplar after feeding with larvae of Micromelalopha troglodyte and proved that poplar had developed an

adaptive mechanism of photosynthesis compensation in response to the damage (Jun-Sheng Lianget al., 2012). LI (2015)

investigated potential effects of artificial defoliations at 0%, 25%, 50% and 75% levels to imitate the defoliator-caused

damages on biomass and chlorophyll contentsm in poplar (P. simonii× P. nigra) 5, 10, 15, 20 and 25 days after each

treatment. The results showed that defoliations pose significant impacts on carbon sequestration and photosynthetic

physiological responses of both poplar and larch seedlings.

4.1.3 Insect-Resistant Transgenic Poplar and Insect-Resistant Poplar Varieties The study on insect-resistance of transgenic poplars was mainly focused on transport of two types of Bt genes

(BtCry3A and BtCry1A), whether the pattern was one by one or both at the same time. A study on Hyphantria cunea, found that transgenic poplar 741 still had a stable resistance to H. cunea, which could be concluded through the decrease

on activities of the midgut proteases and retardation of the growth of the larvae. Transgenic hybrid Europe and American

black poplar showed that deratization rate of Hyphantria instar larvae obviously increased. BtCry3A and BtCry1A

double-transgenic poplars were fed to H. cunea and Plagiodera versicolora, results showed that the double Bt -transgenic

741 popolar was Lepidopteran pests- and Coleoptera pest-resistant, widening the insect-resistance spectrum. For

Aprionagermari, all 6 strains of Bt Cry3Ac-transgenic poplar showed certain inhibitory effect in terms of oviposition of

adult and growth of the larva of A. germari. For Clostera anachoreta, which were fed with leaves of Bt Nanlin 895 poplar,

we found that the transgenic poplar inhibited the activities of esterase and carboxylesterase, disturbed the protection

enzyme system and had an insecticidal effect of the larvae. Under the same Bt-concentrations, the C. anachoreta

experimental population’s mortality decreased with growth, i.e. the Bt-resistance in pests increased with age. Under

different Bt concentrations, C. anachoreta experimental population’s mortality increased with Bt concentrations. For

scion’s insect-resistance, studies showed that scions from transgenic plants which were grafted onto non- transgenic plants

maintained high insect-resistance, while scions from non-transgenic plants which were grafted onto transgenic plants

became to a certain degree insect-resistant too. For populations, transgenic poplars have changed Arthropod population

and community structure, and the diversity of the insect community has been increased. Two kinds of transgenic poplars

restrained target pests, avoiding pest eruption. And the temproal dynamic trend of the arthropods community was the same

in the two kinds of transgenic poplars and non-transgenic poplar. A study on the ecosystems of cotton-poplar intercrops

found that intercrops containing transgenic poplar significantly increased the inhibitory effects of Bt-transgenic cotton on

Fall web worm moth. Analysis on insect-resistance of species or strains found that poplar strains with high resistance to

Crptorrhynchus lapathi was Leuche and its hybridism, the native tree P. maximowiczii, while P. nigra and its hybrid mand

Tacamahaca were highly cold-resistant. Poplar strains high resistant to Paranthrene tabaniformis was Zhungeer NO.1-20,

Zhungeer NO.3, Nanlin106-Nanlin105, NO.96 poplar K15 and triploid Chinese white poplar.

Different varieties of poplar species show different levels of resistance to certain insect species. Feng-Yan Wang, et al.

(2011) investigated the survival condition of eggs and larvae of A. germariin in 12 varieties of poplars using cage

inoculation, results showed that P. deltoides cl. ‘Sangju’ was the most resistant, P. nigra and P. × deltoides cv. ‘74 /76’

came after, P. deltoides cv ‘Nanyang’ was theleast resistant. Jian-Jun Hu, et al. (2013) cultivated P. deltoides “Nanyang”,

which had high resistance to A. glaberipennis and moderate resistance to A. germari. In addition, Hu (2014) cultivated P.

deltoides ‘Zhongcheng1’and ‘Zhongyu1’ which have high resistance. Fu-Sen Wang, et al. (2014) found that P.

euramericana “N3016” × P. ussuriensis had stronger resistance to the main boring beetles (S. populnea, Paranthrene

tabaniformis and Siricidae species). Zhi-Guo Ding, et al. (2014) found that Triploid Chinese white poplar and P.

adenopoda were resistant to Batocera lineolate. The attacking rate increased first and decreased afterwards with the

increase of tree ages, 5to15-year-old poplars were more seriously damaged. Injury rate also increased first and decreased

afterwards with the increase in tree height, and peaked at the height of 8-14 meters. Injury rate topped at DBH of 5-11

centimeters, and decreased afterwards with the increase of DBH. Mixed forests were less damaged by B. lineolata than the

pure forests. The more abundant the food source was, the more serious the damages to poplars were. The effect of

different poplar varieties on population of Hyphantria cunea was evaluated, their resistance from high to low was as

follows: P. ×euramericana ‘L35’, P. ×euramericana (Dode) Guiner cl. ‘Zhonglin 46’, P. ×euramericana-W141, P. ×euramericana Carppaccio, P. deltoides ‘L323’, P. deltoides ‘PE-19-66’, P. ×euramericana ‘Guariento’ L35 and W141

were the optimal varieties for the control of H. cunea. Qing-Jie Cao & De-Fu Chi (2015) carried out a study to find out the

relationship between the resistance level of poplar strains to Osier weevil and the physical properties of their trunks. The

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results showed that the harder the phloem and xylem of poplar strains were, the higher their resistance level to Osier

weevil was, and layed foundation for the breeding of highly resistant strains to Osier weevil．

4.1.4 Pest risk analysis

During the last 5 years, only a few researches in China were focused on the risk analysis of pests damaging poplar and

willow trees. However, the importance to predict and monitor the occurrence and development of insect pests is obvious.

The risk of Melanophila decastigmain invading Xin Jiang provience was analyzed by Nuerguliet al. (2013), results proved

that it a high risk insect pest. The risk of Cryptorrhynchus lapathi invading Qing Hai Province was analyzed, it was also a

high risk pest with the trend of spreading all over Qing-Hai Province. Jue-Wen Li (2014) investigated the tolerance to

extreme low and high temperatures and the relevant physiological variation of Xylotrechus rusticus, and analyzed the

spreading risks of this long horned beetle. The results showed that the high-adaptive areas were northern, northwestern,

southwestern China, and most part of northeastern China. The moderately-adaptive areas were Fujian, Zhejiang and

Jiangxi province, most part of Jiangsu, Anhui, Hubei and Guangdong province, northern part of northeastern China,

southeastern part of Henan province, and central part of Ejina County.

4.1.5 Control

In the past 5 years, numbers of new control methods, pesticides, and natural enemies have been developed to control the

insect pests damaging poplar and willow trees. Xiu-Ping Niu, et al. (2015) indicated that both the nymphs and female

adults of Drosichacorpulenta (Kuwana) displayed obvious taxis responses to the volatile of host plants Diospyroskaki, Ziziphus jujube and P. tomentosa, and provided a potential inter-copping pattern of Zanthoxylum bungeanum and

Ailanthus altissmato to achieve biological control of D. corpulenta. Yun-Peng Liu, et al. (2012) suggested that

Lambda-cyhalothrin and Acetamiprid could be considered as the first selected pesticides to control D. corpulenta. To

control Micromelalopha troglodyte, Clostera anachoreta and Botyodes diniasalis, the best control effects could be

achieved by spraying 1:600 dilution of matrine-nicotine missible oil with 1.2% potency. Yuan-Yuan Li, et al. (2014)

proved Methyl jasmonate as an inducer can enhance defensive responses (resistance) of poplar against defoliators.

However, it can also weaken the carbon sequestration capacity of poplars. Feng-Yan Wang, et al. (2011) investigated the

lethal effects of 5 pesticides on Aprionagermari with the soil spraying method, results showed that imidacloprid and

Actara were effective．

Considering natural enemy, Yue Gao, et al. (2013) conducted a field experiment releasing Trichogramma dendrolimi in poplar plantations to study the control of Notodontidae's eggs in P. ×euramericana. Chao-Yang Yue, et al. (2013) found

that the average control effect of releasing Dastarcushelophoroides adults in the forest and border trees reached 63.82%

and 76.85%, respectively, whlile the average control effect of releasing of D. helophoroides eggs was 65.88% and 67.42%,

respectively. Hamili et al. (2013) selected four parasit species to control the larvae of Saperdcarcharias in laboratory, the

control efficiency ranking from high to low was as follows: D. helophoroides>Sclerodermus pupariae>S. sp.1= S. sp.2.

4.2 Poplar Diseases

4.2.1 Basic Research

The type III secretion system (T3SS) cluster was identified in the poplar canker pathogen Lonsdalea quercina N-5-1 genome.

The 23 kb T3SS included 26 genes, 9 of which were highly conserved hrc genes. T3SS hrc V mutant and complemented

mutant HBhrc V were inocluted on P. × euramericana ‘Zhonglin 46’. The Δhrc V was less virulent, while the HBhrc V

virulence to the wild-type strain. The hrc V mutation abolished the HR, but did not influence growth, motility, and biofilm

formation, suggesting that the T3SS is an essential pathogenic factor. The hrcJ was introduced into N-5-1 by vector

pEX18Km-hrcJ. The hrcJ mutants were screened and verified by PCR and Southern blot. P. ×euramericana cv. ‘74/76’ was

inoculated, with wild-type, the hrc J mutant, and the complemented HBhrc J mutant. The hrcJ mutant was less virulent.

Growth capacity of hrc J mutant had no significant change compared with wild-type, and the ability of biofilm formation

showed that the motility of hrc J mutant decreased 21%. The cultivable bacteria and fungi from healthy and diseased P.

×euroamericana in Puyang, Henan, China show that the dominant fungi are Alternaria alternate and Fusarium solani,

respectively. And the dominant bacterial is L. quercina. Furthermore, F. solania and L. quercina became the preponderant

species. P. tomentosa H2O2 content was higher than P. ×beijingensis at the early stage of Botryosphaeria dothidea inoculation. After

72h, H2O2 content reached its maximum (737.52 mol/g) and a large number of H2O2 -CeCl3 appeared. After B. dothidea

inoculation, APX and POD of P. tomentosa were higher than that of P. ×beijingensis. H2O2, APX and POD were related to

resistance. Twelve poplar housekeeping genes and 9 poplar plasma membrane intrinsic protein (PIP) genes were detected by

RT-qPCR in P. beijingensis infected with B. dothidea. The expression patterns responding to fungal and drought was diffrent,

and the water transportation mechanisms were different too. Five PIP genes in drought-pathogen interaction were higher

expressed than in drought or pathogen alone. Solexa cDNAs sequencing of control and B. dothidea treated conditions resulted

in a total of 339,283 transcripts and 183,881 unigenes. A total of 206,586 transcripts were differentially expressed. There was

significant accumulation of energy metabolism- and redox reaction-related-macromolecules according to GO and KEGG

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enrichment. A total of 852 transcripts (575 up and 277 down) were involved in plant–pathogen interaction, signal transduction,

defense, and cofactors. Moreover, GST reached high levels, revealing key genes and proteins potentially related to pathogen

resistance. RT-qPCR validation revealed highly reliability. The unisequences, from B. dothidea inoculated P. tomentosa cDNA

library, were selected and analyzed by RT-qPCR. Randomly selected 199 positive clones were sequenced, and 172 EST

homologous were found. Ten defense transcription associated sequences were divided into 4 categories, i.e. Zinc finger protein,

CONSTANS-like protein, transcription factor (TF), and WRKY21. RT-qPCR showed that the expression of these 3TF

significantly increased. Poplar infected with Dothiorella gregaria and control were analyzed by GC-MS. A total of 4,051

features were detected and 44 significantly changed metabolites. Metabolism pathways and networks were constructed.

The pathogenicity of 64 Cytospora chrysosperma strains, isolated from 31 cities of 11 provinces in China, did not related to the

geographical origin, while it showed relevance to host species. The strains isolated from poplar showed stronger pathogenicity

than that from non-poplar hosts. The study indicated an obvious relationship between the geographical origin and the genetic

diversity grouping. CHH001 isolated from P. alba ×P. berolinensis was identified as C. chrysosperma by morphology and

ITS-PCR. RT-qPCR indicated poplar ZFP1 and 69-Ⅳ-2-4 had higher levels of relative expression. ZFP1 may participate in

plant-pathogen recognition and defense. Northeast China102 Cytospora were divided into five morphological groups based on

locules, discs, conceptacles, conidia of anamorphs and associated teleomorphs, and cultural characteristics. The classification

of the 5 groups were well supported by the ITS phylogenetic.

4.2.2 Disease Diagnosis and Identification A Gram-stain negative, Neisser-stain negative, aerobic, non-motile, non-spore-forming, slimy, glossy bacterial strain with

single or clustered coccoid cells and white colony color, designated as 2-binT

,was isolated from cankered P. ×euramericana

from Qingfeng, Puyang, Henan, China. Strain 2-binT is a novel species, for which the name L. puyangensis sp. nov. is

proposed.

Five Tylenchida and 2 Dorylaimida nematodes were identified from poplar rhizosphere soil in 54 different sites from

Zhenjiang and Jiangsu province. These species included Filenchus orbus, F.vulgaris, Tylenchorhynchus brassicae,

Helicotylenchus digitiformis, Scutellonema brachyurus, Xiphinema X. americanum and X. hunaniense. F. vulgaris was a

new record in Jiangsu, and the poplar was the new host of F. vulgaris, T. brassicae and X. hunaniense.

Poplar powdery mildew in Jiangsu and Shandong infect many poplar hybrids and cultivars. It was identified as

Phyllactinia populi. It was reported for the first time on Italian hybrid poplar cultivars and is co-occurrent with M.

larici-populina and Marssonina brunnea. Thirty-one isolates of M. larici-populina from 8 provinces, 17cities were

grouped separately into 4 physiological races and 4 new pathotypes.

Studies on P. ×euramericana canker indicated that antagonistic relations did not exist between Lonsdalea quercina and

Fusarium solani. L. quercina played the major pathogenic role. Lower virulent F. solani played an aggravating role in

the occurrence of poplar canker disease.

Studies showed that poplar canker was caused by Dothiorella gregaria Sacc., C. chrysosperma Fr., Coniothyrium populinum Schulz. Et Sacc. in Shaanxi province of China. Cytospora and Valsa, Leucostoma, Valseutella, Valsellawere

gathered on populus in China. ITS and β-tubulin genetic diversity of C. chrysosperma was studied using RAPD. C.

davidiana, C. atrocirrhata and C. kantschavelii were newly reported from China. C. chrysosperma, C. translucens, and C. fugax corresponded with the previous taxa. The pathogenic, molecular and morphological identification of P.

alba×berolinesis diseases in Harbin was done and was identified as Fusichadium tremulae (Fr.) .Canker fungus of P. ×euramericana CL ‘74/76’ was identified as Apiocarpella macrospora, which was reported for the first time and was also

a new disease on poplar in China.

4.3 Disease Resistance SA and hydrogen peroxide H2O2 were analyzed in P. tomentosa and P. × beijingensis inoculated with B. dothidea. Poplar

resistance was relevant to the accumulation of SA and H2O2. After M. larici-populina –infection of poplar clones with

different levels of M. larici-populina-resistance , PPO, PAL, chitinase and β-N-Acetyl -D-glucosaminidase enzymatic

activities were all higher than the control. The fat soluble differences are significant in the poplar buds with different

levels of anti-rust resistances. The buds of N195 and N177 contained α-Caryophyllene, α-Bisabolol, and methylarachidate.

Cinnamic acid, 4-Cyanophenyl-propylbenzoate, 9-Phenanthrol, retinaldehyde, chlorodiphenylmethane, and

p-Hydroxy-cinnamic acid only existed in N195, while α-cadinol, 2-phenethyl octanoate, 9-Aminoacridine, and

1-Docosanol only existed in N177.

Experiments on P. deltoids-resistance to rust showed that the seedling height of 6 families was in normal distribution,

whereas the basal diameter was concentrated within 5-9 mm. There were significant differences both in height and basal

diameter. The ZS8×2-33 was more susceptible, while the 2-2×2-9 was highly resistant. Urediospores of M. larici-populina

spread from August to early November, the urediospores spread the most in the mountainous region at mid-September and

in plain regions at mid-October. This disease occurred in the west of Guanzhong, and spread from west to east, from low

to high latitude, from high to low altitude and from the mountainous to the plain areas.

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The Lonsdalea disease indexes of P. ×euramericana cv. ‘Zhonglin 46’ were higher than that of ‘74/76’. The canker had a

significant correlation with accumulated precipitation, daily average temperature, maximum temperature, minimum

temperature, relative humidity and wind speed. RT-qPCR detect SA and JA showed that in resistant Lonsdalea quercina

subsp. populi, the expression of PR1-1, PR1-2, NPR1-1, NPR1-2, TGA1, TGA2, MYC2-1and MYC2-2 was higher in P.

tomentosa than susceptible P. deltoids cv. ‘Zhonghe 1’. While, JAZ1, COI1-1 and COI1-2 were expressed lower. It

suggested that the canker resistance induces the SA and JA signal transduction.

P. tomentosa inoculated with Rhizoctonia solani Rs-1 after Endophytic Chaetomium globosum ND35 inhibited pathogenic

expanding, but significantly increased the activity of POD, PPO and PAL. The 3 defense enzymes were induced by ND35

and enhanced resistance. When inoculated with canker, the BG2 transformed P. ×euramericana cv. ‘Neva’, T-107, grew

better than the C-107. The T-107 MDA levels were lower than C-107. Although both increased firstly and then decreased,

the PAL content of T-107 was always higher than C-107. After 15 d, all C-107 were dead, but T-107 were still alive,

indicating that the BG2 improved resistance. The meteorological suitability index was divided into 4 grades of very

suitable, suitable, basic suitable, not suitable, which could reflect the suitable degree of meteorological condition for

occurrence and development of Valsa sordida Nits.

4.2.4 Control Twenty four out of 115 strains could inhibit mycelium growth of poplar canker B. dothidea, among which 5 strains were

selected for good control effect on poplar canker, and the strain YGF9 was determined as the most effective antagonist of

B. dothidea. It was found that the two biocontrol strains, Trichoderma aureoviride YGF9, and Fusarium equiseti LX6F2,

could produce antagonism enzymes and inhibit pathogen’s growth.

Characteristics of β−glucanase produced by Bacillus velezensis YB15 showed that thestrainplayedan played antagonistic

roles against many pathogenic fungi. Width of inhibition zone against Helicobasidium purpureum was 11.0 and 10.6 mm

by YB15. The YB15 β−glucanase genenamedas Bglu1 was 732bp and encoded 243 aminoacids.

A chitinase gene (Bbchit1) from Beauveria bassiana was introduced into P. tomentosa which over expressed LAR3.

Bbchit1 and LAR3 were detected in transgenic plants by real time-PCR. The transgenic poplar plants displayed a

significant reduction in their disease symptoms after they were infected with Alternaria alternate.

Bacteriostatic activity of Inonotus obliguus products had inhibitory effects on 7 pathogenic bacteria, and the highest

inhibition rate of B. laricina and C. chrysospermwas was discovered to be after 23 days. Alcohol extracts contained the

main antibiotic active substance. Bacillus pumilus JK-SX001antifungal substances on poplar canker pathogen C. chrysosperma, Phomopsis macrospora and Fusicoccum aesculi were used. The non-protein antifungal substances and

inhibitstomycelia and germinated-spores were studied while physical and chemical properties were measured.

Thenon-protein antifungal substances had a strong inhibitional effect on mycelia growth and spore germination, and could

dissolve the spore. Ethanol conidial extracts of T. harzianum against C. chrysosperma showed the highest inhibition rate.

There was significant difference between different treatments. Antibacterial substances from Phellinus linteuss were used

on 7 pathogenic bacteria. The highest inhibitory rate was appeared on20 days treatment. The ethyl acetate extracts T.

virens T43 reduced C. chrysosperma enzymes activities, the soluble sugar and protein contents, with SOD activity also

decreasing. However, it increased the MDA content in pathogens, and hence destroyed cell integrity. The extracts

Trichoderma T-33, T-14, T-09 from 29 domestics inhibited C. chrysosperma mycelium growth and conidia germination.

Phylogenies of 18S r DNA showed that T-33 was T. viride. From Populus, 23 out of 56 strains belonged to endophytic

antagonistic bacterium. Resistance against C. chrysosperma showed that Y-S-Y12 had the most significant effect,

followed by Y-S-Y2. Y-S-Y12 was Bacillus amyloliquefaciens according to 16S r DNA. It was found that 10%

difenoconazole water dispersant, 250g/L azoxystrobin suspending agent, 70% thiophanate methyl wettable powder

showed high virulence to C. chrysosperma and Dothiorella gregaria.

Eight fungicides used against poplar powdery mildew showed that the control effect of carbendazim 50% WP, be diluted

600 times, was 72. 25%. Trichloroisocyanuric acid SP (85%), azoxystrobin SC (40%), acetic acid bacteria amine salt AS

(1.8%), asomate WP (40%) could control Melampsora larici-populina effectively. Humic acid copper and

thiophanate-methyl asomate showed higher control ability against the Cytospora of P. tomentosa canker. Carbendazol

wettable powder and thiophanate-methyl asomate had better control effect to Dothiorella gregaria Sacc. canker.

5．Harvesting and Utilization

5.1 Processing and Utilization of Poplar

5.1.1 Study of Poplar wood properties It has been found that the normal wood and tension wood of P. ×euramericana cv. ‘Neva’ should be treated differently in

processing and utilization because of the different chemical composition, fibre morphology and pulping and papermaking

properties (Zhou et al., 2012). The chemical composition, physical and mechanical properties are significantly different between transgenic and non-transgenic P. alba× (P. davidiana +P. simonii) ×P. tomentosa (Zhang et al., 2014; 2015). The

physical and mechanical properties of 11 clones of Populus deltoides were compared, and there were significant linear

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correlations between them except the impact toughness (Pan et al., 2014). And Wang et al. (2015) found that there were no

obvious differences between the normal fiber and gelatinous fiber of Populus deltoides normal wood.

5.1.2 Reinforcing Modification of Poplar Wood

5.1.2.1 Compression and Densification of Poplar Wood

The poplar P. ×euramevicana veneers have been compressed under mechanical pressure, and fixed to avoid deformation by

high temperature heat treatment (Chen et al., 2013). Transverse compression method was used in poplar wood densification

treatment, and the properties of the treated wood under optimization process were better than oak wood (Chen et al., 2012).

Wang et al. (2012) and Xia et al. (2013) studied the surface densification and fixation technology of Chinese white poplar

wood under the control of water and heat. They found that the treated wood surface density and hardness could reached 0.92

g/cm3 and 22.3 N/mm

2, which were 1.8-2.1 times and 2.4 times of that of the control samples, respectively. Moreover, when

the compressed wood were treated under 180℃ for 4h, its deformation recovery rate could be reduced by 30%. Du et al.

(2013) found that the tangential dimension stability of the P. tomentosa wood which has been treated under the condition of

195℃ for 3h was 1.9 times of that of Fraxinus mandshurica.

5.1.2.2 Chemical Impregnation Reinforcing Modification Lang et al. (2012) modified P. ×euramericana cv. ‘Neva’ with highly reactive amino methylurea usingvacuum-pressure

method. Succinic anhydride pre-treatment poplar was modified by in-situ polymerization using styrene monomer and

Styrene-glycidyl methacrylate copolymer. Wang et al. (2013) grafted fast-growing poplar with methyl methacrylate monomer.

Sun et al. (2015) treated poplar with PEG1000 and DMDHEU. Bi (2015) impregnated poplar using the compound of

DMDHEU and methylolurea. Chen et al. (2013) prepared PF-CaCO3-wood composite material. Some scholars impregnated

poplar with water-soluble resin, which improved the density and mechanical properties of poplar wood. Moreover, it has been

found that the plywood and laminated wood which was prepared by resin impregnated poplar veneer could reach the standard

of outdoor timber or some structural timber.

The combined modification technology based on impregnation reinforcing has also been studied. Xu and Hou (2015) studied

the heat treatment process of PF and UF impregnated wood and the properties of heat-treated impregnated wood, and found

that heat-treatment could further improve the dimension stability of resin impregnated wood. The 150mm ×2400mm ×25mm

PF impregnated wood was heat treated for 3h under 190℃ and 160℃, respectively. These results show that the MOE and

MOR of impregnated heat-treated wood were both about 50% higher than that of heat-treatment wood, and mechanical

strength improved significantly (Unpublished data). Chai and Wang et al. (2015) treated poplar with MUF and boron modified

agent, and the dimension stability and mechanical properties of the treated wood were comprehensively promoted.

Additionally, Zhang et al. (2014) and Peng et al. (2015) explored drying process of 46mm and 25mm thickness UF

impregnated P. tomentosa respectively, and found that the drying period of impregnated wood was longer than that of

untreated wood.

5.1.2.3 Application of resin impregnated wood

Due to the better dimensional stability and higher hardness, density and mechanical strength, resin impregnated wood was used

in furniture components and products. Li et al. (2015) used UF impregnated poplar to prepare the tenon assembly parts, and

found that the tenon grip force was improved. In addition, Zhang et al. (2015) discussed the bleaching and finishing process of

the furniture using resin impregnated modified wood.

5.1.3 The study on poplar wood-based panel

5.1.3.1 Applied basic research

Qin (2014) studied the relationship between surface free energy, wettability and bonding strength of PF poplar plywood. Wang

(2013) studied the bonding interface property of poplar LVL. Chen et al. (2014) explored the differences of wood properties

among different varieties of poplar plantation and their impacts on veneer bonding strength. Xu et al. (2015) analysed the

effects of poplar dynamic mechanical properties on energy consumption during hot mill.

5.1.3.2 Raw material and adhesive

Raw materials diversification is an important direction of poplar wood-based panels. Some mixing raw materials like

poplar-straw, poplar-waste paper, poplar-paper sludge, poplar-reed, and poplar-bamboo were used in producing particleboard

plywood or MDF.

The development of environmental protection (low formaldehyde or formaldehyde-free), water resistant adhesive, and even

non-adhesive bonding technology are important research directions in poplar wood-based panel industry. The use of high

density polyethylene (HDPE) to replace the traditional synthetic resin wood adhesive has opened up a new direction. Soybean

adhesive was modified aimed at its water resistance and mildew resistance. Guo et al. (2014) tested the poplar plywood

non-adhesive bonding by wood liquefaction technology. Xie (2013) and Jin et al. (2014) discussed the non-adhesive bonding

process and chemical characteristics of poplar fibreboard by using the bonding effect of lignin. Furthermore, Liu et al. (2012) introduced the oxygen plasma technology to modify the enzymatic hydrolysis lignin in order to improve the ‘self-bonding’

properties of poplar fiber.

5.1.3.3 Development of new products

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In these years, structural poplar artificial board has become an important research field in the processing and utilization of

poplar in China. Huang et al. (2013) produced the LVL using high-frequency hot-pressing technology. Liu (2012) discussed

the miter quality improvement of poplar large span LVL. Heilongjiang Wood Science Research Institute determined the

mechanical properties eigen value of poplar LVL. Glue application and hot-pressing technology, the mechanical model and the

creep properties of Parallel Strand Lumber (PSL) were studied in Nanjing Forestry University. Zuo et al. (2014) chose poplar,

SPF and pine as raw materials to develop prism glued-laminated timber. Similarly, Yangzhou University developed glued

laminated columns using rotary veneer. Moreover, Nanjing Forestry University developed the laminated veneer hollow

column.

With the development of nanotechnology in the world, poplar biomass nano-material has become a popular research area in

China. Yang (2013) and Li et al. (2013) have prepared poplar micro/nano fibril from wood fiber, and explored the properties

of polyvinyl alcohol film which was modified by poplar micro/nano fibril. In other applications, Huang et al. (2012) and Pan et

al. (2012) applied poplar micro/nano fibrils and MF/epoxy resin to prepare composite material. Liu et al. (2015) used poplar

Nanocrystalline Cellulose (NCC) to improve the thermodynamic property of soybean adhesive.

There are also many other poplar products, such as lightweight foam material, wood-organic aerogel composite materials (Li,

2013), sliding bearing (Wu et al., 2012), copper plating at man-made board (Hu et al., 2013), aluminum-wood decorative

composite, Dyed poplar veneer and products, etc.

5.1.4 Utilization of poplar wood pulp and biomass

Yu et al. (2013), Wang et al. (2014), Tang et al. (2014) studied poplar pulping process of alkaline hydrogen peroxide

pre-treatment, nitric acid method and no-catalyzed glycerol method, respectively. Du et al. (2014) studied the effects of sodium

bisulfite pre-treatment on the chemical composition and enzymatic hydrolysis of poplar pulp. Zhang et al. (2012) and Qi et al. (2013) studied the effects of low and high consistency refining on the property of poplar PRC APMP. Wang et al. (2013) used

ultrasonic treatment to improve the properties of poplar APMP fiber.

Comprehensive utilization of waste water from pulp and paper making has been the focus of pulp and paper industry. Su et al. (2013) studied the thermogravimetric characteristics of aspen APMP effluent solid under different temperature and heating rate.

Li et al. (2014) tried to use aspen APMP pulping waste liquor in surface sizing of fluting medium.

In order to develop and utilize the biomass in pulping waste liquor, Dong et al. (2014) analysed the compositions of APMP

effluent. Before used to produce biofuel, lignocellulose was always pre-treated by dilute-sulfuric acid hydrolysis. Fang et al.

(2015) measured the polysaccharide conversion rate to find the suitable particle size range in dilute-sulfuric acid hydrolysis

pre-treatment of poplar effluent.

5.2 Processing and Utilization of Willows

Fast-growing Willows like S. discolor, S. psammophila, Salicaceae and S. gordejevii are widely introduced and industrial

application test are carried out in these years. Yang et al. (2012) found that the fiber length of S. gordejevii which is 2-3 years

old and grown in eight areas of Inner Mongolia was too short to use solely in the producing of fiber board, but some of them

can be used as high quality pulp raw material. Application researches were focus on S. discolor, S. psammophila and

Salicaceae in these years. Based on the traditional crafts and weaving tools industry, researchers have studied the utilization of

willows in artificial boards, pulp, carbon materials, and bioenergy.

In the field of pulp and paper, Shandong Polytechnic University chose S. psammophila as raw material to study the optimal

technological conditions of P-RCAPMP high yield pulping and the effects of xylanase, laccase-mediator and laccase-xylanase

treatment on the pulp properties and lignin structure. Furthermore, Yuan (2012) studied the biobleaching technology and

mechanism of S. psammophila chemical pulp.

Nanjing Forestry University found that the fiber morphology of S. discolor was similar to P. simonii× P. nigra, and its main

chemical compositions were nearly the same as Fraxinus mandshurica and triploid Populus tomentosa. In addition, some

scholars have studied the production process of Salix discolor products such as LVL, fibreboard, particleboard (Dong et al.,

2013), and reconstituted wood. Inner Mongolia Agricultural University has found out that S. psammophila could be used as

raw material for the production of MDF, light wall material and ultra-light material combined salix fiber with waste paper fiber.

Moreover, Zhengzhou University studied the preparation process of microcrystalline cellulose from S. psammophila. In the

field of bioenergy development, Inner Mongolia Agricultural University studied the baking characteristics and biomass baking

process of S. psammophila (Liang, 2014).

5.3 Pulp production from poplar wood in China There are 34 wood pulp manufacturers in China, with 51 wood pulp lines in total and an annual grand total wood pulp

production capacity of 10.73 million metric tonnes. Among these 51 wood pulp lines, poplar wood chips alone or

poplar-eucalypt wood chip mixtures are applied as raw fiber materials in 25 pulp lines, where P-RC APMP or CTMP

puling processes were installed for production of bleached chemimechanical pulps, mainly. Those pulp lines are located in

areas such as Yangtze river basi, the plain between the Yellow River and Huai River, North China Plain and Northeast

regions, including manufacturers such as Shandong Chenming paper group Co. Ltd., Shandong Sun paper Co. Ltd.,

Huaitai group Co. Ltd., Golden east (Jiangsu) Co. Ltd., Hunan Tiger group Co., Ltd., Henan Puyang Longfeng Paper

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Industrial Co. Ltd. and Henan Jiaozuo Ruifeng Paper Industrial Co. Ltd. etc (Table 2). Since some specific high-quality

wood properties for pulp wood, with suitable basic density and light wood colour, pulp lines using poplar wood chips

achieve good performances including lower chemical consumption, lower specific refining energy and higher pulp yield

and so on. Thus, high quality pulps could be produced from poplar woodchips in present pulping lines.

Meilun Paper Co. Ltd. of Chenming Group, located in Shandong province, has installed a BCTMP pulping line with an

annual production capacity of 250,000 metric tonnes of bleached chemimechanical pulps, using poplar-eucalypt chip

mixtures for bulky pulps as furnishes to produce coated ivory card board and art paper products. All facilities were

supplied by Valmet Co., Finland. Their tech-economic specification could be summarized as: Dosage of caustic soda

40-60 kg/mt, hydrogen peroxide 70-100 kg/mt, specific refining energy 1100-1300 kWh/mt, pulp freeness 250-350 mL

CSF, bulk >2.40 g/cm3，tensile index >24 N.m/g，brightness 72-80%，opacity >88%.

Yueyang Paper Industrial Holdings Co. of Tiger forest-paper group had installed 2 chemimechanical pulp lines, the first

APMP production line in the world with an annual production capacity of 30,000 metric tonnes of poplar pulp was

installed in 1997, and a P-RC APMP production line with an annual production capacity of 100,000 metric tonnes of

poplar pulp was installed in 2005, using American black poplar hybrids wood from plantations in Tongtinghu lake basin

as fibrous material. All poplar pulps are applied for manufacturing News print and LWC grades. Multiple modifications

and technical optimization had been taken for its P-RC APMP lines, resulting in reduction of production cost and

improvement on pulp qualities, for instance, Dosage of caustic soda 40-50 kg/mt, hydrogen peroxide 60-80 kg/mt, specific

refining energy 1200-1500 kWh/mt, pulp freeness 150-250 mL CSF, bulk 1.80-2.30 g/cm3，tensile index 32-40 N.m/g，tear

index 3.0-4.0 mN.m2/g, brightness 76-80%, opacity >85%.

Jiaozuo Ruifeng paper industrial co. Ltd. completed its P-RC APMP pulping lines with an annual capacity of 150,000 mt

pulps in 2006, using commercial chips from P. tomentosa hybrids plantations growing on the plain between the Yellow

River and Huai River, to produce bleached poplar pulps. The pulping system was supplied by Anritz AB Austria and

effluent treatment system Park Co. Holland. Its technical economic parameters are specified as follows, dosage of caustic

soda 50~60kg/mt, hydrogen peroxide 60~80kg/mt, specific refining energy 1000-1200 kWh/mt, freeness 250-350 ml CSF,

bulk 2.40 g/cm3, tensile index 24 N.m/g, brightness 76-80%. Those pulps could be applied into production of the paper

grades: off-set paper, LWC, news print, art paper, carbon free copying paper and LWC base paper etc.

Table 2 List of Bleached chemi-mechanical pulps using poplar wood chips in China

Enterprises Annual capacity,

10,000 mt/a

Start up

time

Wood Process

Pu Yang Longfeng 10 2005 Poplar wood P-RC APMP

Jiaozuo Ruifeng 15 2006 P-RC APMP

Henan Xinya 10 2007 P-RC APMP

Yuanjiang Paper 20 2014 P-RC APMP

Yueyang Forest-paer 10 2005 P-RC APMP

Yueyang Forest-paper 3 1997 APMP

Chenzhou Yurong 17 2013 Poplar and

eucalypt chip

mixtures

BCTMP

Jilin Chenming 9 2013 P-RC APMP

Golden east Jiangsu 26 2011 P-RC APMP

Bohui, Jiangsu 51 2013 BCTMP

Meili, Ningxia 10 2007 Poplar P-RC APMP

Yinhe, Shandong 10 2011 P-RC APMP

Sun paper, shandong 22 2013 Poplar and

eucalypt chip

mixtures

P-RC APMP

Sun paper, shandong 15 2011 P-RC APMP

Sun paper, shandong 19 2009 P-RC APMP

Sun paper, shandong 10 2007 Poplar P-RC APMP

Zhongmao sengyuan, Shandong 10 2006 P-RC APMP

Meilun, Chenming 6 2003 Poplar and

eucalypt chip

mixtures

P-RC APMP

Meilun, Chenming 17 2011 BCTMP

Meilun, Chenming 25 2004 BCTMP

Zhengda, shandong 9 2010 BCTMP

Huatai, shandong 11 2004 BCTMP

Bohui, shandong 22 2009 BCTMP

Bohui, shandong 22 2004 BCTMP

25

6．Environmental Applications

6.1 Carbon sink function of poplar plantation

The carbon fixation ability of forests in China was primarily derived from forest plantations. Among the different types of

plantations, poplar plantations have great potential in carbon sequestration in China due to their fast growth and high

productivity. The carbon storage of poplar plantations accounted for 15.9% of total plantations in China.

6.1.1 The carbon sink of poplar plantations in China

The researches related to carbon sink of poplar plantations in China have made remarkable progress. For example, the

Beijing Forestry University (BFU) investigated the carbon storage and density of poplar plantations according to the data

of the Seventh National Forest Inventory. The total carbon storage and carbon density of poplars in China was 261.84 Tg

and 25.92 t·hm-2

, respectively, and the carbon storage and density of poplar plantations was 179.22 Tg and 23.67 t·hm-2

,

respectively. In Inner Mongolia, Henan and Shandong, the carbon storage was 35.45, 24.51 and 22.42 Tg, respectively,

which accounted for 55.9% of the total carbon storage in China. Carbon storage in young- and middle-aged poplar

plantations was 117.95 Tg, accounting for 65.9% of the total, i.e. showing great potential in carbon sequestration.

6.1.2Carbon sink of poplar plantations in typical areas in China

The Nanjing Forestry University (NFU) estimated that the carbon storage and density of poplar plantations were 138.128

Tg and 150.389 Mg·hm-2

, respectively, in Jiangsu province. The NFU used the data of forest resources assessment in

Jiangsu province to analyze the carbon storage distribution of poplar. They found that there were large differences in

regional carbon storage. The poplar plantation exhibited a huge potential in carbon sequestration and the differences in

carbon storage of poplar plantations of different ages were mainly caused by the carbon storage of tree layer.

BFU studied the carbon storage of poplar plantations in Heze, Shandong Province based on Landsat TM5 data. The carbon

storage was 13.93 Tg accounting for 25.39% of forest vegetation in Shandong Province. The carbon density was 43.82

t·hm-2

, which was 21.82% higher than the national average level. The Chifeng Institute of Forestry Science found that the

soil carbon content decreased with depth, and soil carbon density showed concave-shaped trend with increasing depth in

Xinhui forest farm in Aohan Banner.The carbon content and density of poplar plantations were calculated using the NPP

method in Tongliao City by the Inner Mongolia Agricultural University, they found that the carbon densities of tree, grass,

litter and soil layer were 31.83, 0.13, 0.65 and 72.38 t·hm-2

, respectively. The Xinjiang University found that the carbon

intensity of hungriness shrubbery was 0.47-1.44 kg m-2

after afforestation in Karamay of Xinjiang.

The Institute of Geographic Sciences and Natural Resources Research of Chinese Academy of Sciences investigated the

poplar plantations in Tianjin city. Total ecosystem carbon storage of young, medium and mature poplar plantations were

estimated to be 84.3, 121.0 and 121.7 t C·hm-2

, respectively.The carbon storage of poplars measured by the Anhui

Academy of Forestry was 196.0 t·hm-2

in Yixiu District of Anhui Province. Whereas, the value measured by Hubei

Academy of Forestry ranged from 41.3 to 117.1t·hm-2

in 4- to 8-year-old plantations in Jianghan Plain. The Linyi

University found that the microbial biomass carbon in middle and mature poplar plantations were 120.7-323.9 and

183.7-418.2 mg·kg-1

, respectively. Thus, the poplar plantations in China could have a huge carbon sequestration potential

in the future.

6.1.3 Effects of cultural operations on carbon sinks in poplar plantations At present, there are many researches on different cultural operations to promote the carbon sequestration of poplar

plantation in China. The tree carbon of Dl (wide and narrow row + subsurface drip irrigation with water, fertilizer +

intercropping cotton and wheat) and D2 (wide and narrow row + irrigation +alfalfa intercrop) were 53.7% and 7.9%

higher than that of CK (uniform spacing + irrigation + intercropping cotton), respectively, in 4-year-old triploid P.

tomentosa plantations in the Yellow River flood plain of Shandong province. The annual carbon sequestration capacities

were 14 and 16t·hm-2

, respectively, which were higher than that of CK (9t·hm-2

). The technique for increasing carbon sink

in this area was the combination of wide and narrow row planting scheme, subsurface fertigation, and alfalfa

intercropping.

The carbon storage under subsurface drip irrigation was 76.5t·hm-2

, which was 54.2% higher than that under normal

irrigation in 6-year-old poplar plantations of I-214 at sandy soil in Chaobai River in Beijing. The carbon storage of tree

story, understory plants, litter floor and soil of stump grafting plantation were 2.6, 4.1, 3.1 and 1.1 times of that in

reforestation plantation in the 9-year-old protection poplar plantation in Daxing of Beijing, and the annual net carbon

increment was 10.0t·hm-2

. Therefore, stump grafting is an carbon sink enhancement technology, which could serve as an

improvement of poplar plantation protection method in Daxing District, Beijing. Carbon storages and distribution of three different patterns of poplar-crop intercropping patterns were studied with a biomass measurement method in the North of

Jiangsu Province by NFU. Results showed that soil carbon storage of the three patterns were 71.19, 40.67 and 42.64 t·hm-2

,

respectively.

6.2 Environmental protection and control

26

6.2.1 Sandy land control

Although the role of poplar in sandy land control is controversial in China, some breakthroughs have been made in the recent

years. Sand-fixing poplar forests with low coverage banded planting scheme has been planted by the Chinese Academy of

Forestry (CAF) in southern Horqin, and its effects on sand fixing was significant, especially under the forest band with 20 m

width. The ‘low coverage sand fixing method’ achieved that quicksand could be fixed completely when the vegetation

coverage reached 20%, which was a breakthrough of the traditional concept that the quicksand could not be fixed with a

vegetation coverage under 40%. It could not only accelerate the natural restoration process of the inter-band vegetation, but

also it can also improve soil conditions.

In the east Bashang forest-steppe and northwest basin-mountain of Hebei province (two types of heavy sandification lands), a

model of comprehensive assessment for sand-fixing plantations was built up by CAF based on experiments conducted in the

fifteen types of sand-fixing stands composed of different tree species including Larix principis-rupprechtii Mayr, Pinus

sylvestnis, P. beijingensis, Ulmus pumila L., Platycladus orientalis, P. simonii Carr., P. popular’s and P. bolleana. Research

results showed that concerning the scattered sandy land of northwest basin-mountain in Heibei province, P. popular’s and P. bolleana could be used for afforestation. In order to understand the effect of sand-fixing plantation in scattered sandy land,

stand structure factors and sand transporting rate were observed by Hebei Academy of Forest Science (HAFS) focusing on

eight types of poplar stands including three tree species of P. simonii Carr., P. popular’s and Populus bolleana. The research

results showed that the sand transporting rate was influenced by canopy density and average tree height in horizontal and

vertical direction, respectively, and their coupling effects could significantly decreased the sand transporting rate. In general,

different types of sand-fixing poplar plantations could intercept sand and reduce sand erosion to different degrees.

6.2.2 Farmland sheltbelt To protect farmland from natural disasters and improve productivity, a large area of shelterbelts consisting of poplars have

been widely planted in the northern part of China. The research conducted by the Second Institute of Forestry Monitoring and

Planning of Inner Mongolia Autonomous Region showed that, soil physical properties in the sheltbelt could be improved, such

as reduction of the coarse and middle sand content, increase of clay particle content and soil porosity, and increase of soil

organic matter and total nitrogen, etc. Besides, under the protection of the sheltbelt, the production of maize, wheat and

soybean increased by 6.5%, 6.4% and 20%, respectively. The Xinjiang Academy of Forestry Sciences found that, in Hetian

region of Xinjiang province, the proportion of biomass in P. bolleana sheltbelt accounted by trunk increased with forest age.

The soil carbon storage decreased with depth in stands within different age classes, and the carbon density was higher in

surface soil than in other layers. Besides, carbon storage in mature stands was 17.4 times of that in young stands.

6.2.3 River and beach land treatment

The long-term subsidence and severe soil erosion on the ground contributed to the formation of sand shoals and flaky beaches

with different width along the downstream segment of the Yangtze River and Yellow River and its tributaries. Beaches of

Yangtze River are low and flat with an altitude ranging from 13 to 17m. The loose and fertile stratification soil is exposed out

of water during common water period but often gets flooded during the flood period. Thus, afforestation in beaches should

apply the appropriate tree species to the suitable planting site, and subsequently improve the afforestation quality in beaches in

the middle and lower reaches of the Yellow River and Yangtze River, and establish good ecological network system in these

beaches. In order to select the poplar clones suitable to be planted on the beaches of Yangtze River, the growth and survival

rate of twenty poplar clones were tested and compared by NFU. The results showed that the integrated values of poplar clone

895, clone 324 and clone 1388 were the highest. The research conducted by Anhui Agricultural University indicated that,

afforestation of poplars in beaches could significantly enriched the botanical community diversity, and limited the

development of snail community. In addition, under the background that afforestation has been conducted in a large area of the

Yangtze River beach, NFU investigated the effects of thinning treatments on the nitrogen transformation in poplar plantations,

which provided the theory basis for plantation structure adjustment and big-diameter timber poplar cultivation. There is a

larger area of beach in the middle and lower reaches of the Yellow River, and poplar is the main species for afforestation in

this region. Thus, afforestation with poplar species in beaches could not only increase the ecological benefits, but also increase

the economic benefits. For example, the water bureau of Binzhou City investigated the effects of different vegetation types on

sand fixation, water saving and soil protection, and soil quality improvement. The research results showed that, poplar

plantations had strong ability in resisting wind erosion, and could improve water storage in surface soil and soil permeability to

a certain extent.

6.2.4 Phytoremediation of polluted soil and water

Poplars are often used for phytoremediation due to their fast growth, deep rooting and strong water absorption ability.

Poplars can uptake a lot of pollutants, including fertilizer, metal, non-metal, etc. However, if the polluted water is used to

irrigate the forests, the chemical composition in it will do harm to the trees. Damage caused by polluted water include leaf

damage, leaf early maturity and aging, biomass decrease, etc. A better understanding of the negative influence posed by

polluted water on trees in short term is important, since it helps to predict the influences in long term. To study the effects

of domestic waste water on soil microbial community, biomass and enzymes activities, a wastewater irrigation experiment

27

was conducted by Zhengzhou Agriculture and Forestry Science Institute in poplar woodland with different irrigation

volumes (0, 300, 600,900, 1200 and 1500 m3·hm

-2).Results showed that when the irrigation volume was 600 -900 m

3·hm

-2,

the amount of soil microorganism, the content of soil microbial biomass and the enzyme activity was higher. And the soil

indicators changed with irrigation volume. The soil microbe amount decreased, the soil physical and chemical properties

also showed a decreasing tendency. The Chinese Academy of Forestry did a research about the influence of compost

sludge on the two varieties P. euramaricanacl ‘Lingfeng3’ and P. euramericana ‘Guariento’ based on greenhouse pot test,

the results showed that some of the heavy metal elements such as Cu, Zn, As, Hg mainly accumulated in roots, and Cd

mainly accumulated in leaves; with the addition of sludge, the accumulation of heavy metal in leaves, stems and roots

increased, especially in roots. BFU did a research on the effect of irrigation with different dilutions of paper mill effluents

(PME) on growth and nutrient status of P. tomentosa seedlings. The findings showed that PME irrigation had no

significant effect on the pH and available P content of soil, while percentages of organic matter, total N, and available N

increased significantly with increasing concentration of PME. Thus, PME irrigation promoted the growth of P. tomentosa

seedlings, and increased plant nutrient status and soil fertility. The dilution concentration of PME for P. tomentosa should

be 16%—25%. A soil culture experiment was carried out by the Guangxi University to investigate the effects of Cd, Zn

and Pb combined pollution on biomass, heavy metal concentration and total uptake, bioaccumulation coefficient (BCF),

transportation factor (TF) in 14 poplar and willow species. Results showed that with the increasing of heavy metal

concentration in soil, heavy metal concentration and total uptake in poplar and willow species increased significantly, BCF

decreased obviously, whereas TF showed no change. The absorption and enrichment of heavy metal elements by leaves of

P. euramericana cv. ‘Neva’ was analyzed by CAF through content assessing of heavy metal elements in soils of three

forest lands at Fangshan District in the southern suburb of Beijing. P. euramericana cv. ‘Neva’ could absorb and

accumulate Pb，Cd，Cu and Zn in soil but showed different capacities of absorption and accumulation. Moreover, its Cd

absorption and accumulation capacity was strong, whereas its Pb and Cu enrichment capacities were relatively poor. The

analysis of the composition of the polychlorinated biphenyls in various organs of P. tomentosa and reed plant was

conducted by the Agricultural University of Hebei, it was speculated that poplar and reed had a certain bioremediation

effect on polychlorinated biphenyls.

Ⅲ. GENERAL INFORMATION

1．Administration and Operation of the National Poplar Commission or equivalent Organization 李金花

（a）Indicate here any changes in the composition of the Commission, amendments to its statutes, changes of address, etc.

The National Poplar Commission of China was established in 1980 and renamed as the Poplar Special Commission (PSC), a

secondary sub-society of Chinese Society of Forestry (CSF) in 1998. The PSC secretariat is affiliated to and located in

Research Institute of Forestry, Chinese Academy of Forestry, Beijing. In 2009, the seventh term of the board of the Poplar

Special Commission has been reelected, presently comprising the following members:

Director, Academician and Prof. Yin Weilun,

Vice Director, Prof. Lu Mengzhu,

Vice Director, Prof. Fang Shenzuo,

Vice Director, Prof. Lv Jianxiong,

Secretary Genera, Prof. Lu Mengzhu

The contact address of the Commission is as follows:

Poplar Special Commission, Chinese Society of Forestry

Research Institute of Forestry, Chinese Academy of Forestry

Yiheyuanhou, Beijing 100091

Tel: +86 10 62889606

Fax: +86 10 62872015

Email: lumz@caf.ac.cn

（b）Report briefly on meetings, congresses and study tours, and on other activities of a general nature organized by the

Commission at the national level.

With the leadership of Chinese Society of Forestry (CSF), the Poplar Special Commission (PSC) is annually active in

organizing and hosting conferences or meeting of CSF on scientific and technological themes each year as well as several

meetings of the board during the last four years. In some cases, PSC also is also involved in public discussions, technical

consulting activities and provides technical advices to relevant organizations dealing with poplar and willow.

（c）Indicate also the difficulties encountered by the Commission in the course of its work and any lessons learned

2．Literature

28

List here publications on poplars and willows issued in the period under review, (2012-2015) including technical papers

presented at meetings, congresses, etc.

Genetics and Breeding

Huang Qinjun, Su Xiaohua, Wang Shengdong, Man Shengjun, Yang Zhiyan, Shen Yingba (2014). Integrative Evaluation of

Populus×euramericana cl. ‘Bofeng1’ and Populus ×euramericana cl. ‘Bofeng2’ (Chinese). Scientia Silvae Sinicae, 50(5):

75-81.

Zeng Xianjun, Li Dan, Hu Yanpeng, Huang Qinjun, Su Xiaohua (2014). A Preliminary Study on Construction of High-Quality

Core Collection of Populus nigra (Chinese). Scientia Silvae Sinicae, 50(9): 51-58.

GAO Ming, DING Chang-jun, SU Xiao-hua, HUANG Qin-jun (2014). Comparison of Photosynthetic Characteristics of Populus

deltoides and Their F1 Hybrid Clones (Chinese). Forest Research, 27(6): 721-728.

DONG Yu-feng, JIANG Yue-zhong, ZHANG Ming-zhe, WANG Wei-dong, QIN Guang-hua, ZHAI Yang , YU Zhen-xu

(2014). Correlation between branch characteristics and growth traits, stem form for varieties in poplar plantation (Chinese).

Journal of Central South University of Forestry & Technology, 34(2): 34-38.

Hu Jianjun, Zhao Zicheng, Su Xuehui, Li Xilin, Lu Mengzhu (2014). A New Poplar Variety of Populus deltoides ‘ Zhongcheng

1’ (Chinese). Scientia Silvae Sinicae, 50(5): 159.

Hu Jianjun, Zhao Zicheng, Su Xuehui, Li Xilin, Lu Mengzhu (2014). A New Poplar Variety of Populus deltoides ‘Zhongyu 1’

(Chinese). Scientia Silvae Sinicae, 50(7): 170.

Hu Jianjun, Lu Mengzhu, Zhao Zicheng, Su Xuehui, Li Xilin, Li Shumei, Han Yifan (2013). An Elite Variety of Populus

deltoides ‘Nanyang' (Chinese). Scientia Silvae Sinicae, 49(7): 188.

张德强

Chai G, Hu R, Zhang D, Qi G, Zuo R, Cao Y, Zhou G (2012). Comprehensive analysis of CCCH zinc finger family in poplar

(Populustrichocarpa). BMC genomics, 13(1), 1.

Chai G, Qi G, Cao Y, Wang Z, Yu L, Tang X, Zhou G (2014). Poplar PdC3H17 and PdC3H18 are direct targets of PdMYB3

and PdMYB21, and positively regulate secondary wall formation in Arabidopsis and poplar. New Phytologist, 203(2),

520-534.

Chai G, Wang Z, Tang X, Yu L, Qi G, Wang D, Zhou G (2014). R2R3-MYB gene pairs in Populus: evolution and contribution

to secondary wall formation and flowering time. Journal of experimental botany, eru196.

Chen, J., Chen, B., Zhang, D. (2015a). Transcript profiling of Populustomentosa genes in normal, tension, and opposite wood by

RNA-seq. BMC genomics, 16(1), 1.

Chen J, Chen B, Yang X, Tian J, Du Q, Zhang D (2015b). Association genetics in Populus reveals the interactions between

Pt-miR397a and its target genes. Scientific reports, 5.

Chen J, Quan M, Zhang D (2015c). Genome-wide identification of novel long non-coding RNAs in Populustomentosa tension

wood, opposite wood and normal wood xylem by RNA-seq. Planta, 241(1), 125-143.

Chen J, Song Y, Zhang H, Zhang D (2013a). Genome-Wide Analysis of Gene Expression in Response to Drought Stress in

Populussimonii. Plant Molecular Biology Reporter, 31(4), 946-962.

Chen J, Xue B, Xia X, Yin W (2013b). A novel calcium-dependent protein kinase gene from Populuseuphratica, confers both

drought and cold stress tolerance. Biochemical and biophysical research communications, 441(3), 630-636.

Chen J, Zhang D, Zhang C, Xia X, Yin W, Tian Q (2015). A Putative PP2C-Encoding Gene Negatively Regulates ABA

Signaling in Populuseuphratica. PloS one, 10(10), e0139466.

Chen L, Ren Y, Zhang Y, Xu J, Sun F, Zhang Z, Wang Y (2012a). Genome-wide identification and expression analysis of

heat-responsive and novel microRNAs in Populustomentosa. Gene, 504(2), 160-165.

Chen L, Zhang Y, Ren Y, Xu J, Zhang Z, Wang Y (2012b). Genome-wide identification of cold-responsive and new

microRNAs in Populustomentosa by high-throughput sequencing. Biochemical and biophysical research communications,

417(2), 892-896.

Chen M, Wei M, Dong Z, Bao H, Wang Y(2015). Genomic identification of microRNA promoters and their cis-acting elements

in Populus. Genes & Genomics, 1-11.

Chen S, Bai S, Liu G, Li H, Jiang J (2014). Comparative Genomic Analysis of Transgenic Poplar Dwarf Mutant Reveals

Numerous Differentially Expressed Genes Involved in Energy Flow. International journal of molecular sciences, 15(9),

15603-15621.

Chen S, Jiang J, Li H, Liu G (2012). The salt-responsive transcriptome of Populussimonii× Populusnigravia DGE. Gene, 504(2),

203-212.

Chen S, Yuan HM, Liu GF, Li HY, Jiang J. (2012). A label-free differential quantitative proteomics analysis of a

TaLEA-introduced transgenic Populussimonii× Populusnigra dwarf mutant. Molecular biology reports, 39(7), 7657-7664.

Chen Z, Yang X, Su X, Rao P, Gao K, Lei B, An X. (2015a). Identification and expression analysis of APETALA1 homologues

in poplar. Acta Physiologiae Plantarum, 37(3): 50

Chen Z, Ye M, Su X, Liao W, Ma H, Gao K, An X. (2015b). Overexpression of AtAP1M3 regulates flowering time and floral

development in Arabidopsis and effects key flowering-related genes in poplar. Transgenic Res, 24(4), 705-715.

29

Cheng S, Huang Z, Li Y, Liao T, Suo Y, Zhang P, Kang X. (2015a). Differential transcriptome analysis between Populus and its

synthesized allotriploids driven by second-division restitution. J Integr Plant Biol, 57(12), 1031-1045.

Cheng S, Yang J, Liao T, Zhu X, Suo Y, Zhang P, Kang X. (2015b). Transcriptomic changes following synthesis of a Populus

full-sib diploid and allotriploid population with different heterozygosities driven by three types of 2n female gamete. Plant

molecular biology, 89(4-5), 493-510.

Chu Y, Huang Q, Zhang B, Ding C, Su X. (2014). Expression and molecular evolution of two DREB1 genes in black poplar

(Populusnigra). PloS one, 9(6), e98334.

Ci D, Song Y, Du Q, Tian M, Han S, Zhang D. (2015a). Variation in genomic methylation in natural populations of

Populussimonii is associated with leaf shape and photosynthetic traits. Journal of experimental botany, erv485.

Ci D, Song Y, Tian M, Zhang D. (2015b). Methylation of miRNA genes in the response to temperature stress in Populussimonii.

Frontiers in plant science, 6.

Dai X, Hu Q, Cai Q, Feng K, Ye N, Tuskan GA, Luo W. (2014). The willow genome and divergent evolution from poplar after

the common genome duplication. Cell research, 24(10), 1274.

Deng S, Sun J, Zhao R, Ding M, Zhang Y, Sun Y, Hou P. (2015). Populuseuphratica APYRASE2 enhances cold tolerance by

modulating vesicular trafficking and extracellular ATP in Arabidopsis plants. Plant physiology, 169(1), 530-548.

Dong CB, Mao JF, Suo YJ, Shi L, Wang J, Zhang PD, Kang XY. (2014a). A strategy for characterization of persistent

heteroduplex DNA in higher plants. Plant J, 80(2), 282-291.

Dong CB, Suo YJ, Wang J, Kang XY. (2014b). Analysis of transmission of heterozygosity by 2n gametes in Populus

(Salicaceae). Tree genetics & genomes, 11(1).

Dong Y, Du S, Zhang J, Yang M, Wang J. (2014c). Differential expression of dual Bt genes in transgene poplar Juba (Populus

deltoids cv. ‘Juba’) transformed by two different transformation vectors. Canadian Journal of Forest Research, 45(1),

60-67.

Dong Y, Wang C, Han X, Tang S, Liu S, Xia X, Yin W. (2014d). A novel bHLH transcription factor PebHLH35 from

Populuseuphratica confers drought tolerance through regulating stomatal development, photosynthesis and growth in

Arabidopsis. Biochemical and Biophysical Research Communications, 450(1), 453-458.

Du FK, Xu F, Qu H, Feng S, Tang J, Wu R. (2013a). Exploiting the transcriptome of Euphrates Poplar, Populuseuphratica

(Salicaceae) to develop and characterize new EST-SSR markers and construct an EST-SSR database. PloS one, 8(4),

e61337.

Du N, Liu X, Li Y, Chen S, Zhang J, Ha D, Pijut PM. (2012). Genetic transformation of Populustomentosa to improve salt

tolerance. Plant Cell, Tissue and Organ Culture (PCTOC), 108(2), 181-189.

Du QZ, Zhang DQ, Li BL. (2012). Development of 15 novel microsatellite markers from cellulose synthase genes

inPopulustomentosa (Salicaceae). American journal of botany, 99(2), e46-e48.

Du Q, Gong C, Pan W, Zhang D. (2013b). Development and application of microsatellites in candidate genes related to wood

properties in the Chinese white poplar (Populustomentosa Carr.). DNA Res, 20(1), 31-44.

Du Q, Pan W, Tian J, Li B, Zhang D. (2013c). The UDP-glucuronate decarboxylase gene family in Populus: structure,

expression, and association genetics. PloS one, 8(4), e60880.

Du Q, Pan W, Xu B, Li B, Zhang D. (2013d). Polymorphic simple sequence repeat (SSR) loci within cellulose synthase

(PtoCesA) genes are associated with growth and wood properties in Populustomentosa. New Phytol, 197(3), 763-776.

Du Q, Tian J, Yang X, Pan W, Xu B, Li B, Zhang D. (2015). Identification of additive, dominant, and epistatic variation

conferred by key genes in cellulose biosynthesis pathway in Populustomentosa. DNA research, 22(1), 53-67.

Du Q, Wang B, Wei Z, Zhang D, Li B. (2012). Genetic diversity and population structure of Chinese white poplar

(Populustomentosa) revealed by SSR markers. Journal of Heredity, ess061.

Du Q, Wang L, Yang X, Gong C, Zhang D. (2015). Populusendo-β-1, 4-glucanases gene family: genomic organization,

phylogenetic analysis, expression profiles and association mapping. Planta, 241(6), 1417-1434.

Du Q, Xu B, Pan W, Gong C, Wang Q, Tian J, Zhang D. (2013e). Allelic Variation in a Cellulose Synthase Gene (PtoCesA4)

Associated with Growth and Wood Properties in Populustomentosa. G3, 3(11), 2069-2084.

Du S, Wang Z, Ingvarsson PK, Wang D, Wang J, Wu Z, Zhang J. (2015). Multilocus analysis of nucleotide variation and

speciation in three closely related Populus (Salicaceae) species. MolEcol, 24(19), 4994-5005.

Fan D, Liu T, Li C, Jiao B, Li S, Hou Y, Luo K. (2015). Efficient CRISPR/Cas9-mediated targeted mutagenesis in Populus in

the first generation. Scientific reports, 5.

Gao M, Huang Q, Chu Y, Ding, C, Zhang B, Su X. (2014). Analysis of the leaf methylomes of parents and their hybrids

provides new insight into hybrid vigor in Populusdeltoides. BMC genetics, 15, S8.

Guo Y, Song X, Zhao S, Lv J, Lu M. (2015). A transient gene expression system in PopuluseuphraticaOliv. protoplasts prepared

from suspension cultured cells. ActaPhysiologiaePlantarum, 37(8), 1-8.

Han X, He G, Zhao S, Guo C, Lu M. (2012). Expression analysis of two NAC transcription factors PtNAC068 and PtNAC154

from poplar. Plant Molecular Biology Reporter, 30(2), 370-378.

Han X, Tang S, An Y, Zheng DC, Xia X L, Yin WL. (2013). Overexpression of the poplar NF-YB7 transcription factor confers

drought tolerance and improves water-use efficiency in Arabidopsis. J Exp Bot, 64(14), 4589-4601.

30

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Numerous Differentially Expressed Genes Involved in Energy Flow. Int. J. Mol. Sci., 15: 15603-15621.

Environmental use

Jia LM, LiuSQ, Zhu LH, et al. 2013. Carbon storage and density of poplars in China (Chinese). Journal of Nanjing

Forestry University, 02: 1-7.

So J, Jia LM, Wei YK, et al. 2012. Carbonstorage in fast-growing and highyield poplar plantations under subsurface drip

irrigation (Chinese). Journal of Beijing Forestry University, 01: 14-18.

Xu K, Xi Y, Zhang MS, et al. 2014. Effects of simulated nitrogen deposition on soil active organic carbon in poplar

plantations along Northern Jiangsu coast (Chinese). Chinese Journal of Ecology, 06: 1480-1486.

Cui HX, Tang WP, Hu XY, Pan L. 2012. Carbon Storage Dynamics During theGrowth of Poplar Plantation (Chinese).

Journal of Northeast Forestry University, 02: 47-49+60.

Xie T, Wang MH, Zheng AB, et al. 2012. Characteristics of soil labile organic carbon in poplar plantations of different

ages in coastal area of North Jiangsu (Chinese). Chinese Journal of Ecology, 01: 51-58.

Liu SQ. 2013. Carbon Storage and Characteristics of Carbon Pool of PoplarPlantations in Heze. Shandong (Chinese).

Beijing Foresty University.

Si J. 2012. Carbon Sequestration and Sink Enhancement Technologies of Several Kinds of Poplar Plantations in The

North of China (Chinese). Beijing Forestry University.

Wu D, Zhang R, Gao SH, et al. 2015. Effects of simulated nitrogen deposition on the each component of soil respirationin

the Populus L. plantations in a riparian zone of the mid-lower Yangtze River (Chinese). Acta Ecologica Sinica, 03: 717-724.

Xu GL, Feng ZH, Bai YR, et al. 2015. Distribution Characteristics of Soil Carbon Storage in Poplar Plantation in Chifeng

(Chinese). Journal of Inner Mongolia Forestry Science and Technology, 01: 15-16+22.

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Xing W, Bu DR, Ge ZW, et al. 2014. Study on carbon storage of poplar plantation at different stand ages (Chinese).

Ecological Science, 01: 154-160.

Bu DR, Zhou DY, Ge ZW, et al. 2015. Effects of biogas slurry on soil labile organic carbon of poplar plantation in a

coastalof northern Jiangsu (Chinese).Chinese Journal of Ecology, 07: 1785-1790.

Zheng SK, Liu FJ. 2015. Quantitative study on carbon sink function of Poplar Plantation in intensive cultivation (Chinese).

Forest Science and Technology, 11: 3-9.

Zhai MY, Zhou M, Zhao PW, et al. 2014. Carbon content rate and carbon density of Poplar Plantation in Tongliao City

(Chinese). Journal of Arid Land Resources and Environment, 06: 57-62.

Hao YP, Miao TT, Liu SQ. 2012. Research on the Forest Carbon Storage in Artificial PoplarPlantations in Yixiu District of

Anhui Province (Chinese). Journal of Sichuan Forestry Science and Technology, 02:65-69.

Li P, Xiao Y, Yang Y, et al. 2014. Ecosystem carbon storage in poplar plantations of different stand ages in Tianjin plain

(Chinese). Chinese Journal of Ecology, 03: 567-574.

Zhang WJ, Ma K, Shi QD, et al. 2012. The Study of the Influence Poplar Plantation CarbonSink Forest Acting on Soil

Organic arbon in Karamay (Chinese). Xinjiang Agricultural Sciences, 05: 856-861.

Yan MF, Wang L, Guo N, Shi H. 2015. Study on Fine Root Biomass and C Stock in a Poplar Plantation in Loess Plateau

(Chinese). Chinese Agricultural Science Bulletin, 35: 146-151.

Xing W, Qi WL, Zhao Q, Ge ZW. 2015. Analysis on carbon storage of poplar plantation in Jiangsu Province (Chinese).

Journal of Jiangsu Forestry Science and Technology, 02:15-18.

Zhao D, Ma X. 2012. Study on carbon storage and carbon density of poplar forest in Jiangsu Province (Chinese). Jilin

Agriculture, 05: 139-140.

Wei HD, Dong B. 2012. Spatial-temporal dynamics of soil microbial biomass carbon in Populus tremula plantations in

thesoutheast of Shandong province (Chinese). Ecology and Environmental Sciences, 02: 233-238.

Jing LN, Yang WB, LU Q, et al. 2013. The effect of low-covered sand-fixing forest belts on restoration of the soiland

vegetation.Acta Ecologica Sinica, 33(10): 3192-3204.

Ma ZW. 2013. Study on Characteristics and Comprehensive Assesmentof Sand-fixation Plantations in Northern Hebei

Province (Chinese). Chinese Academy of Forestry.

Wu X Q. 2013. Study on the Growth Advantage and Interface Effect of Low Coverage Banded Sand-fixing Forest

(Chinese). Chinese Academy of Forestry.

2013. Study on sand transporting rate of different types of Poplarsand-fixation plantation in scattered sandy land of in

Northern Hebei.Journal of agriculture of Hebei, 5:015.

Zhu JJ. 2013 .A review of the present situation and future prospect of science of protective forest (Chinese). Chinese

Journal of Plant Ecology, 37(9): 872-888.

Fu JM. 2013. The ImpactonEcological and Economic Benefits of Farmland PasturesShelter Forests Construction in Horain

Left Back Banner (Chinese). Inner Mongolia Forestry Investigation and Design, (03): 16-17.

Bao CR. 2015. The role of farmland protection forest in Northwest China (Chinese). China Agriculture Information, (04):

38-39.

Sang BY, et al. 2015. Carbon storage of Populus albs var. pyramidalisa Bungefarmland shelter forest with different ages

(Chinese). Journal of Southern Agriculture, (08): 1455-1456.

Tang LZ, Wu L, Ge XM, et al. 2013. Comparative Studies on the Growth of Different Poplar Clones on Beach Land of

Yangtze River (Chinese). Forest Research, (1):123-128.

Sun YY, Wan LH, Huang CL. 2012. Study onthe Botanical Diversity in Marshland Poplar Plantations in the Middle and

Lower Reaches of Yangtze River (Chinese).Anhui Forestry Science and Technology, 2012, 38(2): 3-6.

Wang WX, Ke WS, Wu MY, et al.2013. Study on the effect of nine kinds of Yangtze River forestry model on Oncomelania

allelopathy (Chinese). Summary of the Symposium on the sixth annual plant of China.

Dun XJ, Qu HH, Tian Y, et al. 2013. Effects of thinning treatments on soil available nitrogen of the poplar plantationsin

flooding land of Yangtze River.Journal of Nanjing Forestry University(Natural Sciences Edition), 37(4)：45-50.

Wamg GX, Xoa JB, Sun NN, et al. 2015. Studyvegetationon Function of Soil and Water ConservationTypes of Yellow

River Irrigation Area in thefor DifferentYellow River Delta (Chinese). Journal of Soil and Water Conservation, (2):

111-116.

Liu YL, Wu FX, Xu Y, Di KB, et al. 2012. Research Progress in the Remediation of Heavy MetalContaminated Soils with

Populus (Chinese). Forest Research, 48(9): 139-144

Bai BX, Shen ZG. Effect of Domestic Wastewater Irrigation on Soil Microbial Community (Chinese). Jourof Fujian

Forestry Sci and Tech, 2014，41(2)：42-46.

Bai BX. 2013. Effect of Domestic Wastewater Irrigation on Soil MicrobialBiomass and Enzymes Activities.Henan

Science, 31(10): 1628-1630.

Qi HT, Bai LP, Lu HB, et al. 2014. Effect of Composted Sewage Sludge on the Changes of Heavy Metal Accumulations

36

in Different Poplar Varieties (Chinese). Journal of Northeast Forestry University, 42(11): 22-27.

Wang Y, Xi BY, Cui XD, et al. 2013. Effectsof irrigation with paper mill effluent on growth and nutrient status of Populus tomentosa seedlings.Acta Ecologica Sinica, 33(5): 1626-1635.

Zhang CY, Wang RG, Fan ZL, et al. 2013. Difference in Cadmium, Zinc and Lead Accumulation of Poplar and Willow

Species (Chinese). Journal of Agricultural Environmental Science, 32(3): 530-538.

Zhang CY. 2013. The Effects of Carbon Dioxide and Burkholderia onRemediation of Heavy Metal by Poplar and Willow

(Chinese). Guangxi University, 1-50.

Li JH, He Y, Duan JP, et al. 2012. Absorption and Accumulation of HeavyPopulus×euramerzcana cv. Metal from Soil by

Leaves of ‘Neva’ Plantation (Chinese). Forest Research, 25(1): 65-70.

Li Z. 2012. Phytoremediation of Polychlorinated Biphenyls byPopulus tomentosa Carr and Phragmites australis(Cav.)

Trin. ex Steud (Chinese). Hebei Agriculture University, 1-32.

Yang L, Zhang LQ, He W, Chang JP, Guo LM. 2014. Type Ⅲ secretion system is an essential pathogenic factor in poplar

canker pathogen Lonsdaleaquercina.Acta Phytopathologica Sinica, 44(5): 512-520.

Chen L, Ren YY, Zhang YY, Xu JC, Zhang ZY, Wang YW. 2012. Genome-wide profiling of novel and conserved Populus

microRNAs involved in pathogen stress response by deep sequencing. Planta, 235: 873–883

Liao WH, Ji LX, Wang J, Chen Z, Ye MX, Ma HD, An XM. 2014. Identification of glutathione S-transferase genes

responding to pathogen infestation in Populustomentosa. Funct Integr Genomics, 14: 517 –529

Wu QM, Chen M, Zhou HL, Zhou XQ, Wang YW. 2015. Metabolite profiles ofPopulus in response to pathogen stress.

Biochemical and Biophysical Research Communications, 465: 421-426

Zhao H, Wang S, Chen S, Jiang J, Liu GF. 2015. Phylogenetic and stress-responsive expression analysis of 20 WRKY genes

in Populus simonii × Populus nigra.Gene, 565, 130–139.

Ma J, Liu ZY, Lü Q ,Liang J, Yan DDH, Zhang XXY. 2012. Difference in expression of hydrogen peroxide and oxidative

eenzymes in different resistant poplars inoculated with Botryosphaeria dothidea. Journal of Northeast Forestry University,

40(12): 118-122, 146.

Liu WX, Ma CM, Zhao JP, Wan XC. 2015. Expression pattern of aquaporin genes under drougt-Botryosphaeria dothidea

interaction in Populus beijingensis .Journal of Agriculture University of Hebei, 38(2): 19-24.

Yang MX, Song RQ. 2014. Expression of zinc finger protein gene in Populus alba × P. berolinensis in the infection process by

Cytospora chrysosperma.Bulletin of Botanical Research, 34(4): 510-515.

Li B, Li AM, Wei Q, Wang HM, He W. 2015. Functional analysis of hrcJ gene in Lonsdalea quercina sub sp. populi. Scientia

Silvae Sinicae, 51(12): 71-78.

Li Y, Piao CG, He W, Guo LM, Chang JP, Xie SJ, Guo MW, Lin LM. 2013. Analysis ondominant population of fungus and

bacteria from healthy and canker disease-infected Populus × euroamericana bark. Forest Research, 26(1): 41-45.

Zhang XY, Song RQ, Zhang XY.2015. Response of transcription factors of Populus tomentosa to inoculation with

Botryosphaeria dothidea.Scientia Silvae Sinicae., 51(4):110-115

Zhang YB, You CJ, Fan XL, Tian CM. 2014. Taxonomy and phylogeny of Cytospora in Northeast China.Mycosystema, 33(4):

806-818.

Yang MX, Song RQ. 2013. Pathogenic differentiation and genetic diversity of Cytospora chrysosperma in China.Scientia

Silvae Sinicae, 49(6): 115-121.

Disease Diagnosis and Identification

Li Y, Wang T, Piao CG, Wang LF, Tian GZ, Zhu TH, Guo MW. 2015. Lampropedia puyangensis sp. nov., isolated from

symptomatic bark of Populus × euramericana canker and emended description of Lampropedia hyaline (Ehrenberg

1832) Lee et al. 2004. Antonie van Leeuwenhoek, 2015, 108:321–328

Pan YW, Tan JJ, Ye JR. 2012. Description of several nematode species of Tylenchida and Dorylaimida from poplar

rhizosphere in Jiangsu province. Scientia Silvae Sinicae, 48(8): 161-165.

Zhang H. 2013. Pathogenicity and genetic diversity of poplar rust, Melampsora larici-populina Kleb, Thesis for Masters

Degree of Northeast A&F University. 2013.

You X, He W, Chang JP, Guo LM, Xie SJ, Yang YQ. 2013. The effect of Fusarium solani on the occurance of Populus×euramericana canker disease,Chinese Agricultural Science Bulletin, 29(19):21-25.

Jiang ZR, Zhang GL, Cao ZM, Zhou L. 2012. Geographical species of Poplar canker pathogen in Shaanxi province.

Journal of Northwest Forestry University, 27(2):102-108

Zhao GH, Li DW, Xi GJ. 2013. Studies on the symptoms and Phyllactinia populi on Italian hybrid poplars and Populus deltoides cv. Zhonghua hongye,Journal of West China Forestry Science, 42(3): 1-6.

Wang YL. 2013. The phylogeny and genetic diversity of Cytospora spp. species isolated from poplar canker. Doctoral Dissertation of Nanjing Forestry University.

Wang YL, Lv Q, Decock C, Li YX, Zhang XY. 2015. Cytospora species from Populus and Salix in China with C. davidiana sp. nov. Fungal Biology, 119: 420-432.

37

Liu XY, Panaxi S, Liu XF, Ma L. 2014. Pathogen identification of Populus alba × berolinesis poplar scab. Journal of

Anhui Agri. Sci. 42(17): 5451-5452, 5454.

Zhao GH, Xu JJ, Li GH, Meng QL, Shi LY,Yang HG. 2013. Study on Canker of Populus × euramericana CL ‘74

/76’Caused by Apiocarpella macrospora. Journal of West China Forestry Science, 42(6): 10-16.

Disease Resistance

Ma J, Liu ZY, Lv Q, Liang J,Yan DH, Zhang XY. 2013. Differential expression of SA and H2O2 between susceptible and

resistant poplars challenged by Botryosphaeria dothidea. Scientia Silvae Sinicae, 49(1): 107-113.

Yang HY, Du X, Pan SH, Teng WF. 2013. Study on changes of defense enzymatic activity for different Populus with

Melampsora resistance. Modern Agricultural Science and Technology, 12: 139-141.

Zhu JF, Zhou YB. 2012. Differences in chemical constituents of poplar varieties with different anti-rust resistances.

Journal of Northeast Forestry University, 40(9): 72-76.

Liu ZY, Su YX, Zuo T, Chang JP, Guo LM, He W, Wang YW. 2015. The Differential expression analysis of the SA and JA

signal transduction related genes in poplar varieties susceptible and resistant to canker. Chinese Agricultural Science

Bulletin, 31(14): 156-163.

Huang GW, Wan ZB, Qiao SH, Ma LJ, Liu SF, Zhang XY. 2013. Comparative study on the growth characteristics and

resistance to rust disease of Populus deltoides saplings among different families. Journal of Southwest Forestry University,

33(4): 12-16.

Gao GZ, Li C, Wang QH, He BL, Nie HD, Gao KX. 2012. Influence ofendophytic fungus Chaetomium globosum ND35 on

resistance to plant diseases and activities of defense enzymes.Shandong Agricultural Sciences, 44(8): 86-88, 91.

Niu QL, Wang Y, Luo L, Huang YY, Liu J, Feng D, Cao BH. 2013. Transformation of BG2 Gene into Populus × euramericana cv. ‘Neva’ and resistance of the transgenic poplar to canker disease.Scientia Silvae Sinicae, 49(11): 60-66.

Wang CZ, Guo AH, Zhang YS, Zhang XD, Mao LX. 2012. Study on Meteorological Forecasting Model of Valsa sordida Nits

in Northeast China. Chinese Agricultural Science Bulletin 28(10): 47-52.

Ni L, He W, Chang JP, Guo LM, Xie SJ, Yang YQ, Xu QG, Shang J. 2014. Forest stand and meteorological factors effect on

occurrence of Lonsdalea canker of poplar. Journal of Central South University of Forestry & Technology, 34(8): 53-58.

Zhao GC. 2012. Analysis on urediniospore spreading law of Melampsora larici-populina in Guanzhong area of Shaanxi

Province. Journal of Shouthwest Forestry University, 32(1): 56-60.

Pest Control

Yang L, Zhou GY, Liang J. 2015. Inhibitory effects of two biocontrol fungous strains on poplar canker Botryosphaeria

dothdea.Scientia Silvae Sinicae, 51(8): 67-73.

Xu T, Zhu TH, Li SJ, Qiao TM. 2014. Fungus-inhibitory activity and gene cloning of β−glucanase from Bacillus velezensis YB15. Chinese Journal of Biological Control, 30(2): 276-281.

Yan AQ, Wu XQ, Ye JR, Fan B. 2012. Isolation, antifungal effect and characteristics of non-protein substances produced

by Bacillus pumilus JK-SX001. Journal of Nanjing Forestry University (Natural Science Edition), 36(3): 13-16.

Yang L, Zhou GY, Liang J, Ni Y, Lü Q, Zhang XY. 2014. Isolation, screening and identification of the endogenous

microorganisms antagonizing poplar canker. Acta Phytophylacica Sinica, 21(4): 438-446.

Huang Y, Liu H, Yuan L, Jia ZC, Luo KM. 2012. Overexpression of LAR3 and Bbchit1 genes in transgenic Populus

tomentosa raising the resistance to Alternaria alternate.Scientia Silvae Sinicae, 48(7): 92-97.

Chi YJ, Yi HW, Li DD. 2012. Antagonistic action of conidial extracts of Trichoderma harzianum on Cytospora chrysosperma and Magnaporthe grisea .Journal of Northeast Forestry University, 40(9): 90-92,106.

Zou L, Tan Y,Yang MB, Sun TT. 2012. Antimicrobial activity of fermented product from Inonotus obliguus. Journal of

Northeast Forestry University, 40(11): 123-126.

Zou L, Tan Y, Yang MB. 2013. Study on the Antimicrobial activity from Phellinus linteus fermentation product.Chinese

Agricultural Science Bulletin, 29(21): 78-82.

Yin DC, Deng X, Chet I, Song RQ. 2014. Inhibiting effect and mechanism of Trichoderma virens T43 on four major

species of forest pathogen. Chinese Journal of Ecology, 33(7): 1911-1919.

Li CW, Yang LB, Deng X, Chet I,Song RQ. 2012. Inhibiting effects and mechanism of Trichoderma strains to Cytospora

chrysosperma.Scientia Silvae Sinicae, 48(9): 88-94.

Li CW, Song RQ. 2015. The Screening and physiology characteristic of efficient antifungal strain on Cytospora chrysosperma.Chinese Agricultural Science Bulletin, 31(1): 150-155.

Jin HQ, Jia B, Li XY. 2012. Identification of endophytic antagonistic bacteria from Populus sp. and its application in

control.Forest Pest and Disease., 31(6): 1-5.

Liu BS, Gu XS, Liu XL, Zhang SQ, Kang SH, Zhang SF. 2013. Indoor toxicity determination of 7 fungicides against

Cytospora chrysosperma and Dothiorella gregariain poplar. Forest Pest and Disease, 2013,32(5):1-3.

Liu BS, Gu XS, Sun SQ, Zhang SF, Kang CH, Wang DJ. 2013. Effect of 8 fungicides on poplar powdery mildew and

chlorophyll content.Forest Pest and Disease, 32(4): 36-38.

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Liu BS, Bai PH, Feng YR, Zhang LQ, Meng LH, Zhang SQ. 2015. Indoor toxicity determination and field efficacy test of

ten fungicides against poplar rust.Forest Pest and Disease, 34(3): 44-46.

Hong XJ, Pi XJ, Cui BY, Zhou F, Liu M, Cui JY. 2014. Chemical control trials for Cytospora and Dothiorella gregaria

Sacc. canker of poplar sp.Tianjin Agricultural Sciences, 20(6): 118-123.

Utilization

Bi Z. 2015. Research on the properties and mechanisms of chemical modified wood by DMDHEU. Thesis for Masters

Degree of Beijing Forestry University.

Cai XR. 2015. The study on structural processes and performance of laminated veneer hollow column. Thesis for Masters

Degree of Nanjing Forestry University.

Chai YB, Liu JL, Sun BL, et al. 2015. Dimensional stability, mechanical properties and combustion performance of poplar

wood modified with a mixture of MUF/ boric acid/ borax. China Wood Industry, 29(3): 5-9.

Chang L. 2014. Formation Mechanism and Interface Status Evaluation of High Density Polyethylene Poplar Composite

Plywood. Thesis for Doctors Degree of Chinese Academy of Forestry.

Chen C, Fan XL, Deng YH, et al. 2013. Densification of poplar veneer. Journal of Zhejiang A & F University, 30(4):

536-542.

Chen GZ, Gao ZX, Ma H, et al. 2013. Investigation and characterization on synthesis of nano-CaCO3 and composite with

fast-growing poplar. Journal of Northeast Forestry University, 41(4): 108-111.

Chen M, Deng YH, Chen C, et al. 2012. Study on poplar densification by cross-grain compression. Journal of Southwest

Forestry University, 32(5): 80-85.

Chen MJ, Wu JR, Deng YH, et al. 2015. Research on the properties of salix discolor branch of its scrimber. Journal of

Southwest Forestry University, 356(1): 75-81.

Chen XY, Sun DD, Wang ZP, et al. 2014. Creep behavior of poplar parallel strand lumber. Journal of Northwest Forestry

University, 29(4): 203-207.

Chen Y, Chen MZ, He MP, et al. 2014. Hot pressing technique for poplar plywood bonded with modified soybean protein

adhesive. China Forestry Science and Technology, 28(4): 102-105.

Chen YP, Wang Z, Chang L, et al. 2014. Analysis on properties diversity of different species of poplar plantation and their

effects on the bonding strength of plywood. China Forest Products Industry, 41(4): 11-14.

Dong GP, Deng YH, Wang XZ, et al. 2013. Study on salix discolor properties and its particleboard manufacturing

technology. Journal of Southwest Forestry University, 33(3): 92-96.

Dong HG, Wang CG, Tu DW, et al. 2014. Manufacture and performance analysis of composite board using poplar veneer

and paper sludge. China Forest Products Industry, 41(5):27-29.

Dong LY, Hu HR, Cheng F, et al. 2015. Analysis of the compositions of APMP effluent. China Pulp & Paper, 34(1):

29-33.

Du C, Tu DY, Lao YM, et al. 2013. The experiment on hot pressing process for thermally treated Populus tomentosa Carr.

Lumber. China Forestry Science and Technology, 27(6): 105-107.

Du J, Wang WX, Meng X, et al. 2014. Effects of sodium bisulfite pretreatment on the chemical composition and

enzymatic hydrolysis of poplar pulp. Journal of Cellulose Science and Technology, 22(1): 18-24.

Fang GG, Liu SS, Shen KZ. 2014. Optimization of dilute-sulfuric acid pretreatment of poplar residues by using response

surface design. Biomass Chemical Engineering, 48(6): 18-24.

Fang L, Chang L, Guo WJ, et al. 2014. Performance comparison of HDPE plywood with UF resin plywood．Journal of

Beijing Forestry University, 36(2): 125-128.

Fang L. 2014. Interfacial modification methods and mechanism of high density polyethylene film/poplar veneer plywood.

Thesis for Doctors Degree of Chinese Academy of Forestry.

Guo S, Hou LD, Ou SX, et al. 2014. Techniques of self-bonding by interfacial liquefaction for poplar plywood processing.

China Forestry Science and Technology, 28(6): 124-126.

Han J, Zhou WJ, Zou Y, et al. 2014. Tensile and bending properties of bamboo/wood composite board. Journal of Central

South University of Forestry & Technology, 34(10): 107-110.

He SS. 2015. Investigating the properties of small diameter Salix discolor and its medium density fiberboard. Thesis for

Masters Degree of Nanjing Forestry University.

He W, Jiang SX, Zhang QS, et al. 2013. Properties of poplar modified with monomers using in situ polymerization. China

Wood Industry, 27(1): 17-20.

Hou RG, Li XJ, Liu Y, et al. 2015. Study on impregnation technology by using UF resin for fast-grown poplar wood.

Journal of Central South University of Forestry & Technology, 35(1): 122-125.

Hou RG. 2015. Study on impregnation enhancement-heat treatment technology about poplar lumber. Thesis for Masters

Degree of Central South University of Forestry and Technology.

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Hu SW, Cui WY, Shen Y, et al. 2013. The Preparation and the study of mechanical properties of the copper plating at

man-made board. Journal of Inner Mongolia Agricultural University, 34(1): 128-132.

Huang MX. 2014. Study on the preparation process of microcrystalline cellulose from salix psammophila. Thesis for

Masters Degree of Zhengzhou University.

Huang RZ, Zhou ZB, Zhang Y, et al. 2012. Immersion treatment of straw fiberboard with micro poplar fibrils. China

wood Industry, 26(1): 24-26.

Huang RZ, Zhang Y. 2012. Study on the properties of straw fiberboard improved with micro/nano poplar fibril. China

Forest Products Industry, 39(3): 20-23.

Huang XB, Wei PX, Wang QZ. 2013. Measurement and analysis of longitudinal elastic modulus and poisson’s ratio of

high frequency hot pressing poplar laminated veneer lumber. Packaging Engineering, 34(5): 1-4.

Jia C, Zhang Y, Wu DY, et al. 2013. Processing and properties of poplar multi-plywood with soybean adhesive. Journal of

Northwest Forestry University, 28(3): 190-193.

Jin CD, Li JP, Yang W, et al. 2014. Morphological characteristics and chemical properties of wood fiber in the binderless

fiberboard during the manufacture process with the acidic steam steaming hot mill method. Journal of Northeast

Forestry University, 42(2): 104-107.

Ke Q, Yang SY, Wang JY, et al. 2015. Preliminary study on pivotal technology of furniture design based on modified

fast-growing poplar. China Forestry Products Industry, 42(2): 8-14.

Lang Q, Chen HY, She Y, et al. 2012. Effect of wood modifiers on the physical properties of fast-growing poplar wood.

Journal of Zhejiang A & F University, 29(5): 686-690.

Li B. 2014. Dyeing behavior based on dyed poplar with reactive dyes. Thesis for Masters Degree of Northeast Forestry

University.

Li CG, Wang BY, Xie DW, et al. 2015. Effect of dimensional stability assembly performance following impregnation

treatment of poplar wooden parts. China Wood Industry, 29(6): 30-32.

Li F, Ou YL, Wang L, et al. 2014. Effect of AC/ZnO composite foaming agent on properties of EVA/poplar wood powder

foaming composites. Plastics Science and Technology, 42(1): 120-123.

Li JX, Chen GH, Wang JL, et al. 2013. Effect of modified PF adhesive on the properties of decorative fiberboard with

aluminum foils. Journal of ZheJiang Forest Sci. & Tech, 33(2): 15-18.

Li J. 2013. Wood-organic aerogel composite materials research. Thesis for Doctors Degree of Northeast Forestry

University.

Li Q. 2012. Study on basic theory and key technology of salix medium density fiberboard reinforced by poplar or willow

wood fiber. Thesis for Doctors Degree of Inner Mongolia Agricultural University.

Li SS, Zhang Y, Wang C, et al. 2013. Preparation of micro/nanofibrils with synergistic treatment of cellulase and

mechanical processing. Tianjin Agricultural Sciences, 19(11): 4-8.

Li SJ, Feng GP. 2014. The application of aspen APMP pulping waste liquor in surface sizing of fluting medium. East

China Pulp & Paper Industry, 45(3): 21-23.

Liang YF. 2014. The study on the properties of salix torrefacted coal. Thesis for Masters Degree of Inner Mongolia

Agricultural University.

Liu C, Zhang Y. 2015. Thermal analysis on the bond strength of the soybean adhesive improved by nanocrystalline

cellulose. Packaging Engineering, 36(13): 15-19.

Liu XY, Zhou XY, Zhang WD, et al. 2012. Study on hot-pressing of poplar fiberboard with oxygen plasma-treated

enzymatic hydrolysis lignin as a natural binder. China Forest Products Industry, 39(4): 24-27.

Liu Yuan-qiang. 2012. Miter Quality Improvement for Poplar Laminated Veneer Lumber. China Wood-Based Panels, 8:

14-16.

Luo L, Zhang HY, Liu Y, et al. 2014. Manufacturing Technology Study of reed /wood composite packaging materia.

Packaging and Food Machinery, 32(2): 1-4.

Luo L, Zhao F, Liu Y, et al. 2014. Study of hot pressing process for composite packaging material made from waste paper

and wood. Packaging Journal, 6(1): 44-47.

Na B, WanG WW, Wang SJ et al. 2012. Glue application and hot-pressing technology of parallel strand lumber. Journal

of Northwest Forestry University, 27(1): 241-245.

Pan B, Wang F, Lian CP. 2014. Physical and mechanical properties of new Populus deltoides clones. Journal of Anhui

Agricultural University, 41(6): 928-933.

Pang J, Li DG, Deng QY, et al. 2012. Light transmittance study on cellulose nanofibers/epoxy resin composite film. China

Plastic Industry, 40(9): 108-111.

Peng C, Zhang ZW, Xia CY, et al. Optimized drying process for resin impregnated Aspen wood. Journal of Fujian

Agriculture and Forestry University, 44(3): 329-332.

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Peng XX, Sun FW, Liu LL. 2015. Properties of poplar lumber modified by impregnation of three resins. China Forestry

Science and Technology, 29(5): 111-114.

Qi ST, Zhang MY, Wang J, et al. 2013. The effects of fines on beating performance and paper properties of bamboo pulp.

Paper Science & Technology, 32(5): 7-10+18.

Qin ZY. 2014. Study on wood and adhesive surface/interface wettability characterization and influencing factors. Thesis

for Doctors Degree of Beijing Forestry University.

Shan L. 2014. Axis force property study on the laminated veneer lumber column. Thesis for Masters Degree of Yangzhou

University.

Shen DJ, Lin ZS, Yang CF et al. 2015. Poplar wood modification treated with low molecular weight phenolic resin.

Journal of BeiHua University, 16(3): 385-388.

Su ZH, Feng WY, Wang CL, et al. 2013. Thermogravimetric analysis of aspen APMP effluent solid and corresponding

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47

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49

Zhang YX, Liu F, Batu G, et al. 2015. Evaluation of Growth Adaptability of 20 Poplar Species in Oasis Region of Ulan

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Zhao Y, Zhu JL, Ma ZG, et al. 2014. Responses of Poplar Canker and Growth to Pruning[J]. Journal of Northeast Forestry

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3．Relations with other countries

Exchange of scientific materials and research-relevant ideas in order to promote science has been frequently done thanks to the

generosity from both the Chinese and foreign sides. Permanent connections has been held with specialists from Italy, USA,

Canada, Germany, France and UK.

4．Innovations not included in other section

List here any new developments not included elsewhere.