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Effects of gaps on regeneration of woody plants: a meta-analysis

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Journal of forestry Research 2014年第3期25卷 501-510页

作者： Jiaojun Zhu Deliang Lu Weidong Zhang State Key Laboratory of forest and Soil ecology Qingyuan Experimental Station of Forest Ecology Institute of Applied Ecology Chinese Academy of Sciences University of Chinese Academy of Sciences

forest gaps, openings in the canopy caused by death of one or more trees, have a profound effect on forest regeneration and drive the forest growth cycle. It is therefore necessary to understand the effects of forest gaps on regeneration for modern forest management. In order to provide a quantitative assessment of the effects of forest gaps on regen-eration of woody plants, we conducted this review of gap effects on woody plant regeneration on the basis of 527 observations from 42 indi-vidual papers, and reported the results of these data in a meta-analysis. Overall, densities of regenerated woody plants were significantly greater （359%） in forest gaps than on the closed-canopy forest floor. The regen-eration density in gaps of plantation forests was significantly greater （P＆lt;0.05） than that of natural forest because the regeneration in gaps of plan-tation forests was improved by both gap effects and experimental meas-ures. Similarly, in comparison to natural gaps, regeneration was better enhanced in artificial gaps. Regeneration density exhibited a significantly positive correlation with gap size, but a negative correlation with gap age because the gap size decreased with increasing gap age. Shade tolerance of woody plants affected regeneration density in gaps and understory. Average regeneration density of shade-tolerant species exhibited a sig-nificantly positive response to gaps but densities remained lower in total than those of intermediate and shade-intolerant species. Gap effects on regeneration decreased in response to increasing temperature and pre-cipitation because of the limiting effects of lower temperature and moisture on woody plant regeneration. In summary, forest gaps enhance woody plant regeneration, and the effects of gaps varied by forest type, gap characteristics, environmental factors and plant traits. The results of this meta-analysis are useful for better understanding the effects and roles of gaps on forest regeneration and forest manage

关键词： forest gap regeneration disturbance gap size gap age,shade tolerance

Causal effects of shelter forests and water factors on desertification control during 2000–2010 at the Horqin Sandy Land region, China

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Journal of forestry Research 2015年第1期26卷 33-45页

作者： Qiaoling Yan Jiaojun Zhu Xiao Zheng Changjie Jin State Key Laboratory of forest and Soil ecology Institute of Applied EcologyChinese Academy of Sciences

The Horqin Sandy Land（HSL）, the largest sandy land in the semi-arid agro-pastoral ecotone of Northeast China, has been subject to desertification during the past century. In response, and to control the desertification,government implemented the Three-North Shelter/Protective forest program, world＇s largest ecological reforestation/afforestation restoration program. The program began in1978 and will continue for 75 years until 2050. Understanding the dynamics of desertification and its driving forces is a precondition for controlling ***, there is little evidence to directly link causal effects with desertification process（i.e., on the changing area of sandy land） because desertification is a complex process,that can be affected by vegetation（including vegetation cover and extent of shelter forests） and water factors such as precipitation, surface soil moisture, and *** objectives of this study were to identify how influencing factors, especially shelter forests, affected desertification in HSL over a recent decade. We used Landsat TM imagery analysis and path analysis to identify the effects of spatiotemporal changes in water and vegetation parameters during2000–2010. Desertification was controlled during the study period, as indicated by a decrease in desert area at a rate of163.3 km2year-1and an increase in the area with reduced intensity or extent of desertification. Total vegetation cover in HSL increased by 10.6 % during the study period and this factor exerted the greatest direct and indirect effects on slowing desertification. The contribution of total vegetation cover to controlling desertification increased with the intensity of desertification. On slightly and extremely severe desertified areas, vegetation cover contributed 5 and 42 % of the desertification reduction, respectively. There were significant correlations between total vegetation cover and water conditions（i.e., evapotranspiration and precipitation）and th

关键词： The Three-North Shelter forest program Precipitation Remote sensing Vegetation cover Semi-arid region

Influencing Factors of Seed Long-distance Dispersal on a Fragmented forest Landscape on Changbai Mountains,China

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Chinese Geographical Science 2016年第1期26卷 68-77页

作者： ZHAO Fuqiang QI Lin FANG Lei YANG Jian State Key Laboratory of forest and Soil ecology Institute of Applied EcologyChinese Academy of Sciences

Seed long-distance dispersal(LDD) events are typically rare, but are important in the population processes that determine large-scale forest changes and the persistence of species in fragmented landscapes. However, previous studies focused on species dispersed via animal-mediated LDD, and ignored those dispersed by wind. The aim of this study was to assess the effects of canopy openness, edge, seed source, and patch tree density on the LDD of seeds by wind in forest. We collected birch seeds, a typical wind-dispersed species, throughout a larch plantation. We then assessed the relationship between birch LDD and each factor that may influence LDD of seeds by wind including distance to edge, canopy openness size, distance to mature forest, and the tree density of the larch plantation. We used univariate linear regression analysis to assess the influence of those factors on birch LDD, and partial correlations to calculate the contribution of each factor to LDD. The results showed that both canopy openness and edge had significant influences on birch LDD. Specifically, a negative relationship was observed between distance to edge and birch LDD, whereas there was a positive correlation between canopy openness size and LDD. In contrast, the distance to the mature forest was not correlated with birch LDD. Our results suggest that patch tree density could potently affect the probability of LDD by wind vectors, which provides novel and revealing insights regarding the effect of fragmentation on wind dynamics. The data also provide compelling evidence for the previously undocumented effect of habitat fragmentation on wind-dispersed organisms. As such, these observations will facilitate reasonable conservation planning, which requires a detailed understanding of the mechanisms by which patch properties hamper the delivery of seeds of wind-dispersed plants to fragmented areas.

关键词： seed long-distance dispersal (LDD) forest fragmentation patch property wind dispersal Changbai Mountains

Carbon storage in evergreen broad-leaf forests in mid-subtropical region of China at four succession stages

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Journal of forestry Research 2013年第4期24卷 677-682页

作者： ZENG Zhangquan WANG Silong ZHANG Canming GONG Chao HU Qing Huitong Experimental Station of forest ecology State Key Laboratory of Forest and Soil EcologyInstitute of Applied EcologyChinese Academy of Sciences Huitong National Research Station of forest Ecosystem Graduate School of Chinese Academy of Sci- ences Hunan Academy of forestry Hengshan Station of Forest Ecology Northeast Institute of Geography and Agroecology Chinese Academy of Sciences

To better understand the effect of forest succession on carbon sequestration, we investigated carbon stock and allocation of evergreen broadleaf forest, a major zonal forest in subtropical China. We sought to quantify the carbon sequestration potential. We sampled four forest types, shrub （SR）, pine （Pinus massoniana） forest （PF）, pin~ and broadleaf mixed forest （Mr） and evergreen broadleaf forest （BF）. A regression equation was constructed using tree height and diameter at breast height （DBH） and elements of total tree biomass. The equation was subse- quently utilized to estimate tree carbon storage. The carbon storage of understory, litter, and soil was also estimated.

关键词： Biomass carbon Carbon allocation Carbon sequestration Soil organic carbon China subtropical forest

Variations in root chemistry of three common forest species,southwestern China

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Journal of forestry Research 2019年第3期30卷 827-834页

作者： Qun Liu Wanqin Yang Fuzhong Wu Bo Tan Li Zhang Zhenfeng Xu Long-term Research Station of Alpine forest Ecosystems Institute of Forest and Ecology Sichuan Agricultural University

Root chemistry varies with tree species and root diameter but little information is available about Tibetan forest species. The root chemistry of three root diameter classes (fine: 0–2 mm, medium: 2–5 mm, coarse: 5–10 mm) of three subalpine species (Abies faxoniana Rehd. and Wild, Picea asperata Mast., and Betula albosinensis Burkill) were investigated. Carbon concentrations, and carbon/nitrogen and carbon/phosphorus ratios increased but nitrogen, phosphorus and nitrogen/phosphorus ratios decreased with increasing root diameter. The roots of the conifers had higher carbon levels, and higher carbon/nitrogen and carbon/phosphorus ratios than birch roots. The opposite was found with nitrogen and phosphorus levels and nitrogen/phosphorus ratios. Lignin concentrations decreased but cellulose concentrations increased with greater root diameters. The results indicate that diameter-associated variations in root chemistry may regulate their contribution to detrital pools which has important implications for below-ground carbon and nutrient cycles in these subalpine forests.

关键词： Root diameter Lignin Cellulose Stoichiometry Subalpine forest

forest Carbon Storage and Tree Carbon Pool Dynamics under Natural forest Protection program in Northeastern China

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Chinese Geographical Science 2014年第4期24卷 397-405页

作者： WEI Yawei YU Dapao Bernard Joseph LEWIS ZHOU Li ZHOU Wangming FANG Xiangmin ZHAO Wei WU Shengnan DAI Limin State Key Laboratory of forest and Soil ecology Institute of Applied Ecology Chinese Academy of Sciences Shenyang Agriculture University

The Natural forest Protection(NFP) program is one of the Six Key forestry Projects which were adopted by the Chinese Government since the 1980s to address important natural issues in China. It advanced to protecting and restoring the structures and functions of the natural forests through sustainable forest management. However, the role of forest carbon storage and tree carbon pool dynamics since the adoption of the NFP remains unknown. To address this knowledge gap, this study calculated forest carbon storage(tree, understory, forest floor and soil) in the forest region of northeastern(NE) China based on National forest Inventory databases and field investigated databases. For tree biomass, this study utilized an improved method for biomass estimation that converts timber volume to total forest biomass; while for understory, forest floor and soil carbon storage, this study utilized forest type-specific mean carbon densities multiplied by their areas in the region. Results showed that the tree carbon pool under the NFP in NE China functioned as a carbon sink from 1998 to 2008, with an increase of 6.3 Tg C/yr, which was mainly sequestrated by natural forests(5.1 Tg C/yr). At the same time, plantations also acted as a carbon sink, reflecting an increase of 1.2 Tg C/yr. In 2008, total carbon storage in forests covered by the NFP in NE China was 4603.8 Tg C, of which 4393.3 Tg C was stored in natural forests and 210.5 Tg C in planted forests. Soil was the largest carbon storage component, contributing 69.5%–77.8% of total carbon storage; followed by tree and forest floor, accounting for 16.3%–23.0% and 5.0%–6.5% of total carbon storage, respectively. Understory carbon pool ranged from 1.9 to 42.7 Tg C, accounting for only 0.9% of total carbon storage.

关键词： biomass-volume linear regression models mean carbon density method national forest inventory Key forestry Projects northeastern China

Simulating Impact of Larch Caterpillar(Dendrolimus superans)on Fire Regime and forest Landscape in Da Hinggan Mountains,Northeast China

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Chinese Geographical Science 2011年第5期21卷 575-586页

作者： CHEN Hongwei HU Yuanman CHANG Yu BU Rencang LI Yuehui LIU Miao State Key Laboratory of forest and Soil ecology Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110164 China

Larch caterpillar (Dendrolimus superans) is very common in the Da Hinggan Mountains, Northeast China, affecting fire regime and forest ecosystem change at large spatio-temporal scales. In this study, we used a spatially explicit landscape model, LANDIS, to simulate the changes of fire regime and forest landscape under four larch caterpillar disturbance intensity levels scenarios in Huzhong forest area, northern of Da Hinggan Mountains. The results indicate that larch caterpillar disturbances would decrease fine fuel load and increase coarse fuel load in the 300 simulation years. Larch caterpillar disturbances would decrease fire frequency in the first 200 years, and the disturbances also decrease fire intensity and fire risk in the early and late stage of simulation. Larch caterpillar disturbances would decrease the area percent of larch cohorts and increase the proportion of white birch, and increase the degree of aggregation of white birch as a result of its strong seed dispersal and colonization ability. Disturbances would also decrease the mature and over-mature larch cohorts and increase all cohorts of white birch, especially the mature and over-mature cohorts. Larch caterpillar disturbances will decrease the stability of forest landscape, therefore,some measures preventing in- sect outbreak and ensuring the sustainable management of forest ecosystem should been taken in the study area.

关键词： forest landscape larch caterpillar fire disturbance LANDIS model

Reductions in non-point source pollution through different management practices for an agricultural watershed in the Three Gorges Reservoir Area

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Journal of Environmental Sciences 2010年第2期22卷 184-191页

作者： Yaowu Tian Zhilin Huang Wenfa Xiao School of Life Science Sun Yat-sen University Guangzhou 510275 China. Key Laboratory of forest ecology and Environment State Forest-ry Administration China Research Institute of Forest Ecology Environment and Protection Chinese Academy of Forestry Beijing 10091 China

Non-point source water pollution generated by agricultural production is considered a major environmental issue in the Three Gorges Reservoir Area （TGRA） of China. The Annualised Agricultural Non-Point Source Pollution （AnnAGNPS） model was selected to assess the impact of the application of various management treats, including seven crops, five fertilizer levels and three-group management practice scenarios, on water quality from Heigou River Watershed in TGRA. The scenario subsets include conservation tillage practice （CTP）, conservation reserve program （CRP） and conversion of cropland into forestland program （CCFP）. Results indicated that tea can not be replaced by other crops because comparatively tea resulted in a higher sediment yield. CTP with no-tillage was more effective to reduce sediment yield, but could increased nutrient loss. CRP reduced sediment yield significantly, but slightly benefited on nutrient loss. CCFP reduced not only sediment yield but also the nutrient loss significantly. The conversion of cropland with a slope greater than 10° into forestland was found to be the best scenario as the sediment yield export is less than 5 tons/ha and nutrient loss is within the permissible limit.

关键词： non-point pollution management practice reduction the Three Gorges Reservoir Area

Biomass accumulation and nutrient uptake of 16 riparian woody plant species in Northeast China

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Journal of forestry Research 2014年第4期25卷 773-778页

作者： Shuai Yu Wei Chen Xingyuan He Zhouli Liu Yanqing Huang State Key Laboratory of forest and Soil ecology Institute of Applied Ecology Chinese Academy of Sciences University of Chinese Academy of Sciences

Our research focused on eutrophication control and species screening for riparian zone vegetation restoration in the upstream reach of the Hun River. We studied 16 hardwood plant species to investigate nutrient concentrations and nitrogen and phosphorus accumulations. After about 120 days of growth in pots, these 16 species varied in dry matter biomass, ranging from 15.13 to 637.16 g. Total nitrogen （TN） and total phosphorus （TP） concentrations and distribution in roots, stems and foliage differed both within and between tested species. Mean TN and TP accumulation ranged from 0.167 to 14.730 g per plant and from 0.016 to 1.20 g, respectively. All 16 species, but especially Lespedeza bicolor, Robinia pseudoacacia and Sorbaria sorbifolia had strong potential to remove TN and TP from soil and could be widely utilized for the restora- tion of destroyed riparian zones in northeast China.

关键词： Nitrogen phosphorous ecological restoration foliage