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Luo Y.,Chinese Institute of Urban Environment | Wang X.,CAS Research Center for Eco Environmental Sciences | Zhang X.,Nature Conservancy China Program | Ren Y.,Chinese Institute of Urban Environment | Poorter H.,Julich Research Center
Annals of Forest Science

• Context: Biomass expansion factors (BEFs, defined as the ratios of tree component biomass (branch, leaf, aboveground section, root, and whole) to stem biomass) are important parameters for quantifying forest biomass and carbon stock. However, little information is available about possible causes of the variability in BEFs at large scales. • Aims: We examined whether and how BEFs vary with forest types, climate (mean annual temperature, MAT; mean annual precipitation, MAP), and stand development (stand age and size) at the national scale for China. • Method: Using our compiled biomass dataset, we calculated values for BEFs and explored their relationships to forest types, climate, and stand development. • Results: BEFs varied greatly across forest types and functional groups. They were significantly related to climate and stand development (especially tree height). However, the relationships between BEFs and MAT and MAP were generally different in deciduous forests and evergreen forests, and BEF-climate relationships were weaker in deciduous forests than in evergreen forests and pine forests. • Conclusion: To reduce uncertainties induced by BEFs in estimates of forest biomass and carbon stock, values for BEFs should be applied for a specified forest, and BEF functions with influencing factors (e.g., tree height and climate) should be developed as predictor variables for the specified forest. © 2013 INRA and Springer-Verlag France. Source

Luo Y.,Chinese Institute of Urban Environment | Zhang X.,Nature Conservancy China Program | Wang X.,CAS Research Center for Eco Environmental Sciences | Ren Y.,Chinese Institute of Urban Environment

Biomass conversion factors (BCFs, defined as the ratios of tree components (i.e. stem, branch, foliage and root), as well as aboveground and whole biomass of trees to growing stock volume, Mg m-3) are considered as important parameters in large-scale forest biomass carbon estimation. To date, knowledge of possible sources of the variation in BCFs is still limited at large scales. Using our compiled forest biomass dataset of China, we presented forest type-specific values of BCFs, and examined the variation in BCFs in relation to forest type, stand development and environmental factors (climate and soil fertility). BCFs exhibited remarkable variation across forest types, and also were significantly related to stand development (especially growing stock volume). BCFs (except Stem BCF) had significant relationships with mean annual temperature (MAT) and mean annual precipitation (MAP) (P<0.001). Climatic data (MAT and MAP) collectively explained 10.0-25.0% of the variation in BCFs (except Stem BCFs). Moreover, stronger climatic effects were found on BCFs for functional components (i.e. branch, foliage and root) than BCFs for combined components (i.e. aboveground section and whole trees). A general trend for BCFs was observed to decrease and then increase from low to high soil fertility. When qualitative soil fertility and climatic data (MAT and MAP) were combined, they explained 14.1-29.7% of the variation in in BCFs (except Stem BCFs), adding only 4.1-4.9% than climatic data used. Therefore, to reduce the uncertainty induced by BCFs in forest carbon estimates, we should apply values of BCFs for a specified forest type, and also consider climatic and edaphic effects, especially climatic effect, in developing predictive models of BCFs (except Stem BCF). © 2014 Luo et al. Source

Tansey B.,Nature Conservancy China Program | Yimin Z.,Yangtze Fishery Bureau | Bo Y.,Nature Conservancy China Program | Weizhi Y.,Southwest University | And 2 more authors.
Journal of Renewable and Sustainable Energy

How does one connect two of the most important rivers in the world? In the East, China's longest river, the Yangtze, stretches 6300km from the Tibetan Plateau to the port of Shanghai. In the West, the longest river in the United States, the Mississippi, runs 5970km from northern Minnesota down to the Gulf of Mexico. Both rivers play vital roles in the cultures and economies of their respective countries. Each river system gives life to a wealth of biodiversity while providing millions of people with drinking water, hydroelectric power, and a number of other services. The vitality of the Yangtze and Mississippi faces challenges, however, and the fisheries resources of these two great rivers face specific and common threats. That is why The Nature Conservancy and the Yangtze River Basin Fisheries Resources Management Commission (YFC) came together to form an EcoPartnership to help preserve the natural fisheries of these two great rivers. (Note: YFC recently became the Yangtze Fisheries Bureau, with fisheries responsibilities for all rivers in China from the Yangtze on south and greater administrative authority. The great rivers partnership logo uses the rubric of the Changjiang Fisheries Agency, retaining the Chinese pinyin for the name of the river. © 2015 AIP Publishing LLC. Source

Wong M.,Yunnan University | Duan C.-Q.,Yunnan University | Long Y.-C.,Nature Conservancy China Program | Luo Y.,Nature Conservancy China Program | Xie G.-Q.,Yunnan Climate Center
Physical Geography

The changing recruitment rate of subalpine tree populations could indicate the effects of climate change on a mountain ecosystem. The population of the dominant tree species of the Baima Snow Mountains in northwestern Yunnan, Abies georgei Orr, was investigated with a vegetation survey and tree-ring analysis. Structural and age characteristics were used to indicate the process and rates of geographical change, and the altitudinal range and size of forest were predicted using GIS with various climate change scenarios. The greatest increase of recruitment has occurred near the upper treeline on north-facing slopes, and the regeneration rate has been reduced at and below its once-optimal altitudinal range. The species limit has advanced upslope at an average rate of 11 m per decade, while the lowest limit of regeneration has retreated upslope at an average rate of 31 m per decade. In the 21st century, the altitudinal range of A. georgei forest may decrease by 13.6-25.9% and the forest size may contract by 16.4-38.6%. We demonstrate that the study of both upper and lower species limits of migrating subalpine species is crucial for predicting forest change, and suggest the involvement of spatial (geometry) as well as temporal (climate) factors in the shifting of alpine treeline. Source

Wu R.,Yunnan University | Long Y.,Nature Conservancy China Program | Malanson G.P.,University of Iowa | Garber P.A.,Urbana University | And 5 more authors.

By addressing several key features overlooked in previous studies, i.e. human disturbance, integration of ecosystem- and species-level conservation features, and principles of complementarity and representativeness, we present the first nationalscale systematic conservation planning for China to determine the optimized spatial priorities for biodiversity conservation. We compiled a spatial database on the distributions of ecosystem- and species-level conservation features, and modeled a human disturbance index (HDI) by aggregating information using several socioeconomic proxies. We ran Marxan with two scenarios (HDI-ignored and HDI-considered) to investigate the effects of human disturbance, and explored the geographic patterns of the optimized spatial conservation priorities. Compared to when HDI was ignored, the HDI-considered scenario resulted in (1) a marked reduction (∼9%) in the total HDI score and a slight increase (∼7%) in the total area of the portfolio of priority units, (2) a significant increase (∼43%) in the total irreplaceable area and (3) more irreplaceable units being identified in almost all environmental zones and highly-disturbed provinces. Thus the inclusion of human disturbance is essential for cost-effective priority-setting. Attention should be targeted to the areas that are characterized as moderatelydisturbed, <2,000 m in altitude, and/or intermediately- to extremely-rugged in terrain to identify potentially important regions for implementing cost-effective conservation. We delineated 23 primary large-scale priority areas that are significant for conserving China's biodiversity, but those isolated priority units in disturbed regions are in more urgent need of conservation actions so as to prevent immediate and severe biodiversity loss. This study presents a spatially optimized national-scale portfolio of conservation priorities - effectively representing the overall biodiversity of China while minimizing conflicts with economic development. Our results offer critical insights for current conservation and strategic land-use planning in China. The approach is transferable and easy to implement by end-users, and applicable for national- and local-scale systematic conservation prioritization practices. © 2014 Wu et al. Source

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