Beta diversity determinants in Badagongshan, a subtropical forest in central China.

Xiujuan Qiao,Haibo Liu,Yili Guo,Mingxi Jiang,Dachuan Bao,Zhijun Lu,Junmeng Lu,Zhiyao Tang,Scott Franklin,Qianxi Li,Yaozhan Xu,Qinghu Jiang,Qinggang Wang,Jiaxin Zhang

doi:10.1038/srep17043

Abstract

Niche and neutral theories emphasize different processes contributing to the maintenance of species diversity. In this study, we calculated the local contribution to beta diversity (LCBD) of every cell, using variation partitioning in combination with spatial distance and environmental variables of the 25-ha Badagongshan plot (BDGS), to determine the contribution of environmentally-related variation versus pure spatial variation. We used topography and soil characteristics as environmental variables, distance-based Moran’s eigenvectors maps (dbMEM) to describe spatial relationships among cells and redundancy analysis (RDA) to apportion the variation in beta diversity into three components: pure environmental, spatially-structured environmental, and pure spatial. Results showed LCBD values were negatively related to number of common species and positively related to number of rare species. Environment and space jointly explained ~60% of the variation in species composition; soil variables alone explained 21.6%, slightly more than the topographic variables that explained 15.7%; topography and soil together explained 27%, slightly inferior to spatial variables that explained 34%. The BDGS forest was controlled both by the spatial and environmental variables, and the results were consistent across different life forms and life stages.

Highlights

Temperate forest, whereas dispersal limitation has a higher explanation power than environmental variables in the tropics[26]
If beta diversity is strongly correlated with environmental variables, processes associated with environmental filtering are likely operating; otherwise, spatial processes are likely playing a stronger role
Our analyses compared separately how the spatial and environmental factors influence the structure of various life stages and tree layers along with composition and beta diversity in the BDGS subtropical forest community

Summary

Introduction

Temperate forest, whereas dispersal limitation has a higher explanation power than environmental variables in the tropics[26]. Most of these studies focused on the species turnover in a large region (for example, all of North American or China) with only coarse climatic data as environmental variables, which may not reflect the controlling factors of beta diversity in a local community. The relationship of environmental variables versus pure spatial variables to tree beta diversity at the scale of the forest plot; and 3. Differences in these relationships among life stages and tree layers

Methods

Results

Conclusion