Relative importance of spatial processes and environmental factors in shaping alpine meadow communities  

作　　者：Qi Li Xue Yang Janne Soininen Cheng-Jin Chu Jie-Qi Zhang Kai-Liang Yu Gang Wang 

机构地区：[1]MOE Key Laboratory of Arid and Grassland Ecology,Lanzhou University,Lanzhou 730000,China [2]Department of Environmental Sciences,University of Helsinki,Helsinki,PO Box 65,FI 00014,Finland

出　　处：《Journal of Plant Ecology》2011年第4期249-258,共10页植物生态学报（英文版）

基　　金：National Natural Science Foundation of China(30970465 and 31000199);Research Station of Alpine Meadow and Wetland Ecosystems of Lanzhou University;Academy of Finland.

摘　　要：Spatial processes and environmental control are the two distinct,yet not mutually exclusive forces of community structuring,but the relative importance of these factors is controversial due to the speciesspecific dispersal ability,sensitivity towards environmental variables,organism’s abundance and the effect of spatial scale.In the present paper,we explored spatial versus environmental control in shaping community composition(i.e.b-diversity)and species turnover(i.e.change of b-diversity)at an alpine meadow along a slope aspect gradient on the Qinghai–Tibetan Plateau at different spatial scales of sampling(quadrats and plots),by taking account of seed dispersal mode and abundance.Methods We examined the relative importance of spatial processes and environmental factors using all species and four additional subsets of selected species.Moreover,we attempted to explore the effect of scale(quadrat refers to scale of;0.3 m and plot of;8 m)on their counter balance.The data were analyzed both by variation partitioning and multiple regressions on distance matrices.The spatial structure was modelled using Moran’s eigenvector maps(MEM).Important Findings Both spatial processes and environmental factors were important determinants of the community composition and species turnover.The community composition in the alpine meadow was controlled by spatially structured environment(17.6%),space independent of environment(18.0%)and a negligible effect of environment independent of space(4.4%)at the scale of quadrats.These three components contributed 21.8,9.9 and 13.9%,respectively,at the scale of plots.The balance between the forces at different spatial scales drove community structures along the slope aspect gradient.The importance of environmental factors on b-diversity at alpine meadow increased with scale while that of spatial processes decreased or kept steady,depending on dispersal mode and abundance of species comprising the subset.But the‘pure’effect of spatial processes on species turnover increased with scale

关 键 词：alpine meadow dispersal environmental factor slope aspect spatial process spatial scale 

分 类 号：Q94[生物学—植物学]