Geography, environment, and spatial turnover of species in China's grasslands

Authors

  • Zhiyao Tang,

    1. Dept of Ecology, College of Urban and Environmental Sciences, and MOE Laboratory for Earth Surface Processes, Peking Univ., Beijing 100871, China.
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  • Jingyun Fang,

    1. Dept of Ecology, College of Urban and Environmental Sciences, and MOE Laboratory for Earth Surface Processes, Peking Univ., Beijing 100871, China.
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  • Xiulian Chi,

    1. Dept of Ecology, College of Urban and Environmental Sciences, and MOE Laboratory for Earth Surface Processes, Peking Univ., Beijing 100871, China.
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  • Yuanhe Yang,

    1. Dept of Ecology, College of Urban and Environmental Sciences, and MOE Laboratory for Earth Surface Processes, Peking Univ., Beijing 100871, China.
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  • Wenhong Ma,

    1. Dept of Ecology, College of Urban and Environmental Sciences, and MOE Laboratory for Earth Surface Processes, Peking Univ., Beijing 100871, China.
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  • Anwar Mohhamot,

    1. Dept of Ecology, College of Urban and Environmental Sciences, and MOE Laboratory for Earth Surface Processes, Peking Univ., Beijing 100871, China.
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  • Zhaodi Guo,

    1. Dept of Ecology, College of Urban and Environmental Sciences, and MOE Laboratory for Earth Surface Processes, Peking Univ., Beijing 100871, China.
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  • Yining Liu,

    1. Dept of Ecology, College of Urban and Environmental Sciences, and MOE Laboratory for Earth Surface Processes, Peking Univ., Beijing 100871, China.
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  • Kevin J. Gaston

    1. Dept of Ecology, College of Urban and Environmental Sciences, and MOE Laboratory for Earth Surface Processes, Peking Univ., Beijing 100871, China.
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Z. Tang, Dept of Ecology, College of Urban and Environmental Sciences, and MOE Laboratory for Earth Surface Processes, Peking Univ., Beijing 100871, China. E-mail: zytang@urban.pku.edu.cn

Abstract

Environment and spatial processes are key factors in shaping species composition in a community. These two factors make competing predictions concerning the decay of species composition similarity with environmental divergence and geographic distance. Unfortunately, these can be difficult to test independently because changes in environment are commonly well correlated with geographic distance. However, an opportunity is provided by exploiting marked regional differences in the spatial structure of the environment. In this study, we test the predictions of environment filtering and dispersal in explaining species turnover using > 300 study sites spanning ˜4000 km, across three major grasslands in China in which the environment is spatially structured to different degrees. We find that species composition similarity decayed with environmental divergence in the same way in all three regions, and even across biogeographic regions between which dispersal barriers are evident; in contrast, the decay of species composition similarity with geographic distance depended largely on the spatial structure of the environment. We conclude that, at the scale of study, environmental filtering rather than spatial processes best explains patterns of species turnover in China's grasslands.

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