Biogeographic patterns of soil diazotrophic communities across six forests in the North America |
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Authors: | Qichao Tu Ye Deng Qingyun Yan Lina Shen Lu Lin Zhili He Liyou Wu Joy D Van Nostrand Vanessa Buzzard Sean T Michaletz Brian J Enquist Michael D Weiser Michael Kaspari Robert B Waide James H Brown Jizhong Zhou |
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Institution: | 1. Department of Marine Sciences, Ocean College, Zhejiang University, Zhejiang, China;2. Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK, USA;3. Research Center for Eco‐Environmental Science, Chinese Academy of Sciences, Beijing, China;4. Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, USA;5. Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, USA;6. The Santa Fe Institute, Santa Fe, NM, USA;7. Department of Biology, EEB Graduate Program, University of Oklahoma, Norman, OK, USA;8. Smithsonian Tropical Research Institute, Balboa, Republic of Panama;9. Department of Biology, University of New Mexico, Albuquerque, NM, USA;10. State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China;11. Earth Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA |
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Abstract: | Soil diazotrophs play important roles in ecosystem functioning by converting atmospheric N2 into biologically available ammonium. However, the diversity and distribution of soil diazotrophic communities in different forests and whether they follow biogeographic patterns similar to macroorganisms still remain unclear. By sequencing nifH gene amplicons, we surveyed the diversity, structure and biogeographic patterns of soil diazotrophic communities across six North American forests (126 nested samples). Our results showed that each forest harboured markedly different soil diazotrophic communities and that these communities followed traditional biogeographic patterns similar to plant and animal communities, including the taxa–area relationship (TAR) and latitudinal diversity gradient. Significantly higher community diversity and lower microbial spatial turnover rates (i.e. z‐values) were found for rainforests (~0.06) than temperate forests (~0.1). The gradient pattern of TARs and community diversity was strongly correlated (r2 > 0.5) with latitude, annual mean temperature, plant species richness and precipitation, and weakly correlated (r2 < 0.25) with pH and soil moisture. This study suggests that even microbial subcommunities (e.g. soil diazotrophs) follow general biogeographic patterns (e.g. TAR, latitudinal diversity gradient), and indicates that the metabolic theory of ecology and habitat heterogeneity may be the major underlying ecological mechanisms shaping the biogeographic patterns of soil diazotrophic communities. |
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Keywords: | biogeography diversity gradients
nifH
soil diazotrophs taxa– area relationship |
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