Linking community size structure and ecosystem functioning using metabolic theory |
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Authors: | Gabriel Yvon-Durocher Andrew P Allen |
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Institution: | 1.School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK;2.Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9EZ, UK;3.Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia |
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Abstract: | Understanding how biogeochemical cycles relate to the structure of ecological communities is a central research question in ecology. Here we approach this problem by focusing on body size, which is an easily measured species trait that has a pervasive influence on multiple aspects of community structure and ecosystem functioning. We test the predictions of a model derived from metabolic theory using data on ecosystem metabolism and community size structure. These data were collected as part of an aquatic mesocosm experiment that was designed to simulate future environmental warming. Our analyses demonstrate significant linkages between community size structure and ecosystem functioning, and the effects of warming on these links. Specifically, we show that carbon fluxes were significantly influenced by seasonal variation in temperature, and yielded activation energies remarkably similar to those predicted based on the temperature dependencies of individual-level photosynthesis and respiration. We also show that community size structure significantly influenced fluxes of ecosystem respiration and gross primary production, particularly at the annual time-scale. Assessing size structure and the factors that control it, both empirically and theoretically, therefore promises to aid in understanding links between individual organisms and biogeochemical cycles, and in predicting the responses of key ecosystem functions to future environmental change. |
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Keywords: | climate change allometry size structure ecosystem functioning metabolic theory global warming |
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