A METHOD FOR SCALING VEGETATION DYNAMICS: THE ECOSYSTEM DEMOGRAPHY MODEL (ED)

Ecological MonographsVolume 71, Issue 4 p. 557-586 Regular Article A METHOD FOR SCALING VEGETATION DYNAMICS: THE ECOSYSTEM DEMOGRAPHY MODEL (ED) P. R. Moorcroft, P. R. Moorcroft Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544-1003 USA Present address: Department of Organismal and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 USA. E-mail: [email protected]Search for more papers by this authorG. C. Hurtt, G. C. Hurtt Complex Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire 03824 USASearch for more papers by this authorS. W. Pacala, S. W. Pacala Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544-1003 USASearch for more papers by this author P. R. Moorcroft, P. R. Moorcroft Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544-1003 USA Present address: Department of Organismal and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 USA. E-mail: [email protected]Search for more papers by this authorG. C. Hurtt, G. C. Hurtt Complex Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire 03824 USASearch for more papers by this authorS. W. Pacala, S. W. Pacala Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544-1003 USASearch for more papers by this author First published: 01 November 2001 https://doi.org/10.1890/0012-9615(2001)071[0557:AMFSVD]2.0.CO;2Citations: 521 Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Abstract The problem of scale has been a critical impediment to incorporating important fine-scale processes into global ecosystem models. Our knowledge of fine-scale physiological and ecological processes comes from a variety of measurements, ranging from forest plot inventories to remote sensing, made at spatial resolutions considerably smaller than the large scale at which global ecosystem models are defined. In this paper, we describe a new individual-based, terrestrial biosphere model, which we label the ecosystem demography model (ED). We then introduce a general method for scaling stochastic individual-based models of ecosystem dynamics (gap models) such as ED to large scales. The method accounts for the fine-scale spatial heterogeneity within an ecosystem caused by stochastic disturbance events, operating at scales down to individual canopy-tree-sized gaps. By conditioning appropriately on the occurrence of these events, we derive a size- and age-structured (SAS) approximation for the first moment of the stochastic ecosystem model. With this approximation, it is possible to make predictions about the large scales of interest from a description of the fine-scale physiological and population-dynamic processes without simulating the fate of every plant individually. We use the SAS approximation to implement our individual-based biosphere model over South America from 15° N to 15° S, showing that the SAS equations are accurate across a range of environmental conditions and resulting ecosystem types. We then compare the predictions of the biosphere model to regional data and to intensive data at specific sites. Analysis of the model at these sites illustrates the importance of fine-scale heterogeneity in governing large-scale ecosystem function, showing how population and community-level processes influence ecosystem composition and structure, patterns of aboveground carbon accumulation, and net ecosystem production. Citing Literature Supporting Information Filename Description https://dx.doi.org/10.6084/m9.figshare.c.3308964 Research data pertaining to this article is located at figshare.com: Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article. Volume71, Issue4November 2001Pages 557-586 RelatedInformation