Wednesday, August 6, 2008: 1:30 PM-5:00 PM
202 B, Midwest Airlines Center
OOS 16 - Grinnellian Niches or Just Statistical Correlates? Opportunities for Ecological Inference From Species Distribution Models
Correlative species distribution models have gained dramatic popularity in ecology, conservation, and global change research. These statistical models employ environmental correlates of species presences to characterize geographic distributions. Recently, distribution models have found widespread use for projecting species occurrences into environments that are novel, either spatially or temporally. Most noticeably, such models are often used to predict the future ranges of species under global warming and have become the basis of some widely debated impact assessments of projected climate change. Such extrapolation beyond the conditions present in the data used to calibrate the model assumes that some underlying mechanistic relationship is being captured. It is assumed that distribution models capture the environmental factors constraining distributions adequately enough to represent the environmental niche of a species. However, it has been shown that even randomly generated data can produce apparently significant correlations and statistically "explain" distributions. In response to this, some modelers have attempted to build more mechanistic models of species distributions that incorporate physiology and population dynamics. Such models are highly restricted in their use due to their demand for long-term data. Correlative distribution models offer a widely usable approach, but one that lacks a well-articulated ecological foundation or paradigm to date. Given the rapid rate of global climate change and its potentially massive impacts on biota, some tool is needed to assess the future of biodiversity in a changing world. Distribution models have been by far the most popular tool to date, but serious challenges remain. In this symposium, we set out to review and critically evaluate the ecological meaning and interpretation of species distribution models. We explore a selection of past and potential future uses for tackling long-standing questions in ecology and evaluate the ecological underpinning of the validity of species distribution models for climate change and conservation research. We hope that the symposium will facilitate synthesis in this multidisciplinary field and further the development of a more ecological foundation. Specifically, we aim to address the following questions: (1) How well do species distribution models capture ecological niches of species across scales and taxa (Soberon, Graham, Guisan, Chase)? (2) Can identified correlations be given an ecologically relevant interpretation and what opportunities/limitations for inference for long-standing questions in ecology exist (Soberon, Graham, McGill)? (3) Are alternative, more mechanistic models viable (Buckley, McGill)? (4) What are the consequences for use in conservation and global change research (Scott, Guisan, Araujo, Buckley)?
Organizer:Walter Jetz, University of California, San Diego
Co-organizer:Brian J. McGill, McGill University
Moderator:Walter Jetz, University of California, San Diego
1:30 PMGrinnellian and Eltonian niches and geographic distributions of species
Jorge Soberon, University of Kansas
1:50 PMFinding constraints on the abundance of species: A path forward in large-scale distribution modeling
Volker Bahn, Wright State University, Brian J. McGill, McGill University
2:10 PMDeriving environmental niches from species distributions
Catherine Graham, State University of New York
2:30 PMEcological inference from environmental niche models
Walter Jetz, University of California, San Diego, Jana McPherson, Dalhousie University
2:50 PMThe role of physiology in determining range limits of rainforest invertebrates: Implications for future climate-change impacts
Susan E. Cameron, Harvard University
3:10 PMBreak
3:20 PMMechanistic distribution models: Incorporating demography and physiology
Lauren B. Buckley, National Center for Ecological Analysis and Synthesis
3:40 PMAssessing habitat models: Do they work? Are they evidence for mechanism?
Brian J. McGill, McGill University, Volker Bahn, Wright State University
4:00 PMWhat is a metacommunity?
Brian A. Maurer, Michigan State University
4:20 PMUsing functional traits and null models to determine macroinvertebrate community assembly processes at local and regional scales
Eric R. Sokol, Virginia Tech, E. F. Benfield, Virginia Tech

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See more of The 93rd ESA Annual Meeting (August 3 -- August 8, 2008)