2006 Ton Damman Award Recipient

Jeff Lake, of the University of Georgia, has won the 2006 Ton Damman award for his paper Community assembly in a temperate forest tree community: Testing limiting similarity, environmental filtering, and functional equivalence with leaf functional traits co-authored with S.P. Hubbell and L. Borda de Agua, and presented at the 2006 ESA meeting in Memphis. Jeff currently holds a postdoc at the University of Michigan, Department of Ecology and Evolutionary Biology. Here is the abstract of his winning paper

Community assembly in a temperate forest tree community: Testing limiting similarity, environmental filtering, and functional equivalence with leaf functional traits

Community niche structure and limiting similarity have seldom been tested in the context of plant communities, particularly in a size-structured forest system. Recent advances in niche metrics, such as Mouillot et al's (2005) group of nonparametric indices, provide new opportunities to test community niche structure using continuously distributed functional trait values. We propose an index of community niche overlap based on Mouillot et al's nonparametric indices, but that weights species for abundance, biomass, and other issues influencing the importance of a species within a community. We then apply these methods at a variety of spatial scales to a southeastern US piedmont forest at Thompson Mills, GA. Leaf functional traits, including specific leaf area ( SLA ), leaf nitrogen content (LNC), carbon:nitrogen ratios (C:N), as well as a number of measures of leaf morphology, are used in the tests of trait overlap. Each hypothesis of community assembly would predict different patterns of trait overlap. 1. Limiting similarity would lead to low trait overlap, particularly at smaller spatial scales where most cross-species interactions occur, and would decay over larger spatial scales. 2. Environmental filtering would lead to high levels of overlap at small scales, decaying as the environment changes. 3. Similar measures at all spatial scales would be consistent with predictions of neutrality. While results are mixed, within this community, we found a larger degree of overlap in most traits at all spatial scales than would be predicted by classical niche theory, suggesting a stronger role for habitat filtering and a degree of neutrality, particularly in morphological traits.

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