Wednesday, August 4, 2010 - 3:40 PM

OOS 31-7: Determinants of community structure along climatic gradients: Insights from patterns of phylogenetic β diversity

Jean-Philippe Lessard1, Michael Krabbe Borregaard2, James A. Fordyce1, Susanne Fritz2, Michael D. Weiser3, Robert Dunn4, Nathan J. Sanders1, and Carsten Rahbek2. (1) University of Tennessee, (2) University of Copenhagen, (3) North Carolina State University, (4) NCSU

Background/Question/Methods

Macroecologists tend to focus on variation in species richness among regions or broad geographic provinces to examine the drivers of species richness. Community ecologists often focus on a single community or on a set of geographically clustered communities. Studying multiple local communities of interacting species along climatic gradients can help determine the degree to which various ecological and evolutionary processes contribute to shaping contemporary community structure. By examining community phylogenetic structure for multiple communities of locally interacting species along climatic gradients, or in regions that differ in evolutionary history, one can assess variation in the relative importance of ecological and evolutionary process in shaping communities. We used ant species composition data encompassing North America to test whether dissimilarity in species composition among sites (beta diversity) correlated with differences in phylogenetic structure (phylogenetic beta diversity).
Results/Conclusions

We show that the relationship between beta diversity and phylogenetic beta diversity varies in function of spatial variation in temperature. We discuss potential explanation for this pattern