Large-scale diversity gradients are some of the longest-recognized and longest-studied patterns in ecology. We actually know a great deal about what causes these patterns. Despite this, much is often made of what we do not know, and how many hypotheses there are to explain these patterns.
I am interested in causes of diversity gradients in all organisms, and have worked particularly with plants, mammals and amphibians. Diversity gradients can also mean several things, including traditional species richness, phylogenetic diversity and functional diversity. My research to date has focused on
- The importance of geometric constraints for diversity patterns,
- The role of long-term climate stability in generating patterns and
- The role of species interactions in generating and maintaining diversity.
I also work on small-scale diversity patterns, and am intrigued by the ways that diversity patterns change as a function of spatial scale. I have worked quite a bit on the species-area relationship (e.g. Sandel and Corbin 2012) and its functional diversity equivalent (Smith et al. 2013). Recognizing that SARs can have different slopes, and that those slopes are sensitive to environmental conditions, has fundamental consequences for the interpretation of experiments, broad-scale diversity patterns, and ecological theory (Sandel and Smith 2009).