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Peter Adler, Ph.D.
Utah State University
Abstract
The puzzle of species coexistence has fascinated ecologists for over a century, but only recently have we developed the theory and tools to quantify the stability of coexistence in natural communities. My collaborators and I have used long-term demographic data sets from semiarid plants communities to fit multispecies population. Simulations of those models indicate that the common co-occurring species have surprisingly low niche overlap, leading to weak interspecific interactions, minimal competitive release, and indirect effects of climate change small enough to justify the use of single-species forecast models. However, because these results are based on observational data sets, they should be viewed with caution until confirmed by independent tests. While a literature review revealed patterns consistent with very stable coexistence, a removal experiment suggested that our models might underestimate the strength of some interspecific interactions. I conclude that common species in these semiarid communities are coexisting stably, but I am still not satisfied that we have accurately quantified the degree of stability.
About the Speaker
Dr. Adler is a plant ecologist interested in explaining population and community dynamics in space and time. He, along with his lab group, study coexistence and patterns of diversity, climate change impacts on plant populations and communities, and plant-animal interactions. Much of their field work is in arid and semiarid ecosystems, but they also rely on statistical and simulation modeling techniques that apply to many ecosystems.
