John Vandermeer

Asa Gray Distinguished University, Arthur R. Thurnau, University of Michigan

John Vandermeer is Asa Gray Distinguished University Professor and Arthur R. Thurnau Professor of Ecology and Evolutionary Biology and a professor in the Program in the Environment at the University of Michigan.  He teaches three courses, 1) food, energy and environmental justice, 2) the ecology of agroecosystems, and 3) complex systems in ecology. His research focuses on the coffee agroecosystem for which he delves into recent advances in complex systems in attempting to understand the biological, social, and political aspects of this important ecosystem. He is author or editor of 16 books and over 300 scientific publications. He is also a political activist, a founding member of the New World Agriculture and Ecology group, a current member of the revived organization “Science for the People,” and a founding member of the University of Michigan “Sustainable Food System Initiative.”

Intransitive and transitive couplings in the structure of an ecological community

The structure of multiple species assemblages, referred to as an ecological community, is frequently dominated by the dynamic process of competition. It has been a standard assumption that if competitive intensity is too large, the species involved cannot persist in the same place forever. Recently this canonical idea has been questioned both empirically and theoretically. In particular the presence of intransitivities and higher order interactions can dramatically alter the underlying dogma that competition among species must be relatively weak for multispecies persistence. Using a model community of ants on a coffee farm in Puerto Rico we explore the joint operation of an intransitive loop and a higher order effect.