LAWRENCE — Erik Van Vleck, professor of mathematics, along with his co-authors, was awarded the 2021 Robert P. McIntosh Award as the best nominated paper in vegetation ecology in the previous two years by the vegetation section of the Ecological Society of America.
The paper, titled "Dispersal limitations and fire feedbacks maintain mesic savannas in Madagascar," appeared in the journal Ecology in 2020. The authors are Nikunj Goel, University of Texas; Van Vleck; Julie C. Aleman, University of Montreal; and A. Carla Staver, Yale University. Van Vleck’s main contribution to the paper was in the development of a stepping-stone model with dispersal barriers and the mathematical analysis of the impact of such barriers on wavelike solutions of bistable spatially discrete reaction diffusion equations.
Madagascar is regarded by some as one of the most degraded landscapes on Earth, with estimates suggesting that 90% of forests have been lost to indigenous tavy farming. The model in their paper predicts that the savannas in Madagascar are not the result of tavy (slash and burn) farming but were maintained due to geographical barriers (mountains, modeled as obstacles) to limit dispersal and fire in the savannas that suppress woody encroachment. This work challenges the view that highland savannas in Madagascar are derived by human‐lit fires and, more importantly, suggests that partial dispersal barriers and strong nonlinear feedbacks can pin biogeographical boundaries over a wide range of environmental conditions, providing a temporary buffer against climate change.
Robert P. McIntosh was a renowned ecologist and historian of ecology. His breakthrough work in the study of terrestrial plant ecology changed the way in which ecologists look at plant communities.