He is a Professor of Biology and Senior Ecologist for the Graduate Degree Program in Ecology at Colorado State University. Previously, he served as PI of the NSF-funded Konza Prairie LTER site in NE Kansas and as a University Distinguished Professor at Kansas State University. His research has assessed both direct and interactive effects of fire, grazing, and climate in grasslands. Current research interests focus on understanding how climatic variability drives ecosystem dynamics, and on interactions between projected global change phenomenon and plant ecophysiological, organismal and community responses.