Our research spans ecological scales, with spatially- and temporally-broad studies complemented by mechanistic ecophysiological investigations. Current interests include: global change ecology, especially manipulations of precipitation extremes (droughts and deluges), and large-scale comparisons of ecosystem sensitivity to climate, fire, grazing, and nutrients. Most of our research is conducted in grasslands, which are ecologically and economically important systems that respond rapidly to change and are amenable to field manipulations.