I am the Sidman P. Poole Professor, Emeritus of Environmental Sciences at the University of Virginia.
My biogeochemical research includes investigations on the natural and anthropogenic controls on chemical cycles at the watershed, regional and global scales. I started first with trace metal biogeochemistry of the coastal ocean, and then expanded to investigations on the increased acidification of the atmosphere, soils and fresh waters.
My current research focuses on beneficial and detrimental effects of reactive nitrogen as it cascades between the atmosphere, terrestrial ecosystems and freshwater and marine ecosystems. My most recent work examines how to maximize the use of nitrogen for beneficial purposes (i.e., food production), while minimizing its negative impacts on people and ecosystems.