Biogeochemistry and nutrient cycling in terrestrial ecosystems, including the effects of management, land use change, and climatic change on soil C and N stocks, trace gas emissions from soils, and leaching of plant nutrients to streams and groundwater. Current study areas include the Brazilian Amazon Basin and Cerrado region and the forests of New England.
Past President and Fellow of the Amercian Geophysical Union; Fellow of the AAAS; Past Jefferson Science Fellow; Web of Science Highly Cited Researcher