The mission of the Global Change and Photosynthesis Research Unit is to identify factors affecting food and bioenergy crops, with emphasis on global environmental change, and to utilize this information to provide new opportunities for solving emerging agronomic problems.  Our research addresses 1) the major features limiting photosynthetic productivity of food and bioenergy crops as well as key functions of soil microorganisms in future environments of elevated CO2, O3, temperature, and water stress; 2) the ecology and management of weedy and invasive species in a changing environment; and 3) issues of bioenergy crop adoption in farming systems.