As a physiological ecologist, my primary interests are to understand how environmental stresses on leaf gas exchange and plant carbon allocation control carbon gain, plant growth and reproduction. My research focuses on environmental factors likely to be affected by global change, particularly direct effect of carbon dioxide (CO2) and tropospheric ozone (O3) on physiology, and indirect effects on species interactions and distribution. My current research addresses two topics: i) the effects of environmental stress, including elevated CO2, on stomatal function, plant growth, and carbon allocation, and ii) controls on establishment of an invading species.