For centuries, scientists have studied how the environment affects plants. Only recently, with climate change threatening plant communities, have researchers begun to ask how plants affect their environment. My research examines the relationship between plants and their environment. I would like to understand how plant productivity is determined by the availability of resources such as water, light and nutrients, and how the complex variation of resources along environmental gradients combines to mediate vegetation processes. Understanding how plant processes are structured by environmental resource availability is critical for predicting the responses of plants to environmental change, as well as subsequent effects on natural resource use by humans. In our study of drought resistance of native shrubs in southern California, we have specifically studied how possible changes in plant community composition in response to climate change will affect plant-mediated ecosystem processes such as transpiration, infiltration, and groundwater recharge.