This U.S.-Mexico award supports Professor F. Stuart Chapin of the University of California-Berkeley in collaboration with Professor Emmanuel Rincon of the Ecology Center of the Universidad Nacional Autonoma de Mexico (UNAM) in Mexico City, Mexico. The major objective of the proposed research is to understand the effects of variation in resource supply on the growth of tree species from dry tropical forests. The researchers will combine glasshouse field and laboratory studies to test a series of hypotheses concerned with the role of plasticity and mycorrhizae in resource capture and use. They will determine whether the extent of plasticity that a species exhibits influences its capacity to exploit temporal pulses of light, water, and nutrients, and whether differences in plasticity affect the outcome of competition among species either in simple experimental microcosms or in synthetic communities. Finally they will explore the role that mycorrhizae play in influencing competition and species interactions in communities. The proposed research provides an opportunity to combine the complementary research expertise of researchers with substantially different backgrounds. The Mexican PI has worked extensively on studies of relative growth rate and plasticity in plants while the U.S. PI's work has dealt more with mineral nutrition. The project will also involve Professor Edith Allen from San Diego State University and her expertise on mycorrhizal techniques will add an essential component to the proposed research.
