ABSTRACT 96-15941 Bever Competition and coexistence: The role of soil community feedback This study will examine how feedback through the soil community changes the outcome of competition between plants. The identity of plant species is known to change the composition of their associated soil community. These changes may then influence the plant's performance-either positively or negatively. Such feedback could exert strong effects on the growth of plants, but the role of such feedbacks in natural communities has rarely been investigated. This project focuses on two well-studied plant species, Anthoxanthum odoratum and Panicum sphaerocarpon. The investigators have repeatedly observed negative feedbacks between these two species resulting from changes in the soil communities. This project will using parallel greenhouse and field experiments to test whether this feedback influences the outcome and intensity of competition between these species. These results will be used to parameterize population dynamic models with which the investigators will evaluate the soil community's contribution to the maintenance of plant biodiversity.
