This award will support collaborative research between Dr. Jacob Weiner, Swarthmore College and Dr. Michael J. Crawey, Imperial College at Silwood Park, England. The objective of the project is to examine the interactions between competition and herbivory in determining the size variability in plant populations. This will be accomplished in two ways. First, the investigators will execute a large multifactoral experiment which will look at the effects and interactions between plant density and slug herbivory on size distributions in greenhouse populations of white clover. This will enable them to test several hypotheses about the influence of herbivory on plant size distributions, and how the effects of herbivory are mediated by competition between plants. Second, the investigators will use new statistical methods to analyze large data sets which have been collected over several years at Silwood Park on the effect of rabbit herbivory on populations of winter wheat. This will submit the hypotheses to the more rigorous test of field conditions. This project will combine Dr. Crawley's expertise with herbivory and Dr. Weiner's expertise in the analysis of plant population structure. The performance of this study at Silwood Park is particularly important, due to the strong research faculty present. The results of this research will contribute to our understanding of the mechanisms that produce size variation in plant population.
