Spatial heterogeneity has been shown to exert a strong influence on population and evolutionary dynamics. The nature of the spatial structure as well as intrinsic characteristics of the population affects the dynamics. Using techniques from population genetics and ecological theory, the effects of spatial structure on host-pest interactions, specifically plant-herbivore or plant-pathogen systems, will be modeled. Questions of the evolution of resistance of plants and the potential for the spread of pests will also be addressed. The P.I. will incorporate into these models the nature of spatial structure; characteristics of the plant population such as the mating system, local adaptation, and dispersal ability; and characteristics of the pest such as host specificity and dispersal patterns. In addition, these models will be applied using the well studied system of Brassica campestris to obtain realistic bounds on parameter values and make quantitative predictions. These models will also be used to develop qualitative predictions for managed plant systems.
