I. Nonlinear dynamics, especially as applied to population models. Analytical and theoretical models of coupled predator/prey dynamical systems. Intransitive loops and the structure of communities.
II. Ecology of multidimensional agroecological systems -- intercropping systems and agroforestry systems in Tropical America, field work in Mexico amd Puerto Rico. The focus is on the role of biodiversity in the functioning of agroecosystems, especially the multispecies systems so common in tropical areas. Currently very active in the study of the ecology of the coffee rust disease.
III. Dynamics of biodiversity destruction and conservation -- socioeconomic and political analysis of neotropical conversion. Focus is on the quality of the matrix within which patches of natural habitat occur. Includes sociopolitical as well as ecological forces involved in current debates about biodiversity conservation.