9321680 Platt Mesic hardwood forests of the southeastern United States have two distinct strata with a rich mixture of evergreen and deciduous species of trees. Hurricanes are a major and common disturbance in these forest systems. Two contrasting theoretical models have been proposed: the cyclical succession model and the disturbance dynamics model. The PI's will test specific hypotheses derived from these contrasting models. The hypotheses focus on effects of large scale disturbances on the expected trend in populations of overstory species, specifically in reference to the impacts of Hurricane Kate which struck this area in the mid-1980's. The analyses will be based on data derived from a 4.5 ha permanent plot that was originally sampled and mapped in 1978. The PI's will remap the plot and use the temporal data set to address a series of questions and predictions concerning patterns of species replacement and community dynamics over time in these forests. %%% Although this project will focus on dynamics in southern coastal plain hardwood forests, these analyses address general problems and questions regarding the relative importance of autogenic and allogenic factors in the control of community dynamics and species diversity in forest ecosystems. ***