9801521 Bertness and Rand This research will examine how multiple ecological factors work together to structure a community of halophytic forbs known as the New England cobble beach community. This unique estuarine habitat is found along moderately protected coastlines from Long Island Sound to northern Maine. It comprises a dense assemblage of forbs restricted to sites behind beds of the grass Spartina alterniflora. One goal of the study is to elucidate the relative roles of seed supply and post-dispersal environment in setting patterns of plant distribution and abundance across marsh zones. Another goal is to examine the relative effects of post-dispersal factors, biotic interactions and physiological stress, on these patterns, with particular attention given to their potential interactions. Results from this study will provide an unusually complete understanding of this unique plant community and further our understanding of populations of sparsely distributed plants.