The structure of a shrub community in the understory of a tropical rainforest will be studied by determining the site- specific demography of several species of Piper with overlapping, but not identical, distributions relative to site disturbance history. Measurements of survival and growth rates of plant life stages in different habitats will indicate to what extent the distributions and abundances of Piper species are due to the differential mortality, if any, of life stages in various each habitats. These data will also help elucidate the ecological roles and relative importance of vegetative propagation versus seed production. Dispersal and differential reproduction will also be examined. The distributions of all of the Piper species in the locality will be quantified with respect to a series of environmental parameters. The morphological and reproductive charateristics of all of these species in this locality will be compared to those from another location to ascertain if there are suites of characters in this genus that are consistently correlated with species distributions. The project will contribute to our understanding of the ways in which plant distributions and population sizes are regulated, and hence to our understanding of plant community structure.
