Tree growth, mortality, physical condition, and microsite in an old-growth lowland tropical rain forest

Tree species richness in tropical rain forest typically exceeds several hundred species over mesoscale landscapes. There is no generally accepted ecological theory that accounts for the coexistence of so many species with the same general morphologies and the same basic requirements of light, nutrients, water, and physical space. In part, this lack of theory rests on the lack of understanding of the post-establishment ecology for the vast majority of tropical tree species. Of even more immediate concern is the lack of data on tree performance in relation to climate; such data are critical to project effects of global climate change on tropical forests.

Here we present data from a project designed to examine the post-establishment ecology of 10 species of tropical wet forest trees selected to span a range of predicted life history patterns. The study site was terra firme old-growth tropical wet forest at the La Selva Biological Station in Costa Rica. Particular emphasis has been placed on evaluating the precision of measurements, metadata development, and annual measurements of all individuals. Because the climates of all forest environments show significant interannual variation, the annual time interval is a powerful scale at which to study the relation of tree performance to climate variation. It is also a temporal interval that captures the scale of microhabitat variations and the responses of trees to this variation in tropical rain forest.