The long-term dynamics of epiphyte communities are little studied although such baseline data are urgently needed, in particular in the context of global change. Census data of a vascular epiphyte community from 0.4 ha of undisturbed lowland forest in Panama were used to infer future changes in community composition by deducing population growth from the current size class structure of populations. The study includes 11 387 individuals out of 45 species, ranging in abundance from 16 to 1568 individuals. There was a significant negative correlation between the size of a population and the steepness of the size distribution, indicating that more common species are likely to increase in abundance in the future, while rarer species apparently depend on immigration from other populations to allow local persistence.