Factors Affecting Community Composition of Forest Regeneration in Deforested, Abandoned Land in Panama

We tested alternative hypotheses concerning factors affecting early forest succession and community composition in deforested and abandoned areas invaded by an exotic grass, Saccharum spontaneum, in Panama. We hypothesized three barriers to natural regeneration: (1) Saccharum competition, (2) seed dispersal limitations, and (3) fire. We measured natural tree and shrub regeneration in a factorial experiment combining distances from adjacent forest, mowing treatments of the Saccharum, and a prescribed burn. To determine the applicability of the general model of neotropical succession and the nucleation model of succession to species composition of forest regeneration in these anthropogenic grasslands in Panama the effect of time since fire and distance to remnant vegetation (isolated trees, shrubs, and large monocots) was measured. Fire significantly affected species composition and decreased species richness because most species had either their resprouting ability or seed germination inhibited by fire; th...