Wind dispersal and 1‐year survival of Vataireopsis iglesiasii (Fabaceae) seedlings in a Neotropical lowland rain forest

Abstract

AbstractPopulations of many tropical tree species are regulated by negative distance‐ and density‐dependent processes (NDD), yet most studies on the effects of conspecific seedling and adult neighbors on seedling survival have focused on animal‐dispersed species. Species with seeds dispersed by wind may not be moved as far on average as seeds dispersed by animals, but some seeds may be dispersed a lot further, suggesting that knowledge of dispersal mechanism may help in our understanding of NDD. In this study, we took advantage of a high‐fecundity reproductive event that occurred for an individual isolated canopy tree of Vataireopsis iglesiasii in a tropical lowland rain forest site in Amazonian Ecuador to document seed dispersal and seedling survival to 1‐year post‐dispersal. Most seeds did not disperse far: 86% of germinated seedlings were found within 100 m. Mortality was high: only 49 of the 1732 monitored seedlings survived one year and only five survived a further four years. We found a significant negative effect of conspecific seedling density (but no effect of distance from the parent tree) on 1‐year survival. Rare long‐distance dispersal events may increase the probability of a seed reaching specific habitats, such as high‐light patches, and surviving beyond one year, thereby shifting the population recruitment curve outwards away from adult trees and maintaining diversity in species‐rich forests.Abstract in Spanish is available with online material.