Seed rain under the canopies of female and male Myrsine coriacea, a pioneer tree from the Brazilian Atlantic forest

Isolated pioneer trees have been shown to increase the deposition of animal-dispersed seeds. The effect of gender on seed rain has not yet been investigated, and this study aimed to evaluate whether female and male plants of a pioneer dioecious zoochoric tree differ with respect to the seed rain under their canopies. Seed rain was evaluated for 13 mo, from October 2009 to October 2010, in secondary vegetation of the Atlantic forest in southern Brazil. We used 60 seed traps (0.5 m(2)): 40 traps under the crowns of 40 Myrsine coriacea (Primulaceae) trees (20 male and 20 female individuals) and 20 at sites without trees. We found 365 071 diaspores belonging to 115 morphospecies from 37 families, and 38.3% of the morphospecies were trees, most of them zoochoric. The female trees accumulated a greater number of diaspores and species richness than male trees. The male trees accumulated a higher number of seeds and species than areas without trees. This study shows that sites containing female and male trees of M. coriacea and sites without trees differed significantly in terms of seed rain, and there is a gender effect in this dioecious, pioneer tree species because female plants promote an increase in the richness and abundance of diaspores.