Seed traits, not density or distance from parent, determine seed predation and establishment in an Afrotropical forest

Seed predators drive patterns in seed mortality and seedling establishment and are posited to contribute to the maintenance of plant species diversity through several mechanisms. Negative density dependence and spatially-restricted recruitment are apparently widespread in Neotropical forests, but are little studied in Afrotropical forests, where generalist vertebrates may contribute more to seed mortality than do specialized invertebrates and fungi. We experimentally assessed the roles of seed density and distance from the parent tree for ten tree species in a forest in northeastern Gabon, using exclosures to isolate the effects of different seed predator types. Vertebrates caused greater seed losses than all other mortality agents combined. Unexpectedly, seeds under fruiting conspecific trees had significantly lower removal and higher seedling establishment than those under heterospecific trees or in neutral non-fruiting locations. Seed density did not significantly affect seedlin...