Data from: Negative density dependence in the mortality and growth of tropical tree seedlings is strong, and primarily caused by fungal pathogens

Natural enemies have been implicated as agents of negative density
dependence (NDD) in tropical forests, but their relative contributions to
NDD, and thus to the maintenance of diversity, are largely unknown. We
monitored the rates of survival and relative growth rates on seedlings for
ten years in tropical moist forest in Manu National Park, Peru. We then
experimentally manipulated the plots to exclude fungal pathogens, insects,
small mammals, and large mammals for an additional 31 months to assess the
influence of these natural enemies on density-dependent interactions among
tropical seedlings. Fungal pathogens made the most important contribution
to negative density dependence. The application of fungicide led to lower
mortality rates, faster growth rates, and decreased species diversity.
Other taxa of natural enemies had at most minor effects on seedling
performance. Synthesis. We conclude that fungal pathogens are the
strongest contributors to the widely observed NDD that occurs among
seedlings. Moreover, the presence of fungal pathogens augments the species
diversity of seedlings, indicating their critical contribution to the
maintenance of species coexistence and the structure of tropical tree
communities.