Neighborhood diversity of large trees shows independent species patterns in a mixed dipterocarp forest in Sri Lanka

Abstract

Interactions among neighbors influence plant performance and should create spatial patterns in local community structure. In order to assess the role of large trees in generating spatial patterns in local species richness we used the individual species-area relationship (ISAR) to evaluate the species richness of trees of different size classes (and dead trees) in neighborhoods with varying size around large trees of different focal species. To reveal signals of species interactions we compared the ISAR function of the individuals of focal species with that of randomly selected nearby locations. We expected that large trees should strongly affect the community structure of smaller trees in their neighborhood, but that these effects should fade away with increasing size class. Unexpectedly we found that only few focal species showed signals of species interactions with trees of the different size classes and that this was less likely for less abundant focal species. However, the few and relatively weak depa...