Identidade vs. características da planta hospedeira : o que importa mais para a diversidade funcional de aranhas?

Abstract

Taxonomic diversity is the variety of species present in a given community, while functional diversity is the variety of attributes that relates to the functioning of that community. Approaches based exclusively on species identity have been complemented by studies aiming at the functional attributes of the species, since the former has certain limitations in studies of Community Ecology. In the present study, we tested whether the taxonomic and functional diversity of spiders responded more significantly to intraspecific or interspecific variation of their host plants, bromeliads. We used a statistical method that quantified beta-diversity of spiders in response to intraspecific and interspecific variation of bromeliads. We also did a decomposition of the bromeliad attributes in the phylogeny in order to investigate if there was any node that contributed disproportionately to the current diversity of spiders. The data of this study were obtained in an area of Neotropical Atlantic Forest located in the state of Espírito Santo, southeastern Brazil. The functional diversity of spiders was obtained through traits related to habitat use (response traits), while the traits of bromeliads were obtained from the possibility of habitat use by spiders (effect traits). We searched recent phylogenetic studies to decompose bromeliad traits into their phylogeny. We used the proportional contribution of intraspecific and interspecific variation of bromeliad traits as predictors of spider diversity. Our results showed that the interspecific variation of one of the bromeliad traits positively affected spider beta diversity (P < 0.05), reinforcing the necessity to use approaches that extrapolate species identity as a single or main measure of diversity.