Ecological constraints and trait conservatism drive functional and phylogenetic structure of amphibian larvae communities in the Brazilian Atlantic Forest

Abstract

Ecologists strive to untangle the complex interplay of current and historical factors, along with evolutionary history of species, to understand communities’ structure. However, this can be achieved by integrating different approaches to expanding our knowledge about the underlying processes connecting assemble rules of ecological communities. In order to better understand how ecological and/or evolutionary factors may affect the structure of communities, we assessed the phylogenetic and functional structure of 33 tadpole communities in the Atlantic Forest Southeastern Brazil and tested whether phylogenetic conservatism drives tadpole traits. We identified 19 communities which were significantly phylogenetic clustered and 10 which were significantly functional clustered. Trait diversity was skewed towards the root, indicating phylogenetic trait conservatism as an important driver of the structure of tadpole communities. The best explanatory model of the phylogenetic diversity included, in order of importance, presence of potential fish predators, water conductivity, external diversity of vegetation structure, canopy cover, internal diversity of vegetation structure and dissolved oxygen. Most variables were negatively correlated with phylogenetic diversity, but the presence of potential fish predators was positively correlated. For functional structure, external diversity of vegetation structure, canopy cover, area, dissolved oxygen and presence of potential fish predators were selected as the best explanatory model (presented in order of importance). Furthermore, of the 10 functionally structured communities, eight were also phylogenetically structured. In this sense, environmental variables could be filtering tadpole lineages interacting with phylogenetically conserved species traits, thus driving anura tadpole species’ occurrence on communities. Our study provides evidence that anuran communities structure results from interacting ecological and evolutionary processes.