Influência de fatores ambientais e espaciais sobre múltiplas facetas da diversidade beta e padrões de diversidade alfa filogenética em comunidades aquáticas.

Abstract

Understanding the mechanisms that drive the structuring of biological communities is a central theme in ecology. In freshwater ecosystems, environmental and spatial factors are important predictors of beta diversity in metacommunities, but their performance depends on several factors, including different facets of diversity and biological groups. Based on a dataset obtained from the literature, the main findings on the contribution of environmental and spatial factors to beta diversity in freshwater communities were synthesized, considering different organism groups, environment types, spatial scales, diversity facets, and components of beta diversity. Additionally, an empirical evaluation was conducted to assess the contribution of these predictors to beta diversity in zooplankton metacommunities (across taxonomic, functional, and phylogenetic facets), as well as the patterns of phylogenetic alpha diversity in communities from 23 lakes within the Upper Paraná River floodplain. The results revealed that environmental factors predominate over spatial factors in the structuring of metacommunities, and that the contribution of these factors varies among the different categories considered in this study, reinforcing the importance of including them in future studies. In the Upper Paraná River floodplain, beta diversity showed high values, and its dominant component was the “abundance difference”, especially in the rotifer metacommunity. The variation in dissimilarity was explained only by spatial factors in the three facets and metacommunities. At the local scale, the 23 lakes showed high values of phylogenetic alpha diversity, with most of them structured by stochastic factors. Therefore, the use of an integrated approach, considering different groups of organisms, different types of environments, facets and components of beta diversity, is relevant for a more complete understanding of the diversity patterns observed in freshwater aquatic ecosystems. The investigation of the effects of biotic interactions and temporal dynamics on metacommunities are also important factors to be considered in future studies.