Efeitos do ambiente sobre estimativas de diversidade taxonômica, funcional e filogenética de anuros em bancos de macrófitas lacustres na Amazônia Central

Abstract

Assemblages can be structured by neutral, niche-based processes, or combinations of both. Understanding the influence of these processes and evaluating diversity measures like taxonomic, functional, and phylogenetic metrics on the structure of ecological assemblages can show patterns and unravel community assembly mechanisms. Anurans (frogs and toads) represent a large part of the diversity of vertebrates in tropical environments and are a key group in assessing diversity patterns at different spatial scales. They can be terrestrial, aquatic and also found in macrophyte banks. These banks or floating meadows are aquatic and semiaquatic rooted or freely floating plants, which provide shelter, feeding, reproduction, spawning and nursery habitats for many organisms, including anurans, and can promote faunal long-distance dispersal and gene flow. Given that macrophyte meadows can influence the structure of anuran’s diversity, our study aimed to test the roles of spatial and environmental factors on the taxonomic, functional, and phylogenetic diversity of anuran assemblages found in floating meadows. Our study was held at Catalão lake, Central Amazonia. Sampling on fifty 50 x 5 m plots occurred during the flood period, in macrophyte banks distributed throughout the lake. Geographical and environmental variables were measured at six equidistant points in each plot. We showed that macrophyte height influences taxonomic α diversity; macrophyte height and nearest margin distance influence taxonomic β diversity; water pH influences functional α diversity; and macrophyte height and nearest margin distance influence phylogenetic α diversity. Our study also suggests that geographic distances do not influence the anuran assemblage. We conclude that the anuran assemblages from this lake are niche structured. Anurans in general have limited dispersion ability and are affected by local environmental characteristics. When in fragmented habitats, these characteristics can reduce their dispersion, and since macrophytes can be seen as habitat patches for anurans, spatial processes have limited influence in this environment.