Estrutura de metacomunidade de morcegos filostomídeos (Mammalia, Chiroptera) na Mata Atlântica brasileira

Abstract

Metacommunity ecology has provided the understanding of how multiple species interact, vary and are organized in suits of communities throughout ecological gradients. Community composition is determined by combinations of environmental and spatial processes, and the emergent properties of species distribution form spatial patterns (metacommunity structures). We used 54 species of phyllostomid bats and 30 sites (with ≥ 19 species) along the Atlantic Forest biome of Brazil to (1) determine the species distribution, (2) characterize the metacommunity pattern, and (3) identify environmental and spatial characteristics that give rise to such pattern. The Elements of Metacommunity Structure (coherence, range species turnover and range boundary clumping) were used to determine the best-fit idealized metacommunity pattern in relation to empirical distribution of bats. Canonical Correspondence Analysis and Variation Partitioning were used to determine the latent environmental gradient and the relative contribution of temperature, precipitation and space in structuring local species composition, respectively. We also tested the effect of Coastal and Seasonal forests on phyllostomid bat groups, using the Kruskal-Wallis test. Both the phyllostomid bat metacommunity, and animalivorous and herbivorous bats exhibited positive coherence, indicating that most species of each bat group responded to a latent environmental gradient. However, all phyllostomids showed a quasi-Clementsian structure, animalivores exhibited a quasi-nested structure with stochastic species loss, and herbivores showed a Clementsian structure. The detected environmental gradient comprised joint variation in temperature, precipitation, and space, and was pervasive in all bat groups. These three factors together explained from 48.3% to 66.2% of variation in species composition among sites regarding bat groups. No pure effect of suits of environmental variables was found for all phyllostomids or animalivorous bats. However, pure space and precipitation features were significant for herbivorous bats. The quasi-Clementsian and Clementsian patterns highlighted by all phyllostomids and herbivores indicate that species with similar distributions share evolutionary and xiii ecological characteristics forming groups of species along the observed gradient. Clementsian compartments were delimited by anthropogenic historical processes, such as sites comprising fragments of original Atlantic forests and sites comprising spatial alterations related to human land use. Conversely, the quasi-nested pattern with stochastic species loss presented by animalivores indicates that range boundaries of species were determined by species-specific environmental tolerances throughout the observed gradient. Phyllostomid bat species present non-random distributional patterns that are molded by a spatially-structured environmental gradients throughout the Atlantic forest biome in Brazil. Analysis of functional groups of species provided additional ecological information on species distributions that are obscured when considering a functionally heterogeneous group of species. Finally, habitat fragmentation associated with human activities likely plays a crucial role in modern phyllostomid species distributions throughout the Atlantic Forest of Brazil