Influência dos traços funcionais na distribuição de morcegos insetívoros aéreos em uma paisagem insularizada

Abstract

The construction of hydroelectric dam results in habitat loss and tropical forest fragmentation. This modification of the environment hinders the dispersion of the species between continuous forest and fragments or has difficulties to establish itself in a new place. One reason for this exclusion is that functional traits may limit the species' ability to inhabit sites with certain characteristics. The reservoir of hydroelectric water generates a landscape where the environmental attributes are completely modified by the flood, forming islands with a gradient of environmental attributes between them. This causes the composition of species to be modified relative to the continuous forest and the distribution of the species to be filtered by the environment. In this study, we evaluated whether the insectivorous bats community is structured by functional traits or environmental characteristics on a local scale and landscape scale in a region insularized by the reservoir of a hydroelectric plant in the Amazon. We used PGLS models to adjust the phylogenetic dissimilarity among the 18 species of bats and verified through the AIC c which of the nine models are more sensitive to insularization. Through the RLQ statistic we identified which associations between functional traits and environmental attributes are stronger, from these associations we used the fourth-coner statistic to test whether the bat community was structured by environmental characteristics or functional traits. As a result, we found that the functional traits of body mass and ultrasound bandwidth had greater influence on the insularization of the environment. The functional traits that are associated with local variables are also associated with the landscape scale and the attributes of the environment have a greater influence on the structuring of the bats community than their functional traits. The great variability of the functional traits allows the bats to forage in different environments, but the persistence of the species varies with the reduction of the forested area, leading to the exclusion of certain species due to the different characteristics in the insularized islands.