Influência do manejo florestal madeireiro de impacto reduzido sobre a assembleia de morcegos em uma floresta tropical chuvosa no baixo Rio Amazonas

Abstract

Tropical forests, which concentrate the largest number of species of terrestrial ecosystems, are rapidly disappearing because of land-use changes. Logging is one of the main threats. Reduced Impact Logging - RIL techniques have been considered for mitigating the impacts of logging on wildlife. We used a Before-After-Control-Impact (BACI) design to evaluate the effects of RIL on bats, in two study sites located in a logging area in the west of Amazonia. Furthermore, we measured vegetation structure in each plot to relate with changes in bat assemblage. After 64 nights of sampling effort, we captured 719 individuals of 36 species, 24 genera and four families (Phyllostomidae, Molossidae, Mormoopidae and Thyropteridae). The main species caught were Carollia spp., Artibeus lituratus, Lophostoma silvicolum, A. obscurus, Tonatia saurophila, Phyllostomus elongatus, Lonchophylla thomasi and A. planirostris. For the richness, abundance or composition of bat species in the short term, the impact area did not suffer major changes than the control area. However, bat composition changed between years (P = 0,002). Nevertheless, the relationship between abundance and vegetation structure variables (canopy opening and vegetation clutter) changed within the areas, between the years of sampling, suggesting that changes in species composition between years can be responsible for these changes. This is the first study using a BACI design for evaluating the effects of logging on bats. Our results suggest that Reduced Impact Logging did not have a significant effect on the abundance and composition of understory bats in the short term. Monitoring is needed to evaluate the long-term effect of RIL on those assemblages