The Effect of the Landscape Matrix on the Distribution of Dung and Carrion Beetles in a Fragmented Tropical Rain Forest

Understanding the response of species to anthropogenic landscape modification is essential to design effective conservation programs. Recently, insects have been used in empirical studies to evaluate the impact of habitat modification and landscape fragmentation on biological diversity because they are often affected rapidly by changes in land use. In this study, the use of the landscape matrix by dung and carrion beetles in a fragmented tropical rain forest in the Los Tuxtlas Biosphere Reserve was analyzed. Fragments of tropical rain forest, forest-pasture edges, pastures, isolated trees, living fences (trees connected with barbed wire) and barbed wire fences were studied both near and far from forest fragments. Forest fragments had the highest abundance values, but pastures had the highest dung and carrion beetle biomass. Habitat specificity was high for the beetles in the most dissimilar habitats. Forest fragments and forest-pasture edges had and shared the highest number of species, but they shared only two species with pastures, barbed wire fences and isolated trees. Only one forest species was found within living fences far from the forest fragments. However, approximately 37% of the forest species were caught within living fences near the forest fragments. Therefore, forest-pasture edges function as hard edges and prevent movement among forest fragments, but living fences seem to act as continuous habitat corridors when connected to forest fragments, allowing forest beetles to move between the fragments. Further studies are necessary to determine the minimum width of living fences necessary to provide good corridors for these beetles and other species.