Efeito de borda sobre a comunidade de formigas em remanescentes de mata atlântica nordestina em relação ao agroecossistema de cana-de-açúcar

Abstract

he Atlantic rainforest for centuries has been undergoing profound changes in its structure and composition due to anthropogenic pressure and agriculture. This process has consequences for the forest and edge effects causing changes in species composition, structure, and therefore the regulatory entomofauna ecosystems. Therefore, we aimed at verifying the effect of edges on the creation of an ant community in a remnant of Atlantic forest in northeastern Brazil, inserted in an array of cane sugar. In the three habitats studied pitfall traps were mounted in 40 transects (20 for forest, 10 two months for cane sugar and 10 for six months), 50m away, 100m and 200m from the edge into the forest and also for matrix cane sugar. We collected 118 ant species, distributed in 40 genera, 25 tribes and nine subfamilies. The subfamilies were found more representative: Myrmicinae, Dolichoderinae, Formicinae and Ponerinae. In terms of more diverse genres found Crematogaster, Pheidole and Solenopsis, 12, 11 and 10 species respectively. Species richness, abundance and diversity of nesting species varied significantly among habitats and distances studied. In general, species richness, abundance and diversity of nesting species for the forest 200m from the edge was significantly higher than that observed for 50 m of forest edge. Additionally, these parameters studied showed higher values at all distances to the forest habitat, habitat for the intermediate array with six months of age and the lowest number of species to the habitat matrix with two months of age. The three habitats studied had different species composition, with greater differences occurring between native forests and cane sugar. In summary, the results here reported indicate that the ants feel abiotic changes in the area of cane sugar to 100 m inside the forest, while the distance from the edge into the cane, has the opposite effect. Furthermore, with increasing age of the agroecosystem, increases the recolonization by the ants, indicating that the microclimatic conditions of this area are becoming milder and more forest species adapted to disturbed areas will recolonizing areas of sugar cane.