Levantamento de formicídeos de fragmento de Floresta Atlântica no município de Eng. Paulo de Frontin, RJ (Hymenoptera, Formicidae)

Abstract

The east coast of Brazil, is lined with a chain of mountains where a forest known as Mata Atlântica develops. The vegetation of these mountains, because of its proximity with the coast, is under the influence of the trade winds full of humidity, from the ocean. Originally the forest extended for almost all the coast, from Rio Grande do Norte to the Rio Grande do Sul. Even in the Northeast the forest occupied a great area, that nowadays, practically has disappeared. The study of the biodiversity is fundamental to establish new strategies in environmental issues. The insects have been the subject of many studies with the objective of catalogue and find subsidies to not only know its biodiversity, as well as use them as a support to evaluate the environmental conditions. The insects are present in different habitats, they are the main consumers of the terrestrial ecosystem and represent the most important feeding resource to animals of different taxonomy groups. The biodiversity of the ants has been studied with the objective of comprehend the disturbs caused by the constant simplifications of the natural ecosystems, like the monoculture of the eucalyptus; because, besides responding the environment stress, the ants have broad distributions and local abundance, high richness of species, they are easily sampled and relatively easier to identify than other organisms. Because of that, this study had the objective of study the antfauna in the Floresta Atlântica fragment, determining the ants in morphospecies level, observing the ones that present a bioindicator power of environmental quality. The study was done in the Instituto Zoobotânico de Morro Azul IZMA, with an area of approximately 19 ha in a fragment of Florest Atlântica of approximately 120 ha localized on the third district of the Eng. Paulo de Frontin county, where was installed a transect in which were determined four spots approximately 250m far from each other. On these spots, were installed five pitfall traps. The traps are 5m inward the trail and 10m far from each other. The traps remained in the field for 48 hours. The most representative genus in relation to the number of morphospecies was Pheidole, with eight morphospecies itemized, followed by Apterostigma (three), Strumigenys (three) and Azteca (three). The other genus presented one or two morphospecies. The sampling spots I and II were the most representative in relation to the number of individuals and diversity of genus found, because these spots show an abundance of leaf litter and a rich variety of vegetal species, important factors to the survival of many species that live of the litterfall like a lot of species of Ponerinae and Ectatomminae. The balance between the occurrence of rare and common species is a parameter to the evaluation of environmental impact. The rare species need a more harmonic ecological structure, that is to say climax environments or in complete state of recuperation, as the fragment studied, but the common species inhabit not only climax environments, as well as environments disturbed by the anthropic action or by ecology succession processes.