Diversidade de formigas em fragmentos florestais no Vale do Paraíba, Vassouras, Rio de Janeiro

Abstract

The region of Vale do Paraíba is part of the Atlantic Forest and presents a history of environmental degradation, like many other regions in Brazil, caused at first by wood extraction and coffee plantations, and later by other crops and cattle farming. Now, despite the remarkable headways in this biome’s biodiversity research, some groups still show little knowledge of the geographic scope and neglect the research when conducting management and conservation studies. This study’s greater objective was to assess the composition and abundance of ant species in different forest fragments in Vassouras, RJ, over the influence of environmental and structural attributes. the research was developed between march and april 2008. The ant fauna was analyzed through 620 litter samples of 1m2 each, submitted to the Winkler extractor for 48 hours. They were equally distributed in 31 forest fragments belonging to three different landscapes (A, B and C), creating a gradient of forest covering and altitude with different uses of the soil. 170 ant species were found, belonging to 10 subfamilies and 49 genera, with an average of 10 (± 3.3 of standard deviation) species by square meter. The average of species for fragment was 50 ± 9.2. The highest richness was found on landscape A with 133 species (187 estimated), followed by B with 122 spp. (160 estimated) and C with 100 (111 estimated). The largest composition and richness differences were found between landscapes A and C. Despite being fragmented, all three landscapes obtained a good representation of the ant fauna, showing distinct values for the biodiversity’s conservation. The results showed that more heterogeneous landscapes have greater richness and a more heterogeneous composition of species, although no significant relation to the size of the fragments was found and the ant fauna between landscapes. The results can still suggest that the differences found could be related to the succession state and the floristic composition of the forest fragments.