Os efeitos da fragmentação da Mata Atlântica sobre a riqueza e abundância de Accipitriformes e Falconiformes na Zona da Mata de Minas Gerais

• Autor(a) principal: Zorzin, Giancarlo
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2259
• topic: Mata Atlântica; Fragmentação; Accipitriformes; Falconiformes; Atlantic Forest; Fragmentation; Accipitriformes; Falconiformes; CNPQ::CIENCIAS BIOLOGICAS::ZOOLOGIA::ZOOLOGIA APLICADA::CONSERVACAO DAS ESPECIES ANIMAIS

This dissertation investigated the diurnal raptor assembly in Atlantic forest fragments in the Viçosa region, Minas Gerais, Brazil, by studying the species composition and abundance in forest fragments and how these parameters are influenced by the landscape. Data were collected in 2009 and 2010, in 35 forest fragments, using three census methods: i) 5 h point counts from outside forest fragments (7:00 am - 12:00 pm); ii) playbacks inside forest fragments and; iii) transects in existent trails inside forest fragments. The punctual abundance índex (IPA) and the frequency of occurrence (FO) for each species was calculated. Landscape influence on both species richness and abundance was analyzed considering both patch (area, isolation, vegetation types, and topography types) and landscape variables. Landscape variables were measured from the centroids in each fragment for 500m, 1000m, 1500m, and 2000m radius, considering percentage of forest cover (PLAND), average distance between fragments (ENNMN), fragment density (PD), amount of core area (CORE) and average size of fragments (AREAMN). Correlations among variables were tested with path analysis. Seventeen Accipitriformes and eight Falconiformes were recorded. Generalist and open area species were the most frequent and abundant while most forest species presented low abundance. Five species have become extinctin the region in accordance with previous surveys. Path analysis indicated that at the local level, fragment area was the main variable explaining the raptor species richness in forest fragments, exertinga direct effecton the abundance of forest species. PLAND and CORE were the most important variables explaining bird abundance and richness. Both richness and abundance of forest raptors were strongly influenced by fragment area, as well as the amount off avorable habitat in the surrounding landscape, with the metrics available for isolation and assuming marginal importance. Both species richness and abundance of forest species were primarily dependent on the area of forest fragments, as well as the amount of favorable habitat in the landscape. We conclude that the effects of forest fragmentation on the taxa studied must be analyzed under different spatial scales. Additionally, current public policies for the conservation of these species should prioritize a landscape approach in order to conserve more sensitive forest species.