Conservação de aves de sub-bosque em paisagens fragmentadas: Importância da cobertura e da configuração do hábitat / Influence of habitat amount, fragment size and connectivity in Atlantic Forest bird species conservation

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Landscape aspects such as habitat amount, fragment size and connectivity, have been suggested as key features for maintaining species in altered landscapes, and thus are essential to be modeled and comprehended for management and conservation purposes. To test their effects on understory Atlantic forest bird species, we built models with variables representing fragment size and functional connectivity in 3 landscapes with different proportions of forest (14, 31 and 45%), and confronted with data from more than 4,818 individuals captured in 53 fragments of different sizes (2.06 to 158.45 ha) and connectivitys (connected by corridors, or by short distances), and then we ranked under a model selection approach (AIC). A total of 117 species were recorded, and the landscape with higher amount of forest was richer (87) than the two others which presented a similar lower richness (62 and 70), what suggests a threshold amount of habitat between 32 to 44%. Configuration aspects were important in all cases; however, different characteristics influenced species richness and abundance in each landscape. Patch size was important in determining species richness and abundance in the landscape with low amount of habitat, while connectivity aspects were crucial in the landscapes with higher amounts of habitat. Within the connectivity models, particularly the ones that take in to account the connectivity by corridors, but also the ones that consider short movements through the matrix are far better supported, then the ones by longer distances gaps. Moreover, specieslevel analyses yielded results similar to the pattern found for the whole assemblage, and the configuration variable influence varied along the habitat conversion gradient. The results presented here are important for management planning towards conservation, and should be considered in site selection for conservation, restoration or any other kind of management.

ASSUNTO(S)

proporção de habitat atlantic forest functional area conectividade funcional Área funcional configuration functional connectivity mata atlântica aves amount of habitat configuração

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