Influências multi-escala da paisagem e limiar da fragmentação em morcegos no cerrado

• Autor(a) principal: Muylaert, Renata de Lara [UNESP]
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/121888
• topic: Bats; Morcego; Cerrados; Ecologia da paisagem; Paisagens fragmentadas; Morcego - Habitat; Biodiversidade

The knowledge about which factors determine biodiversity on the present conditions of habitat loss and fragmentation is essential to develop strategies for species conservation. The biodiversity can present threshold responses to landscape structure variation (fragmentation threshold), particularly to habitat amount. Detecting these thresholds might support conservation, restoration and management programs. This study explored bat responses to landscape composition and configuration variables (exploratory approach), and we tested if there is a threshold response in bat richness as a function of habitat amount on landscape. We used richness as an operational variable for biodiversity, capture number for abundance and forest cover for adequate habitat amount to the group. We evaluated abundance responses of bat guilds to local and landscape structure variables on a multi-scale approach (0.5 to 5 km): frugivores, nectarivores, animalivores and sanguivores. The study was conducted on 15 landscapes spread on a gradient of habitat amount (9 to 100%) on southeastern Brazil, in forest cerrados. We sampled bats with mist nets with the same effort in four sampling points for five nights per landscape. The analysis was made by model selection by multiple hypotheses based on Akaike Information criterion and restricted maximum likelihood estimates. Bat guilds presented nonlinear responses to habitat amount, edge, mean fragment shape, connectivity, habitat diversity and local variables (fruit availability and canopy height). We identified a threshold around 45% of habitat amount to bat biodiversity, with a accentuate drop on landscapes below this threshold point. We suggest that restoration strategies look for increasing the connectivity of these landscapes, since the region is on a context of moderate to low landscape resilience. This study is novel because supports the fragmentation threshold hypothesis using such an ecologically diverse and abundant...