Responses of birds to the natural re-establishment of wilderness in montane beechwoods of North-western Italy

摘要

Habitat structure and its effect on bird communities in logged and abandoned montane beechwoods of North-western Italy were analysed to assess bird responses to natural regenerative aspects of succession. In the study area three seral and management types of beechwoods were identified: up to 15 years old beech coppices, 30-50 years old stands where small scale selective cutting still occurs, and natural regenerating 30-50 years old stands located in a wilderness preserve (Val Grande National Park). Bird species richness, abundance and diversity were significantly greater in naturally regenerating stands, whereas little differences existed between the two managed stands. This suggests that bird diversity of beechwoods younger than 50 years might depend on management-policy more than on the successional stages. Species-specific logistic regression models and canonical correspondence analysis indicated that micro-habitat features such as the amount of snags and the presence of edges were important predictors of bird community composition. In our study area, natural habitat recovery appears sufficiently robust to achieve 'passive' restoration of wilderness without intervention. Our results indicate that simple measures could be taken to improve biodiversity in the managed landscapes. (C) 2004 Elsevier SAS. All rights reserved.