Impacts of logging on autumn bird populations in the southern forests of Tasmania

Abstract

Bird assemblages were documented in different forest types in the Warra Long Term Ecological Research Site in Tasmania's southern forests. Sampling was undertaken in areas immediately after clearfelling and burning, in regrowth up to 26 years after this treatment, in selectively logged forest, in regrowth following wildfire, and in old-growth forest. It was found that areas subjected to clearfelling and burning supported assemblages which were distinct from areas with other histories, in that they comprised fewer species and individuals. This adverse impact of silvicultural practices on bird populations was apparent in all strata of the forest; canopy, mid-layer and ground. Immediately after clearfelling and burning, coupes were colonised by ground-feeding insectivores more typical of open country than of the surrounding wet sclerophyll forests, but these were quiddy displaced with the advent of young regrowth, which was gradually colonised by forest-inhabiting species. However, these assemblages were still depauperate as much as 26 years after clearfelling. Comparisons with previous studies suggest that this deleterious impact of forestry operations on birds may be ameliorated by the retention of patches in logging coupes. This is supported by the absence of significant impacts on birds in parts of the area which were selectively logged 25 years earlier.