Thinning, fire and birds in Boola Boola state forest, Victoria, Australia

Thinning is a silvicultural technique used extensively throughout Australia s production forests. The longer-term effects of thinning on forest biota are not well understood. This study provides an insight into the effects of thinning on avifauna and vegetation, 5-10 y after a thinning operation. A paired-site experimental design was used to compare bird density and species richness at thinned and unthinned sites in a mixed eucalypt production forest in Gippsland, Victoria. The 2006-2007 fires across Gippsland directly affected eight of twelve sites in this study, providing an opportunity to investigate the immediate effects of wildfire on birds. Significantly greater numbers of birds and bird species were found at thinned sites, compared with unthinned sites. Differences in vegetation structure and habitat quality were also apparent between thinned and unthinned sites. A reduction in both bird abundance and species richness occurred immediately after the wildfire. Research into the impact of silvicultural techniques, such as thinning, on forest biota is an important step towards achieving ecologically sustainable forestry. Improved understanding of the effect of forestry operations is imperative in order to maximise conservation in production environments.