Impacts of fire on bird assemblages

117
RESEARCH AREA
117

This week’s featured research article has just been published in Biological Conservation and quantifies the impacts of fire on bird assemblages in the peri-urban temperate woodlands of the Mount Lofty Ranges, South Australia. Prescribed burning is a commonly adopted fire-management strategy that aims to protect human life and assets by removing accumulated, flammable biomass. Using comprehensive spatiotemporal monitoring data, the researchers quantified the impacts of fire on bird assemblages in the peri-urban temperate woodlands of the Mount Lofty Ranges where the frequency of prescribed burning is increasing. After accounting for regional trends and site effects, sites burnt 20 years previously accommodated 15% fewer birds than unburnt sites, while sites burnt in the preceding year had 22% fewer birds. Fire also modified bird assemblages, favouring generalists and ground-feeding species. Of 60 species considered, 37% were both declining and negatively impacted by recent burning, while burning reinforced increasing trends in 30% of species, particularly large, common birds (e.g., magpies, ravens, wattlebirds). Simulations of avian alpha-, beta- and gamma-diversity under different fire-management scenarios predicted higher avian diversity for scenarios that retained unburnt woodlands relative to those that managed all sites. Relative to a no-fire scenario, for example, burning sites once every 10 years was simulated to reduce the abundance of woodland generalists by 7% and woodland specialists by 10%, while retaining some long-unburnt woodland ameliorated these effects. The researchers state there is a trade-off between fuel-reduction burning and conservation goals and that to maximise avian diversity and avert the replacement of woodland bird species with generalists, fire-management planning should preserve long-unburnt woodland habitat. The researchers conclude that the results support the notion that development planning regulations should be adjusted to limit new developments in high fire-risk zones to restrict future prescribed-burning requirements. They state that without changes to current human development trends in the Mount Lofty Ranges, the increasing social and political imperative for fuel-load reduction will risk the continuing decline and local extinction of more woodland bird species. The paper can be downloaded here (or email jennie.fluin@sa.gov.au for a copy). Image by Thomas Hunt