Project BD4: Koala and habitat response post-wildfires

In August 2020, the NSW Forest Monitoring Steering Committee approved funding to investigate the impact of the 2019-20 wildfires on koalas and their habitat. This leveraged existing research in a cost-effective way and provides priority information for decision making and community.

Researchers from the Australian National University and the NSW Department of Primary Industries led the investigation. We produced a summary paper and a research note to outline their findings.

Researchers from the Department of Primary Industries published their findings in a peer reviewed journal and on the Department's website.

Researchers from the Australian National University provided a report on koala habitat response post-wildfires which is available as an addendum (page 35) to their report on harvesting impacts provided to us under the Koala Research Program.

The approach

The research used existing pre-fire data and analysis, including from our Koala Research Program and annual koala monitoring by Department of Primary Industries, combined with targeted sampling after the wildfires.

Knowledge gaps around the impacts of fire on koala density (site scale), koala occupancy (regional scale) and nutritional value of trees and sites for koalas were addressed.

Findings

In the summary paper, overall the researchers found:

  • koala occupancy remained stable in north-east NSW after the 2019-20 wildfires (as measured across 50 sites)
  • areas with a greater extent of medium or high fire severity experienced larger declines in koala density than areas with only low severity fire
  • koalas were temporarily absent in some areas where high fire severity dominated the landscape but began to return after a year
  • the epicormic post-fire growth of some tree species was found to have higher nutritional quality for koalas than mature leaves from the same trees pre-fire.

While koala populations at the research sites were relatively resilient following the 2019-20 wildfires, future fires may lead to more significant adverse effects as habitat quality, connectivity, and refuge areas may decrease and koalas may have less opportunity to recolonise between fire events.

The report examines a range of opportunities to improve outcomes for koalas following wildfires, for example reviewing koala browse species list to ensures species with high post-fire nutritional value are retained.

Papers and reports