Prescribed burning as a conservation tool for management of habitat for threatened species: the quokka, Setonix brachyurus, in the southern forests of Western Australia

Abstract

Prescribed burning is frequently advocated as a means of managing habitat for threatened species. We studied effects of fire on the quokka (Setonix brachyurus), a species currently used as a focal species for planning prescribed burns in the southern forests of Western Australia. We examined (i) the recolonisation of burnt areas; (ii) the refuge value of unburnt vegetation; and (iii) fire prediction variables that may help to guide fire planning to achieve desired habitat management outcomes. We hypothesised that fire regimes promoting vegetation structure and patchiness of burnt and unburnt vegetation would result in more rapid recolonisation of burnt areas by quokkas. Occupancy modelling identified the most important variables for recolonisation as retention of vertical vegetation structure and multiple unburnt patches across >20% of the total area. These outcomes were associated with high surface moisture, low soil dryness and slow fire rates of spread. Intense wildfire resulted in complete loss of vegetation structure and a lack of unburnt patches, which contributed to these areas remaining uncolonised. Burning with high moisture differentials, maximising the effectiveness of edaphic barriers to fire, retaining unburnt vegetation and maintaining vegetation structure were found to be important elements of fire regimes in this region.

Mechanisms by which growth and succession limit the impact of fire in a south‐western Australian forested ecosystem

“…The basal bark of these trees provides habitat for the Tingle Pygmy Trapdoor Spider Bertmanius tingle, which is vulnerable to the lowest severity fires and extremely slow to recolonise (Main, 1987(Main, , 1991. Species such as Quokkas which are sensitive to both fire frequency and severity (Bain et al, 2015(Bain et al, , 2016 become rare in regrowth forest where the understorey is dense (Bain et al, 2015), and where the likelihood and severity of fire are highest (Zylstra et al, 2022 and this study). As mentioned earlier, the persistence of such species over geological time is difficult to explain if the build-up of fuels in unburnt forest serves to increase the likelihood of widespread, high-severity fire.…”

Mosquito-Borne Viruses and Non-Human Vertebrates in Australia: A Review

“…Most recently in 2019, New South Wales, Queensland, South Australia and Victoria experienced intense bushfires [ 170 ], and undoubtedly have led to a decrease in wildlife populations [ 171 ]. Previous intense bushfires have caused devastating impacts on various marsupials including the koala [ 172 ], quokka [ 173 ], and possums [ 174 ].…”

A conservation-significant threatened mammal uses fire exclusions and shifts ranges in the presence of prescribed burning

“…Vegetation density typically declines after 24 years and can be burned to regenerate senescing vegetation that no longer has sufficient structure and density to provide protection (Hayward 2002). Recent work carried out across the southern forests showed that quokkas are dependent on a mosaic of fuel ages that provide suitable vegetation for both food and refuge (Bain et al 2015;Bain et al 2016). Finding a balance of fire age mosaic is therefore an important conservation management consideration.…”