By Pedro Palheiro, Department of Biodiversity, Conservation and Attractions WA, Parks and Wildlife Service

Millstream Chichester national park, located in northern Western Australia, has rich Aboriginal heritage, outstanding tourism attractions, and significant environmental values. Spinifex hummock grasslands dominate the landscape, with a high incidence of lightning over the summer months, creating conditions for large-scale bushfires. Bushfires impact national park values, surrounding mining and pastoral operations with potential for significant loss at a local, regional and State level.  

Yindjibarndi and Ngarluma traditional owners and the Department of Biodiversity, Conservation and Attractions (DBCA) have a long history of implementing prescribed burns to reduce the size of bushfires in the landscape. A patch-burn mosaic through ground and aerial burning is used to protect communities, cultural heritage, infrastructure and the environment. 

37-years of fire data were used to compare the area burnt by bushfires and prescribed burns under different management strategies, treatment scales and intensities. The landscape scale fire management strategy has evolved from a linear buffer approach (1987-2014) focused on creating large homogeneous compartments to a fine grain mosaic approach (2015-present) creating diverse vegetation ages across the management area.

Results indicate that contemporary strategies involving a targeted approach, with ground and aerial ignitions combined, are effective in reducing the size of bushfires while preserving areas of high ecological and cultural values. This approach also resulted in the reduction of number of fires requiring direct suppression allowing natural fires to self-extinguish. This presentation will illustrate the success of the fine grain mosaic approach to prescribed burning at a landscape scale.