By Ben Corey, Department of Biodiversity, Conversation and Attractions

Northern Australia’s tropical savannas are one of the most fire-prone landscapes on Earth and fire is a fundamental part of savanna ecology. Still, present-day fire patterns – following the disruption of fire management by Indigenous people post-European colonisation – have become dominated by frequent, large, high-severity wildfires, which threaten biodiversity.

Fire management plays a critical role in savanna biodiversity conservation. Land managers carry out prescribed burns annually in the late wet and early dry seasons. These fires then create breaks that limit the spread of the late dry season wildfires that will inevitably occur from lightning and people's careless use of fire.

Much of the fire management discourse has focused on the concept of fine-grained patch mosaic burning. Here, fire managers try to provide multiple patches within the landscape with different times since the last fire, under the premise that pyrodiversity benefits biodiversity.

In the north-west Kimberley where fire management has been occurring for the last 15 + years, we have had the opportunity to test this ‘pyrodiversity benefits biodiversity’ paradigm through an adaptive management program. This has involved the interrogation of on-ground biodiversity monitoring data and burnt area mapping. Looking specifically at small-medium sized mammals (a group of fauna which is acutely sensitive to fire) we found that pyrodiversity had a negative influence on the number of different species and their abundance. The most vital factor was vegetation that remained long unburnt (four or more years). Furthermore, the benefits for small mammals increase with the size of the unburnt patch – bigger is better.