Savanna burning has a long history in Australia, with Aboriginal use and management stretching back for millennia. Across northern Australia, it is a landscape-scale activity that affects vegetation and biodiversity. Many factors affect the frequency and timing of burning including land tenure (e.g. protected areas, pastoral, Indigenous land) and related management objectives (e.g. biodiversity, emissions trading, grazing, weed management, fire prevention). The various fire management aspirations for Indigenous land have been well described in the literature and continue to be the focus of discussion at annual north Australia savanna fire forums.
The impact of different fire regimes on biodiversity is of global interest and is a common aim of many savanna fire management programs. This project aimed to review the current burning regimes in northern Australia and the existing understanding of their relationship to biodiversity conservation. A secondary aim of the project was to identify pathways and opportunities for monitoring activities and future research which can help to inform how different fire regimes can benefit biodiversity.
There are some excellent published long-term systematic biodiversity surveys in the Northern Territory – particularly in Kakadu and Nitmiluk national parks – and several large-scale ongoing monitoring programs measuring different elements of biodiversity in partnership with land holders (e.g. Karrkad Kanjdji Trust). These monitoring programs will become important future studies to better understand the responses of biodiversity to different fire management practices applied across the region.
By and large, the most instrumental driver of change to savanna burning regimes has been the implementation of carbon farming methodologies. Carbon farming methodologies within this zone promote the change of fire regimes from predominantly late dry-season, intense fires to lower-intensity, lower-emissions, early dry-season fires. This is achieved through the promotion of early dry-season fire which decreases fuel loads before they can build to destructive levels. Although carbon farming methodologies are a dominant driver of fire management, there are many different reasons why fire is used and these change across and within tenure types. We summarised fire historical fire regimes in major land-use types across the region to explore broad trends in fire management between sectors.
The current knowledge base for biodiversity responses to fire regimes is concentrated in the Northern Territory, with Queensland and Western Australia having significantly fewer studies. Due to the vast range and variations throughout northern savanna bioregions and subregions, this limits the opportunities and appropriateness of applying NT-based knowledge to other locations.
Seeking to improve understanding of biodiversity responses also provides opportunities to capture, review and integrate other knowledge sources, such as Indigenous knowledge, into existing understanding of using fire for land management. There is also a concurrent opportunity to better describe and create metrics for how to implement specific fire regimes on-ground as well as increasing use of remote sensing technologies to aid the development metrics and improve the database on changing fuel loads across savanna landscapes.
Given the increasing development and uptake of savanna burning programs and methodologies in northern Australia and a growing interest in biodiversity, cultural and social benefits in response to a changing climate, this project reinforces the need for systematic and comparable studies into biodiversity responses to savanna burning.
This project was lead by Justin Perry, with assistance from Helen Murphy, Anna Richards, Eric Vanderduys (CSIRO), Graeme Gillespie, John Patykowski (NTG), Samantha Setterfield, Michael Douglas (UWA) and numerous other biodiversity and fire experts.