Fire has shaped the evolution of Australia’s landscapes and native species over millions of years.
There's a great diversity in the fire regimes (frequency and severity of fires) across Australia. Influences include both human intervention and natural factors such as changes in vegetation patterns over millions of years and fluctuations in weather and climate.
Aboriginal people have also played a significant role in past and present fire regimes over many thousands of years and continue to manage large parts of Australia through the careful use of fire.
One of the best tools to combat wildfires is fire itself. Quite literally, fighting fire with fire.
Historically fire was an important tool to maintain plant and animal species that people relied on for survival. Parts of the North Kimberley (where we have a partnership with Wunambal Gaambera) are among the only places in Australia to record no small mammal extinctions. Here plant and animal communities still rely on small, low-severity fires burnt under Aboriginal stewardship.
Strict cultural protocols around lighting fires were once common and today many of our Partnerships with Aboriginal groups still maintain these protocols through the role of elders in determining where and when controlled burns are ignited.
In addition to natural fire regimes there are many contemporary threats including arson, climate change, land clearing and land degradation (primarily from agriculture).
Invasive grasses such as Buffel (Cenchrus ciliaris) and Gamba grass (Andropogon gayanus) are now significantly increasing the wildfire risk and ecological degradation across large areas and are a key threat we target.
Fire management planning
There’s no 'one-size fits all' approach to fire management. Every landscape is unique, and so is the potential impact of wildfire.
National Fire Program Manager, Richard Geddes, leads our reserve staff and science team in individually assessing every property. We combine the latest satellite technology with the knowledge of key partners on the ground (including neighbours and Traditional Owners) to map key conservation targets and threats.
The tropical savannas of Northern Australia are some of the most naturally fire-prone landscapes in the world. A high risk of wildfires comes with the annual ‘dry season’ that leaves the landscape tinder dry at the hottest time of the year and lightning regularly starts wildfires.
Bush Heritage has several important partnerships with Aboriginal groups in Northern Australia including across Arnhem Land, the North Kimberley and Cape York, where the careful use of fire through prescribed burning is the most important tool for conserving biodiversity and cultural sites.
Our Reserves at Yourka and Carnavon are under threat most years due to lightning strikes.
In other parts of Australia fire frequency is much lower and is influenced by longer climatic conditions such as El Niño–Southern Oscillation or well-above-average rainfall (promoting growth and fuel loads) followed by hot, dry conditions.
At our reserves in Tasmania, Victoria, NSW and southern WA, small amounts of prescribed burning may be considered to help areas recover from past clearing or to maintain vegetation structure and diversity.
In the arid zone fire frequency and severity is directly related to well-above-average rainfall events, which can lead to prolific growth in grass and vegetation and raise the risk of large fires when the landscape dries out.
Our Ethabuka and Cravens Peak reserves experienced large rainfall events in 2016 and 2017. We responded by mitigating the risk of wildfire through strategic prescribed burns over relatively small areas.
We also have an important partnership with Birrliburu in the arid zone where we work closely with senior Traditional Owners and rangers to plan and implement prescribed burns.
Controlled burns vs wildfires
The difference between proactive, controlled burns and uncontrolled wildfires is stark. It’s often the difference between life and death for native species.
Controlled burns are carried out in cooler conditions, often after recent rainfall, to create slow-moving, low-severity fires in carefully selected areas with appropriate vegetation communities.
On our reserves we work closely with our ecologists and the latest research to recreate a mosaic pattern of fire histories, which supports biodiversity and fire-sensitive plant and animal species. These controlled burns in cool conditions can reduce fuel build-up in the undergrowth and help control weeds.
Wildfires that often start in hot, dry, windy weather can quickly burn through weeds and undergrowth, gaining momentum to reach into tree canopies, destroying nesting hollows and food sources, killing small mammals and devastating ecosystems.
We also create strategic fire breaks that help control prescribed burns and can restrict the spread and movement of large wildfires.
“When you get those severe wildfires, it can burn everything,” says Richard. “Anything that doesn’t have wings can get caught – there’s often very little left alive in the landscape. Everything is black, every leaf on the tree – every hollow is burnt out”.
The impact of wildfires can be confronting. Millions of animals perish, and the ones that survive are left without crucial cover and susceptible to attacks by predators – especially feral cats.
Fire management is collaborative
Wildfires have no respect for property borders and can burn out cattle stations and agricultural land, impacting pastoral livelihoods as well.
We work together with neighbours and local stakeholders to ensure that together we’re protecting the landscape. With approval from the local fire authorities, we conduct controlled burns on reserves with strict supervision by reserve managers, and the support and on-ground assistance (where required) of relevant park or fire agencies.
How the land responds
When burning is skilfully carried out in the correct season it can reinvigorate ageing vegetation communities, encourage flowering and seeding and provide a flush of new green shoots and highly nutritious small herbs for grazing wildlife.
By strategically burning small areas of bush across a reserve, we build complexity into the vegetation over successive seasons. After some years this creates patches of bush at different stages of regeneration that can provide the resources animals need, no matter what the season.