Prescribed burning frequently asked questions

Fire modelling and observation of bushfires have demonstrated the effectiveness of prescribed burning and provided evidence for its importance in reducing the impact of bushfires on communities and the environment. It is also an important tool in maintaining and enhancing biodiversity with many vegetation types requiring periodic fire to maintain healthy ecosystems.

Prescribed burns won’t stop all bushfires, but they may limit their spread and impact, and make them easier and safer to suppress. Each prescribed burn has a fixed period of effectiveness and is site specific.

Research into the effectiveness of prescribed burning by fire management authorities, fire scientists and ecologists continue to inform DEW activities. A background paper by the Royal Commission into National Natural Disaster Arrangements, representing findings from a selection of scientific papers, reported that reducing fuels can slow the initial rate of fire spread and intensity, provide opportunities to suppress fires and reduce the risk of them escalating into extreme events.

However, under extreme and catastrophic weather conditions, fuel loads may have less impact on fire behaviour. But as the commission reported, these elevated conditions don’t persist, and opportunities to suppress fire in areas previously managed with prescribed burns can then occur as the weather moderates.

While there’s a range of views on prescribed burning, NPWS is committed to the nationally-agreed position.

Where high bushfire risk is identified, fuel is reduced with prescribed burns or other methods, to reduce a bushfire’s speed, intensity, flame size, and ember and spotting potential. This makes bushfires less damaging and easier to put out. With this reduced risk, prescribed burns also help protect biodiversity as they are less harmful to our native plants and animals than the intense bushfires they can prevent.

Many native plants and animals have evolved with the natural fire regime they’ve been exposed to. Too much or too little fire in the landscape can be harmful, so before every prescribed burn staff undertake environmental assessments and ensure there is enough unburnt habitat nearby for populations to use while the burnt area regenerates.

Prescribed burning is part of a broader strategy to combat bushfires and is generally considered the most effective and ecologically sound method of reducing fuel loads across large areas. Other methods include mechanical thinning, slashing and weed control. It is important to remember that prescribed burning is most effective when incorporated with individual property preparedness. Visit the CFS for information on how to prepare your property for bushfire.

To work out where to burn, life, property, and environmental assets at risk from bushfire are identified. Areas with higher risk are prioritised to keep communities safe and ensure we meet CFS and other legislative requirements.

How we burn includes annual on-ground work guided by a 3-year rolling program. This gives us flexibility to bring forward or postpone works, depending on forecast weather, bushfires, or other factors which influence the risk. Ecological fire management guidelines also ensure biodiversity values aren’t compromised and our environmental assessments identify threats such as Phytophthora cinnamomi (a root rot disease) and describe measures to reduce its spread (e.g. avoidance or hygiene). Environmental assessments also ensure enough unburnt habitat is in the landscape for native animals to use while burnt habitat regenerates.

Every prescribed burn gives us the opportunity to learn more about fire ecology and behaviour, and our monitoring builds on knowledge learnt from previous burns. This helps us adapt our program to any changing conditions. This is integral to our planning and in the way we conduct prescribed burns. Any habitats or species of concern from fire (too much of it or too little) are identified in fire management plans, and strategies are built in to conserve them.

Most prescribed burns are in spring and autumn when there is enough moisture in the landscape to make them easier to control but weather conditions are warm and dry enough to achieve the desired fire intensity.

The Bureau of Meteorology is consulted and a burn is only scheduled if the conditions are appropriate. There is generally a short window of time when fuels are dry enough to burn and the weather is mild enough to make it safe to conduct. Proposed burns not completed one season are rolled over and may be prioritised the following spring or autumn.

Careful planning, preparation and management are key. However, even with the most meticulous planning, prescribed burning has inherent risks. Less than 3% of NPWS prescribed burns, since 2013, escaped their planned burn areas. In all these cases contingencies were in place to manage the risk and impacts of these fires. This is due to our highly qualified and experienced personnel and the significant planning that goes into every burn.

Staff understand fire behaviour and how it can be manipulated. They’ll wait for the right mix of fuel and weather conditions before going ahead. Many months of research, planning, and approvals occur before staff attempt to ignite a burn. They will cancel a burn if the conditions aren’t right e.g. test burns show if the fire won’t behave as planned. Once the main burn is lit, if the fire doesn’t behave as planned (e.g. it’s faster, more intense, is spotting etc.) the burn size can be reduced, or put out and rescheduled.

The days following a prescribed burn are critical and heavily resourced until the burn is declared safe, with crews patrolling and mopping up, paying particular attention to large trees, stumps, logs, and boundary areas.

Prescribed burning generally targets ‘fine fuels’ such as dry grass, leaf litter, twigs, bark and other vegetation, similar to what you would use to light a campfire or a fireplace in your lounge room. This fuel type ignites the easiest and carries the fire front.

Larger fuels, such as tree branches and fallen logs, typically don’t burn in the fire front or carry the fire and are far less combustible. Reducing the fine fuels, as well as some of the bark on trees, will make the area safer from bushfires for a number of years.

In mallee areas it is sometimes necessary to burn the tree tops to achieve the desired fuel reduction and ecological outcomes. Temporarily reducing this canopy cover can provide access to light and nutrients for a greater variety of plant species, improving the biodiversity of the area.

Prescribed burns give wildlife the best possible chanceof finding shelter or escaping from fire as they are generally less intense and burn more slowly than bushfires. Each burn has an environmental assessment, which identifies strategies to minimise impacts to wildlife, including protecting hollows and large logs that might be used as habitat, leaving unburnt patches to provide areas of refuge during and after a fire, and excluding areas known to be critical breeding or feeding habitat for threatened species.

Wilderness Protection Areas are home to significant natural and cultural values that support a functioning ecosystem. Fire has played an integral part in shaping their ecosystems and proactive fire management, such as prescribed burning, can help conserve their environmental values including for endangered species or ecological communities.

Fire management activities can also help protect life and property by helping to limit the spread and impact of bushfires. Where bushfires occur, the protection of human life is the primary focus, however, when the opportunity arises, a Natural Values Officer works closely with the CFS Incident Management Team working on the bushfire response, to provide local ecological information for the team to consider when developing suppression strategies.

Under the Burning on Private Land program, prescribed burning is undertaken by skilled NPWS fire practitioners as part of an agreement between the landholder and the Department for Environment and Water.

Back burning involves burning strategic locations around the path of an approaching bushfire. It requires the permission of the incident controller and needs careful consideration, planning and resourcing to implement under conditions that keep firefighters safe. It’s a complex operation in a dynamic environment which is why it’s not undertaken lightly.

Hazard reduction is the planned prescribed use of fire to strategically reduce fine fuel hazards to manage native vegetation and protect assets, life, and biodiversity. It can also include removing fuel around areas we don’t want to burn, such as fence lines, infrastructure, or vegetation we want to protect such as large trees with hollows. This work is determined by a fire management plan.