Fuel reduction burning - misunderstood and irrationally maligned

Recently, the Victorian Government released a list of 52 localities expected to be most at risk from bushfires during the upcoming summer.

Question: What will be the safest places in Victoria this summer?
Answer: The areas that burned last summer.

Admittedly, the uncommon severity of last summer’s Black Saturday bushfires makes them a hugely exaggerated metaphor for the benefits of forest fuel reduction. Nevertheless, the burnt areas north of Melbourne graphically illustrate the point that if there is less to burn there is a correspondingly lower bushfire threat.

While this is simple common sense, it is widely misunderstood and is being irrationally branded as a “myth” in some quarters. Indeed, proposals for more fuel reduction burning are being routinely met with calls that the practice is both environmentally irresponsible and of little value for bushfire control.

These responses largely reflect a lack of public understanding about forest fire in general, and about the planning and conduct of fuel reduction burning (FRB) in particular.

Much of the public discussion of FRB in the mainstream media (where it is often erroneously referred to as “back burning”) has created an unreal expectation of it as a “magic bullet” that can somehow prevent bushfire and guarantee the protection of human life and property. Some of this misrepresentation has been driven by those most opposed to it. By building it up, they can more easily knock it down by highlighting examples of bushfire loss and damage adjacent to areas subject to recent fuel reduction burns.

In reality, the effectiveness of FRB in limiting bushfire damage is highly variable and dependent on a wide range of factors. These include the number of years since it was done, the size and configuration of the fuel reduced area, the degree of fuel reduction achieved, the prevailing weather conditions driving the bushfire, and its consequent intensity. Then there are separate, but highly influential factors such as the nature of private property and the bushfire preparedness of landowners.

Given the inherent variability of these factors it is ludicrous to suggest that FRB can guarantee the protection of life and property during bushfires. No forest management practitioner advocating its use has ever claimed otherwise. However, what can be said with certainty is that:

• communities located in close proximity to recently fuel reduced forests have a better chance of emerging unscathed from bushfire than if the same forests are long unburnt with heavy fuel accumulations;
• lower intensity bushfires passing through fuel reduced forests will do far less damage to soil, water and wildlife compared to high intensity fires burning in heavy fuel accumulations; and
• fire-fighting in fuel reduced forests is far easier and safer than in forests with heavy fuel accumulations.

Citing Black Saturday as a measure of the effectiveness of FRB - as many of its critics have done - is simply inappropriate. On that day, the fires were so large and their behaviour so extreme that relatively small and scattered fuel reduced areas were easily by-passed by long-distance spotting and could have no influence on improving the (already non-existent) capability to control them.

However, even under extreme circumstances, extensive areas of well-conducted FRB would somewhat reduce the development of crown fires and spotting thereby reducing environmental impacts and improving the capability to defend well prepared properties or provide residents with more time to safely evacuate. On the other hand, poorly prepared properties are indefensible and FRB would make little difference.

Burn severity mapping produced after the Black Saturday fires has clearly shown that low fuel areas had a pronounced impact on comparatively reducing the fire’s impact on environmental values. In addition, part of the fire was slowed and eventually stopped where it ran into the large consolidated area of fuel reduced forest that had been burnt by the 2006 Kinglake bushfires.