Ask any fire-fighter : prescribed burning mitigates bushfire losses
There has been a lot of comment in the media lately from Eastern States academics claiming that prescribed burning (also known as fuel reduction burning) is of no use in preventing large damaging wildfires, which is almost all totally divorced from reality. We even have local academics jumping on the bandwagon. Here is an example and here is why they are completely wrong.
Considerable publicity is being given to an article by Byron Lamont and Tianhua He entitled ‘Why prescribed burns don’t stop wildfires’.
Professor Lamont and Dr He are academics from Curtin University in Western Australia, the former a botanist and the latter a molecular biologist. They argue against the use of fuel reduction burning in bushfire management because it does not stop bushfires.
The article exposes the fact that the authors have no experience or operational understanding of fire behaviour, and have not got the faintest appreciation of how a prescribed burning program works, or how bushfires are controlled.
Their baseless and inhumane opinions, if given any credibility, would give rise to dangerous fire management policies, a continuation of the cycle of devastating bushfires in Australia, and to further losses of lives and beautiful forests. The title of their article is a clue to their utter lack of understanding. Fuel reduction burning is not designed to “stop wildfires”. The purpose is to make them easier, safer and cheaper to control.
Experienced land managers, firefighters, and bushfire scientists are in no doubt about this. The scientific, experiential and historical evidence all demonstrate that prescribed burning, done properly, is highly effective at mitigating the bushfire threat, and assists with the control of fires even under severe weather conditions.
Identifying the flaws in their argument takes only a few seconds.
Firstly, Professor Lamont and Dr He ignore fire science. Reducing fuel loads and simplifying fuel structures by regular burning reduces the speed of a bushfire, its intensity, the size of the flames and its ember and spotting potential.
All of this makes bushfires easier to put out and less damaging.
In mature forests, crown fires cannot be sustained if the surface and near surface fuels are at low levels as a result of regular fuel-reduction burning.
This crown fire ran into one-year old fuelled was easily controlled
Professor Lamont and Dr He make the extraordinary assertion that long-unburnt forest fuels are of low flammability and therefore of no significant threat to communities. This is not only demonstrably untrue, it is dangerously wrong.
For example, in long-unburnt karri forest, much of the live, green understorey dies and becomes dead, dry fuel on the forest floor after about 25-30 years. Bushfires are most likely to occur well before that time. Dead scrub, together with accumulated dead leaves, twigs and bark, the surface and aerated near-surface fuels can be a metre or more deep with total fuel loads of up to 50 tonnes per hectare.
We have studied actual fuel measurements in forests all over Australia and never once have we found a situation where the forests become non-flammable in time. The reverse is the case.
Second, Professor Lamont and Dr He ignore the real-world experience of generations of land managers and firefighters.
We know of hundreds of examples where prescribed burning has ‘saved the day’. Hot fires ran into areas of low fuel and the resulting reduced fire behaviour enabled firefighters to gain the upper hand.
Conversely, we can cite numerous recent examples where a lack of prescribed burning has resulted in unstoppable fires and considerable losses.
Ask any firefighter whether they would rather fight a bushfire in four-year-old fuels or in 40-year-old fuels? We know what the answer will be.
Academics like Professor Lamont and Dr He disdain the experience of bushmen and experienced firefighters, seemingly preferring computer models developed on a green, leafy campus.
In doing so they reject the experience of real-world Australians and their experience over the past 200 years.
Third, Professor Lamont and Dr He seem never to have studied bushfire history. There are almost 60 years of historical data from the forests of south-west WA, and this data unequivocally shows that when the area of prescribed burning trends down, the area burnt by bushfire trends up.
There is a simple explanation: bushfires are more difficult to put out in heavy fuels. The area burnt by wildfire escalates rapidly when the area of prescribed burning in a region falls below about 8 per cent per annum.
Finally, Professor Lamont and Dr He have no understanding of the strategic planning involved in a prescribed burning program. To be effective, the burning must also be strategic. The fuel reduction cells need to be large enough to ensure a sufficient area for the spread of a bushfire to be slowed and controlled. Burns must be bounded by roads or tracks to enable rapid access by firefighters and the edges to be mopped up.
Burning must be done to appropriate standards of fuel removal and fire intensity. Prescribed burns that are too patchy or too small or narrow may not slow a bushfire, and in some forests, burns that are too hot can stimulate the regeneration of dense scrub.
The article by Professor Lamont and Dr He is not only factually incorrect and demonstrates a significant ignorance about bushfire science, history and management, it is dangerous and inhumane.
If the authorities were to take any notice of their assertions and curtail the fuel reduction program, the result in Western Australia would be identical to that currently occurring in NSW – in other words, death, destruction, and heartbreak.
Our advice to Professor Lamont and Dr He is to get some actual fire experience in the bush, spend time on the back of a fire truck or the end of a hose, and then let’s see what they think about the value of fuel reduction in assisting with bushfire control.
Dr Neil Burrows has 42 years experience as a bushfire scientist, fire investigator, fire policy advisor and fire behaviour analyst in Incident Management Teams.
Rick Sneeuwjagt has 50 years experience in bushfire research and management at district, regional, state and national levels.