The WA government's fire management strategies are outdated and damaging to the bushland burned and the surrounding communities, according to a range of scientists, medical experts and Indigenous leaders.
A fire and air forum, convened last week by Dr Carole Peters with the support of the WA Forest Alliance and the Royal Society of Western Australia, heard concerns about medical and environmental harm caused by prescribed burning techniques.
The state government's Department of Biodiversity, Conservation and Attractions burns 200,000-hectares of native forest between Perth and Albany every year, with the goal of preventing bushfires.
The department's fire management strategy is based on a fuel management approach that involves the rotational burning of forests at least every six years.
Risk 'reduces with time'
Curtin University School of Molecular and Life Sciences adjunct associate professor Philip Zylstra said analysis of mapped fire history across south-west WA showed the least-flammable areas of forest were the "longest unburned areas".
He said forests were unlikely to burn for a short period after a fire, hence the perceived effectiveness of the department's six-year burn cycle.
"But they are very likely to burn following that period, as the regrowing understorey becomes taller and denser," he said.
"Then, after a total post-disturbance period of 43 to 56 years, fire becomes unlikely and continues to decrease."
Dr Zylstra said his research found forests reduced their own bushfire risk if they were left alone.
But Department of Biodiversity, Conservation and Attractions head of fire management, Stefan de Haan, said the opposite was true.
"There's pretty clear evidence that if you can fight a fire in areas of lower fuels, it is a much safer and easier proposition," he told Nadia Mitsopoulos on ABC Radio Perth.
"Prescribed burning doesn't stop fires, but it does stop them becoming those really destructive, devastating fires."
Dr Zylstra, who worked in fire management for many years in the Southern Ranges branch of NSW National Parks, said the weight of fuel in forests had no relationship to the rate of fire spread.
"It's the density, the cover and the height of the understorey that drives fire, not fuel load," Dr Zylstra said.
"Hazard reduction burning may actually enhance the propagation of wildfire by promoting shrub regeneration."
Concerns over target
Neurologist and medical scientist, Carolyn Orr, from Doctors for the Environment Australia, also referred to the "short-sightedness" of the department's fire management strategy.
Dr Orr called for an urgent and independent review into the policy and practice of prescribed burning in WA.
"By prescribed burning at a regular cycle, we are actually increasing fire risk, not reducing it," she said.
Dr Orr said she was concerned by how the department arrived at its 200,000-hectare target in 1994.
"They averaged the burning they were doing at that stage with the burning they were doing in the 1950s and they said 'we'll burn 200,000 hectares per annum'," she said.
"It's a back of an envelope calculation that got turned into a target that then got locked in stone and in law."
Dr Orr said prescribed burning produced smoke that affected human health, animal welfare and climate change.
"Wood smoke is toxic to the heart, the lungs, the brain and blood vessels, and humans exposed to wood smoke have an increased risk of death, heart attacks, stroke, pneumonia, asthma attacks and birth complications," she said.
"We know that if humans are exposed to a bushfire, there's a dramatic increase in hospital admissions up to hundreds of kilometres away, that lasts for days at a time."
University of WA School of Biological Sciences academic Don Bradshaw also questioned the 200,000-hectare target.
"There's no scientific basis for it and it should be abandoned," he said.
Profesor Bradshaw said he was concerned about the effect of frequent fire on animals.
He found it took a population of honey possums 25.6 years to return after department burns in 1993 and 1999 at Scott National Park in Augusta.
Professor Bradshaw said he was not calling to get rid of prescribed burns entirely, but to adapt the strategy to apply the latest, peer-reviewed science.
"Prescribed burning should be tailored to protect human life and infrastructure, but there is little point in burning forests 40 or 50 kilometres away from homes, which doesn't reduce wildfires at all," he said.
Mr de Haan said the department fire management strategy was informed by "decades of operational experiences and peer reviewed research".
"I guess there's always going to be a diversity of views out there in the public forum, but we're very confident in the research that we've got," he said.
Other ways to manage fire
ANU-Optus Bushfire Research Centre of Excellence director Marta Yebra said early detection and early suppression of wildfires was important.
She said her team was developing a technique using satellites, drones, cameras on towers, on-ground sensors and water gliders to detect and put out fires.
"No single technology offers a complete solution, so we need to integrate them," she said.
"These technologies have the potential to reduce the resource demands."
Traditional methods
Learning from and collaborating with First Nations people was a key theme of the forum.
Noongar custodian Daniel Garlett said there was a long history of traditional burning practices being misunderstood, and that all parties needed to work together in calling for change.
University of WA PhD candidate Ursula Rodrigues said she was researching cross cultural fire management practices with elder Lynette Knapp.
"There's an intense interest about Noongar stewardship [of fire] and a lot of the conversation tends to exclude Indigenous people," Ms Rodrigues said.
"White fellas have the habit of generalising knowledge across place, which is very different to the place-based approach of Indigenous knowledge.
"We also have a habit of corrupting or appropriating knowledge to suit our own agendas."
Ms Knapp said the fires her people burned were smaller and not as hot as the department's prescribed burns.
"They were warm enough to make the seeds grow, compared to fires these days, they just burn the living daylights out of them," she said.
Dr Zylstra said it was an "invasion myth" that current fire management practices adopted ancient Indigenous knowledge.
"A review of Western Australian fire scars says there was a dramatic change in the frequency of intense forest fires in south-western Australia following European colonisation," he said.
"We've heard elders today say 'fire is life'.
"And so what's happened is that in Australian culture, we've said 'well, if fire is life, then more fire is more life'.
"And it's like, if two Panadol can fix your headache, imagine how much a box of it can do."
