Ian Mannix
Cosmos newsroom
One of Australia’s most eminent bushfire scientists has taken aim at fire agencies and researchers who he says are ignoring important forest fuel load fire science.
Professor Mark Adams, from Swinburne University of Technology, says agencies and fire scientists are using “erroneous” assumptions and “misinformation” from the 1960’s about forest floor fuel loads.
“None of these assumptions hold,” Adams says in a perspective article co-written with Mathias Neumann from the university of Natural Resources and Life Sciences in Austria, published in the journal Forest Ecology and Management.
Adams was a member of the expert panel for the 2009 Victorian Bushfires Royal Commission, served on the Board of the Bushfire Cooperative Research Centre and has won numerous global research awards.
His work, which describes the present practice of estimating forest fuel loads, suggests that the underestimation of fire fuels is widespread, possibly exceeding 100% in 40 years.
“Assumptions first made in the 1960’s that litter decomposes to completion; accumulates following a negative exponential pattern; reaches a steady state limit and is constant thereafter, remain overwhelmingly used to parameterize models and predict litter mass and fire risk in south-eastern Australian forest and woodlands,” the authors say.
Thousands of papers over the last 60 years ignored today
In background material in the paper, the authors write: “In 1963 Jerry Olson published a landmark paper on decomposition in which he relied on analogy with radioactive decay.
He published a simple model for litter decomposition and accumulation that relied on Odum’s steady state proposal.
Adams told Cosmos the fuel models used in Victoria are all based on a 1963 decomposition paper written by American ecologist Jerry Olson, who had proposed with contemporaries of the time that ecosystems should develop such that they reached a form of steady state or equilibrium.
“There has been 60 years of decomposition research since Olson – all of which has been ignored,” Adams says. “10,000+ papers… ignored.”
The staggering cost of bushfires
Adams says the Olson work is flawed but: “Remarkably, these erroneous values were republished by the Rural Fire Service of NSW as bona fide limits to accumulation of fine fuels.
“Victoria has spent millions of dollars on visual estimates of fuel in place of quantitative measures.
“Visual estimates of fuel are notorious for their lack of accuracy. Moreover, the problems mount once there is continuous litter cover.
“Humans do not have x-ray vision. Extremely large areas of forest have had no fire for many decades and litter accumulations haven’t been measured …. only visually estimated.
“This is tragic from a science perspective. We could have world best models if even a fraction of the money spent on visual estimates had been spent measuring litter.”
Forest litter encompasses fine fuel smaller than 6mm: mainly leaves and twigs and bark, which is recognised as a major driver of wildfires.
Adams and Neumann say: “Fuel load is also a key determinant of rate-of-spread albeit of reduced significance under extreme weather/climate conditions (low humidity, high temperature, prolonged drought, high wind speeds.).
“For many, if not most forest types globally, there remain crucial gaps in knowledge of the quality of litter and litterfall. Accumulation of litter, and litterfall, are poorly known processes relative to growth of forests.”
Outdated data isn’t “best science”
They refute claims that litter mass in all eastern Australian eucalypt forests and woodlands reaches 95% of steady state limits within 20 years of previous fires.
Adams says: “The values are clearly wrong at order-of-magnitude scales.
“The international literature shows that hundreds to thousands of years, not decades, are required before steady state is attained. Collated Australian data shows that the “limits” are routinely exceeded.
“Statistically… predictions of fine fuel loads were barely an improvement on random guesses.
“In the face of the evidence of the lack of steady state in forests globally (including Australia), multiple recent ‘Olson Curve’ studies that claim eastern Australian forests and woodlands routinely attain steady state within decades of fire are straightforward misinformation.
“An “atlas” to guide prescribed burning at large scales (funded and endorsed by the Bushfire and Natural Hazard CRC, now Natural Hazards Research Australia), relies on the same misinformation.”
Natural Hazards Research Australia CEO Andrew Gissing says the organisation contracts Australia’s best scientists at Australian universities to deliver research aimed at ultimately enhancing the safety, resilience and sustainability of Australian communities.
“Bushfire management across Australia is complex and it is not surprising that scientists are not always in agreement. All science is built on healthy, robust debate, this is what drives improvements and ultimately safer and more resilient communities and ecosystems,” Gissing tells Cosmos.
“This is why we have in the past and continue today to fund a broad program of research and scientists from many universities and research centres, and this has included Prof Adams.
“Natural Hazards Research Australia research and that of our predecessors, is peer-reviewed to ensure scientific quality, and published in high quality academic journals and overseen through strong research governance.”
But Adams says the science community is not helping itself.
“Acknowledged and profound challenges to public trust in science are not helped by researcher use of dogma that clearly runs counter to data and evidence. Finding solutions to wicked problems such as climate change is not helped by use of falsified models, erroneous parameters, or outdated thinking to predict climate-related risks.
“The multi-dimensional nature of the ‘fire problem’ and its human, economic and ecosystem costs, require deep changes in fire science, and moving beyond ‘institutional silos’.
“Governments are quick to claim policies and actions are driven by “the best science”. Yet a range of state and federal Australian governments and their agencies have for more than a decade used falsified models to predict litter (and fuel) accumulation.”
