Professor David Lindenmayer, Fenner School of Environment and Society, Australian National University, 10 February 2025. This submission is in response to the article, Debunking false claims about bushfire risk and native logging in Australia, by Robert Onfray, published on ARR.News on 17 January 2025. The entire series of articles and interchanges is listed below.
In his article in Australian Rural & Regional News, Mr. Onfray states that he is worried about the “troubling narrative” that logging increases the risk of wildfires. He is right to be worried—because the overwhelming body of scientific evidence shows that the narrative is correct. That is, logging does indeed increase the risk of high severity wildfires. And the evidence for this worrying narrative comes from work by many scientists across Australia and in fact around the world. These places include Tasmania, Victoria, New South Wales, western North America, Canada, and South America. As importantly, these elevated fire risks persist for up to 70 years after a forest has been logged and regenerated (Wilson et al. 2022).
Examining the scientific evidence
Let’s briefly examine the scientific evidence—because to deny that evidence puts rural communities in danger.
The first major study examining the link between logging and wildfire was published in 2014 (Taylor et al. 2014). It showed that logged and regenerated forests in central Victoria had a sevenfold increase in the risk of high-severity fire with this effect lasting nearly 40 years (Taylor et al. 2021). Studies by other researchers at the University of Wollongong showed that these risks for forests in New South Wales lasted for 70 years (Wilson et al. 2022). Research in Tasmania also demonstrated a clear link between logging and increased fire risk (Furlaud et al. 2021).
The same pattern is seen internationally. Studies in western North America have also identified higher fire severity in logged forests (Levine et al. 2022) (Mackey et al. 2023). The reasons for the links between logging and fire are well understood: logged forests are warmer, drier, windier, and contain higher fuel loads (Lindenmayer and Zylstra 2024), including literally 100s of tonnes of logging debris left on the forest floor. Scientists now refer to this as “disturbance-stimulated flammability” (Lindenmayer and Zylstra 2024). Many fire authorities are aware of this problem. For example, NSW Rural Fire Service maps produced for ground crews fighting the 2019-2020 wildfires and marked them with warnings about fire risks because of extra debris left after logging.
Flawed arguments about fire risk
Mr Onfray illogically argues that because a limited amount of forest is logged in any given year, the overall fire risk created by logging is negligible. This argument is deeply flawed. Logging occurs over 1000s of hectares of wood production forest every year. That means that year on year more and more forest is logged. But that forest when it is regenerated, remains in a more flammable state for up to 70 years. That means that all forests logged since 1955 remain more flammable today—a pattern we observe during major wildfires.
And that was precisely what occurred after the 2019-2020 wildfires. An analysis across the entire footprint of the 2019-2020 Black Summer fires showed quite clearly that logged and regenerated forests always burned at higher severity than intact forests (Lindenmayer et al. 2022). In fact, the effect was so strong, that the logged forests burning under moderate fire weather conditions still burned at greater severity than intact forests burning under extreme conditions (Lindenmayer et al. 2022). This effect was seen in northern Victoria, southern New South Wales, and northern New South Wales (Lindenmayer et al. 2022).
Does thinning reduce fire risk?
Mr Onfray argues that we should thin forests to reduce fire risks. But what does the scientific evidence on thinning and fire actually show? Our analysis of hundreds of forest sites following the 2009 wildfires showed that thinning had either no effect on the severity of wildfires, or made it worse (Taylor et al. 2020). Similarly, a separate analysis comparing sites that were thinned versus unthinned before they were burned in the 2019-2020 wildfires showed the same—thinning either increased fire severity or made no difference (Taylor et al. 2021). The fact that thinned forests are more flammable is actually well known by foresters, and warnings about it feature in forest management manuals in Tasmania and Victoria {Buckley, 1991 #8} {Forestry Tasmania, 2001 #9}.
What should we do instead?
- Stop logging native forests to reduce landscape-wide fire risks.
- No thinning in national parks—it does not reduce fire severity and may make it worse.
- Transition to plantation timber, which already supplies 90% of Australia’s sawlogs.
- Improve fire detection and suppression, using advanced drone technology and early-response systems. The best time to stop a fire is immediately after ignition.
- Target prescribed burning where it is most effective—close to human settlements rather than in remote areas where it provides little benefit.
The science is clear: logging increases bushfire risk—significantly, over large areas, and for decades. The claim that logging reduces fire risk is a dangerous industry myth that puts communities at greater risk. Policymakers must base fire management strategies on scientific evidence, not lobbying from the forestry industry.
References
Furlaud, J. M., L. D. Prior , G. J. Williamson , and D. M. J. S. Bowman. 2021. Fire risk and severity decline with stand development in Tasmanian giant Eucalyptus forest. Forest Ecology and Management 502:119724.
Levine, J. I., B. M. Collins, Z. Steel, P. de Valpine, and S. L. Stephens. 2022. Higher incidence of high-severity fire in and near industrially managed forests. Frontiers in Ecology and Environment 20:398-404.
Lindenmayer, D. B., and P. Zylstra. 2024. Identifying and managing disturbance-stimulated flammability in woody ecosystems. Biologcal Reviews 99:699–714.
Lindenmayer, D. B., P. Zylstra, R. Kooyman, C. Taylor, M. Ward, and J. E. M. Watson. 2022. Logging elevated the probability of high-severity fire in the 2019–20 Australian forest fires. Nature Ecology & Evolution 6:533-535.
Mackey, B., C. Campbell, P. Norman, S. Hugh, D. A. DellaSala, J. R. Malcolm, M. Desrochers, and P. Drapeau. 2023. Assessing the Cumulative Impacts of Forest Management on Forest Age Structure Development and Woodland Caribou Habitat in Boreal Landscapes: A Case Study from Two Canadian Provinces. Land 13.
Taylor, C., W. Blanchard, and D. B. Lindenmayer. 2020. Does forest thinning reduce fire severity in Australian eucalypt forests? Conservation Letters 14:e12766.
Taylor, C., W. Blanchard, and D. B. Lindenmayer. 2021. What are the relationships between thinning and fire severity? Austral Ecology.
Taylor, C., M. A. McCarthy, and D. B. Lindenmayer. 2014. Non-linear effects of stand age on fire severity. Conservation Letters 7:355-370.
Wilson, N., R. Bradstock, and M. Bedward. 2022. Disturbance causes variation in sub-canopy fire weather conditions. Agricultural and Forest Entomology 323:109077.
Story series (in order of publication):
Debunking false claims about bushfire risk and native logging in Australia;
Logging does indeed increase fire risks!: David Lindenmayer;
An alternative perspective to David Lindenmayer: South East Timber Association;
Logging and bushfire risk: Robert Onfray responds to David Lindenmayer;
Bushfire risk and native forest logging: David Lindenmayer responds to South East Timber Association;
Fire severity is always greater in areas that have been logged: David Lindenmayer responds to Robert Onfray;
David Lindenmayer ignores core points and key questions: Robert Onfray’s further response;
Megafires thrive on high per hectare fine fuel loads across the forest landscape, regardless of land tenure: SETA’s further response to David Lindenmayer;
Robert Onfray’s response misses core scientific realities – logging makes forests more flammable for many decades: David Lindenmayer;
SETA’s claims ignore established science and economic realities: David Lindenmayer
This debate is drawing to a close. Australian Rural & Regional News intends to ask a few questions of each of the participants with a view to rounding out the debate.
‘Independent’ scientist… note the references are pretty much quoting himself. If I say it enough, must be true. Note that the main picture is of post harvest burning not wildfire.. where are the photos demonstrating his argument? Interestingly absent.
Both photos show clearfall, burn and sow coupes. In 5 years time these will be verdant regrowth forests. If logging debris is left behind in partial harvest operations there is an increased fire risk for a couple of years before it rots. In Tasmania, this issue is addressed b top disposal burning, which also assists with preparing a seedbed for eucalypt regeneration. It is patently obvious to anyone who has fought fires that the native forest logging industry has contributed access roads, maintenance of fire breaks, machinery and personnel to fight fires. There is plenty of evidence that prescribed burning to remove logging debris and scrubby undergrowth is effective in reducing fire intensity and rate of spread. But academics in ivory towers know better than those of us who are on the ground.
Lindenmayer is intentionally conflating softwood plantation harvesting and native forest harvesting observations here to draw incorrect conclusions about Onfray’s work.
The review at the following link provides a different perspective to Mr Lindenmayer’s opinion.
https://southeasttimberassociation.com/wp-content/uploads/2025/01/Does-Logging-Cause-or-Exacerbate-Bushfires-26Aug2021
[…] extreme conditions and exceptionally high winds that characterize all large blazes. See here and here for […]
Thanks David Lindenmayer and the dozens of other scientists who have researched this issue (check the refs below the article).
Those who like to see public forests clearfelled, won’t be convinced about any amount of evidence provided. As others have said about this phenomenon – ‘your inability to understand the science, is not an argument against it’.
The evidence is clear. An intact forest has it’s own natural fire resistance – damp ground humus – cooler micro-climate – taller tree canopies of mixed age forests – wind resistance – a healthy mix of diverse plants, insects, fungi, digging mammals and lyrebirds to constantly tumble and turn ground level veg and leaves into compost.
After a forest is logged, it becomes a uniform tree farm and very flammable.
This is how they test for fire effect etc. using lasers for anyone interested in the science. (Other scientists did this study).
https://www.sciencedirect.com/science/article/abs/pii/S0378112721001262
This is an article and study from the US:
https://thehill.com/blogs/congress-blog/energy-environment/590415-logging-makes-forests-and-homes-more-vulnerable-to/
To fact check and access this US scientific study click on the word ‘lower’ in paragraph 5.
To quote the US study:
“In general, our findings—that forests with the highest levels of protection from logging tend to burn least severely—suggest a need for managers and policymakers to rethink current forest and fire management direction, particularly proposals that seek to weaken forest protections or suspend environmental laws ostensibly to facilitate a more extensive and industrial forest–fire management regime. Such approaches would likely achieve the opposite of their intended consequences”
Well I guess we have to believe Supreme Laureate Professor David Lindenmayer OAM because he used an exclamation mark in the title. If people are questioning you, just shout at them, eh? But let’s give recognition where it is due: David is a world leader in his field – of self citations! More than half are references to his own work, which does raise the question of how widespread his assertions are.
It is also telling that David is attempting to scrub from the popular scientific understanding that a series of academics have all reviewed the idea that timber harvesting “always” increases severity, and concluded that its overstated – see links to three papers below, some of which are from high ranking journals. But instead of acknowledging that clearly there is a great deal of complexity in this topic, and perhaps the conclusion that logging always makes fire worse is too simplistic for reality, David is just doubling down and assuming that if you just keep repeating things, it makes it true. It’s a real shame – David’s early work in the Leadbeaters Possum was world leading stuff, which reformed and informed forest management. But now [edited]
– Bowman, D.M.J.S., Williamson, G.J., Gibson, R.K. et al. The severity and extent of the Australia 2019–20 Eucalyptus forest fires are not the legacy of forest management. Nat Ecol Evol 5, 1003–1010 (2021). https://doi.org/10.1038/s41559-021-01464-6
– Keenan, R. J., Kanowski, P., Baker, P. J., Brack, C., Bartlett, T., & Tolhurst, K. (2021). No evidence that timber harvesting increased the scale or severity of the 2019/20 bushfires in south-eastern Australia. Australian Forestry, 84(3), 133–138. https://doi.org/10.1080/00049158.2021.1953741
– Bowman, D.M.J.S., Williamson, G.J., Gibson, R.K. et al. Reply to: Logging elevated the probability of high-severity fire in the 2019–20 Australian forest fires. Nat Ecol Evol 6, 536–539 (2022). https://doi.org/10.1038/s41559-022-01716-z