Logging likely made this year’s bushfires worse, say scientists

  Last updated June 5, 2020 at 5:34 pm


A new review of research has suggested that logging increases the risk and severity of bushfires, and may have contributed to this year’s devastation.

bushfire risk logging


Why This Matters: Land management decisions need to be based on science, especially when dealing with bushfire risks.

As Australia continues to recover from the devastating bushfire season, debate continues about how to reduce the risk of similar incidents in the future.

A Royal Commission has begun into the spring- and summer-long disaster. Scientists have long warned that disasters of this magnitude are more likely due to climate change.

Meanwhile, some vested interests have argued that logging should be increased to reduce bushfire risks. However, scientists have long countered with research showing that logging can make bushfires worse, and harm the recovery of forests post-fire.

Deeper: Yes, Australian bush is recovering from bushfires – but it may never be the same

Now, a collaboration of scientists from the University of Queensland, The Australian National University and Macquarie University have reviewed the research in a peer-reviewed commentary published in the journal Nature Ecology & Evolution. They argue logging may have played a part in the severity of this year’s fires.

They write that while most of the conversation has been, rightly, about the effects of climate change, the impact of land management is often overlooked.

“Logging causes a rise in fuel loads, increases potential drying of wet forests and causes a decrease in forest height,” says University of Queensland’s James Watson, who was one of the authors.

And, they argue, this can not only increase the risk of fires but have long term effects too. Repeated burns can result in tree species failing to resprout, affect seed production, and cause germination failure. In extreme cases there is the potential for young trees to die triggering ecosystem collapse

Logging makes Australian forests more fire prone

“Beyond the direct and immediate impacts on biodiversity of disturbance and proximity to disturbed forest, there is compelling evidence that Australia’s historical and contemporary logging regimes have made many Australian forests more fire prone and contributed to increased fire severity and flammability,” the scientists write.

This is due to logging leaving up to 450 tonnes per hectare of debris at ground level (described by Watson as “incredibly dangerous levels”), increasing flammability and fire severity. Removing tall trees also allows more wind and sunlight into the ecosystem, resulting in the forest becoming hotter and drier. It also changes the makeup of the forest itself, reducing wet tree ferns and creating areas dense with trees of similar ages, including more flammable young saplings.

They found that large areas of East Gippsland forests that had been logged and regenerated had subsequently burnt multiple times in the last 25 years, including in the current bushfires. According to the group, current understanding of ecology suggests that should only burn once every 50-150 years.

logging bushfires in Gippsland

Of the ~1 million hectares burnt in the 2019–2020 bushfire season across East Gippsland, ~36% has burnt two or more times since 1995. Credit: Watson et al 2020, Nature Ecology & Evolution

“By allowing these practices to increase fire severity and flammability, we undermine the safety of some of our rural communities,” says Watson.

“It affects wildlife too by creating habitat loss, fragmentation and disturbance for many species, with major negative effects on forest wildlife.”

Deeper: How you can help – not harm – wild animals recovering from bushfires

Watson is also a director of the not-for-profit Wildlife Conservation Society, which does not have any projects operating in Australia.

The researchers also argue that this season’s bushfires spread from logged areas to old-growth eucalyptus and rain forest areas.

“Forests not degraded by logging, together with the biota they support, are more resilient than degraded forests to pre-fire conditions,” they add.

Rethink logging to reduce bushfire risks

The authors make several recommendations to reduce the risks of further catastrophic fire seasons. The first involves preventing logging of moist forests, and areas where increased fuel loads increase the fire risk to urban areas.

“We must also reduce forest fragmentation by proactively restoring some previously logged forests,” says ANU’s David Lindenmayer, who led the review.

“In the event of wildfires, land managers must avoid practices such as ‘salvage’ logging – or logging of burnt forests – which severely reduces recovery of a forest.”

Deeper: Some say we’ve seen bushfires worse than this – but they’re ignoring a few key facts

There are reports that logging has already resumed in fire-damaged forests. Lindenmayer also told the Sydney Morning Herald that prescribed burning is only effective when done regularly within kilometres of dwellings.

The researchers argue that logging should instead be confined to plantations, preserving native forests.

“We urge policy makers to recognise and account for the critical values of intact, undisturbed native forests, not only for the protection of biodiversity, but for human safety,” says the University of Queensland’s Michelle Ward, also involved in the paper.

“Let’s act strongly and swiftly for the sake of our communities, the species they house, our climate and Australia’s wild heritage.”

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About the Author

Ben Lewis
Ben Lewis is the Editor of Australia’s Science Channel, and a contributor to Cosmos Magazine. He has worked with scientists and science storytellers including Jane Goodall, Dr Karl, Brian Cox, Chris Hadfield, Robert Llewellyn, astronauts, elite athletes, Antarctic explorers, chefs and comedians. Ben has also been involved in public events around Australia and was co-writer, producer and director of The Science of Doctor Who, which toured nationally in 2014 in association with BBC Worldwide Australia & New Zealand. Want more Ben? You can hear him on ABC and commercial radio in Adelaide, regional SA, across NSW, and the ACT. He also speaks at universities around Australia on communicating science to the public. Around the office he makes the worst jokes known to mankind.

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