Tag: prescribed fire

A body of research is challenging long-held beliefs that lessening fuel load inherently lowers fire risk.

Studies published by researchers from the Australian National University and Curtin University since 2022 have claimed long-held research that underpinned the Western Australia Department of Biodiversity, Conservation and Attractions’ burning regime is incorrect.

Their study published in August of that year replicated the department’s underpinning research from 2009 and determined prescribed burns had negligible effects on bushfire area. Another study published in March of 2022 found that forests in southwest Australia are at their highest fire risk during the tens of years of regrowth after a fire, but continuously decrease in fire risk once reaching their mature period.

A new study, just published by the researcher Philip Zylstra, an Adjunct Associate Professor at Curtin University, and David Lindenmayer, a Distinguished Professor at the Australian National University, delved further into this dichotomy and examined whether a full phase-out of prescribed burning would decrease severe bushfires and help forests return to their original, pre-frequent disturbance states.

The researchers said their study shows long-unburnt forests limit fire without human intervention, even as the climate changes. They found that 77% of all areas burned in over 500,000 hectares (1,235,527 acres) of forested national parks in southwest AU were due to prescribed burns, with 20% burned from escaped prescribed burns and 23% from backburning.

“If large-scale prescribed burning and incentives to backburn ended, the area burned annually would immediately fall 87%, leaving only fires started by lightning, accident or arson,” the researchers wrote this month in an article for The Conservation. “Our modelling suggests less area would be burned in the hotter, drier climate of 2100 than it is today if both widespread burning policies were ended.”

“Humans have a deep-seated desire to intervene in nature. But our research shows long-unburnt forests act to limit fire without human intervention – even as the climate changes.”

The researchers instead called on authorities to invest in rapid fire detection and attack, better resourcing firefighters, training and employing more specialist remote area firefighters and exploring fire-fighting drones.

They stressed that these latest findings relate only to the forests of south-west Western Australia. However, they quote their own 2023 research to claim that other Australian forests, and Northern Hemisphere forests, may also become more flammable through burning.

A spokesperson from the Western Australia Department of Biodiversity, Conservation and Attractions said that any claims that forest flammability declines with age rest on inadequate data and following them would be unwise.

“[DBCA] research confirms that prescribed burning is effective in reducing the frequency, severity and size of bushfires in south west forests when at least 45 per cent of the landscape has a fuel age of less than six years since last burnt,” the Department statement sent to The Conversation said. “Removing fire from fire-prone ecosystems often leads to high-severity fires, as seen in a range of significant bushfires that have occurred in Australia and overseas.”

The same researchers faced similar pushback from the department after they published their March 2022 study. The researchers say that scientists from the department told them that their own records contained flawed data and suggested ignoring all records for old forests. The researchers said their findings only became stronger after they removed the reportedly flawed data.

Read the researcher’s full article in The Conversation.

A joint research paper from researchers in California and New South Wales examined the similarities and differences between prescribed fire management in the United States and Australia, and found that Australia is much more efficient in the practice compared to the U.S.

The conclusion stemmed from Australia’s comparatively quick burn implementation process, the paper published in the Fire Ecology journal said. While setting up a prescribed burn on federal lands can take years in the U.S., Australian officials can often plan and set a burn in the same year with specialist feedback.

“The idea that you could plan and implement a burn in the same year, including incorporating specialist feedback and comply with various laws/statutes aimed at environmental protection, is rare in US federal and state agencies,” the paper said. “Australia has streamlined the process to facilitate implementation. Additionally, the responsibility to manage public lands in Australia is primarily the responsibility of states and territories, with the few exceptions of a small number of parks and other lands utilized by the Australian Government agencies and the Department of Defence.”

The U.S., however, has numerous sources of institutional education that Australia lacks, according to the researchers. The U.S. has numerous prescribed fire courses, training centers, and a collection of fuel moisture history, many of which land managers in Australia have learned from and implemented in their nation’s burn programs. Australia, in contrast, mainly relies on a dwindling volunteer workforce supplemented by land managers without dedicated courses that teach ignition patterns or techniques.

“Practitioners across Australia implementing complex burns could benefit from the US learnings, prescribed fire training centers, and firing boss taskbooks which include ignition patterns and techniques,” the paper said. “Prescribed burns are implemented with good success in Australia; however, there can be a lack of efficiency (not maximizing the burn window) or higher severity burns can occur when ignition patterns are not adjusted for the conditions.”

The paper, “Australia and the United States have many similarities and differences in prescribed fire management: learning from each other” is by Brian Levine, NSW National Parks and Wildlife Service, and Scott Stephens, University of California.

Wildfire Today reached out to paper co-author Stephens for further comment on the research. He deferred to the published paper.

Click here to read the full paper.

The Australian “Black Spring” bushfires of 2023 are not well known. Unlike the 2019-20 Black Summer fires, fires in the desert regions receive little public attention outside of their immediate area of impact. And yet the fires in Australian tropical savannas and northern spinifex deserts in late 2023 were Australia’s biggest in more than a decade, around eight times more extensive than the Black Summer fires along eastern and southern Australia.

A closer look at the Black Spring 2023 fires has found that, despite their size and potential impacts on cultural and biodiversity values, they are not acknowledged as a significant national event and barely registered in the national or global media. The limited media that did occur focused on the threat of fire to the small town of Tennant Creek in the Northern Territory, but most Australians remain unaware of the existence or full scale of the fires.

The research describes the extent of the 2023 northern desert fires, and their relationship to lightning strikes, the most common cause of ignitions for these fires.

It also examines fire spread patterns to explore whether the emerging, large-scale fire management programs being delivered by Indigenous ranger groups in one part of these northern deserts influenced the fires.

Wildfires are common across Northern Australia. The annual monsoons bring large amounts of rainfall each Wet Season resulting in extensive grass growth that, come Dry Season, quickly become high fuel loads ripe for dry lightning and other sources of ignition.

In 2022-23 widespread and prolonged rain occurred in Australia’s northern deserts and some parts of the low rainfall tropical savannas. The rain caused biomass accumulation that led to extensive desert fires in the following Dry season (June–November 2023). Whereas the average annual fire extents is around 15 percent – these fires burnt around 40 percent.

Lead researcher Rohan Fisher, a senior research fellow at the Northern Institute at Charles Darwin University, told Wildfire Today: “2023 was Australia’s biggest bushfire season in more than a decade. Fires burned across an area eight times as big as the 2019–20.”

The data calculating the annual fire extent data was obtained from the North Australia Fire Information (NAFI) service (http://firenorth.org.au), which provides 250m resolution fire mapping based on the Moderate Resolution Imaging Spectroradiometer (MODIS).

The researchers stress that these large fires were not inevitable, despite the confluence of high rainfall, fuel loads and lightning. The study found prescribed burns by Indigenous Ranger Groups in some areas had a strong influence on the fire extent.

In the northern savannas, annual, large-scale prescribed burning programs over the past 10–20 years have transformed fire patterns by reducing fire size, frequency and severity of fire, and smoothing out fluctuations in fire extents between years, including in 2023

As Fisher told Wildfire Today, after just a few years of work the rangers of the Great Sandy Desert have made a measurable difference to wildfire spread.

“For many thousands of years, Indigenous people managed fuel loads across these vast landscapes. However, efforts have only just begun to bring good fire management back into these landscapes in a coordinated and large-scale way.

“Our research showed that despite the scale of the fires in 2023, the work by indigenous rangers was effective in reducing the impact of these fires. They need continued support to support the health of this continent for all Australians.”

Read the full article in the International Journal of Wildland Fire.