Health impacts of prescribed burn-offs significant but not well appreciated

 

Cate Swannell, 20 April 2020

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During 2002–2017, particulate air pollution exceeded the national standard on 271 of 5844 days (4.6%), including 197 days (73%) attributable to prescribed burns or wildfires.

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“Total estimated health costs were $188.8 million; $97.1 million (51%) was attributable to prescribed burns and $77.7 million (41%) to wildfires. Mean estimated health costs were lower on days affected by smoke from prescribed burns ($703 984) than those affected by wildfire smoke ($1.3 million), although more days were affected by prescribed burns (138) than by wildfires (59).

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“The estimated smoke-related costs of wildfires were highest in 2012 ($24.8 million); in many years, prescribed fires often accounted for most health-related costs, peaking in 2017 ($24.1 million).”

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“While prescribed burning (ed: might) reduce(s) the risk of wildfire, better understanding and incorporation of their full health impacts into strategies for reducing the impact of bushfires are needed for sustainable fire management.”

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https://www.mja.com.au/.../health-impacts-prescribed-burn...

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The Humane Society International report about the impact to the Weinup numbats and other fauna was released in 2022.

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You can download a copy here.

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Public survey for the Forest Management Plan 24-33

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As you know, in September 2021 the McGowan Government announced an end to the logging of native forests. From 2024 onwards logging will be limited to activities that ‘improve’ the health of our south-west forests (as long as they can still clear for ‘approved mining operations’).

 

Mining and ‘ecological thinning’ still provide DBCA with plenty of opportunities to degrade what’s left of our precious ecosystems so it is more important than ever to hold them to account through whatever means possible.

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In order to manage the new green regime, which apparently factors in a ‘drying and warming climate’, the CPC (Conservation and Parks Commission) are preparing a new FMP for 2024-2033 (through DBCA).

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FMPs provide the policy framework for the management of public land from Lancelin to Denmark, including nearly 62% cent of forest ecosystems in existing or proposed conservation reserves or otherwise protected areas.

 

The goal of FMPs is to ‘conserve biological and cultural values, provide for recreation, tourism and other forest uses, and to protect water catchments’. DBCA are supposed to adhere to FMPs and it is clear they are failing their KPIs in many areas.

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The government needs to be made aware that we know they are failing, and that we expect better.

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The CPC want to know what you think about DBCA’s management, what is not working and what could be done better.

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The survey is easy to do and takes 10-15 minutes. You'll find plenty of information to share with them here on FaBWA's website.

 

Here’s your chance – the survey closes at midnight, 1 May 22.

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A recently published study conducted by Philip Zysltra, David Lindemayer and Don Bradshaw in the SW of WA found that over time, ‘some forests “thin” themselves and become less likely to burn – and hazard-reduction burning disrupts this process’.

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‘In the hottest and driest climate conditions, old, self-thinned forests even out-competed recent prescribed burns – those up to seven years old. Bushfires were three times less likely in old forests than they were in recent prescribed burns’.

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‘Prior to colonisation…the tall forests with the heaviest fuel loads were deliberately left unburned (Pers. Comms Dr Wayne Webb, Pibulmun elder, 24 September 2021, (Pedro 2017 ), so that fire scars on karri were extremely rare prior to 1850, despite their ready scarring by modern prescribed burns (Rayner 1992 )’. 

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‘These traditions fit poorly with a paradigm in which management implies intervention and measures success by the quantity of fuel removed, but are consistent with an approach of ecological cooperation’. 

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MAIN FINDINGS OF THE STUDY

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• Fire (including prescribed burning) affects forest flammability for decades. In SW Australia, the effects lasted 43-56 years.

• After a short (5-7 years) period, the main effect of fire was to increase forest flammability by promoting dense regrowth.

• Forest understoreys naturally self-thin, and after this point, forests in SW Australia were 7 times less likely to burn than forests recovering from fire.

• Although climate change has made forests of all ages more likely to burn, mature forests were 3 times less likely to burn than recently (5-7 years) burned forests, even in the worst years.

• The strongest climatic effect was from an increase in synoptic variability, or the number of high and low-pressure systems per season, allowing less time for suppression operations to contain fires.

 

This latest research is supported by the findings of the review into the Black Summer fires. ‘In the decade before the fires, the NSW National Parks and Wildlife Service doubled the area of prescribed burns compared to the previous decade…. But as we now know, it had little effect’.

 

‘Where prescribed burns had very recently been carried out, the bushfires were marginally less severe, about half of the time. But the bushfires ultimately burned ten times more forest than any other Australian forest fires on record’.

 

The recent study by Zystra, Lindemayer and Bradshaw found that ‘wildfire has been rare (1/323 years, table 1 ) in the Southern Forests of southwestern Australia, except where previous disturbance has promoted the development of a shrubby understorey’. 

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‘Much research has focused on the short period of reduced flammability that may be achieved through disturbance (young period) and excluded the longer term dynamics initiated by this disturbance. Ignoring these long-term dynamics can introduce a misleading anthropocentric conceptualization of fire in forests, in which human intervention is needed to minimise the risks of fire.

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Our findings demonstrate that forests have natural, ecological controls on wildfire that have likely enabled the persistence of fire-sensitive species over geological time (Wardell-Johnson and Coates 1996 , Kooyman et al 2020 ) and continue to operate effectively even in the face of a warming climate’.

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CONCLUSIONS

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‘Our findings indicate that self-thinning forest understoreys result in long-term reductions in fire risk that are robust even in the face of global warming’. 

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‘If human societies are to sustain long-term interactions with forests in the context of a changing climate, it is essential that we develop ecologically cooperative approaches that reinforce rather than disrupt such natural controls’. 

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References:

Self-thinning forest understoreys reduce wildfire risk, even in a warming climate, Philip Zylstra, S. Don Bradshaw, David B. Lindenmayer, 2022 https://doi.org/10.1088/1748-9326/ac5c10, published in Environmental Research Letters on 18.3.22

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Coming of age: research shows old forests are 3 times less flammable than those just burned, 23.3.22

https://theconversation.com/coming-of-age-research-shows...

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In a council meeting on 19 July 22 Cr. Jan Lewis moved a motion requesting that the WA state government publicly ‘review the current prescribed burn policy and practices to ensure both are effective in protecting lives, property and the environment and are aligned with current science and community sentiment’.

 

In her address to the meeting Jan outlined her motivation for moving the motion:

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‘The pictures on the screen (above), taken from our property next to Mount Lindesay National Park, are of the event that prompted me, back in 2019, to question the prescribed burning of our remote wild areas.’

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The Denmark Shire council unanimously passed the motion.

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Cr. Jan Lewis and seconder Cr. Clare Campbell spoke in favour of the motion, as did Dr. Joanna Young, Dr. Cyril Edwards, Bart Lebbing and Melissa Howe. Thanks also to Dr. Carole Peters, Cr. Donald Clarke and Tony Pedro for their contribution.

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Denmark Shire Council has agreed to request:

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a) a public review of the State’s prescribed burn policy and practices to ensure both are effective in protecting lives, property and the environment, and are aligned with current science and community sentiment, and that any such review provide for a 90 day consultation period to receive submissions, and

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b) that the State Government recognise that climate change is creating challenges in managing the increased risk of bushfires regionally and consider providing local governments with additional resources for early detection and rapid suppression.

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A lot of work went on behind the scenes to get this outcome and, given the controversial nature of the ‘prescribed burning’ issue, this is a massive achievement.

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FaBWA hopes that other local councils in WA will be inspired to take Denmark’s lead and pass similar motions.

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