The fires – humanity and science

This season’s bush fires have affected most people – some directly and many indirectly through personal connections or broader concerns for people, animals and the environment.  Reading Annemaree Docking’s article on her personal experiences with fire raised some memories of my past experiences with fires.  The risk of fire is escalating with the climate crisis, and we all – personally and collectively – need to decide how to respond.  And our responses, as Annemaree says, should be based on the best available evidence in these extra-ordinary times.

Our personal responses to the direct threat of fire will depend on the circumstances.  After 2009, I visited many fire-affected properties to support the recovery efforts of the landholders.  And heard many awful and amazing stories.  Before that fire, I had not fully realised how massive and overpowering such a fire could be.  After the fire, we decided that, in similar extreme conditions of ferocious hot winds blasting across the dry landscape, we would leave that morning (or night before) based on the forecast and not the imminent threat of fire.  Even though we only lived on the edge of a town, not in the forest, we did not want to take the risk. 

The Mickleham fire in 2014 may not have been as big and ferocious as the Black Saturday fire but it was big enough to spread widely across farmlands in the district and take a huge effort by fire crews and several days to quell.  18 houses were lost and – significantly – 16,000 livestock were killed.  Annemaree stayed and successfully saved her animals.  But could all the animals have been saved?  In 1978, a hot, fast-moving grass fire near Bairnsdale killed two people who were trying to save their livestock, and  I spent the following week assisting in the shooting of hundreds of badly burnt survivors of the more than 6000 sheep and cattle killed in that fire.  It is often impossible – and very risky – to stay and try to protect or move livestock in front of a fire.  But what an awful decision to have to make.

How do we – collectively – protect people and animals and assets from fire.  This is already being hotly debated with some simplistic solutions around the reduction of fuel in the forests.  To some extent, this is a problem of our own making – more and more people are moving out of cities into forested areas – very attractive places to live but also very dangerous in summer.

So do we burn – and graze and mulch and trample – the forests to reduce fuel loads?  From my readings on this, the evidence is very confusing.  Are controlled burns effective in moderating fires and making them easier to control?  Hard to imagine in extreme crown fires in forests.  But also, how much does the regular burning of forests affects the biodiversity and ecological functions of forests and even possibly increase fire risks with the regrowth? 

The Royal Commission after the 2009 Black Saturday fires recommended that 5% of crown land be burnt every year.  This 5% rule resulted in inappropriate burns in sensitive and remote country, at least in part because it was more possible to get to 5% within the verynarrow window for controllable burns in Spring and Autumn and with the limited resources available to do the burns. 

But a real concern from ecologists was about the impact of regular burns on forest environments.  Regular fire is good in some ecosystems such as grasslands and heathlands), but is disastrous in others.  For example, three fires from 2003-2013 near Mt Feathertop has wiped out a lot of species including Alpine Ash that didn’t have time to recover between burns.  And fuel reduction burns are often very hot.  There was a lot of damage in Tallarook Flora Reserve and the Cobaws (including big loss of old trees) after “controlled” burns and it will take a long time if ever for full recovery.  In some forests, there is a period of higher fuel loads as trees and shrubs come back more densely in the first phase of recovery. 

But other scientists – and popular demand from some sectors – are saying that we need to burn even more.  So lots of different opinions from people coming from different directions and in different situations.  No one rule will work in all bushland environments.  And what is the purpose of fuel reduction burns – to reduce fire intensity and spread (but with climate change and extreme weathers, how much can we really do?) or protect people and assets with more strategic burns?

One of my favorite parts of Victoria are the alpine areas.  And alpine grazing is one of those issues that come up after fires.  Annemaree deferred to “greater minds” on this topic, but I want to state my position more strongly.  As with climate change denial, inconvenient science is easily dismissed by many people with opposing interests.  Grazing has caused a lot of damage to fragile ecosystems in the alps, particularly the wonderful bogs and waterways.  From 1939, exclusion plots on the High Plains were studied to assess the long-term impacts of grazing.  Despite the evidence, it took until after fires in 2003 and a lot of polarised debate to halt alpine grazing – and there have been efforts to reintroduce grazing since then. 

“Alpine grazing reduces blazing” was a popular car sticker but where was the evidence?  In December 2002, I walked through mobs of cattle, cow dung and polluted streams around the Tawonga Huts on the High Plains.  One month later, it was all burnt.  Dick Williams and others looked at the wider evidence, and found that grazing did not stop blazing.  (Williams, R. J., Wahren, C., Bradstock, R. A., & Müller, W. J. (2006). Does alpine grazing reduce blazing? A landscape test of a widely-held hypothesis. Austral Ecology, 31(8), 925-936. doi: 10.1111/j.1442-9993.2006.01655.x.).  So fuel reduction (if any) from grazing had little effect, and I think the catchment and biodiversity values of the alpine areas are a far more important consideration, especially with the serious impacts predicted for climate change on alpine ecosystems and species.  I wouldn’t want to go back to that grazing debate again in this world of populist politics rather than earlier evidence-based decision making that finally excluded grazing in the alps.

One final concern.  After 2009, many areas of the central highland forests were logged before “dead” or damaged trees were no longer useful as timber.  Instead of allowing natural recovery from the surviving plants and the seed bank released after the fire, the ground was disturbed by machinery and by the removal of a significant component of the habitat – the large trees.  Work by David Lindenmayer and others have shown that there are many losses after two successive major disturbances, with increased runoff from disturbed ground, loss of soil nutrients, and impacts on the recovery of plants and animals (including some significant threatened species).  Conservation groups are trying to persuade the government to halt logging in forests burnt this season.  But on March 1st …. Logging is due to start in fire-ravaged forests this week. It’s the last thing our wildlife needs

I am very thankful that this summer has ended with a whimper, but we need to be alert and support all efforts to protect our bushland environments against hasty, ill-informed and populist policies.

Peter Mitchell

4th March 2020

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