Prescribed burns and wildfires

Bushfires have ravaged our country over the past few months, with over 700 homes destroyed, lives lost, and more than a billion native animals killed. Many thousands of people have been exposed to hazardous air quality.

The, still active, fire emergency coincides with severe heatwaves and the changes in the climate which could see a 20% drop in water availability in SE Australia in the coming years. 

We must look at the long-term but also take some immediate actions to reduce fire risks and help repair the damage that will reduce the percentage of reoccurrence.

The current opinion, influencing the government from some sectors, is solely increasing prescribed hazard reduction burning. This means fires created by fire-management authorities to reduce fuel to stop possible future wildfires.

There is a suite of hazard reduction activities, including controlled burns, manual reduction and weeding, cultural burns, identifying fire-resistant ecosystems, landscape hydration, restricting of dangerously isolated bush housing and development, etc.

But controlled burning does not always work or is even possible across a vast landscape. Wildfires can assume a life of their own and bypass hazard reduction areas through canopy fires and generating ember attacks many kilometres ahead of a fire front

That’s why we have to move ahead with a whole suite of actions not just one.

Our landscape is drying out as temperatures climb and bushfires are likely to be more frequent, so we must look at the underlying environmental issues. Firstly, we must stop making the problem worse by curbing our emissions, but what else should we do?

We also need to increase our landscape’s ability to withstand drier and hotter conditions, and in doing so reduce fire risks.

In parched land with degraded soils water, rather than soaking in, it washes away over the surface into gullies, carrying topsoil and increasing high-energy flows in gullies.  This depletes our vital soil water which helps pastures and trees withstand drought and heat.

There is a strong case for increasing soil moisture and recovery of our landscapes by rehydrating our soils. This can be done by slowing the rush of water by natural or man-made obstructions, creating ponds, slow flowing creeks, constructed weirs. In the cities, water-sensitive urban design, constructed wetlands and the protection of the functions of floodplains and waterways should be looked at as essential adaption/protection.

The regeneration of our soils and landscapes will help restore the balance to our ecosystems and will result in better use of precious rainfall. It will promote biodiversity, which increases resilience against drought and bushfires.

This cannot stop weather extremes or fires, but it will reduce their scale and impact. Improved soil moisture and vegetation increases humidity and the potential for cloud and rain formation, for instance.

Let’s hope we have a wide-ranging scientific discussion about the fires and ways we can properly respond.  The solutions will be varied and  have to include new practices and better funding for land management, stricter planning controls and developing new technology. Let’s avoid purely simplistic actions that will not provide solutions.

Wayne Cameron

Sources: Byron Lamont, Professor in Plant Ecology, Curtain University. Prof Eelco Rhohling at ANU’s Research School of Earth Sciences.  Ashish Sharma, UNSW.

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