This page contains some of my writing on fire over the last ten years since the “Pure State of Nature” (see History tab). It includes a parliamentary submission, material from a conference, and various other posts on fire topics.
Fire with fire
Fire in the environment is one of those topics that everyone has an opinion on, rather like, say, how to teach children to read, or running a health system, or managing federal budget deficits, or responding to terrorism, and on which popular opinion is completely wrong.
In the warmer months of the year, out here in the country, I read reports of bushfires elsewhere with horror and empathy, and sniff the air as keenly as any Bambi or Skippy. My eyes scan the horizon as well, but I have found that you can often smell smoke before you can see it. If the Inuit have 52 names for snow then Australians should have 52 names for smoke – the pale grey of a grass fire, the black of rubbish burning, the dark grey column with an acrid smell from forest burning, the generalised odourless haze from distant fires, the smoke seen at sunset, the smoke column frighteningly bending in your direction, the moist smoke rolling in from the coast, the smoke that generates cumulus cloud, the fading smoke of an extinguished fire.
Once the smoke was either from an unthreatening domestic cause, or was the sign of imminent or distant danger from a wildfire. But these days most of the smoke is from prescribed burning, the practice of deliberately setting fire to large or small areas of grass or woodland or forest in order to burn it, in what is portrayed as a harmless way, before it is subject to wildfire. After every bushfire there are calls for much more of the bush to be deliberately burnt more often, and the more egregious of the shock jocks blame “greenies” for resisting prescribed burning, one particularly nasty piece after recent bushfires demanding that conservationists be tried for murder.
“Burning off” has long been used to protect farm houses by removing long grass in the near vicinity, or along roads to reduce the chances of cigarette butts starting fires, or to create fire breaks to facilitate fire-fighting efforts in a wildfire. But in the past its use was limited to those immediately protective functions because it was understood that all fire caused environmental damage, and it made no sense to protect the bush itself from fire by burning it. More extensive use of deliberate burning began after theories were developed that Aborigines had once used fire extensively and that therefore it couldn’t really be harmful.
The other day someone typed in to Google the following search string “aborigines fire farming destroyed green australia” and finished up here. I guess the searcher thought that Aboriginal use of fire in the past had been extensive and systematic and had changed the Australian environment in such a way that we should follow their example and keep burning the bush. They would have had a shock when they arrived at my blog to discover there had been no extensive and systematic use of fire by Aborigines, and that the environment has been altered by climate change not by “fire sticks”.
A second development was the theory that the Australian fauna and flora was “adapted to fire”. This glib proposition, adopted enthusiastically by the media, was just as wrong as the first. But putting the two together enabled some people to say that not only was it ok to preemptively burn the bush extensively, but it was essential to the well-being of the environment. In fact no Australian plants or animals are adapted to fire (to say that the bush can “recover” after fire is like saying it can recover after cyclone or flood or landslide).
The final part of the equation related practice to theory. If you were still concerned about fire, even though told it was essential to the bush and had been used by Aborigines for thousands of years, then prescribed burning advocates promised “cool burns” done only when conditions were cool and moist in Spring and Autumn and carefully directed so as to create a “mosaic” or “patchwork” of areas burnt at different times. These controlled techniques were said to be modelled on those used by Aborigines.
One problem with this description is that the demands for ever more prescribed burning are resulting in fires having to be lit at other times (councils who say there hasn’t been enough suitable weather to do prescribed burns are met with howls of outrage and derision by shock jocks of print and broadcast). And much bigger areas being burnt for logistical reasons (although in any case prescribed burning has never had “creating mosaics” as a primary aim, even if fire behaviour could be controlled to the extent that would be needed). As a consequence fires frequently escape and become wildfires, but even where they don’t, the temperature of the burns, and their effects, are considerably different to the popular image of tiny flames gently burning through moist leaf litter with green plants.
But let us say that popular perception matched reality, that so much money and resources and staff and training had been poured into the prescribed burning program to make it perform the way well-intentioned people want it to. Would that be ok? Well, no. The aim of the exercise is to remove what is called “fuel load”, by which is meant dead leaves, bark, sticks, branches, logs, dead grass and other small plants. But to the forest ecosystem this isn’t “fuel”, but a vitally important part of the forest which (think garden mulch) helps to prevent erosion, retain soil moisture, break down to recycle nutrients, and provide a structural home for thousands of small animal species.
When fire is running through leaf litter as well as removing mulch it is killing small mammals, small birds, lizards, frogs, insects, worms, molluscs, spiders, and sterilising the bacteria and fungi in the soil. Keep on burning at an interval shorter than that in which shrubs can grow and set seed and you begin destroying the shrub layer as well. You have to keep on burning regularly, because otherwise (particularly in a global warming induced dry climate) litter will quickly build up again. With forests fragmented by farming. clearing, roads, tourist activities, housing developments, the chances of small plants and animals recolonising burnt areas is slim. And the pattern of vegetation may change (including weed invasion) to one more susceptible to fire, so prescribed burning will need to be even more frequent. For some years it will seem, with trees and large fauna still present, that the forest is unchanged by fire, but gradually the reality will become evident.
There are many things that need to be done (some here) to support our brave firefighters and try to prevent the terrible losses that bushfires can bring. And one of the techniques to be used should continue to be strategic burning to protect life and property, done judiciously and sparingly. But the demands for massive increases in prescribed burning across all our forested areas should be resisted, or, without realising it, we will gradually destroy the habitats we want to preserve. Global warming makes this an even more urgent consideration.
Cross-posted at ABC Unleashed.
16 August 2009