Our bush a million years in the making

Our bush a million years in the making

14 February 2007

published by www.geelongadvertiser.com.au


The large fires burning in eastern Victoria, thankfully, have been containedat last.

Many believe that these fires are unnatural, disasters for the environmentand they wouldn’t have happened if National Parks hadn’t been locked up and thecattlemen kicked out of the high country.

Are these views a sober appreciation of the facts? What do history andscience tell us about bushfires?

In fact, while large areas of national parks were affected, the bulk of the2006-07 fires started in and burnt through other types of land such as stateforests.

History shows that occasional large fires in south-eastern Australia are thenorm. More than a million hectares were burnt in 2003, 1939, and 1851. In thecentral Victorian highlands, magnificent forests of mountain ash _ a specieswhose persistence depends on occasional intense fire _ began life about 1750.

Large fires occur in south-eastern Australia because forests are flammable,the terrain is rugged and, most importantly, because ignition, severe fireweather and intense drought conditions occasionally coincide. Large fires alsooccur in other parts of the world for the same reasons. Large fires will occuragain. The question is how often?

Here, as elsewhere, scientists are investigating whether changes to climateor changes to land management are altering contemporary patterns of major fires.Recent published research for the fire-prone ecosystems of the western USAsuggests that climate is the main driver of large fire activity in many forestsand shrublands.

Are ecosystems destroyed by large fires? No _ they are burnt and theyregenerate. And they do not burn with uniform high intensity; some patches areroasted, others are lightly scorched. This variability of burning is also commonin other parts of the world subject to large fires.

The regeneration capacity of local ecosystems is enormous. The Australianflora and fauna, from the alps to the desert, have mechanisms that allow them tocope with, and even prosper, after large fires provided they are not toofrequent. Plants re-sprout and re-seed. Animals migrate, switch diet, andcontinue reproducing.

This capacity has been hardened over millions of years of evolution on aflammable continent. However, the ability of Australian ecosystems to cope withoccasional major fires has been compromised by clearing, ferals, fragmentation,logging and grazing.

We now have a major new challenge _ climate change. Research, here andoverseas, suggests that major fires will happen more often because of this. Withthis prospect in mind, we must do everything we can to protect people, propertyand the environment.

But can we eliminate these sorts of fires? Science says this is highlyunlikely, so therefore we need to know how to lower the risks large fires poseto the things that we value _ people, property, and the natural environment.Research and experience shows this is a complicated business. It involvesinformed compromise and trade-offs, and the adaptation of solutions to suitlocal circumstances.

Fires respond to many influences _ weather, terrain, fuel and human behaviour.Our options for managing these influences are limited. We can’t change theweather, at least in the short term, but we can alter the behaviour of peopleand some fuels.

Resources and opportunities to achieve this are finite but the extent towhich various options actually alter risks to key values in our fire-pronelandscapes is very poorly known. Management options, such as fuel reductionburning, have their own effects, which must be understood and factored intodecision-making.

Lowering risk may involve more cleverly targeted and increased fuel reductionburning in some forest areas _ as recommended in the Victorian Bushfire Inquiryand Council of Australian Governments Inquiry.

However, in other areas, such as alpine landscapes, frequent prescribedburning is not justified because of increased risk of environmental damage.Reducing risk may also require changes to the way we suppress fires and how weequip the community to cope before, during and after major events.

Some fuel treatments, such as grazing the high country, are simplyineffective. Grazing did not `reduce blazing’ during the 2003 fires, or in 1939.After fire, stock eat the `green pick’ and this hinders the natural regenerationof flora and fauna after the fires.

No solution, short of the removal of all natural vegetation, will totallyeliminate risks to the things we value. There is no single silver bullet andthere will always be considerable uncertainty surrounding the outcomes of ourchoices.

The science supporting alternative management strategies to reduce risk is inits infancy and requires considerable future support and funding.

One thing is certain _ playing histrionic blame games is pointless. Itdiscourages us from gaining the understanding needed to solve a highly complexand poorly understood problem. Getting fire management right, rather, needs hardthought and informed choices about when and where to act.

Over past months almost 20,000 firefighters have put themselves on the lineto protect their neighbours, in the true Australian spirit. Can the rest of ushelp? Yes, by building on the knowledge we do have, and working with provenfacts, rather than unsubstantiated dogma and speculation.

We need to look more carefully at history and learn from it, and factor inthe future, with drought and climate change foremost in our minds.

We can then, together, come up with new solutions for a changing world.
*  Bruce Esplin is Victorian Emergency Services Commissioner and Chair ofthe 2003 Victorian Bushfire Inquiry; Dr Dick Williams is Senior PrincipalResearch Scientist, CSIRO Sustainable Ecosystems, Darwin; Prof Ross Bradstock isdirector of the Centre for Environmental Risk Management of Bushfires,University of Wollongong.

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