|
|
       |
 |
 |
    |  |
 |
|
Environment Forest Ecosystems Forest Industries Forest Management Forest Products Greenhouse Gases NAFI Submissions Policy and Politics Renewable Energy Sustainability |
| |
Burning Bush - Burning QuestionsThere are three fundamentals for the start and spread of bushfires - ignition source, weather and fuel load. In the aftermath of the Dandenong bushfires, we are shocked by the alleged, criminal act of lighting fires in a season and on a day where the weather had produced a very high fire danger. But we should also reflect on fuel load and on the nature of the Australian bush. The bush has evolved with fire and is in many ways dependent on fire. It is highly flammable and, given the right conditions, it is explosive. Our immediate feeling from the perspective of life and property is that fire is bad. If fire is bad, it follows that all fires must be suppressed. Such a conclusion accords with the popular view that forests are tranquil and perpetual, progressing harmoniously toward a perfect and pre-ordained state. However, nature is far from tranquil. Bush fires are natural and unpredictable. They burn at irregular intervals, at various times of the year, at various intensities and over a range of areas. Fires over evolutionary time have given diversity to our forests. Our eucalypt forest produce up to 10 tonnes of litter per hectare each year. Most of this litter - dead leaves, branches, bark - falls during summer. Over years without fires, the build-up of this litter together with the accumulated growth of understorey plants produces a very high fire-risk. Should we therefore have 'prescribed' fires - strategically planned that aim to reduce the fuel load? Prescribed burning in the jarrah forests of Western Australia over the past 40 years has been highly successful in limiting the destructive effects of bushfires, with negligible ecological cost. Prescribed burning results in a mosaic of fuel loads. With the inevitable outbreak of bushfire, fire-fighting resources can then be directed to areas under the greatest threat. Bushfires in Australia over tens of millennia were due to lightning and to continual burning by aborigines. Records from the first voyagers noted smoke covering much of the eastern coast. Some of the early explorers and surveyors wrote of a well-developed grass lay in a number of forests, rather than the thick, shrubby understorey that we have today. European settlement has changed the fire regime in most parts of Australia and as a result the balance between many species has altered. The management of forest diversity - including national parks and wilderness areas - there posts many questions about the use of fire. We must dispel the myth that fires is ecologically bad, and we must ensure that management of our forests is based on the best knowledge of the ecology of natural disturbance. Fuel load is the direct consequence of forest growth and forest management. The problems for land managers are many. Should we aim to suppress all fires? Who then takes responsibility for the inevitable major fire, of unnaturally high intensity due to the enormous build-up of fuels? Furthermore, a policy of total fire suppression will have major consequences for diversity. Should we let fires caused by lightning run their course? Who then takes responsibility for the inevitable escape of some lightning fires from State-owned forest into private land? Two programs of ecological research in Victoria are urgently needed. First, we should have a thorough examination of the early records so that we can reconstruct the fire-histories of our major forest types. Second, we should step up research on the ecological effects of regular fires so that programs of prescribed burning can be fully implemented within an ecological framework. |
|
 |
      |
|
|
|
| Site development by Rendrag Networks, Canberra - Graphic design by Swell Design Group, Canberra | |