Fire debate generates more heat than light

Fire debate generates more heat than light

13 November 2008

published by

Australia — It is difficult to have a cool discussion about fire because the topic generates so much heat. I hope facts, scientific evidence and opinion presented here provide light rather than heat.
Since there have been plants that would burn, lightning has caused natural fires. Today, lightning still causes some bushfires, but most are started by humans. Such fires are not natural. A fire started by an incendiary dropped from a helicopter is no more natural than pivot irrigation.
Over time, Australia has become hotter, drier and more flammable, and the frequency of bushfires has increased.
Our plants and animals have evolved with these changing conditions. Some have died out; others have moved or developed features that allow them to survive drought and natural fire.
Since Europeans arrived, we have cleared much of the native vegetation and fragmented most of what is left. We have made the environment more flammable by logging forests and introducing flammable weeds into bushland.
We have lost most of the once common small animals, such as the woylie, that reduced the “fuel load” by eating and burying it.
All through the forests and bush we have built communities and structures needing protection from bushfire.
A major Federal inquiry into bushfires reported in 2005 that the most important measure to prevent losses from “natural” disasters is land use planning that takes account of hazards such as bushfire.
In other words, don’t build fire-sensitive structures in high fire-risk areas.
Planners, councils, land developers and home-owners have ignored such advice. Today, there are thousands of inappropriate houses in inappropriate places, such as homes in coastal heath with a single access road. They are a disaster waiting to happen.
The same Federal inquiry found that having an annual burn target is unhelpful, even counterproductive. Land managers tend to burn big remote areas that help reach the target and to avoid small difficult burns around towns, suburbs and farms, which should be done to help protect human lives and property.
Having an annual burn target could contribute to complacency on the part of homeowners who may think that because land managers have reached the target they are protected when they are not.
All home owners must take responsibility for their own fire safety and prepare and implement bushfire response plans. Fire-fighters must get adequate funding, equipment and training to do the best they can without endangering their own lives.
Research by scientists at Australian universities and in North American Forest Services, reported in 2007, indicates that prescribed burning is less effective than claimed for reducing the area burnt in bushfires. This research shows that the prevailing weather conditions, preventing fires from starting in the first place, and rapid suppression when they do start, are more important than prescribed burning.
The report of the 1961 royal commission into the 1960-61 bushfires says most of the forest around Dwellingup had been control-burnt by the Forests Department for 40 years and the “fuel load” was between zero and eight years old — much the same as land managers aim for today.
That amount of prescribed burning seems to have made little difference to Dwellingup.
Ironically, current prescribed burning makes forests and bush more flammable. It opens up forest canopies, dries out the understorey and promotes rapid and prolific growth of fire-loving plants. Land managers then feel obliged to burn again, which produces an increasingly fire-prone environment.
Repeated burning is a major threat to biodiversity. Kings Park scientists say frequent fires have a disastrous effect on many flora and fauna. Native species needing long fire-free periods disappear from places burnt at short intervals.
Research reported in the Royal Society’s Journal this year shows that fires in the jarrah forest must be at least 10 years apart or some plant species will disappear.
Prescribed burning planned to meet the needs of plants does not necessarily meet the needs of animals.
Fire kills animals that cannot escape. Those that can escape may lose their homes and food supply. For example, honey possums, which eat only nectar and pollen, need 15 to 30 years before there are enough flowering plants for them to survive. Birds may return but their numbers dwindle with frequent fires and some species, such as the ground parrot, could become extinct.
As for getting more water from catchments, killing trees and burning forests and bush increases run-off into dams but only for a few years. The killing and burning must be repeated at short intervals to maintain the flow, and that increases the risk of salinity and phytophthora dieback. This method of getting more water for humans is a serious threat to biodiversity.
Prescribed burning is also bad for climate change. Recent research at the Australian National University shows that vegetation and soil in eucalypt forests store far more carbon than previously estimated. Frequent burning reduces these stores and increases greenhouse gas emissions.
The whole of our South-West is suffering from drought. Jarrah, marri, tuart, wandoo and peppermint are in decline, and more animals, such as the phascogale and the woylie, are becoming endangered. 

Frequent burning adds to drought stress and threatens biodiversity. It is time we adopted a different approach to mitigating and managing bushfires, one informed by best science. Open and honest discussion would be a good place to start.

Beth Schultz is vice-president of the Conservation Council of WA.

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