Effects of Australian Bush Fires
The Survival and Growth of Plant Life in Australia after Fire
Nov 13, 2008
Bush fires occur at various times of the year in Australia; in the north, fires are prevalent in the dry winter season, whereas in the south west of Australia, fires occur in the dry summer season. Bush fires may be natural, man made or as part of a prescribed burn; naturally occurring bush fires are most common during drought years and particularly severe in El Nino years.
The Effect of Bush Fires on Australia's Environment
Bush fires have been a part of Australian history for hundreds of years; aboriginal people used bush fires to their benefit to manage the land and as a hunting aid. However, the influx of immigrants into Australia intensified the frequency of bush fires, whether deliberately set or as a result of an accident. The devastating effect of any bush fire results in the loss of native flora and fauna which may take several years to regenerate.
The Australian bush fires of 2002/2003 burned through four million hectares of land and one scientist predicted that it would be 200 years before some of Australia's forests would recover. However, some plants actually benefit from the result of a bush fire and have adapted numerous strategies to survive them.
Plants which Benefit from Bush Fires
Many Australian plants have evolved to survive the effects of a bush fire. Australian Wattle, banksia and the grass tree are all common Australian plants and have some abilities to adapt to or benefit from bush fires for future regeneration. Some plants have reserve shoots which grow after fire and others have seeds which are either fire-resistant or triggered by fire.
The Australian Mountain Ash tree requires fire in order to survive; Mountain Ash seeds need fire for the regeneration of seeds. However, the Mountain Ash tree only produces seeds at maturity, age 50 years, so should fire occur before then, the Mountain Ash species may not survive in a particular area.
The Eucalyptus tree is one of the most adaptable of plant species to bush fires. The Eucalyptus tree is a botanical species which thrives in fire conditions; the Eucalyptus tree has leaves which contain flammable oils, thus encouraging the start of a fire and a way to eliminate plant species which are not fire-tolerant.
The bark of the Eucalyptus tree protects the tree during a fire as it acts as insulation agent. The Eucalyptus tree regenerates itself after fire from lignotubers, located on underground roots or stems which contain bud and food reserves. The lignotubers use fire as a stimulant to develop new growth.
Prescribed Fire Burns of Australia's Bush
The Aboriginal people used controlled burns of the bush to encourage new plant growth; however, there is much debate over the use and effects of prescribed burns today. The Department of Environment and Conservation in Western Australia maintains that prescribed burns of the bush benefit the biodiversity of Australia's eco-systems and helps offset the disturbance of plant life from mining and harvesting.
However, this view is not shared by all and various studies are investigating the effects of prescribed fire burns over a period of time in different areas of Australia to establish how bush fires effect both the ecology and the wildlife habitat. Australia is the world's driest inhabited continent and factors of climate change are contributing to prolonged periods of drought; bush fires, either natural or prescribed, are an inevitable part of the natural plant ecology system of Australia.
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