Bushfire has been part of the Australian landscape for millions of years but while we consider it a threat, some of our flora and fauna depend upon it.
Much of Australia’s vegetation has evolved with fire and curiously, like the vegetation in other harsh dry environments, it has developed characteristics that promote the spread of fire:
1. Eucalypt litter is coarse and decays slowly, ensuring that after several years there will be an abundant build-up to carry the next fire.
2. The bark of many species is flammable and loosely attached to the trees, making ideal firebrands to carry fire across natural barriers.
3. The green leaves contain highly flammable oils and resins that act as a catalyst to promote combustion before the leaves are fully dry.
All the potentials are there and sooner or later, in some part of Australia, weather patterns will occur so that strong, hot, dry winds will blow from the centre of the continent after the fuel has been preconditioned by drought.
All that is needed is a spark to produce a conflagration that simply cannot be stopped until the weather moderates.
Fire is not the foreigner in this country – people are.
Since European settlement, the total amount of fire in the landscape has declined.
The first inhabitants of this country learnt that they had to break up the fuel to survive.
They burnt extensively and often.
They learnt the responses of the plants and animals to burning and took advantage of these responses to coexist.
The bushland areas and particularly those around Sydney, New South Wales, have thickened and accumulated more fuel.
As a result, the infrequent fires that now occur under extreme weather burn much more intensely and have a significant impact on the built environment.
Fragmentation of the bush by different land use practices, such as urbanisation and agriculture, means that the Aboriginal fire regime is no longer possible or desirable.
However, our flora and fauna came from this regime. If we want to maintain the biodiversity in our native areas we have to accept that fire is a process that must be used to manage our native bushland.
We need to accept fire for what it is – an ecological process that determines the composition of our flora and fauna.
Fire is as natural as the sun and the rain.
Nothing else can replace it completely.
Nothing else produces the chemicals in the ash to stimulate new growth – or in the smoke to stimulate the flowering and regeneration of particular species.
Nothing else produces the heat pulse that removes growth-inhibiting toxins in the litter, or opens tightly-closed fruits to release new seed, or penetrates deep into the soil to stimulate the germination of long-buried seed.
Nothing else produces the succession of plant development to which our native fauna have adapted to meet their requirements for food, shelter and reproduction.
If we want to reduce fire intensity and make fire suppression safer and easier we need to accept that it is the dry undergrowth and dead leaf, bark and twig litter that provides the fuel for bushfires, and use prescribed fire to reduce fuel loads.
If we want to secure our homes and property we need to zone our bushland areas so ecotypes that require frequent fire regimes are adjacent to assets of high value and thereby reduce the impact of wildfires and promote biodiversity.
We need to support the fire service and the land management agencies when there is no emergency and accept the minor inconvenience of smoke in the air when fire is prescribed for hazard reduction, forest regeneration or biodiversity management.
Finally, we need to individually take responsibility for managing the fuels we own and maintain our property and garden so that they do not burn in summer.
