By Tom Kelly
A key question in the bushfire debate is the relationship of fire to the ecology of the Australian bush. Perspectives on this question are crucial in assessing the role of burning in any fire management strategy, and in any conservation strategy.
A pervasive reason for mistaken assumptions about the place of fire in Australia's ecology is a lack of awareness of the impact of Aboriginal burning practices on Australia's flora over the tens of thousands of years before the European invasion.
Apart from using fire for cooking and warmth, Aborigines used fire when hunting, to flush game out into the open. They also burned vegetation in order to initiate fresh growth of grasses, which served to attract browsing animals to the area, thereby improving their hunting prospects. In some areas burning was used to encourage the growth of important edible plants. Fires were also lit simply to clear the way for easier travel.
The overall result of Aboriginal use of fire - what has been termed "firestick farming" - was a "regular, light, mosaic pattern of burning" that created a varied array of neighbouring habitats at different stages of regeneration after fire. This acted to conserve plant-eating marsupials, providing good grazing and a refuge from fire in more recently burned areas, and shelter in unburnt areas. Significantly, this mosaic pattern, by creating belts of firebreaks and of areas low in fuel density, lessened the occurrence of disastrous wildfires of the type Australia so often has had to contend with in the last century.*
Regular burning by Aborigines also had long-term effects in altering habitats and the species composition of regional ecosystems. Grasslands, open woodlands and heaths encountered by early colonial explorers were largely the results of Aboriginal burning practices - so much so that many of these more open areas began to disappear following the destruction or displacement of the traditional Aboriginal communities that maintained them.*
Aborigines used different fire regimes in different parts of Australia. The frequency of burning and the time of the year chosen were influenced by the impact this would have on food supplies and other survival factors. Contemporary observations suggest that areas that sustained fire-sensitive edible food plants were usually spared from burning, sometimes through the careful establishment of fire breaks around them.*
Thus the plant communities and ecosystems encountered by the European invaders had been very much modified by Aborigines through their burning practices over many thousands of years. The result is that a whole range of Australian ecosystems are dependent on, or at least tolerant of, some degree of burning.
A key point that advocates of broad "hazard reduction burning" are often ignorant of is that repeated frequent burning can still greatly modify ecosystems, but not always with the desired effect.
For example, regular hazard reduction burning can change the species composition of a region in a way that makes it more susceptible to wildfires and so necessitates even more frequent burning. In the end, such a process could transform forest into a weed-infested grassland that might need to be burned annually.
Control burning as such is not the issue; in some cases burning is vital to the maintenance of a particular ecosystem. The issues are the length of the interval between burnings, the scale, intensity and time of year that the burning is carried out (in relation to cycles of reproduction of flora and fauna) and the social and ecological priorities that burning is intended to reflect.
It is not until the community as a whole is clear about these priorities, and their implications for fire management, that democratic decisions can be made about burning regimes.
From this perspective, it is clear that the attempt by some government MPs to convert community feelings about the fires into opposition to the declaration of wilderness areas, and hostility to national parks in general, is a cynical attempt to short-circuit the necessary community discussion about priorities and the allocation of resources. It plays on, and is perhaps based on, lack of knowledge about the longer term ecological impact of regular burning. They are trying to impose their own priorities without having community support for their real implications.
So, calls from Greens (WA) Senator Christabel Chamarette to be wary of blanket demands for regular burn-offs, and from Dr Judy Messer of the Nature Conservation Council of NSW for an integrated strategy based on knowledge from the whole range of disciplines relevant to fire and ecology, as well as community involvement in planning, should not be dismissed as fudging the issue.
Rather the only adequate response to the danger of fire in Australia is the implementation of a plan of action that takes real account of the complexity of the situation. Clearly, this implies the allocation of adequate resources to implement such policies over the long term, and not just when the horror of wildfires is fresh in people's minds.
Those trying to score cheap points by pushing an oversimplified view of the issues are in fact placing obstacles in the way of the development of an effective fire risk minimisation strategy.
* Josephine Flood. Archaeology of the Dreamtime. 1983.