/ Decision tree analysis was used to predict the distribution of forest communities in an area on the south coast of New South Wales. Australia, The analysis was carried out using a geographical information system environmental data base of those topographic and geological variables thought to influence the distribution of vegetation and derived from cartographic sources. The resulting maps of forest communities are of a resolution sufficient to delimit individual forest stands and contain much ecological information.A major priority of environmental ntanagement in Australia is the developntent of cost-effective methods for mapping native forests. The aim is to produce maps of these forests that provide information not only about the location and extent of timber resources, but also ecological information to assist forest HI~:lltagers in developing and implententing muhiuse management policies. For forest managentent purposes, vegetation maps should be of sufficient resolution to delimit forest stands, which are contiguous regions occupied by a single community. Such maps would show the extent of forest communities within ntanagement compartments. Survey of forest communities at such fine resolutions is a labor-intensive and costly exercise because of the size and highly variable nature of many of the forests.Most vegetation surveys in these torests employ some combination of field work and phutointerpretation, sometimes in conjunction with satellite image analysis. These are not alternative ntapping ntethods. Manual survey can be assisted greatly by photointerpretation, and the production of reliable vegetation maps from aerial photographs or satellite data requires a significant investment of field work for interpretation and verification (Zonneveld 1988). htitially it appeared that multispectral satellite dam could be digitally analyzed to produce vegetation maps with little investment of labor. Such dam would appear to have great potential as a cheap, readily updaud)le

Characteristics of trees used for shelter during the day by brushtail and ringtail possums were identified in a study in open forest dominated by Eucalyptus marginata and E. calophylla in the Perup Fauna Nature Reserve, SW Western Australia. The effect of high-intensity fire on the availability of trees used by the possums was studied by comparing a burnt area (36 ha) with an unburnt area (22 ha) one and 32 months after the fire. Suitable hollows were used by possums regardless of the species, condition, height or size of the tree. Hollows deeper than 1 m were used significantly more frequently than shallow ones. Hollows of suitable size appear to develop in E. marginata when trees reach a mean age of about 300 yr, and in E. calophylla when trees reached a mean age of about 200 yr. The average age of trees inhabited by possums could be as high as 500 yr for E. marginata and 400 yr for E. calophylla. About 3 trees/ha were used by possums for diurnal refuge; the distribution of these trees was random. Fire of high intensity (1000-1400 kW/m) destroyed 38% of the trees previously inhabited by possums; the damage to other inhabited trees was related to their condition and the intensity of fire. In the longer term, high-intensity fire increased the rate of formation of hollows by direct excavation or by providing new sites for fungal and termite infestation. Thirty-two months after the fire, the average age of trees containing suitable hollows was estimated to be about 100 yr less than before the fire because of the destruction of older trees and the formation of new hollows, or the deepening of existing ones, in younger trees.

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Fire has been part of the natural environment of southeastern Australia for tens of millions of years. Aboriginal people used fire selectively, with skill, for many reasons. The removal of Aboriginal people from most of the region after European settlement changed fire regimes and the composition and structure of vegetation. This study explores the history of fire in southeastern Australia, describes the development of prescribed burning as a forest management tool, and discusses the factors that have influenced changes in fire regimes. It draws on published and unpublished literature and data held by the Forest Fire Management Committee of the Institute of Foresters of Australia. The study finds that the use of prescribed burning in southeastern Australia in the past 100 years has been driven primarily by political and legal factors. Since 1939, more than 50 public inquiries, reviews and royal commissions have been held into matters concerning the management of fire in landscapes, including prescribed burning. Prescribed burning has been used for wildfire mitigation, agricultural practices (such as stubble reduction and grazing land management), property protection, the maintenance of ecological processes and biodiversity conservation. Prescribed burning in the region has only ever been practised on a small percentage of forest and land each year. The study finds that a substantial body of fire and ecosystem science has been generated in the past 50 years, with rapid technological developments to support prescribed burning and fire management. Research has provided tools and methods for broadscale prescribed burning, but negative public perceptions of fire have prevented the deployment of comprehensive fire management programs in the region. Although much has been achieved, considerable changes are still required in fire management for it to be sustainable and optimal in protecting economic, social and environmental values. The risks to human lives, property, biodiversity and the environment associated with wildfire are increasing in southeastern Australia due to climate change, and the wider use of prescribed burning is essential for managing these. The increasing extent and occurrence of wildfire disasters in the region indicates that current fire management will not sustain the full range of ecosystem processes and biodiversity, nor reduce to an acceptable level the impact of wildfires on human lives and property. There is compelling evidence for the greater use of prescribed burning to reduce wildfire risks and impacts, rather than committing increasing resources to wildfire suppression. The potential negative impacts of prescribed burning can be managed effectively using existing knowledge and tools. Clear communication of the benefits of prescribed burning can influence political and public opinion in its favour. More investment in training, human capacity and supporting resources is required to safely and effectively deploy prescribed burning more widely to reduce future wildfire risks.

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