The Bushfire CRC was formed in 2003 to carry out research into a suite of issues relating to bushfires. Researchers in the DFES Fire Ecology and Management Group lead the following projects:
Project A4: Bushfire Risk Management Model – Dr Kevin Tolhurst
Project B2.2: Smoke composition and impact on human health and ecosystems – Dr Tina Bell
Project B3.1: The effect of fire on ecosystem processes and biodiversity – Dr Alan York
A4.1 Bushfire Risk Management Model
The overall objective of the Bushfire Risk Management sub-program is:
To develop a risk management decision support system for communities living in the rural-urban interface, town planners, power supply companies, fire fighters and land managers.
There is currently no bushfire risk management system in the world. Fire managers have resorted to the use of “Threat Analysis” and work environment risk management, but not to the overall management of risks associated with bushfires. Risk assessment must be assessed in terms of the potential consequences to environmental, economic and social values. Bushfire risk management must incorporate the complex interactions between the dynamic fire environment, the complex ecological environment and the complex and politically sensitive social and economic environments. Nobody in the world has yet been able to develop such a holistic approach to Bushfire Risk Management.
The first component of the Bushfire Risk Management Model is a clear definition of the Bushfire Management Business Model. This includes the array of management objectives, the social, political, environmental, economic, and operational context of bushfire management and a mathematical definition of how all these factors interact. An in-depth survey of senior fire managers from around Australia provided the basis for this model. This model will then become the basis for the business of Bushfire Management, i.e. mitigation, in the Bushfire Risk Management Model. A demonstration version of this model has been produced. An automated process to revise and customise the nature of the interactions in the model is yet to be developed.
The second component of the Bushfire Risk Management Model is the fire characterisation model. The interim version of this model has been called PHOENIX. This is a fire spread simulation which records the frequency, intensity, size and time from ignition to impact of fires in a landscape under specified weather and ignition scenarios. The fire characteristics across the landscape are altered by the decisions made in the Bushfire Management Business Model (mitigation scenario). The output from this model can then be used in the third component of the system, the Bushfire Impact Model.
The Bushfire Impact Model is yet to be developed. It is envisaged that the impact model will be used at a broad level – i.e. the impact fire will have on townships, water catchments, major elements of infrastructure, fauna and flora populations or communities, etc., rather than individual houses, powerpoles, plants or animals. The output from the model will be expressed in terms of the probability of particular outcomes such as the probability of local extinction of a specific species, the probability of a township suffering the loss of 1, 10 or 100 houses, etc..
Project B2.2 Smoke composition and impact on human health and ecosystems
Smoke contains a complex mixture of visible products of burning (particulates and water vapour) and gaseous components including CO2, O3, CH4, NOX, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). Most of the information relating to the composition of smoke comes from studies of industrial emissions, tobacco smoke, smoke from residential fireplaces and burning of biomass under controlled laboratory conditions. Fewer studies have determined the composition of smoke from vegetation fires but relevant information is increasing as large-scale wildfires become more prevalent and prescribed burning becomes a more important tool for land managers. The composition of smoke produced will differ depending on the type and condition of fuel, weather conditions and fire behaviour. Certain types and amounts of gases and particulates are formed during flaming combustion while others are released during the smouldering stage. Fires of low intensity tend to produce more particulate emissions than fires of higher intensities and smouldering combustion produces more CO and particulates than flaming combustion. Carbon monoxide, CH3Cl, CH3Br and CH3I, together with NH2, amines and nitriles are formed predominantly in the smouldering stage while nitrogen oxides such as NO, NO2, N2O and molecular N2 are released during flaming combustion.
While regular prescribed or fuel reduction fires may be a perceived method in which the severity of wildfires can be controlled, the impact of the smoke produced on the community may be as great as or greater than that produced by occasional wildfires. With the ability to predict the behaviour and dispersion of smoke plumes the potential risks to human health can be better communicated and therefore potentially minimised. To get to this point we need to know if the smoke produced by prescribed fires differs from that produced by wildfires. This project will help by contributing to a system to predict the composition of smoke from different fuel types and burning conditions. In addition, this project will extend to identifying the impact of smoke on human health. The ecological and environmental considerations of smoke will also be addressed.
Project B3.1 The effects of fire on ecosystem processes and biodiversity
Low intensity fires are used extensively in managed sclerophyll forests in Australia and there is growing concern that inappropriate fire regimes may have a negative influence on plant and animals communities. This project seeks to model nutrient fluxes under different fire regimes, investigating the roles played by mycorrhizal and decomposer fungi and their inter-relationships with plants and invertebrates, and the likely impacts on ecosystem processes and carbon cycling. It has a focus on biodiversity; specifically
looking at functional groups of organisms and how they interact with the processes that determine productivity and ecosystem function (specifically nutrient cycling and carbon flux) and how fire interacts with these processes. This knowledge is essential for the sustainable management of Australian forests; a limited resource contributing substantially to biodiversity conservation, water catchment protection, and the provision of timber and other forest products.
A significant issue for land managers is the implication of both wildfire and hazard reduction burning for Ecologically Sustainable Management (ESM). Maintaining biodiversity and the integrity of ecological functions involves addressing problems associated with vegetation regeneration and succession, soil physical, chemical and biological properties, the conservation of biological diversity at different scales (genetic, species & ecosystem), and the role of soil flora & fauna in soil processes & nutrient cycling. This project has 3 main components, each focussed on long-term ecological research sites:
The Bulls Ground Frequent Fire Effects Study (NSW)
The Eden Burning Study Area (NSW)
The Wombat Fire Effects Study (Vic)
The Wildfire Chronosequence Project (Tas)
Integrated, multi-disciplinary research projects are being conducted at each of these sites to address a range of issues associated with the impacts of fire management on biodiversity and ecosystem processes.
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