Development of a Model System to Predict Wildfire Behaviour in Pine Plantations

We describe the development of a model system for the prediction over the full range in fire behaviour in exotic pine plantation fuel types in relation to environmental conditions. The proposed system integrates a series of sub-models describing surface fire characteristics and crowning potential properties (e.g., onset of crowning, type of crown fire and associated rate of spread). The main inputs are wind speed, fine dead fuel moisture content, and fuel complex structure, namely surface fuel bed characteristics, canopy base height and canopy bulk density. The detail with which the model system treats surface and crown fire behaviour allows users to quantify stand “flammability” with stand age for particular silvicultural prescriptions. The application of the model to a radiata pine plantation thinning treatment case study in Victoria is presented. The results highlight the complex interactions that take place between fire behaviour and attendant fuel and weather conditions. The structural changes introduced in the fuel complex by the treatment altered fire behaviour, but no definite reduction and/or increase in rate of fire spread was identified. The results illustrate the role that simulation models can play in support of silvicultural and fuel management decision making.