DOI: 10.25911/5c45394931e9d
title: Victorian Tall Eucalypt Forest Plot Network: Victorian Central highlands fire refuges project: Fire severity predictions and maps for the O’Shannassy and Maroonndah Water Catchments, Victoria, Australia, 2002-2009
title: Victorian Tall Eucalypt Forest Plot Network: Fire Severity Predictions And Maps, 2002–2009

description: We used a case study in an Australian wet montane forest to establish how predictive fire simulation models can be interpreted as management tools to identify potential fire refuges. We tested the ability of a topographically based fire prediction model developed by Mackey et al (2002) in the O’Shannassy and Maroondah water catchments, NE north-east of Melbourne, Australia, with fire severity data collected following a large wildfire in 2009 in the same area. 

Our study demonstrates that land managers can employ predictive landscape fire models to identify the broader climatic and spatial domain within which fire refuges are likely to be present. It is essential that within these envelopes, forest is protected from logging, roads and other developments so that the ecological processes related to the establishment and subsequent use of fire refuges are maintained.
description: Abstract: We used a case study in an Australian wet montane forest to establish how predictive fire simulation models can be interpreted as management tools to identify potential fire refuges. We tested the ability of a topographically based fire prediction model developed by Mackey et al (2002) in the O’Shannassy and Maroondah water catchments, NE north-east of Melbourne, Australia, with fire severity data collected following a large wildfire in 2009 in the same area. We derived our fire severity data from a larger map created by the Department of Sustainability and Environment (2009), using SPOT satellite imagery and the normalised-burnt ratio. We examined the relationship between the probability of fire refuge occurrence as predicted by an existing fire refuge model and fire severity experienced during a large wildfire. We also examined the extent to which local fire severity was influenced by fire severity in the surrounding landscape. We used a combination of statistical approaches including generalised linear modelling, variogram analysis and receiver operating characteristics and area under the curve analysis (ROC AUC).

We found that the amount of unburnt habitat and the factors influencing the retention and location of fire refuges varied with fire conditions. Under extreme fire conditions, the distribution of fire refuges was limited to only extremely sheltered, fire-resistant regions of the landscape. During extreme fire conditions, fire severity patterns were largely determined by stochastic factors that could not be predicted by the model.  When fire conditions were moderate, physical landscape properties appeared to mediate fire severity distribution. 

Our study demonstrates that land managers can employ predictive landscape fire models to identify the broader climatic and spatial domain within which fire refuges are likely to be present. It is essential that within these envelopes, forest is protected from logging, roads and other developments so that the ecological processes related to the establishment and subsequent use of fire refuges are maintained.

Sampling method: As the region surrounding our study area is subject to heavy logging pressure, we chose to sample the O’Shannassy and Maroondah catchments only to remove any potential influence of logging on fire severity. 

See Mackey, B., D. Lindenmayer, M. Gill, M. McCarthy, and J. Lindesay (2002) Wildlife, Fire and Future 
Climate: A Forest Ecosystem Analysis. CSIRO publishing, Collingwood and Department of Sustainability and Environment (2009) Remote sensing guideline for assessing landscape-scale fire severity in Victoria’s forest estate. Unpublished technical manual, Department of Sustainability and Environment, Melbourne.

Study extent: The predicted severity values were created in 2002 by Mackey et al (2002). The fire severity data were collected by DSE (2009) following the 2009 ‘Black Saturday’ bushfires in the region.

Project funding: This project was not directly funded by any sources. Laurence Berry was supported by an ARC discovery scholarship as part of the Victorian Central Highlands (VCH) long term research project.

Field observations used to cross-validate the DSE (2009) fire severity data were collected from long term monitoring sites across the VCH by project field staff. These observations were made in 2009.  Between 2012 and 2018 the Plot Network infrstructure was funded as part of the Long Term Ecological Research Network (LTERN), a facility within the Terrestrial Ecosystem Research Network (TERN). TERN is supported by the Australian Government through the National Collaborative Research Infrastructure Strategy.