This data contains the visual assessment of fuel layers in fire-sensitive Eucalyptus salubris woodlands using Vesta methods across 24 sites in a multi-century (10 to 260+ years since fire) time-since-fire sequence derived from growth ring-size relationships.
Credit
We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging.
Purpose
Understanding fire behaviour and vegetation flammability is important for predicting the consequences of fires. Visual assessments of fuel, such as those developed in Project Vesta, have been widely applied to facilitate rapid data acquisition to support fire behaviour models. However, the accuracy and potential wider application to other plant communities of Vesta visual fuel assessments has received limited attention. The Great Western Woodlands (GWW) region of south-western Australia supports the world’s largest remaining area of Mediterranean-climate woodland, which in mosaic with mallee, shrublands and salt lakes cover an area of 160 000 km2. Eucalyptus woodlands in this region are typically fire-sensitive, and fire return intervals recorded over recent decades have been much shorter than the long-term average. This has led to considerable conservation concern regarding the loss of mature woodlands, and has highlighted a need to better understand how fuel and vegetation flammability changes with time since fire.
Lineage
Following the methodology of Project Vesta (Gould JS, McCaw WL, Cheney NP, Ellis PF, Knight IK, Sullivan AL (2007a) ‘Project Vesta – Fire in dry Eucalypt forest: fuel structure, fuel dynamics and fire behaviour.’ (Ensis-CSIRO: Canberra and Department of Environment and Conservation: Perth)), ~300 m long transects were established passing through a 24 plots in fire-sensitive Eucalyptus salubris woodlands. At ~30 m intervals, sampling points were established (n = 10 per site) and visual assessment of the height or depth, percentage cover score (PCS) and fuel hazard score (FHS) for Surface, Near-surface, Elevated, Intermediate (within a 5 m radius of the sample point) and Canopy (within 10 m of the sample point) fuel layers. PCS and FHS numerically characterise the fuel layers through visually estimated categorical scores over the range from 0 to 5. Further information on delineation of vegetation layers and scoring PCS and FHS can be found in Gould et al. 2007a (Gould JS, McCaw WL, Cheney NP, Ellis PF, Knight IK, Sullivan AL (2007a) ‘Project Vesta – Fire in dry Eucalypt forest: fuel structure, fuel dynamics and fire behaviour.’ (Ensis-CSIRO: Canberra and Department of Environment and Conservation: Perth) and Gosper et al. 2014 (Gosper CR, Yates CJ, Prober SM and Wiehl G (2014) Application and validation of visual fuel hazard assessments in dry Mediterranean-climate woodlands. International Journal of Wildland Fire 23, 385-393). Vegetation layer heights over 4 m were measured using a hypsometer (Nikon Forestry 550). Following a trial assessment, some tailoring of the Vesta assessment protocols to the study community was required: namely litter depth was assessed in the discrete patches of litter, rather than averaged across the whole Surface layer which often had large areas with no litter cover; and fuel layers consisting solely of fire-killed vegetation or rare, emergent Eucalyptus salmonophloia (which sometimes survive fires) were recorded separately from other vegetation layers and are excluded from the data contained here. Following Gould et al. 2007b (Gould JS, McCaw WL, Cheney NP, Ellis PF, Matthews S (2007b) ‘Field guide – Fuel assessment and fire behaviour prediction in dry eucalypt forest.’ (Ensis-CSIRO: Canberra and Department of Environment and Conservation: Perth)), the mean of the 10 values per site was taken.
