Drought-fire interactions: compound disturbance effects on woodland trees of coastal Western Australia
Fontaine, J., Brace, A., Veber, W. and Miller, B. (2015) Drought-fire interactions: compound disturbance effects on woodland trees of coastal Western Australia. In: Ecological Society of Australia Annual Conference 2015, 29 November - 3 December, Adelaide, South Australia.
Frequency and intensity of disturbance is projected to increase for many ecosystems globally, with uncertain consequences, particularly when disturbances occur in rapid succession. Implications of these changes are most urgent in fire-prone regions undergoing warming and drying (e.g. Mediterranean type ecosystems) where increased fire (both managed and unmanaged) may interact with increasing drought leading to punctuated tree mortality and recruitment failure. We quantified tree mortality and recruitment following historic drought in Banksia-dominated woodlands surrounding Perth, Western Australia. Stands experienced drought alone (N=18), drought and wildfire (N=11) or drought and prescribed fire (N=15). We evaluated species and individual tree susceptibility to mortality and evidence for compound disturbance–whether wildfire or prescribed fire during drought increased tree mortality risk. We further quantified regeneration to understand if the drought or drought-fire event resulted in longer term shifts in stand structure and tree species composition. We observed a shift in dominance towards Eucalyptus and away from Banksia with eIevated mortality of large Banksia. Evidence of compound disturbance effects was modest. Improved understanding of disturbance interactions are critical to forecasting effects of climate change and informing fire management.
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|Murdoch Affiliation:||School of Veterinary and Life Sciences|
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