Fire and carbon dynamics under climate change in south-eastern Australia: insights from FullCAM and FIRESCAPE modelling

Abstract

This study used simulation modelling to investigate fire and carbon dynamics for projected warmer and drier climates in the south-eastern Australian high country. A carbon accounting model FullCAM and the landscape fire regime simulator FIRESCAPE were combined and used to simulate several fire management options under three climate scenarios – the recent climate (1975–2005); a moderate climate projected for 2070 (B1); and a more extreme climate projected for 2070 (A1FI). For warmer and drier climates, model simulations predicted (i) an increase in fire incidence; (ii) larger areas burned; (iii) higher mean fire intensities; (iv) shorter fire cycle lengths; (v) a greater proportion of fires burning earlier in the fire season; (vi) a reduction in carbon stores; (vii) a reduction in carbon sequestration rates; and (viii) an increase in the proportion of stored carbon emitted to the atmosphere. Prescribed burning at historical or twice historical levels had no effect on fire or carbon dynamics. In contrast, increasing the initial attack success (a surrogate for suppression) partially offset the adverse effects of warmer and drier climates on fire activity, but not on carbon dynamics. For the south-eastern Australian high country, simulations indicated that fire and carbon dynamics are sensitive to climate change, with simulated fire management only being able to partially offset the adverse effects of warmer and drier climate.