1 2 Fuels and landscape flammability in an Australian alpine environment 3 4 Fraser, Imogen P.1; Williams, Richard J.2; Murphy, Brett P.3; Camac, James S.4; Vesk, Peter 5 A.1 6 1 School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia. Email: 7
[email protected]. Phone: 0430 433 422. 8 2 CSIRO Tropical Ecosystems Research Centre, Winnellie, Northern Territory, Australia 9 3 Research Institute for the Environment and Livelihoods, Charles Darwin University, 10 Darwin, Northern Territory, Australia 11 4 Department of Biological Sciences, Macquarie University, New South Wales, Australia 12 13 Running head: Australian alpine fuels and landscape flammability 14 15 16 Key words: bulk density, fuel load, vegetation structure, fire severity, fire regimes 17 18 19 20 21 22 23 24 25 26 27 28 29 30 1 31 Abstract 32 Factors governing landscape-scale flammability are poorly understood, yet critical to 33 managing fire regimes. Studies of the extent and severity of the 2003 Australian alpine fires 34 revealed marked differences in flammability between major alpine plant communities, with 35 the occurrence and severity of fire greater in heathland compared to grassland. To 36 understand this spatial variation in landscape flammability we documented variation in two 37 physical properties of fuel – load and bulk density – at the life-form and plant community 38 scale. We measured load (mass per unit area) and bulk density (mass per unit volume) of fine 39 fuels (<6 mm) at 56 sites across the Bogong High Plains, southeastern Australia. Fine fuel 40 load was positively correlated with shrub cover, and fine fuel bulk density was negatively 41 correlated with shrub cover.