Abrupt fire regime change may cause landscape‐wide loss of mature obligate seeder forests |
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Authors: | David M J S Bowman Brett P Murphy Dominic L J Neyland Grant J Williamson Lynda D Prior |
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Institution: | 1. NERP Landscapes and Policy Hub, School of Biological Sciences, University of Tasmania, , Hobart, TAS, 7001 Australia;2. NERP Environmental Decisions Hub, School Botany, The University of Melbourne, , Parkville, VIC, 3010 Australia |
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Abstract: | Obligate seeder trees requiring high‐severity fires to regenerate may be vulnerable to population collapse if fire frequency increases abruptly. We tested this proposition using a long‐lived obligate seeding forest tree, alpine ash (Eucalyptus delegatensis), in the Australian Alps. Since 2002, 85% of the Alps bioregion has been burnt by several very large fires, tracking the regional trend of more frequent extreme fire weather. High‐severity fires removed 25% of aboveground tree biomass, and switched fuel arrays from low loads of herbaceous and litter fuels to high loads of flammable shrubs and juvenile trees, priming regenerating stands for subsequent fires. Single high‐severity fires caused adult mortality and triggered mass regeneration, but a second fire in quick succession killed 97% of the regenerating alpine ash. Our results indicate that without interventions to reduce fire severity, interactions between flammability of regenerating stands and increased extreme fire weather will eliminate much of the remaining mature alpine ash forest. |
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Keywords: | climate change deforestation
Eucalyptus
fire management forest wildfire |
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