Fire regimes and biodiversity in Victoria’s alpine ecosystems

Abstract

Landscape-scale fires occur in Australian alpine ecosystems once or twice per century, primarily when ignition, regional drought and severe fire weather coincide. When alpine vegetation does burn, there is considerable variation in landscape flammability and fire severity. Regeneration following extensive fires of 2003 and 2006-07 across the Bogong High Plains is occurring in all plant communities (heathlands, grasslands, herbfields and wetlands). In heathland and grassland, vegetation composition has converged towards the long-unburnt state (> 50 years) eight years post fire. There was little effect of variation in fire severity on patterns of regeneration in heathland. In burnt wetlands, Sphagnum cristatum and other dominant species are regenerating; the cover of obligate seeding ericaceous shrubs two years post-fire was positively related to the cover of Sphagnum. The endangered mammal Burramys parvus is also capable of persisting in the alpine landscape after individual large, landscape fires. We conclude that there is no scientific evidence that these fires necessarily had ‘disastrous’ biodiversity consequences. After extensive landscape fires, the primary management objective should be to allow burnt alpine ecosystems to regenerate with minimal subsequent disturbance. Monitoring ecological change in the coming century will be essential for effective management of both fire and biodiversity in alpine ecosystems in Victoria and elsewhere in Australia.