Recovery of subalpine grasslands from bushfire

Abstract

In January–February 2003 bushfires burnt 1.75 million hectares of the Australian Alps, including >70% of the subalpine zone of Kosciuszko National Park. The recovery of subalpine grasslands 1 year after these fires was examined by comparing vegetation between paired unburnt and burnt plots at six subalpine grassland sites. Although the cover of vegetation at these sites had largely recovered, there were still differences between unburnt and burnt plots. For example, there were large areas of bare ground (19% v. <1%) in the burnt plots and less vegetative cover (56% v. 87%). The above-ground biomass of the recovering vegetation was much lower, 10% of that in unburnt plots, well below the levels required for adequate soil protection. Weeds did not appear to have spread post-fire, although this may not be the case in burnt areas adjacent to weed seed sources. Both cover and biomass of burnt areas will continue to increase provided there is limited disturbance in the future. Recovery will be uneven, owing to the inherent variability of subalpine grasslands, patchiness in the severity of the fire and differences in post-fire conditions.