Recovery in Alpine Heath and Grassland following Burning and Grazing, Eastern Central Plateau, Tasmania, Australia

Abstract

Long-term data from six sites in treeless subalpine and alpine vegetation in central Tasmania are used to document change in vegetation cover and life form dominance over time. All sites have been disturbed by burning and domestic stock grazing in the past. Although burning ceased at least 8 yr before initial measurements were taken, stock grazing still occurs at one site, and rabbits and native vertebrate herbivores (mainly wallabies) graze throughout the region. Vegetation cover increased across all sites over a 5-to 23-yr period at an average annual increment of approximately 1%. There was no significant relationship between the initial cover of bare ground and change in bare ground over time for most of the sites. Annual increases in vegetation cover were least in locations grazed by rabbits and native vertebrate herbivores and where domestic stock still grazed. Exclosures grazed only by rabbits had an intermediate rate of increase. Vegetation cover was found to increase most in ungrazed exclosures. The rates of increase in vegetation cover suggest that, in the absence of fire, it is a matter of decades before cover will be almost complete in the area.

A Dispersal-Constrained Habitat Suitability Model for Predicting Invasion of Alpine Vegetation

“…Fire (F).-In January 2003, extensive wildfires burned large areas of the Australian Alps (Cheal 2003, Worboys 2003. Fires in Australian alpine environments consume most of the vegetation and the litter layer, leaving extensive areas of bare soil (Wahren et al 2001) that can take decades to return to prefire vegetation cover (Bridle et al 2001). Concern has been expressed that these conditions may favor the invasion of nonnative species (Cheal 2003, Johnston andJohnston 2003).…”

Impacts of nutrient additions and digging for human waste disposal in natural environments, Tasmania, Australia

“…It is tempting to attribute this pattern to the successional status of the vegetation at these four sites, in comparison to the rest. The eastern alpine site is in process of recovery from a regime of burning and grazing by sheep, the latter of which only ceased in the early 1990s (Bridle et al, 2001). The montane moorland, grassy eucalypt forest and heathy eucalypt forest were all burned in the 1990s.…”

A critical review of the science underpinning fire management in the high altitude ecosystems of south-eastern Australia

“…How long alpine grasslands take to establish maximum cover after fire may be qualified by grazing by both native and introduced animals. An ungrazed alpine grassland at Mount Buffalo, Victoria had 95% ground cover at fourteen years after fire (Wahren et al, 1999) while a grazed alpine grassland on the Eastern Central Plateau of Tasmania only had 73% ground cover at 32 years after fire (Bridle et al, 2001). Comparing studies in this way is far from rigorous and the overall lack of long-term, controlled studies, where both before and after treatment comparisons can be properly made, precludes the making of firm conclusions.…”