whole_BarkerMirranieJane1995_thesis.pdf (12.23 MB)
The effects of fire on Tasmania's west coast lowland rainforest
thesisposted on 2023-05-27, 06:34 authored by Barker, Mirranie Jane
This study examined the effects of extensive fires on lowland cool temperate rainforest burnt in 1982. Post-fire vegetation eight years after the fires was dominated by sclerophyll species. On burnt sites, there were more non-rainforest species than rainforest species, though there was regeneration of most rainforest vascular species. Rainforest species that did not appear to regenerate include species of Hymenophyllum, Asplenium and Polyphlebium. Many regenerating canopy species, especially Atherosperma moschatum, were recorded as small seedlings. Their rate of survival to maturity was unknown. Floristic analyses using ordination and classification procedures indicated that rainforest type and burn intensity were the most important variables in determining post-burn vegetation. Regression analysis also showed the importance of rainforest type and fire intensity on individual species. The dominant post-burn species were the non-rainforest species Pterklium esculentum, Leptospermum scoparium and the doubtful-rainforest species Gahnia grandis. The density of P. esculentum was greatest in callidendrous rainforest, while the other dominant species were denser in implicate rainforest (Jarman et al. 1984). Recovery of rainforest species was predominantly by seedlings, though sprouting was important for some species. Eleven rainforest tree and shrub species were recorded sprouting, with the majority of sprouting occurring in implicate rainforest. Recently burnt rainforest had a large component of sclerophyllous species and was considered to be more pyrogenic than mature rainforest. Rainforest regenerating after a recent fire would have burnt in milder conditions than those required for a large scale rainforest fire. Further fires appeared to be the major threat to the regeneration of rainforest as fires resulted in an increased sclerophyllous component and decreased rainforest elements. Additional fires also increased the time taken for rainforest to regenerate fully. The time necessary for the regeneration of rainforest and its future composition in the study areas are not certain. To enable regeneration to mature rainforest a disturbance-free period of at least 100 years is required. This study indicated that lowland rainforest can recover after a major disturbance, such as fire. It is essential that subsequent fires be excluded until the areas burnt are fully regenerated to rainforest, otherwise there will be an increase in the time required for rainforest to fully regenerate. The more fires the longer the period required for rainforest to regenerate fully with a decrease in the number of species regenerating. To ensure that subsequent fires do not occur responsible management by all land managers is required.
Rights statementCopyright 1994 the Author - The University is continuing to endeavour to trace the copyright owner(s) and in the meantime this item has been reproduced here in good faith. We would be pleased to hear from the copyright owner(s). Includes bibliographical references (leaves 97-108). Thesis (M.Sc.)--University of Tasmania, 1995