Approximately 80 ha of warm temperate rainforest in far East Gippsland was severely burnt in February 1983. A study to assess the impact of a wildfire commenced under the National Rainforest Conservation Programme in 1987. Seventy seven permanent Quadrats were established on a grid to monitor vegetation changes, and the numbers and areas occupied by trees, shrubs and seedlings were determined. Five years after the fire, the vegetation composition was dominated by species which characterise mature rainforest. Large increases also occurred in the populations ofAcacia melanoxylon, Eucalyptussp., sclerophyll shrubs and a number of disturbance dependent herbs. Rainforest species recovered through both seedlings and epicormic sprouts. Few species were obligate seed regenerators and these included species restricted to early regeneration stages, as well as uncommon rainforest overstorey species. Populations of several epiphytic species uncommon before the fire may have been reduced, andCyathea leichhardtiana, a tree fern with restricted distribution in East Gippsland, may have to re-establish from spores. It was concluded that earlier fires had influenced the species composition of the rainforest and contributed to its invasion by sclerophyll species. This invasion had been greatly extended by the most recent fire. The distribution and abundance of the sclerophyll overstorey is considered likely to increase with each successive disturbance by fire until eucalypts dominate the area entirely. The future fire regime will also determine the composition of the understorey. An interval between fires of less than 40#x2013;50 years is likely to cause a progressive decline in the proportion of rainforest species, with the rate determined by both frequency and intensity of burning.
展开▼
