The Short-Term Effects of Clearfelling and Slash-Burning on the Richness, Diversity and Relative Abundance of Higher Plant Species in Two Types of Eucalypt Forest on Dolerite in Tasmania

Abstract

The relative impacts of clearfelling followed by slash-burning, clearfelling, and no treatment were monitored for 2 years in two major types of eucalypt forest in south-eastern Tasmania. Rates of change in species cover were significantly greater in the burned area than in both the clearfell and control areas. More than half the species for which suitable data were available increased most in the burned area and least in the control. More higher plant taxa were present in the permanent burned plots 4 months after the burn than before the burn. By the last 8 months of recording, new taxa were invading at a rate of only 0.1 per month. Composites and shrubs constituted most of the late invaders. The behaviour of diversity measures was largely a function of the behaviour of a few of the taxa. Fire intensity, as measured by degree of soil baking, had a pronounced influence on species composition and cover. The species composition of aerially sown seed had little influence on the species composition of the eucalypt regeneration, with species not sown by the Forestry Commission recovering vegetatively, and much of the sown seed not resulting in seedling establishment. The clearfelling and burning, and clearfelling treatments did not result in the loss of any native species but there was substantial invasion by introduced herbs. However, lack of substantial impact in the short term does not guarantee the same in the long term.