Fire and the Vegetation Composition and Structure of Sub-Tropical Heathlands in Southeastern Queensland

Abstract

Six heathland sites were studied in Cooloola National Park, south-eastern Queensland. Vegetation composition (species present and numbers) and structure (plant density, cover, height and vertical foliage density) were examined at each site with respect to time since last fire (0.5-10.5 years) and the two recognised microhabitat types (dry and wet). No significant change in species numbers or composition was detected in sites more than 1 year after fire, although the changing physical status (density and cover) of some plants could give the impression of species being 'lost' or 'gained' over time. On the basis of the structural attributes of the heathlands, and the maintenance of several obligate seed regenerator species, a minimum fire-free interval of 8 or 10 years is suggested for subtropical heathlands. Results from this study are compared with data collected from other Australian heathlands. In composition and structure, the temporal responses to fire in the Cooloola heathlands are similar to those in southern heathlands, albeit occurring at a possibly faster rate.