Fire in Pastoral Areas of Poplar Box (Eucalyptus Populnea) Lands.

Abstract

Fire has been present during the evolution of poplar box communities and the flora is well adapted to fire. Broad fire regions are recognised on the basis of bioclimatic data and the effects of different fire regimcs on plant species and communities arc dis- cussed in relation to these regions. Grazing combined with the variable rainfall makes the accurate prediction of vegetation changes resulting from fire difficult. Fire is currently episodically associated with over-average rainfall in most areas as the predominant fuel is grass. Minimum fuel quantities of 100 g m-2 in pastures where fuel is continuous and 150 g m-' in pastures with discrete tussocks are required to carry a fire. Fire can drastically reduce shrub numbers, especially juvenile and seedling plants in the short term, but attitudes about using fire for shrub reduction vary from region to region according to the likelihood of growth or replacement pastures. Grazing control after burning to permit the recovery of the ground layer is difficult because of grazing by native herbivores. There is a need for further studies on fire behaviour and plant survivorship characteristics as affected by climate and native and domestic animal grazing.