Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Observations of responses to re-introducing fire in a Basalt Plains grassland after the removal of grazing: implications for restoration.

Abstract

Natural grasslands in southern Australia commonly exist in altered states. One widespread altered state is grassland pasture dominated by cool-season (C3) native grasses maintained by ongoing grazing. This study explores the consequences of removing grazing and introducing fire as a conservation management tool for such a site. We examined the abundance of two native and three exotic species, across a mosaic of fire regimes that occurred over a three-year period: unburnt, summer wild-fire (>2 years previous), autumn management fire (<1 year previously) and burnt in both fires. Given that one aim of conservation management is to increase native species at the expense of exotics, the impacts of the fires were largely positive. Native grasses were at higher cover levels in the fire-managed vegetation than in the unburnt vegetation. Of the three exotic species, one was consistently at lower density in the burnt plots compared to the unburnt plots, while the others were lower only in those plots burnt in summer. The results show that the response of a species varies significantly between different fire events, and that the effects of one fire can persist through subsequent fires. Importantly, some of the effects were large, with changes in the density of plants of over 100-fold. Fire is potentially a cost-effective tool to assist the ecological restoration of retired grassland pastures at large scales.