The Influence of Fire, Herbivores and Rainfall on Vegetation Dynamics in the Mallee: a Long-term Experiment

Abstract

Fire regimes, grazing regimes and climatic variation potentially influence the distribution and abundance of plant species in the mallee over long time scales. For example, the timing of fires and rainfall events influences the establishment of many plant species, while herbivory and drought have selective effects on plant survival. Rainfall events influence short-term bushfi re fuel dynamics and, with herbivores, determine landscape flammability. The frequency and spatial pattern of fire regimes have been identified as important management tools that may influence the persistence of mallee biota. A long term ecological experiment has been established in the Tarawi-Scotia-Danggali reserves to improve understanding of the mechanisms that influence vegetation change and the ability of the ecosystem to sustain its characteristic biota. Herbivore-specific grazing exclosures were established in tandem with planned management burning and some unplanned fires over a 12-year period. In this paper we outline the management issues and research questions that the study seeks to address, describe the design of the experiment and the data collected from the treated sites. We discuss the strengths and weaknesses of the experiment and the valuable insights that long term ecological studies of this type can produce.