Retrospective Monitoring of Rangeland Vegetation Change: Ecohistory from Deposits of Sheep Dung Associated with Shearing Sheds

Abstract

This paper explores the potential of a new method of reconstructing historical vegetation change in the Australian rangelands. Historical monitoring of rangeland vegetation has been so deficient that it is not possible to determine whether a long-term trend toward degradation has occurred (as is often assumed) or, indeed, if it is continuing to occur. Because long-term records are unavailable any attempt to monitor vegetation retrospectively must be based on proxy measures rather than direct observation. Where historical data are lacking an integration of palaeoecological, archaeological and ecological methods is required to reconstruct the past. Our research is based on a detailed analysis of sheep faeces deposited near a shearing shed in the semiarid rangelands of south-west Queensland between the late 1930s and the mid-1990s. The faeces in these deposits represent the diet of sheep in the days leading up to the property's annual shearing and as such are a potentially useful index to changes in vegetation. Results indicate significant changes in the diet of sheer since the late 1940s. The potential of this method, and its limitations, are discussed. Long-term records are critical in understanding issues of sustainability in land management and it is intended that this paper will stimulate further research into historical vegetation change in rangelands