The development of a system for monitoring trend in range condition in the arid shrublands of Western Australia.

Abstract

The role of a monitoring system for Western Australian pastoral shrublands is examined. The authors argue that the objective of management is to maximise sustained animal productivity, and that this can only be attained if the soil is maintained in a stable state. In non-degraded rangelands this objective is synonomous with the maintenance of a pasture community with its natural balance of edible and less edible species. In degraded rangelands the objective of regaining the pristine vegetation may, in many cases, be unattainable. Nevertheless, the objective of maximum sustained productivity again appears suitable since this would ensure that, where management is able to influence the direction of change, it is towards a pasture dominated by useful, rather than non-palatable, species. Our monitoring system aims to assist management achieve these objectives. The Western Australian Rangeland Monitoring System (WARMS) has been designed to include the assessment of ecological processes but with a strong bias towards characteristics that can be interpreted in production terms. We expect that the system will primarily and most importantly, aid pastoralists in their season by season decisions on stock movements. It will also provide a tool for the land administrator, who must be able to assure the wider community that the land is being used wisely. Finally, it should assist range scientists towards a better understanding of rangeland ecosystems. The WARMS system involves a series of grazed range monitoring sites, lightly grazed reference areas and ungrazed control areas. At each monitoring site a photograph is taken and plants within a fixed area are identified and marked on an overlay. The number and size of perennial shrubs are recorded within fixed belt transects and the contribution from perennial grasses and biennial species is assessed. Soil stability is also assessed using a rating scale and a modified step point procedure.