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.

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This paper examines the responses of a chenopod community in arid Western Australia to various grazing treatments over an eight-year period. The population dynamics of the major perennial species are analysed in relation to grazing treatments and seasonal conditions. Continuous grazing and spelling had no discernible impact on community composition when compared with the nil- grazing treatment. However, continuous grazing increased population turn-over rate, which reflected a higher level of recruitment and mortality, when compared with the nil-grazing treatment. In general, populations of all major perennial species remained stable or increased during the study period. Both mortality and recruitment were sporadic, corresponding to the erratic rainfall events during the trial period. For the three major perennial species, Maireana georgei, M. pyramidata, and Ptilotus beardii, linear regression analyses reveal that 38-74% of the variation in mortality and recruitment was caused by seasonal conditions.

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A new, fatal mycotoxicosis of cattle has been recognised in north-western Australia. A feeding trial confirmed the toxicity of a previously unknown species of Corallocytostroma that grows on Mitchell grass (Astrebla spp). The disease has been colloquially named 'black soil blindness' because its most prominent features are its confinement to pastures on black soil, and blindness and death of affected animals. Over 500 cattle have died and considerable subclinical disease in present. Above average wet season rainfall and extended growing seasons may explain the emergence of the fungus. The disease is important because cattle production in large areas of Australia utilise Mitchell grass pastures.