Monitoring changes in pastoral rangelands - the Western Australian Rangeland Monitoring System (WARMS)

Abstract

The Western Australian Rangeland Monitoring System (WARMS) consists of a set of ~1620 permanent sites distributed across the pastoral rangelands of Western Australia used for commercial livestock grazing. The system is designed to provide information to government and the general community on changes in Western Australia’s rangelands, rather than to individual landholders. It is designed to report at the regional or vegetation type level by selectively sampling representative areas of the rangelands, with representation occurring at several levels. The system was fully implemented by 1999 and all sites, except a small number of ongoing replacements, have now been re-assessed at least once. Two site types are used. In grassland areas, the frequency of all perennial species is assessed, and an estimate made of crown cover of woody perennials. In shrubland areas, a direct census technique is used, with the demography and maximum canopy dimensions of all shrubs recorded. Changes in soil surface condition and patch distribution are also assessed using standard Landscape Function Analysis (LFA) techniques. The vegetation and soil surface information is used to indicate rangeland change. The system is not fixed within any single model of range dynamics and the outputs of WARMS can be interpreted in various ways, depending on the specific requirements of the end-user. The paper includes discussion of the institutional requirements for WARMS, the site stratification and selection criteria, description of the field methods used and the rationale behind its design. It also considers the implications of the site stratification and selection criteria in terms of the caveats that need to accompany reporting.