Monitoring Australian rangeland sites using landscape function indicators and ground- and remote-based techniques

If the goal for managing rangelands is to achieve a balance between product ion and conservation, then monitoring is essential to detect change and app ly corrective action. In some rangeland areas of northern Australia, monito ring has detected a tilt in the production-conservation balance towards exc essive production. How big is this imbalance? Can it shift back? Robust mon itoring is needed to answer these questions. The aim is to know what to mon itor, and where. For example, to detect changes caused by livestock on rang eland forage production and soil erosion, indicators linking grazing distur bances to landscape function are needed, that is, indicators that signal ho w well landscapes are capturing, concentrating, and utilizing scarce water, nutrient, and organic resources. Studies in Australia and the USA document that simple vegetation and soil patch attributes can be measured as indica tors of the 'state of health' of landscape function. For example, field and remote sensing-based grazing studies in Australia document that landscapes with a high cover of perennial plant patches function effectively to captu re runoff water and nutrients in sediments, whereas landscapes with a low c over of these patches do not - they are dysfunctional - as indicated by lar ge patches of bare soil. Aerial videography is proving tp be a robust techn ique for measuring indicators of landscape function such as small patches o f vegetation and the extent of bare soil. These indicators typically have a sigmoidal response to grazing impacts. We illustrate that if these indicat ors are measured on monitoring sites established near the sigmoidal 'point of inflection', then small changes in these indicators can be detected.