Tropical Grasslands (1994) Volume 28, 206213
State and transition models for rangelands.
JOEL R. BROWN
Division of Tropical Crops and Pastures, CSIRO, Townsville, Queensland, Australia
The objectives of this paper are to: propose criteria for testing the applicability of models for rangeland management; and test 2 competing models using those criteria. Predicting change accurately, detecting change, relevance to management and facilitating communication are the performance criteria. Competing models are the range condition model derived from Clementsian ecology and the state and transition model based on non-equilibrium ecology. The ability of competing models to predict ecosystem change is assessed in terms of ecosystem organising processes and attributes such as competition, resistance and resilience, temporal thresholds and feedback. The ability to detect change is viewed in terms of detection at the community and landscape scales. Relevance to management and communication are assessed within the context of effectively communicating the effects of management decisions on ecosystem processes to both traditional and non-traditional decision makers and a larger public constituency. Although the state and transition model is the most acceptable of the 2 competing models based on the criteria, improvements are needed. Most notable is the need for a spatial component in the application of the model for management purposes, and the need for attention to improved communication with a wide range of resource users.