S.R. McARTHUR1, H.J. CHAMBERLAIN2 and D.G. PHELPS3
1Department of Primary Industries, Cloncurry,
3Longreach, Queensland, Australia
A generalised state and transition model has been developed for the extensive grasslands on heavy cracking clays across northern Australia. This model is a simple means of getting land managers to better understand the management of native pastures if they are to move towards a more sustainable production system.
Its development, in conjunction with land managers, can be defined by looking at differences in pasture composition to give a catalogue of states. The transitions or changes between states, whilst less easily understood, are dependent on a menu of opportunities and hazards presented to the land managers.
Thresholds of hazards and opportunities between states are shown as strategic, critical and major management intervention lines, where changes that are taking place need to be addressed by appropriate decisions to reduce costs associated with increased pasture degradation.
There remains a general lack of knowledge, in some areas, of the reasons why the transitions are occurring, and further research and/or knowledge exchange with land managers, is required. This is especially so given the large and
diverse nature of the specific grassland zones discussed and more specific models are therefore required. The application of state and transition models developed by land managers in conjunction with extension officers will result in improved productivity from our rangeland resources at sustainable levels.