A state-and-transition model to guide grassland management

Grassland ecosystems across the globe have been extensively modified and degraded by agriculture and urban development, leaving conservation managers with a complex set of interacting legacies and opportunities to contend with. We advocate the use of state-and-transition models to assist conservation managers to deal with this complexity. Using a major development and compensation project as a case study (The Melbourne Strategic Assessment under the Australian Environment Protection and Biodiversity Conservation Act 1999), we discuss the uses and limitations of state-and-transition models for conservation management. We define a state-and-transition model for an endangered Australian temperate grassland. Soil and vegetation data are used to evaluate the model and confirm that the assigned states relate to observable agro-ecological patterns. We then discuss the use of this model for several different interacting purposes: as a tool for the simple communication of complex ecological processes; as a tool for landscape stratification to aid the spatial application of management and experimentation; as a framework to set and define conservation objectives; and as an aide for adaptive management.