Uncertainty in comparative risk analysis for threatened Australian plant species

Australian state and federal agencies use a broad range of methods for sett ing conservation priorities for species at risk. Some of these are based on rule sets developed by the International Union for the Conservation of Nat ure, while others use point scoring protocols to assess threat. All of them ignore uncertainty in the data. In this study, we assessed the conservatio n status of 29 threatened vascular plants from Tasmania and New South Wales using a variety of methods including point scoring and rule-based approach es. In addition, several methods for dealing with uncertainty in the data w ere applied to each of the priority-setting schemes. The results indicate t hat the choice of a protocol for setting priorities and the choice of the w ay in which uncertainty is treated may make important differences to the re sulting assessments of risk. The choice among methods needs to be rationali zed within the management context in which it is to be applied. These metho ds are not a substitute for more formal risk assessment.