Embedding economics in weed risk management to assess contentious plants.

The management of the risks associated with the use of exotic plants for production and ornamental purposes has improved considerably in Australasia in the last decade. Nationally, decision support tools and policy instruments are in place, e.g. the Australian Weeds Strategy and pre-border weed risk assessment. States and Territories across Aus- tralia have post-border weed risk management (WRM) systems to identify weed management priorities and how to respond. Despite these advances, contentious plants, those identified as posing a high risk as well as offering potential economic benefits, continue to highlight some weaknesses in current systems and policy. The failure to explicitly incorporate economic analyses into the WRM process is one impediment to the improved management of contentious plants. We outline some suggestions on the economic tools and techniques that could be embedded within the existing WRM process and provide an example of a benefit cost analysis completed for the tropical invasive grass (gamba grass) and how the results were used within a WRM framework to better inform the decision making process.