Improving targeting of weed biological control projects

In consultation with the Australian Weeds Committee and key stakeholders an analytical framework for prioritising weed targets for biological control programs has been developed. The framework presents opportunities for further refinement and integration with the recently developed Weed Risk Assessment process, to become an important national tool in identifying priority weeds species for biological control.

Aims

To develop an analytical framework for prioritising target weeds for biological control programs. This was achieved by recognising that impact and feasibility are important considerations in biological control. The framework for prioritising target weeds for biological control shall consider issues such as: whether the weed has been the subject of a successful or unsuccessful program overseas; whether there is significant opposition to biological control; and the taxonomic proximity to native or valued exotic plants (e.g. congeneric crops), which may increase the risk of non-target damage, thereby reducing the pool of suitable candidate agents.

The project tasks shall be to:

• Review previous work related to selection/prioritisation of weed biocontrol targets.
• Develop the prioritisation framework with input from highly experienced biocontrol researchers, entomologists, pathologists, botanists, and weed ecologists to ensure all relevant aspects are considered.
• Undertake an initial test of the framework: Validate and refine the prioritisation scheme, using international examples of completed projects to compare predictions with real-life outcomes.
• Facilitate a workshop to gain input into the framework.
• Run the Australian weeds through the framework: Acquire relevant data for each species on the WONS and AWC lists and then run each species through the prioritisation scheme.
• Provide a Final Report and the Final Prioritisation Framework outlining the rationale, methodology, and assumptions made in developing the prioritisation scheme and the results of running the WONS and AWC lists through the scheme. This will give recommendations for a nationally prioritised list of weed biocontrol targets, plus recommendations for future application of the scheme. The prioritisation scheme tool will be delivered in a user-friendly format, like similar schemes used for weed risk assessment (e.g. a Microsoft Excel tool).
• Present the Final Prioritisation Framework to stakeholders in Canberra.
  In addition, recommendations shall be made for future application of the scheme, for example, by identifying gaps in knowledge where additional research might lead to refinements of the scheme.

Outcomes

The project reviewed previous work related to selection and prioritisation of weed biological control targets
The project developed and tested an initial framework that incorporates the two main features of previous ranking protocols (weed importance, based largely on the Australian Weeds of National Significance ranking, and predicted impact of biological control), but built on these by testing hypotheses regarding impact of biological control.

To validate this framework we correlated feasibility score against impact index for individual South African and USA datasets.

This preliminary framework was presented to stakeholders to obtain feedback on the proposed scheme and seek further information about the Australian weeds to be prioritised.

Following the workshop the scoring system was further refined by incorporating quantitative data from Australian weed biocontrol programs and refining the scoring system using sensitivity analysis. Using the final scoring system, biocontrol impacts were invariably major against weeds that scored more than c. 70 (out of 100). For weeds that scored between 50 and 70, impact was variable (approximately 40:60 successes and failures), while biocontrol most often had no impact against weeds that scored less than 50.

The revised framework was then applied to Australian weeds on the WoNS and AWC lists, and used to prepare a list of weeds in priority order.

The framework, rationale, methodology, and assumptions made in developing the prioritisation scheme and the results of running the WoNS and AWC lists through the scheme are presented within the final report, which also provides recommendations for a nationally prioritised list of Australian weed biocontrol targets, plus recommendations for future application of the framework.

Background

Most classical biological control projects against weed targets have been conducted in South Africa, Australia, New Zealand, the USA and Canada. Classical biological control tends to be a public, community-level activity carried out by institutions and public departments rather than private enterprise (Van Driesche & Hoddle 2002). The need to account for this public investment should ensure robust decision-making processes, with the intention of selecting biocontrol targets that are important, are biologically and ecologically feasible, and have broad social support. In practice, the means by which targets are selected vary greatly between jurisdictions, and there have been few attempts to develop systems that can achieve this end in a transparent and repeatable fashion. There has also been surprisingly little underpinning research to ensure that the most important criteria are used.

Publications and Resources

None listed

Citation

Land & Water Australia. 2009. Improving targeting of weed biological control projects. [Online] (Updated April 28th, 2009)
Available at: http://lwa.gov.au/node/3040 [Accessed Tuesday 26th of April 2011 05:53:21 PM ].