Prioritisation of species for biocontrol

Summary

Research has been conducted at Wambiana in the Burdekin catchment in Queensland since 1997 under MLA projects NBP.0318 and B.NBP.0379 to test (both ecologically and economically) how a range of grazing strategies (different both in terms of different stocking rates and variable stocking) coped with climate variability. Phase 1 of the trial was completed in 2011, Phase II commencing in 2012.
The objective of this project was to report on:
• The suitability of the Wambiana trial to achieve its objectives and the extent to which they have been achieved;
• Factors (internal or external) that are influencing or will influence the future conduct
of the trial;
• Recommendations for the future of the trial and associated work including research focus and generation of output for producers.
The review concluded that Phase 1 of the trial had essentially achieved its objectives, with research questions and management issues raised in Phase 1 essentially addressed by the reformulated treatments implemented as Phase II. The project has increased the credibility of grazing management recommendations available to industry, has been well conducted, and should continue until at least August 2016. Associated trials, particularly those addressing the recovery of C-condition rangeland, should also continue at the site, as should the studies into faunal biodiversity.
However, a more comprehensive extension programme is warranted which incorporates the Wambiana trial results but addresses more broadly the barriers to sustainable grazing management in the whole property context. In addition, a review of the modelling capacity required to allow extrapolation of trial results (to other environments and to whole businesses) is required, together with an assessment of the requirements for, and constraints to, the development of an appropriate, ongoing modelling capacity in northern Australia. Continuation of the trial after mid-2016 should be considered in light of the modelling capacity developed to that time.
Analysis and publication of the results will require a ‘harvest year’ in which support for the Principal Investigator and a biometrician should be provided by MLA. In addition, MLA should consider support for multivariate analysis of the botanical data available, and an economic analysis of the grazing system in the Burdekin Catchment that would identify privately optimal management strategies as a function of land condition.
Finally, given the investment to date and the positive response of industry to the trial, a full cost-benefit analysis should be conducted to assess the value of research trials such as this compared to other opportunities for funding.