Using science to communicate the benefits of wilding conifer control

A workshop held in Wakatipu to test a web-based tool for delivering forecasts of future wilding conifer control costs and ecosystem impacts.

The impacts of wilding conifers are many: they harm biodiversity, reduce water yield, lower yields on productive land, and increase wildfire hazard. Also, control costs can increase rapidly if seed sources are left in the landscape due to the large amounts of wind-dispersed seed that conifers produce.  

"Until recently, the main challenge for wilding conifer control was inadequate resourcing relative to the scale of the problem," says Norm.

He adds that because of this, the main benefit of spread and impacts forecasting was thought to be in prioritising control efforts toward areas where conifer spread and impact reduction would be most cost-effective – getting the biggest bang for the few bucks available.      

"Everything changed following Budget 2020, in which the Government announced it would spend $100 million over four years to control wilding pines. In Otago and Southland, massive swathes of the vulnerable tussock-clad hillsides have been freed of wilding conifer seed sources. Now the main barriers to removing the remaining seed sources are social, with landowners in and around centres such as Queenstown and Alexandra often opposed to removal of invasive conifer species from their property. The establishment of highly invasive Douglas fir plantations also poses a serious threat in parts of Southland."

The workshops revealed that the main benefit of the web-based tool will be in illustrating how recent control efforts have helped to avoid future control costs and ecosystem impacts as well as demonstrating the risks of the remaining seed sources (and of introducing new seed sources through planting of Douglas fir plantations) to the long-term success of wilding conifer control operations.

The workshops were also a good chance for Norm to see first-hand the threat posed by remaining conifer seed sources around Queenstown and Alexandra, while also sampling some of the native plant biodiversity hidden within these landscapes.   

The challenge now for Norm and his colleagues is to upgrade the web-based forecasting tool in light of the various insights gained through the workshops. "It’s important for us as scientists to make ourselves accountable for the time, energy and knowledge our end users contribute to our projects by showing how this shapes our science," says Norm.