Invasive legume plants targeted in joint approach

Eight organisations have signed up to a project to protect the Desert Road landscape from the adverse effects of three invasive legume plants.

A memorandum of understanding became fully operative last week. It’s been signed by the Department of Conservation, Waikato Regional Council, NZ Defence Force, Horizons Regional Council, Lake Rotoaira Forest Trust, NZ Transport Agency, Genesis Energy and Transpower.

“It’s been fantastic to have the many varied landowners and land managers willingly sign up to work together to protect the iconic Desert Road environment from the landscape-changing impacts of broom, gorse and lupin,” said Peter Russell, Waikato Regional Council’s biosecurity operations manager.

“We’ve agreed to continue working collaboratively until at least 2025 to eradicate where possible or at least significantly reduce the density of these invasive legumes,” Mr Russell said.

“It’s early days, but we are also looking at ways the public can get involved in working with the agencies,” he said.

The Central North Island Desert Road tussock-lands contain unique landscapes and ecosystems that are highly valued. Much of the landscape is legume-free, but there are some large infestations particularly along road verges and in some more remote areas out of sight of State Highway One.

Roads, roading activities and vehicles exacerbate the constant risk of weeds moving across the landscape and are the most important ‘pest pathway’ to manage. But until this project kicked off late last year there was no overall coordination of effort to understand and manage the legume weed invasion.

“The good news is that this collaborative project has been going strong for almost a year and already there are some good synergies and conversations happening,” said Mr Russell.
Landcare Research has mapped sites of gorse and broom infestations as a baseline which will be checked against over the next 10 years. Mapping of the extent of lupin will be carried out this coming summer.

New Zealand Army land has been among the worst affected, but by late winter contractors had carried out extensive control work for gorse, broom and wilding pine trees on Army land one kilometre either side of SH1. Already, motorists will be able to see the evidence of pest plants dying off as a result of this work, combined with programmed work by the New Zealand Transport Agency on the road verges. The group is also talking about new herbicides and control methods, including safely controlling pest plants that are under high voltage powerlines that cross the area.

Several of the biocontrol agents that have been introduced into New Zealand for gorse and broom have also been released in the surrounding area as a longer-term alternative to herbicide application.

Control of introduced legumes is the focus of this project but it builds on a highly successful wilding pine removal control project that most of the eight organisations have been involved with for many years across the wider Central Plateau area.

ends

© Scoop Media