430ha of wilding pines controlled at gateway to Mackenzie Basin

Efforts to clear one of the largest wilding pine infestations in the Mackenzie Basin has seen the invasive weed controlled across 430 hectares — an area equivalent to the size of Auckland’s CBD.

The wilding pines were removed from Ferintosh Station, a 2,500-hectare Crown pastoral lease located on the western shores of Lake Pukaki.

Wilding pines pose a serious threat to New Zealand’s environment and economy. They outcompete native plants, diminish biodiversity, alter natural landscapes, increase fire risk, reduce water yields for hydroelectricity and irrigation, and encroach on valuable farmland.

The extensive control operation over the past year has been a joint initiative between Toitū Te Whenua Land Information New Zealand (LINZ), Environment Canterbury (ECan) and Ministry for Primary Industries, under the National Wilding Conifer Control Programme (NWCCP).

LINZ Biosecurity Manager Tracey Burton says the infestation was identified as a high priority by the national control programme due to the significant natural values of the area, and the risk of wilding pines spreading and reversing gains already made in surrounding areas.

“Despite efforts by the leaseholder over the years to control the wildings, they’ve been fighting an uphill battle given the scale of the infestation and constant pressure from surrounding seed sources,” says Burton.

“Each tree can release up to 15,000 seeds annually, which can travel as far as 40 kilometres on the wind. That’s why this work is so critical.”

A combination of control methods was used to tackle the infestation, including aerial spraying, ground crews, mechanical mulching, and harvesting for biofuel and export timber as a means to help offset the cost of the operation.

“We’ve hit the wilding pines from all angles,” Burton says.

“Initial inspections show the work has been successful, with some areas already regenerating with grass. It’s a significant step toward restoring this iconic landscape and supporting the unique native biodiversity in this region.”

The rugged terrain posed challenges, with steep slopes, dense vegetation, wetlands, waterways, and areas of significant indigenous flora requiring tailored approaches.

Burton says LINZ is working closely with the leaseholder around long-term management of the cleared land, ongoing control works and restoration options.

Funding for the control work was provided by LINZ, with support from the NWCCP, ECan, and the Department of Conservation.

The control operation is part of wider efforts under the NWCCP to stop the spread of wilding pines, which if left unchecked could cover 25 percent of New Zealand within the next 30 years.