Published on 31/03/2022
Wilding pines had long been a significant problem in the area, damaging the area’s scenic qualities and overtaking native plants as the dominant species.
Thick stands of pines also presented a major fire risk and reduced catchment water flows.
When work started, back in 2008, many believed large scale control couldn’t be achieved. However, the Trust, and its collaborators and supporters, have spent the intervening years proving doubters wrong.
Today, the project is one of the most successful of its kind in New Zealand.
Programme manager for the Trust, Andrew Macalister, says community support has been critical. “The project spread its wings across the Sounds on the back of landowners’ enthusiasm.”
He says the changes to the landscape have been rapid, aided by the Sounds high rainfall. “When you look out now, you think ‘wow!’ you can see the hillsides reverting to native bush.”
Not that it has been easy. Each pine tree has been individually poisoned. It is a labour-intensive approach on the steep and challenging terrain but one that is proving very successful. “We’re doing it the hard way. But it’s the best way,” Macalister says.
Poisoning – by injecting a small amount of herbicide into a hole drilled in the tree – is preferred over felling as there is less damage to surrounding native vegetation and less chance of secondary pine re-growth.
The method is also highly targeted, making it environmentally-friendly, with no release of herbicide into the land, waterways or air.
Skilled contractors carry out the work, aided by aerial photos and GPS. The ultimate result is tree decomposition.
To date it is estimated that close to four million trees have been poisoned.
Onboard with the project from the early days has been Nelson-based crop protection company Adama.
Macalister initially contacted the company and asked about their Metsulfuron and Polaris Accelerate products.
Marketing manager Elisabeth Johnston says the Trust and Adama got talking, “and it went from there”.
She says if conditions are right, Metsulfuron works in two to three weeks on the branches and pine needles.
In two to three years, all that is left are the dead pine trunks which will eventually rot away.
Metsulfuron is effective on most pines with the exception being pinaster (maritime pine) which re-quires glyphosate, also supplied by Adama.
Andrew Macalister says the Trust tested the products thoroughly. “We were looking for something that mixes out really well and has the right pH. It was better than anything else we’d used before. We were delighted on that basis.
”If a landowner targeting wilding pines phones him, he’d recommend the ADAMA product. “You can have high confidence in it. It’s done the business.”