One of NZ's worst wilding pine infestations is threatening Marlborough's grapes

Wednesday, 24 March 2021

Volunteers at the Lost Stream Bivvy in South Marlborough: Martin Clapham, left, Ket Bradshaw, James Jenkins, Anita Stanbridge.

Volunteers have spent three days tackling an area with one of the worst wilding pine infestations in New Zealand, which threaten the water supply to Marlborough's vineyards.

A team of four volunteers walked six hours in and out to get the Lost Stream Bivvy, in South Marlborough.

South Marlborough Landscape Restoration Trust co-ordinator Jaquetta Bradshaw said the team managed to “cut’n’paste” around 2000 contorta wilding pines and 50 douglas fir.

Wilding pine have quick and dense growth, and aggressively outcompete New Zealand natives and habitats, turning Marlborough’s mountain tops from gold to green.

The Government is spending $100 million on wilding pine control over the next four years. Video first published in October 2020.

* Battle against wilding pines ramps up in Marlborough

* Wilding pine fight gets major government cash injection

Bradshaw pictured in October, with a wilding pine sapling.

Bradshaw said The Lost Stream was a tributary of the Branch River, which was part of the Branch Leatham Wilding Conifer Control Management Unit, a 50,000 hectare area which was all in the Department of Conservation (DOC) estate.

A stump pictured after it had sawing with cut'n'paste herbicide applied.

The Branch/Leatham fed water into the Wairau River.

“We very much rely on the flow from the branch river for our irrigation,' Bradshaw said.

Trust chair and vineyard owner John Oswald said in October the pines were “thirsty” and could dry up downstream waterways.

Tracking shows the area that the team covered over the three days.

Bradshaw said the team managed to clear a basin above the Bivvy, and got up even higher up into the head of the valley.

“It was really good to get into grips of what the problem is up there,” she said, adding the team made some good progress on the area, but it would still need to be revisited.

The Lost Stream was a tributary of the Branch River, which was part of the Branch Leatham Wilding Conifer Control Management Unit.

“We had saws and cut’n’paste that we could just dab on the end of the cut of the branches, but I think we found the sawing quite physically draining, so we need to, the next time, we want to drill and fill.

Cut’n’paste was a herbicide used to kill the pines.

A pest controller drills holes in a pine before injecting it with poison in October.

“We found even when we were walking up and down the valley, we kept finding little seedlings that you could pull out by hand, but they range from little seedlings you could pull out, to ones where we needed a very big saw.”

The pines were not only a threat to the Wairau River but also the biodiversity in the area, Bradshaw said.

“This unit is a key priority for the South Marlborough Landscape Restoration Trust, so we’re delighted to have made a start on saving the biodiversity and landscape in these high alpine basins,” she said.

Wilding pines in the Branch/Leatham, Molesworth and Waihopai Valley areas were planted in the 1950s and 1960s to prevent erosion.

The Trust received Government funding in September last year to continue its battle against wilding pines, including $115,000 for The Ned, near Blenheim.

It also won $86,700 from DOC in August to control pines in the Ferny Gair/Black Birch area, by The Ned. This was being added to funds from Yealands Estate, as the area fed drinking water to Seddon.

The trust looks after 10 management areas in South Marlborough, each with its own pine control programme, covering about 870,000ha of steep, dry and high land.

The trust aims to reduce wilding pine numbers in South Marlborough by 2030, in line with national objectives. It needs $100,000 alone to finish the Awatere area.

Bradshaw said the Trust were always looking for volunteers that were often helicoptered to where they worked, and anyone who was interested could email info@marlboroughrestoration.org.nz.