The battle to contain the spread of wilding pines throughout Canterbury has just got tougher with a significant reduction in funding looming.

In light of the funding reduction, Environment Canterbury (ECan) has launched a wilding pines handbook. The aim is to inspire control action from urban and rural landholders that is seen as critical if the battle against the tree weeds is to be won.

“Controlling wildings in Canterbury/Waitaha is a big job,” regional councillor Nick Ward​, one of ECan’s two South Canterbury/Ōtuhituhi elected members, said.

“We don’t have the funding available to continue the work we have been doing over recent years to try to get ahead of them spreading.”

ECan has been delivering wilding pine control in Canterbury since 2003, with a large focus on South Canterbury’s Mackenzie District.

In 2016, the regional council partnered with the National Wilding Conifer Control Programme, a partnership between central and local government agencies and primary industries, mana whenua, researchers, farmers and communities.

The programme is led by Biosecurity New Zealand, part of the Ministry for Primary Industries.

A total of $37 million was invested in the national programme from July 2016 to June 2021.

Additional investment was made as part of Budget 2020, with $100m committed over four years. ECan said this allowed national wilding pine control operations to scale up significantly and make great progress.

That funding reduces to $10m a year from 2023-24.

Ward said that although many Cantabrians living in areas with wilding pines were already doing what they could, holidaymakers and the wider community needed to be aware of the fire risks.

“We’re planning to meet with ministers in the new year to discuss the challenges we’re facing in these areas,” he said.

“Until then, we need landowners to help us and take action to help slow the spread of pines on their properties.”

ECan said its new handbook included details on identifying the problem species.

It featured a guide to selecting the best method for pine control and to choosing suitable replacement plants that would deliver what the landowner needed without being invasive.

“The new handbook will help educate and guide about the risks wilding pines pose for our native biodiversity and landscapes, especially as we head into a dry summer and fire season,” a council statement said.

The Mackenzie Basin was becoming increasingly vulnerable to wildfire because of hotter, drier and windier conditions caused by a changing climate, an escalating wilding pine problem, and limited national funding for wilding pine control.

Ross Ivey, who chairs of the Wilding Free Mackenzie Trust, said recent fires at Lake Pukaki and Lilybank Station near Lake Tekapo/Takapō had locals concerned about the risks of fire this summer.

“We’ve had four significant fires in this area in the past few years, fortunately with no loss of life.”

He said that while trees in the right place were valuable for shade, privacy and recreation purposes, self-seeded wilding pines were the perfect fuel for wildfire as they enabled fire to travel quickly and burn longer, putting lives and properties at risk.

“What’s at stake with wilding pine spread is the loss of the Mackenzie as we know it.

“We will quickly lose more than just the iconic views – we’ll lose native species, precious water resources and land for food production, tourism and recreation.

“And the wildfire risk just increases as they spread.”

Cost-efficient control

ECan’s handbook said wilding pines were species that had self-seeded and were “growing where they shouldn’t”.

“Exotic conifers, including pines, were introduced to Aotearoa New Zealand for use as timber, shelter and erosion control.

“They adapted well here – their seeds can travel on the wind for many kilometres, they grow quickly and spread exponentially. They rapidly outcompete native vegetation.”

If left unchecked, the rapid spread of wilding pines would transform land into dense, impenetrable forests.

“We will lose more than just the views – we’ll lose native species, precious water resources and land for food production, tourism and recreation,” the council said.

“Wildfires will become more common and intense, putting lives and properties at risk.

“Unlike well-managed plantation forests, wilding pine infestations are rarely a usable resource.”

The following species were classified as pests and pest agents in Canterbury’s regional pest management plan: Douglas fir (extreme); contorta/lodgepole pine (extreme); corsican pine (high); mountain pine and dwarf mountain pine (high); European larch (high); Scots pine (high/medium); Ponderosa pine (high in low country); maritime pine (high in lowlands, low in high country); radiata pine (high in lowlands, medium/low in high country); and bishops pine (medium).

ECan said the most cost-efficient control strategy was to be proactive by removing seed sources and getting rid of seedlings as soon as they appeared.

“As soon as wilding pine seedlings produce cones they become a seed source – with some species this can happen in as little as three years.

“The seeds within the cones are quickly and effectively spread by the wind … Seed can live in the ground for at least five to six years, known as the seed bank, so even after the seed source has been removed, maintenance work will need to be carried out to remove emerging seedlings.”

Established infestations of wilding pines often needed three or four phases of control. The first phase was the most expensive, and maintenance sweeps must occur within three years, the council said.

“This is crucial to break the cycle.”