Pulling out weeds is the bane of most gardeners’ lives but in the South Island of New Zealand, one of the major weed problems are trees, pines growing in the wild in the mountainous High Country.
According to a Department of Conservation (DOC) strategy paper on wilding pines, more than 210,000 hectares of land administered by the New Zealand conservation agency are threatened by wilding pines.
The government is planning to help by giving the conservation agency more funding.
“Wilding pines are a significant threat to regenerating forests and the spectacular tussock grasslands of the South Island High Country. The pines are long lived and can out-compete plant species in most environments enabling them to swiftly dominate open landscapes and ecosystems completely altering their character,” says the Conservation Minister Chris Carter.
“Dense infestations of wilding pines can also reduce water yields from stream catchments, reduce the profitability of pastoral farming, and restrict access for recreation.
“The problem we face is that unless we deal with wilding pines now we will have exponentially larger difficulties tomorrow.”
Wilding pines are characterised by their ability to disperse, and the vigour of their growth. They can produce cones at between eight and thirteen years of age, and produce vast quantities of seed that can be dispersed for distances of more than 10 kilometres.
DOC has, therefore, decided to launch a major assault on the weed problem. To aid it, the government has allocated a $718,000 a year increase in funding specifically for the task.
The minister said while much of the new control would be focussed on conservation land, it was likely neighbouring farmers would also benefit.
“Wilding pines don’t respect boundaries so we are going to have to work with whole communities to tackle this problem. I would expect to see DOC seeking to conduct wilding pine control on farmland neighbouring conservation land, where it has the permission of the landowner. This will benefit the farmer and the public,” says Mr Carter.
Farmers have welcomed the move, but point out that the funding may not be enough, given the size of the problem. “We are pleased that DOC has recognised that the problem of wilding spread is not restricted to conservation land, and is looking to work with communities to prevent spread beyond DOC’s boundaries,” says Ben Todhunter, chairman of the South Island high country section of Federated Farmers of New Zealand.
“However, the extra funding should be put into perspective. In the budget, the government earmarked to spend $46 million over the next four years to create new parks and reserves in the High Country,” he says. “So the extra funding earmarked for managing its existing estate is tiny compared with how much the government will spend adding to its estate.”
In one part of Southland, the New Zealand government and the Southland Catchment Board planted Pinus contorta and other exotic conifer species from the 1940s to 1980s to prevent soil erosion. The original planting area was 170 hectares, but a study five years ago by public research institute, Forest Research, revealed that that the infestation of wilding pines had spread over 13,650 hectares. Federated Farmers says that removing wilding pines from just that one part of Southland would cost $2.7 million