Conifers threatening land

Efforts are being made to eradicate the region's wilding pines.

About 200,000ha of invasive wilding conifers are encroaching across Hawke's Bay and could have "devastating" economic and environmental effects.

The warning came yesterday from Local Government New Zealand's Regional Sector chairman, Stephen Woodhead, who claimed while the scourge was widespread, Hawke's Bay is "the worst affected North Island region".

"Wilding conifers [also known as wilding pines] are an invasive pest tree affecting landscapes and pastoral productivity across New Zealand," Mr Woodhead said. "They are advancing exponentially across New Zealand - establishing dense stands around some of our most iconic tourist destinations, on farmland and on Crown land, and threatening our economy and environment on a number of levels. Wilding conifers are trees in places they are not supposed to be. They have been branded the number one pest in some regions."

Landcare Research said there are 10 main species that have become wildings including Lodgepole pine (Pinus contorta), Radiata pine (Pinus radiata), Douglas fir (Pseudotsuga species) and European larch (Larix decidua).

The organisation said because the trees grew in dense stands, and are not able to be managed as a plantation, they have "no economic value" for wood. Instead, wildings can reduce the value of pasture, displace native biodiversity, reduce water availability and alter the landscape.

Earlier this year Mr Woodhead said the country had "reached a tipping point" for the control of the pests. "The potential negative impact of wildings on our economy is estimated at $1.2 billion over 20 years ... if we don't act now, they will get away on us so fast it will become uneconomic to attempt to begin and we will have to resign ourselves to widespread landscape and landuse changes.

"Their effect on one of New Zealand's most valuable commodities - water - is significant."

He said there are many initiatives to halt the march of wilding conifers, with investment by landowners, councils and other agencies, and spending of $6.7 million by central and local government last year alone. "Yet they are still spreading at a rate of 90,000ha per year."

Hawke's Bay Regional Council's plant pest team leader, Darin Underhill, said council was aware it was a significant issue in parts of the region, yet said the pines were mostly on Department of Conservation (DOC) land. "We have been working closely with DOC, iwi and our neighbour regional councils, in particular where wilding conifers are present on small areas of private land," Mr Underhill said.

A spokesperson for the Ministry for Primary Industries told Hawke's Bay Today the region had "significant areas impacted by wilding conifers", particularly in the Kaweka ranges. "However, they are not alone with most regions across the country being impacted to some extent."