A group fighting wilding pines in Central Otago says unchecked infestations in remote country are "horrendous" and that those whose forests spread the seed should be made accountable, RNZ's Monique Steele reported in Farmers Weekly. Wilding conifers now affect about 3 million hectares across New Zealand, threatening native biodiversity, productive farmland, tourism and water; about 80% of known infestations are under management.

Seed can travel many kilometres on the wind from forestry plantations, shelter belts, old erosion plantings, urban trees and uncontrolled areas. The Central Otago Wilding Pines Group co-ordinates control across a one-million-hectare catchment, largely by targeting seed sources. Programme director Pete Oswald said the "goodwill" approach of expecting foresters to control pines beyond their boundaries is not strong enough. "The cost shouldn't fall to the person who didn't make the mess, which is currently what's happening," he said, adding that without legal or regulatory repercussions there will always be good and bad players.

Forest owners spent $4 million on wilding control last year, mostly against Pinus contorta, and $13 million over five years, according to a Forest Owners Association survey; Forest Stewardship Council-certified forests must also manage spread where they can reach neighbouring land.

The Ministry for Primary Industries is consulting on a draft 20-year wilding pines strategy, which will feed a National Pest Management Plan for wilding conifers announced in May. It says control cannot rely on government money alone and that shared accountability with the forestry sector should be strengthened; the government has committed $109 million over three years to the National Wilding Conifer Control programme. If left unmanaged, MPI says, infestations could affect up to 25% of the country within 30 years and impose at least $4.6 billion in economic losses over 50 years.

Rules have been tightened over the years, including restrictions on planting Pinus contorta and, since June, a requirement that commercial foresters assess wilding risk with an updated calculator and notify councils, with high-risk plantings needing resource consent. The Forest Owners Association says any new Douglas fir planting, for timber or carbon, needs a wilding score below 12 or a consent, and that the calculator "almost entirely prevents" planting it. Oswald said the calculator does a fair job for new forests but does nothing about legacy forests planted under weaker rules or none at all.

MPI's draft strategy agrees that identifying and managing major seed sources is fundamental, that action should be risk-based and targeted, and that failure to stop seed production leads to persistent re-infestation and rising costs. Consultation closes on 9 October.

Reported by Monique Steele of RNZ, published by Farmers Weekly.

Source: Farmers Weekly NZ