THESE Wilding Pines on the shore have been poisoned, but the fight is far from over. PHOTO SUPPLIED
WILDING pines are species of unwanted fir, larch and pine trees that have self-seeded and are growing across New Zealand in areas such as Ruapehu.
The Horizons senior biosecurity officer Melinda Matthewson said the wilding problem in Ruapehu initially focused on pinus contota, but now it involved a wide range of species. Many conifers had the ability to wild in Ruapehu’s ungrazed areas, such as forests, tussock land and wetlands, Melinda added.
“Tongaririo National Park is vulnerable to wilding invasion and a lot of work has been carried out within the Park by the Department of Conservation with support from Horizons Regional Council, Ernslaw One and the New Zealand Defence Force, controlling areas around the park.”
She said wilding control came down to the “right tree in the right place”, hence even some valuable plantation conifer species had unfortunately become a wilding problem within the district.
“However, significant gains have been made controlling both wilding trees and the removal of parent trees such as amenity plantings and shelter belts in the district. Funding from the National Wilding Programme has accelerated control work and it is hoped that the recent gains made won’t be lost by a reduction in funding.”
The chair of the Wilding Pine Network, Richard Bowman, said the trees posed a big threat to New Zealand’s unique environment, because unlike well-managed plantation forests, wildings did not allow for native undergrowth, were not managed for fire risk and were rarely a useable resource.
Between 2016 and 2022, the total known national infestation area was 3 million hectares, around 70% of which (2.2 million ha) had received at least one round of control work.
Repeat control and ongoing maintenance was needed to remove new growth from seeds already in the ground. The aim was to stop wilding pines from spreading further from land already invaded.
“The national control programme has shown the value of early and effective management while trees are small and before they cone and produce wind borne seed,” Richard said.
“This programme has been working extremely well with a $100 million boost to funding in 2020 from the Jobs for Nature initiative.
“More than 500 jobs have been created with 600,000ha of control work carried out in conjunction with mana whenua, private landowners, NGOs, community groups and the forestry and agriculture sectors.”
Richard said at the recent national Wilding Pine Conference held in Blenheim it was clear that wilding pine projects, which had been underway for more than a decade, were starting to achieve successful “wilding free” outcomes.
However, while spectacular progress was being made with initial control across New Zealand, this work would require at least two rounds of maintenance around three to five years’ apart to remove regeneration and exhaust the seed bank as well as to neutralise other nearby seed sources.
