Source: NZ Department of Conservation
Date: 02 July 2025
State of the art drone mapping and laser rangefinders were used to identify and map the wilding pines.
“Rangitoto is an ecosystem different from anywhere in the world, and wilding pines are one of the greatest threats to it,” says Dr Leigh Joyce, DOC Senior Biodiversity Ranger.
Wilding pines would eventually take over the island’s native vegetation if left uncontrolled – as they have at many locations around New Zealand.
Located in the Hauraki Gulf/Tīkapa Moana, Rangitoto has the largest pōhutukawa and rātā dominated forest in the world and is home to many taonga bird and lizard species, says Leigh.
It’s also the only volcano in Auckland with an intact indigenous ecosystem.
“The maps provided accurate GPS locations of the wilding pines which allowed ground crews to work at pace to remove the threat.”
“A huge thank you to Island Solutions for their expert drone surveying and mapping, and Tree King for their excellent and efficient work felling the trees,” says Leigh.
The island has been predator free since 2011. It’s home to a variety of native bird species, including kākāriki, korimako/bellbird, kākā, tūī, pīwakawaka/fantail, riroriro/grey warbler, and ruru/morepork, as well as five species of native lizards.
Unlike native New Zealand bush, where a wide variety of plant species exist together, wilding pines produce dense overgrowth which supports only other wilding pines.
“If wilding pine numbers increase, they will also have a significant visual impact. Control is needed to prevent them from becoming a dominant weed species on Rangitoto,” says Leigh.
Wilding pines currently affect more than 2 million hectares of New Zealand. Without large scale funding and control, experts estimate that within thirty years, 25% of New Zealand could be covered with wilding pines.
The Rangitoto effort is part of the National Wilding Conifer Control Programme, led by Biosecurity New Zealand in partnership with DOC and many other organisations across the country. The programme has delivered control operations on more than 3 million hectares, or just over 12% of New Zealand, preventing the spread into even more vulnerable land.
Funding to remove wilding pines on Rangitoto was announced by the Minister of Conservation in November 2024 as part of the International Visitor Levy (IVL).
Thanks to additional IVL funding, there is also weed control work underway or planned for several other conservation islands in the Hauraki Gulf.
As part of this funding, DOC and Ngāi Tai ki Tāmaki will now carry out ground control weeding on Rangitoto and neighbouring Te Motutapu-a-Taikehu. This work will target moth plant, gorse, and rhamnus.
As well as being an ecologically and culturally significant site for DOC’s iwi partners, Rangitoto is a tourism and economic drawcard with over 100,000 visitors a year.
Related link
National Wilding Conifer Control Programme
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