A 43-year-old pine forest with native regeneration in Poroporo, Tairāwhiti, provides a clear window into the future of New Zealand Carbon Farming’s (NZCF) programme to restore indigenous forests across Aotearoa.
As most radiata pine forests are clear-felled well before age 30, this area of 43-year-old pine forest with an understory of regenerating native forest stood out to the company’s local land manager, due to the extensive growth of a range of indigenous species, including significant podocarps like kahikatea and tōtora.
In 2024, the NZCF technical team visited the site to undertake extensive measurements to help identify and protect the elements driving high levels of natural regeneration. The research included LiDAR scanning, cutting-edge technology, which uses lasers to measure the characteristics of individual trees more accurately.
NZCF forester Pierre Bellé says the area represents a good model for the future of NZCF’s programme. This focuses on transitioning an exotic nurse crop of trees into a diverse native environment using a range of scientifically established active management techniques. Given the age of the mature forest, this is particularly relevant, as NZCF’s exotic nurse crop forests are almost all below age 31.
“Basically, this stand of regeneration is a good representation of what NZCF wants its forests to look like in the future – but this has happened naturally,” says Pierre.
Forester Pierre Bellé inspecting the native Kahikatea trees under the pine nurse crop at Poroporo, Tairāwhiti East Coast
Over several months, the team undertook a range of detailed measurements of the established pines and the regenerating natives. As part of an ongoing programme, the team – made up of ecologists, land managers and analysts – will also look at soil samples as well as the germination of new seedlings in the area.
“I think this forest will be of major importance in New Zealand because of the information it will provide on many ecological aspects of forest regeneration,” says Pierre. “There is also a bit of disbelief in some quarters that natural regeneration will happen under pine trees. This is a showpiece of what can happen – even without intervention.”
From what they have learned, the team is already looking at several aspects of the forest’s development that mirror NZCF’s programme of active management.
“Stock exclusion was likely to be a big part of it. We saw remnants of a fence around it, so it had a period when that particular stand was probably free of herbivores like goat and deer. That provided the opportunity for the first wave of regeneration to establish.”
“Some of the old pine also had a tough time, with natural attrition meaning there was enough light coming through to make a difference in the regeneration. Native birds probably also played a major role in dispersing the native seeds.”
With over 50 years of local research to draw from, this natural laboratory will continue to build NZCF’s programme of using careful management to support native regeneration at scale.
“It’s a most helpful ecological case study,” says Pierre, “and it will continue to provide new data to feed into our improved ecological management”.
43 year old pinus radiata forest with dense canopy of native podocarp tree species. Poroporo, Tairāwhiti East Coast