Next chapter for the Pakuratahi land use study

This article was originally published by the Forest Owners Association, a key collaborator on the Pakuratahi Land Use Study.

The second Pakuratahi Land Use Study, a groundbreaking initiative in New Zealand’s Hawke’s Bay, is investigating the environmental impacts of forestry and farming to shape sustainable land management practices. By comparing a pine forest catchment in Pakuratahi with an adjacent farmed catchment in Tamingimingi and a native forest catchment (Fisher's Block), the study tracks water quality, soil health and aquatic ecosystems to inform forestry practices amid climate challenges.

In 2024, led by James Powrie and the FOA/FFA Environment Committee and backed by the Forest Growers Levy Trust, the project made significant progress in its mission to document productivity with environmental stewardship for the side-by side differing land cover types.

The original study, started nearly 30 years ago, examined the environmental outcomes of a farmed catchment versus a radiata pine forest, aiming to address the question of whether land in forestry or pasture produces more sediment.

This second study, Pakuratahi version 2.0, aims to provide evidence right across the harvest cycle from pre- to post-harvest to next crop establishment to build an understanding of the environmental effects of harvesting and re-establishment. In this study, the second rotation harvest will also be compared to the first and a native forest catchment has been added. The study will use modern tools like environmental eDNA and LiDAR, and will generate a template for use in studying other catchments around New Zealand.

A cornerstone of the year’s work was the finalisation of a 15-year project plan and the compilation of baseline data into a comprehensive ‘story map’ to guide future research. The plan focuses on data collection, catchment monitoring, education and governance to improve forestry practices amid rising climate risks. A flexible three-year operational plan will be updated annually to adapt to emerging research opportunities.

Water and soil monitoring progressed with two water quality stations scheduled for periodic sampling from early 2025. Soil quality assessments, aligned with the regional Soil Quality Monitoring programme, began across varied land covers, including juvenile and mature forest blocks. These efforts will inform long-term environmental strategies.

Fish surveys, conducted via electric fishing and eDNA sampling, revealed thriving aquatic ecosystems. Pakuratahi’s pine forest stream teemed with koaro, a whitebait species, indicating high water quality. While Tamingimingi’s pasture stream showed similar biodiversity, the native forest stream had fewer fish, possibly due to habitat constraints. These valuable results offer insights into how land use affects freshwater ecosystems.

LiDAR technology mapped erosion patterns before and after Cyclone Gabrielle, enhancing the team's knowledge of sediment movement. A new Ministry for the Environment and Ministry for Primary Industries-backed study will expand the new soil monitoring approaches across seven land cover types including pine plantations, pasture and native forest. This study will leverage LiDAR and satellite data and aims to refine how we measure the long-term environmental effects of land use.

Looking ahead to 2025, the project aims to deliver its first full year of baseline stream monitoring data, establish sediment monitoring and undertake detailed geology and soil studies. A public web portal will be launched to help tell the story behind the data and increased outreach is planned throughout the year to share knowledge and the Pakuratahi study continues to pave the way for environmentally conscious forestry.

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