Transitioning Exotic Forest to NativeProject Status: Current
Native regeneration under mature pine, Gisborne. Photos: Meg Graeme
Introduction
This Tāne’s Tree Trust research programme aims to inform the transitioning of exotic forest to native forest. Results, including management prescriptions and recommendations, will be freely and widely disseminated to landowners, forest owners, forest managers, policymakers and regulators.
Fenced trial site in NorthlandThis is a five-year project supported by MPI through the Sustainable Food and Fibre Futures fund, and our forestry partners.
Fenced trial site in Northland.The key objectives are to:
- Analyse existing LUCAS data to assess native understory development and forest characteristics within plantation forests to better understand these forests and necessary management to encourage a transition.
- Undertake plot surveys to gain information about bioclimatic effects on native understory characteristics around the country.
- Undertake targeted plot surveys to determine what management actions are required to support a pine to native forest transition in Tairāwhiti.
- Establish a nationally relevant network of permanent sample plots to inform carbon and biodiversity forestry models and to empirically refine management practices.
- Model the dynamics of transitional forest for a range of contexts and management objectives (e.g., growth, biodiversity/successional change, and carbon profiles).
- Produce guidelines to manage transitions from exotic pine forest to native forest, highlighting the key factors to address and interventions necessary.
- Recommendations for best-practice transitional forestry and monitoring.
Background
The advent of permanent forestry and carbon farming under the Emissions Trading Scheme (ETS) has sparked debate on the potential to manage transitions from exotic to native forest. The case for using fast growing exotic trees (e.g., Pinus or Eucalyptus) as the primary vehicle for rapid early carbon storage is compelling and is garnering much interest among landowners interested in permanent forestry options. In other circumstances, large tracts of exotic plantation on highly erodible or environmentally sensitive sites (e.g., Tairāwhiti) will need alternative forest management options to conventional clear-fell harvesting. Likewise, effective management options need to be explored for areas afflicted with wilding conifers where a transition to native forest is conceivable (e.g., see video: https://vimeo.com/592450395).
Extensive pine planting programmes have been established with support from Te Uru Rākau and have been incentivised by the ETS. Irrespective of any changes that might occur to the definition of permanent forest in the NZ ETS, permanent exotic forestry is already a major land use across NZ and we urgently need this research to guide its management. This research will help inform relevant policy settings and regulation on this matter, and to inform, and shape, forest establishment and management practices, to ensure that successful transitions to native forest does indeed occur. The current state of knowledge on such transitional forestry and the priorities for research have been presented in the Forbes Ecology 2021 report for MPI.
The first year of the project has concentrated on getting our management systems, reporting standards and field survey methodologies in place. We also gained permission from our forestry partners to access their LUCAS forest plot data and access to plantation stands for the Bioclimatic, Tairāwhiti and Trial workstreams. We thank everyone who has assisted Tāne’s Tree Trust so far - Ministry for Environment, Summit Forests, Ernslaw One Ltd, Aratu Forests Ltd, Ngati Porou Forestry, Manulife Forest Management NZ Ltd, Pan Pac Forest Products Ltd, Rayonier Matariki Forests City Forests, Juken NZ Ltd, Tasman Pine Forests Ltd, Ngai Tahu Forestry, OneFourtyOne, Gisborne District, Nelson City Council, Hawke’s Bay Regional Council and Northland Department of Conservation.
Progress in 2024
Transition site in Northland
Transition site in NorthlandThe LUCAS data analysis and reporting is led by Dr Mark Kimberley and is currently being reviewed. Dr Adam Forbes is undertaking the assessment and reporting on the national bioclimatic plot surveys and this report will be sent out for review in mid-November. Meg Graeme is leading the reporting on the Tairāwhiti pine understory surveys and this will also be sent out for review shortly. Mike Bergin and Meg Graeme are leading the forestry trials.
Paired poisoned/unpoisoned canopy plots with and without fencing have been set up in Omahuta Forest (Northland), Whangapoua Forest (Coromandel) and the upper Maitai (Nelson) to date. These are surveyed annually to gather data on understory planting and natural regeneration survival and growth. It is hoped that a suitable trial site can also be established in Tairāwhiti.
Dr Mark Kimberley is soon to start on the Carbon/Biodiversity modelling utilising all the data collected to date. This will help inform the development of the preliminary best practice management guidelines for transitioning exotic pine forest to native. The preliminary guidelines are to be publicly released early-mid 2025.
Progress to date
See update newsletters:
Contacts for this project
- Meg Graeme, Project Manager [Enable JavaScript to view protected content]
- Paul Quinlan, Trustee, Tāne’s Tree Trust
- TTT Executive Officer: [Enable JavaScript to view protected content]
