Afforestation of difficult sites

A project supported by the Foundation for Research, Science and Technology and the Ministry of Agriculture and Forestry

Principal Investigator: Mark Bloomberg

To meet its national and international carbon commitments, New Zealand needs to increase the land available for carbon sequestration forests (carbon forests), by creating new forests on lower value (“difficult”) land which would not normally be considered by plantation forest investors. The vision is to help landowners afforest at least 30% of this potential area by 2021, which will sequester ~ 21 million tonnes of CO2 (with a potential value of $500 million) per year, once fully established. The carbon forests planted on “difficult” land also have the potential to achieve sustainable land use objectives such as soil and water conservation.

However, because lower-value land is “difficult,” it will have moderate to serious limitations to tree growth and forest management. “Limitations” are site characteristics which result in slower tree growth and/or greater risk of catastrophic damage to stands, or which make forest management more difficult or more costly. Such limitations may mean that forests planted for carbon sequestration or sustainable land use objectives do not meet those objectives or, at worst, fail completely to deliver either biological or legal/economic objectives.

A decision support system is needed which allows forestry decision-makers to:

  1. Identify site limitations to tree growth and to management on "difficult" land.
  2. Evaluate the magnitude of those limitations.
  3. Estimate the effects of limitations on management of planned forests.
  4. Decide if the site limitations allow achievement of afforestation objectives.

Therefore this project will provide a decision-support system, which uses field assessment of potential afforestation sites as input information. The system will be designed to allow accurate field assessment by forest managers and other land management professionals, rather than by scientific or technical experts. This system will provide New Zealand forestry investors with the information they need to identify and evaluate limitations on intended sites for carbon forests.

The proposed research will contribute to MAF Plan of Action Goals:

  • New Zealand forests are widely used in reducing the impacts of climate change
  • Forestry is fully integrated into land use decisions, to help deliver sustainable land management outcomes.