I have become increasingly concerned with so-called carbon farming, which promotes the use of exotic plantations (usually radiata pine but sometimes eucalypts) to earn quick carbon credits while promising a longer-term transition to natives.
While there is some good science by @adamforbesnz and others to show that we can manage mature exotic plantations to encourage native recruitment, there is no good science to show that we can transition 1000s of hectares of new exotic plantations to mature native forest as claimed by those promoting this approach.
For me to have any confidence in such transitions I would want to see carbon farm forests –
(1) planted only in areas where we know there is a good chance of native forest establishing (higher rainfall and close to seed sources),
(2) covenanted to prevent any future harvesting,
(3) include a financial mechanism to guarantee in-perpetuity management funding, and
(4) have a decent management plan that articulates how the transition will be facilitated (including feral ungulate control, weed management, enrichment planting, canopy manipulation, and the infrastructure required to support this).
I have not seen any evidence of these factors being considered and it seems to me that these schemes are essentially money-making ventures that are capitalising on the climate change crisis we are facing.
As currently being implemented, I believe that carbon farming is a massive ecological disaster in the making and government should stop it unless the issues above are addressed.
David Norton is Professor of Ecology and Forestry at Canterbury University.
https://www.canterbury.ac.nz/science/contact-us/people/david-norton.html