The Government is now seeking feedback on ideas to better manage afforestation, and Nash said: "Climate change is a challenge we cannot postpone. The Government wants to encourage afforestation to help meet our climate change targets, offset carbon emissions, and also help farmers, landowners and investors diversify their income streams.
"We want to balance the risks created by new permanent exotic forests which are not intended for harvest," he said.
The Government has "a window" to build safeguards into the system, prior to a new Emissions Trading Scheme framework coming into force in 10 months' time (January 1, 2023).
From then, under current rules, a new permanent forest category of the ETS would allow both exotic and indigenous forests to be registered in the ETS and earn New Zealand Units (NZU).
"We are now proposing to exclude exotic species from the permanent forest category," Nash said.
"We want to encourage the right tree, in the right place, for the right reason. We intend to balance the need for afforestation with wider needs of local communities, regional economies, and the environment."
He said increased plantings of exotic forests are driven by rising carbon prices as landowners and investors seek higher returns.
As a result the NZU price has more than doubled over the past year, from about $35 in late 2020 to over $80 in February.
"Permanent exotic forests like radiata pine have potential environmental and ecological risks," Nash said.
"These include pests, fire, damaged habitats for native species, biodiversity threats, and a relatively short lifespan compared to well-managed mixed indigenous forests.
"Later this year, we will also consult on proposals which could give local councils more powers to decide under the Resource Management Act where exotic forests are planted in their areas," said Nash.
Shaw said planting more trees can help us meet our climate goals, but it is important to make sure all types of afforestation are well-managed through the ETS and the planning process.
"Aotearoa was once blanketed with native forests, home to indigenous birds, insects and other wildlife. Today much of those ancient forests are gone, but what remains is still a vital carbon sink.
"In its advice to Government, the Climate Change Commission said we need to increase both indigenous and exotic tree planting to meet our emissions targets. But they also warned we need to reduce our overall reliance on forestry offsets, and better manage the impacts of afforestation."
A proliferation of permanent exotic forestry could result in lower long-term carbon prices and potentially limit investment in low-carbon technologies, he said, adding: "At the same time, an increase in native forestry will require additional management efforts to eliminate pests that feed on native trees.
"This consultation is an opportunity for anyone with an interest in the future of forestry to have their say. We particularly want to hear from Māori landowners. Iwi-Māori have significant interests in permanent forestry and we want to ensure they are not unfairly impacted."
Shaw said it was "really important we get this right" because decisions made as a result would be felt decades into the future.
Public submissions can be made from March 14 to April 22 and more information can be found at mpi.govt.nz/consultations/managing-exotic-afforestation-incentives
