Reaping what we sow: tree choices in policy spotlight

The Climate Change Commission’s advice to slow the growth of pine forests in 10 years is a welcome path for Otago and Southland, Forest & Bird says.

In years past, the country was hoping vast exotic forests could suck carbon from the atmosphere.

But now, as New Zealand sets its path to net zero carbon by 2050, the Climate Change Commission has argued instead in its draft advice that the best way to hit zero requires deep reductions in overall emissions.

Its new approach suggests an important but different role for forestry, one where native forests overshadow exotic plantations in the years ahead.

Forest & Bird Otago and Southland regional conservation manager Rick Zwaan applauded the new direction.

"It’s great to see the Climate Change Commission advocating a stronger focus on cutting emissions everywhere we can and using native forest restoration to offset the last remaining and hardest to remove emissions," he said.

The shift away from exotic pines to native forest for carbon storage recognised that permanent native forests would store more carbon in the long run, Mr Zwaan said.

Relying on pine plantations alone was like putting carbon emissions on the credit card, he said.

"You have to pay it back one day," Mr Zwaan said.

"Protecting and restoring native forests locks away carbon for the long term and provides more places for native birds to thrive once again."

Replanting native forests would be a win for the climate, for birds and for streams, he said.

The commission called for a better understanding of the role of existing forests, small blocks of trees, soils and wetlands in accounting for carbon capture.

And Mr Zwaan said Forest & Bird would ask it to go further and do more work to look at the role of wetlands, mangroves and the carbon stored in coastal and marine ecosystems as well.

In the commission’s draft advice released for consultation this month, it said there was a role for pine forests in New Zealand while more enduring sources of carbon removal were scaled up.

However, it wanted to see a "significantly smaller" area of new exotic forestry than planned under current policies.

Further, it called for an end to native deforestation by 2025, and it said it wanted a "sustained high rate" of planting native forests through to 2050.

"Native forests can create a long-term carbon sink while providing a range of other benefits, like improving biodiversity and erosion control," it said.

"Incentives are needed to get more native trees planted."

The commission’s advice calls for at least 16,000ha of new native forests a year by 2025, and 25,000ha a year by 2030 until at least 2050.

It says up to 1.4millionha of marginal land could be planted in forestry.

One of the largest private landowners in New Zealand says it could have a role to play.

New Zealand Carbon Farming owner director Matt Walsh said that over the past decade, the amount of carbon captured by the company’s forests was the equivalent of taking "every car" off New Zealand roads for a year.

More than 95% of the company’s 66.7million trees were planted on grade 6, or above, land, Mr Walsh said.

Its forests were planted in areas that were often steep or erosion-prone in such a way that it could also subdivide better land and sell it so it could continue to be farmed, he said.

For more than three years, the company had supported independent scientific research into the establishment and effects of permanent regenerating native forests.

This research demonstrated that planting pine trees, then managing them properly, could accelerate an exotic forest’s transition into a fully native forest.

New Zealand Carbon Farming modelling showed that this process of "permanent regenerating forestry" could remove from 5 to 10 times more carbon over 70 years than planting a native forest from scratch, he said.

"We are not advocating a scattergun approach to tree planting, quite the opposite," he said. The company advocated planting "the right trees" for now and the future in the right places — "something we’ve been doing successfully for over a decade".

The commission’s draft advice is open for consultation until March 14.

Its final advice will then be provided to the Minister for Climate Change by the end of May. New Zealand’s first emissions reduction plan must be in place by December 31 this year.

hamish.maclean@odt.co.nz