Native trees planted as permanent carbon sinks could deliver more than climate change benefits should forestry regulations change in their favour.
Earlier this month, Forestry Minister Stuart Nash stated his desire to see the Emissions Trading Scheme (ETS) forestry regulations change to ensure only native trees could be planted as permanent carbon forests.
The Ministry for Primary Industries (MPI) is receiving submissions on ETS forestry changes.
“My personal view at the front of mind is the ecological and conservation effect of allowing exotics to be planted with a biological lifespan of 100 years,” Nash said.
“We risk not only ending up with unhealthy mature exotic forests that could impact on productive farms, but a potential ecological disaster when you get a storm through on steep planted country, it would be an absolute disaster.”
MPI data indicates over the past three years 83,000ha of land has been planted in exotics, with 12%, or 10,200ha, deemed permanent plantings.
But Nash said a soon to be released MPI report has highlighted how, with escalating carbon prices, this area could surge to significantly greater amounts.
Estimates are it could rise to be as much as 116,000ha a year going to exotic carbon forests from 2025 to 2050.
“It ramps up really quick, and has all but the most highly productive land able to earn more from carbon,” he said.
Taking a longer-term view with slower sequestering, he said natives could deliver some other upfront gains, including extracting compounds for pharmaceutical type applications from native species.
“You end up extracting carbon value and that value, all without having to pick up a chainsaw,” he said.
But Nash acknowledged there were hurdles to overcome to ease the establishment of more natives.
Pest control was a major one.
Forest & Bird has identified major losses in carbon sequestration as a result of pests, with West Coast podocarp forests losing 3.4 million tonnes a year of carbon due to possums and deer.
This is the equivalent to 20% of the vehicle fleet’s emissions.
Pest control at the early establishment phase for natives was critical and establishment costs can be four times more than exotics.
“We have had groups come to us asking about removing pest infestations in pre-1990 forests and being able to claim carbon credits. I would say, yes, this should be an option,” he said.
He also anticipates private funds will be more strongly drawn to native carbon sequestration than if those forests were exotics, also helping fund pest control.
Another area demanding attention was getting accurate numbers on natives’ annual carbon sequestration ability incorporated and updated in the MPI “look up” tables used for carbon calculations.
Work is under way studying the kānuka and mānuka carbon sequestration rates.
Nash said early indications were promising, with these varieties possibly being close to pine in their ability to suck up carbon.
“We expect to see some good news here. Both are good nursery crop plants that grow fast, sequester carbon and set up future native trees,” he said.
“I think we may find the economics of native forests are a lot more effective than what we are measuring right now.”
The Climate Change Commission has recommended NZ plant 300,000ha of new natives and 380,000ha of new exotic forests by 2035 to help meet climate change objectives.
He said a ban on permanent exotic forests could prompt a shift around in that ratio of natives to exotics.
But he felt the risk of establishing permanent exotic forests with their ecological risks was greater than the risk of not hitting our national carbon reduction targets by having less of them in the ground.
He also expected climbing carbon prices will make plantation forestry more appealing to farmers with steeper country that may have typically been too far from ports when carbon was not valued.
Dryland Carbon general manager Colin Jacobs said the majority of his company’s managed forests are planted for plantation, with only pockets left as permanent on exceptionally steep, inaccessible land.
“We do not agree with a plant and leave approach. You need to ensure land has no other purpose, and in choosing a species it would be native,” Jacobs said.
But he suggested government may need to come up with a way of front-loading native carbon credits to recognise the significantly higher costs of establishing them.
He said government was on the right track removing the special forestry test for foreign land purchases and making permanent forest native-only.
However, to encourage planting of trees beyond central NZ, he believed longer rotation forests (50 years) should also be incorporated into the ETS changes.
“Forty years is being proposed, but we believe it should be 50 to really encourage forestry on more marginal land in areas where maybe trees don’t grow as quickly,” he said.
Current ETS carbon payments are averaged based on a 28-year rotation.
“Opening it up to 50 years would open up opportunities for a lot of iwi land well-suited to longer growth periods,” he said.