NZ forests safe from Chile’s pine-killer organism, say experts

Forestry experts have dismissed concerns about a biosecurity threat to New Zealand’s pine tree plantations.

Phytophthora pinifolia is a chromist, or plant-like organism, causing decay and death among radiata pine forests in Chile.

New Zealand forests are 89 per cent radiata, which Green Party forestry spokesperson Catherine Delahunty says is an example of a monoculture creating a risk for the country’s economy.

However, industry experts have rejected this and have confidence in New Zealand’s border controls.

New Zealand Forest Owners Association senior policy analyst Glen Mackie says it would be very serious if phytophthora pinifolia arrived here.

But he emphasises that it is not present in New Zealand and never has been.

Although it would be impossible to test every tree in the country, he says it is “virtually certain” the phytophthora has not entered New Zealand.

Mackie says the forestry sector has been keeping a close eye on the situation in Chile.

Lindsay Bulman, a project leader at forestry research institute Scion, travelled to Chile to observe the effects of phytophthora pinifolia.

He says the organisms probably travel via fog and mist, but strict quarantine impositions on imported pine means the likelihood of the phytophthora infiltrating New Zealand is low.

Delahunty disagrees, saying shipping is not monitored as it was before New Zealand “moved into the glories of the globalised market”.

She wants to see more diversity in plantations, including native hardwoods like kauri and totara.

“The most robust environments are biodiverse,” she says. “It’s very disturbing to be putting all our eggs in one basket.

“Our forests could be knocked out by a single disease.”

Mackie says local forestry does have a large monoculture, but the level of investment in radiata allows the industry to direct a lot of resources towards ensuring forests remain disease-free.

“There are only a small number of catastrophic diseases and pests to focus on. If we had a wider range of trees, there would be a wider range of threats,” he says.

“So you’ve got to balance the monoculture against the positive facts.”

Delahunty says hundreds of jobs could be created if the industry begins to look at sustainable long-term plans and branches out into other species of trees.

Radiata pine is generally harvested at the 30-year mark, which Delahunty calls a “quick fix”.