Disease new threat to forest industry

A disease is currently devastating trees overseas.

A disease that is devastating trees in Europe and the western United States would be a major threat to New Zealand plantations and ornamental trees, should it ever arrive, according to Forest Owners' Association biosecurity manager Bill Dyck.

The forest industry was concerned that even the suspicion that Phytophthora ramorum was present in New Zealand could have a major effect on log exports and employment in forest regions.

P. ramorum was causing the now widespread disease known as sudden oak death in California and Oregon, and had spread to most European countries in the last decade.
Mr Dyck said the disease was just one of many, along with pests, that were threatening the industry.

"Last year we had two species of beetles that feed on eucalypts arrive in our forests. One, near Waikanae, we thought had been eradicated, and the other, in Hawke's Bay, we haven't ever seen here before," he said.

Rotorua-based Scion plant pathologist Lindsay Bulman said one of the concerns was that the ramorum pathogen was infecting an increasing range of tree species.

"We don't know if ramorum would infect our main plantation tree, Pinus radiata, but it has now been seen on Douglas fir and Japanese larch overseas, and previously plant pathologists thought it wouldn't infect any conifer species," he said.

The ornamental trees that were particularly susceptible were rhododendrons, camellias and viburnums.

"I have to emphasise as well that the implications of any arrival of this pathogen in New Zealand may not be confined to potential effect on the trees themselves.

"Log exports from the west coast of the United States to East Asia have had a major hit from importing countries not wanting to introduce the pathogen there

"Trees and vines are the Bay of Plenty's biggest businesses, and the forest and kiwifruit industries share a concern that it would be so easy for insects or pathogens to slip through the border if tight vigilance is not maintained," he added.

"There are various eradication or control options, so long as new incursions are detected early.

"Surveillance by specialists and biosecurity awareness from the public are crucial for early detection.

A third of New Zealand's $5 billion forest product export trade goes through the Port of Tauranga. If those exports were disrupted there would be a lot of people who work at and service that port who might find themselves out of work for a long time."