Taskforce will battle fungus threat to kauri | Northland News | Local News in Northland

by Andr? Hueber

Government agencies and councils are banding together to tackle a fungus threatening New Zealand's iconic kauri trees.

Waipoua Forest eco-warrior Stephen King said the fungus - Phytophthora taxon agathis, or PTA - had not been officially identified at Waipoua, but it "looked like it was there".

PTA attacks stressed trees, leading to thin canopies, dead branches and lesions that bleed resin. It has been detected at Trounson Park, south of Waipoua, and the Waitakere Ranges near Auckland.

It was carried by dirt spread by pigs, dogs and humans - but also triggered by gravel tracks which harmed tree roots, Mr King said.

Countering the problem involved building boardwalks and employing kaitiaki to trap, kill and poison pigs, he said. Allowing pig hunters in did not help, because dogs spread PTA and killed kiwi.

Mr King told authorities in 1978 that putting gravel in forests would be damaging. "They went ahead and did it anyway, and now you see a line of dead trees alongside the track. Money needs to be spent on upgrading tracks otherwise the ground will compact and tree roots will asphyxiate."

A boardwalk all the way to Tane Mahuta was still incomplete, despite being started 10 years ago, and needed to be finished "as soon as yesterday". Ironically, Tane Mahuta's advanced age - more than 2000 years - meant it might not be at risk from PTA.

"So far I've never seen any ancient trees affected by PTA. It seems to have more impact on younger and middle-aged trees up to 600 years old. I don't know whether the ancients are resilient or just lucky."

The taskforce tackling the kauri killer is made up of the Ministry of Agriculture and Forestry, DOC and four regional councils, including Northland's.

Advice to the public includes staying on marked tracks; cleaning footwear, tyres and equipment in contact with soil before and after leaving kauri forests; and avoiding disturbing kauri tree roots.