Kauri dieback: what the agencies record

This page reports what the official source says. It is not legal advice: ask the office named here. It lists what the New Zealand agencies record about kauri dieback and does not diagnose any tree. It states rules from the National Plan and controlled area notices, so the exact wording is on the pages linked below. The list of other diseases is on the tree diseases page, and the reporting line for New Zealand is in the New Zealand report-a-pest guide.

At a glance

Item	What the sources say
Pathogen	Phytophthora agathidicida, called PA for short, a soil-borne water mould. Tiakina Kauri says it was formally named in 2015.
Host	Kauri. The Department of Conservation says it can kill kauri of all ages.
Where	The Department of Conservation says it has been found in Northland, Great Barrier Island and the Coromandel Peninsula.
Management agency	Tiakina Kauri, the national programme based in Biosecurity New Zealand, part of the Ministry for Primary Industries.
Cure	The Department of Conservation says there is no known cure.

How the sources say it spreads

Tiakina Kauri says the pathogen infects through the roots and restricts the movement of water and nutrients between roots and leaves. It describes a cycle in which resting spores arrive in soil, usually through human activity but also on animals such as pigs, and it says it takes only a speck of soil to move enough of them to cause disease. The spores germinate and release swimming spores during and just after rain. These move through soil moisture to kauri roots. The Department of Conservation says the pathogen spreads easily on soil that travels with muddy boots, animals, equipment and vehicles. Tiakina Kauri adds that the pathogen could stay in soil for many years even when no kauri are present.

Symptoms as the sources state them

What Tiakina Kauri lists. Yellowing of leaves, a thinning canopy, dead branches, and bleeding gum from basal trunk lesions. It says not all infected kauri show these symptoms, and not all trunk lesions are caused by the pathogen. The last stage is death of the tree.
Timing. Tiakina Kauri says symptoms can take years to appear: seedlings may show them within weeks of infection, young trees in a few years or more, and mature trees possibly after decades. The pages give no season for symptoms.

Look-alikes and testing

Tiakina Kauri says the symptoms are definite but not unique, that similar symptoms may occur for other reasons such as drought or age, and that you often cannot tell by looking at the tree whether the pathogen is the cause. It says soil tests can be done to help detect the pathogen. The programme asks for reports of kauri showing the symptoms so it can learn where the pathogen is, and the Department of Conservation gives 0800 275 362 for symptoms seen on public conservation land.

The National Plan rules

Tiakina Kauri says 10 rules took effect on August 2, 2022 under the National Pest Management Plan for the pathogen. Its summary page words four of them as follows.

Rule 1. Owners of kauri on land they live on or own must report sick-looking kauri to Tiakina Kauri or the regional council.
Rule 5. From August 2, 2023, earthworks inside a kauri hygiene zone, which is three times the radius of the canopy dripline, need an earthworks risk management plan.
Rule 8. When going off track or onto a track where the forest floor will be touched, visible soil and organic matter must be cleaned off tools, cars, bikes, sticks, shoes and gloves before entering and when leaving.
Rule 9. Hygiene stations met in the forest must be used.

The page says infringement fees range from NZD 300 for Rule 8 to NZD 400 for Rule 9, and that a charge under the Biosecurity Act 1993 can bring a maximum fine of NZD 5,000 for an individual and NZD 15,000 for a corporation. Tiakina Kauri's page on working around kauri says civil works, forestry operations, and mining and quarrying carry a risk of spreading the pathogen through the movement of soil, gravel and fill, and offers contractor, forestry and quarrying guidance.

Controlled areas

Tiakina Kauri says a controlled area notice is issued under section 131 of the Biosecurity Act 1993, and only Tiakina Kauri or the Chief Technical Officer of Biosecurity New Zealand can issue one. It names controlled areas in the Auckland region: certain open tracks in the Waitakere Ranges, the Goldie Bush Scenic Reserve, and parts of the Hunua Ranges. It says the movement of goods such as footwear and equipment may be restricted inside them and that non-compliance can lead to prosecution.

What the agencies list for management

The Department of Conservation says the response is to avoid moving soil around tree roots, using wash stations, clean gear and staying on tracks, and that it grades tracks, installs cleaning stations and may close tracks. Neither page lists a chemical treatment.