Some tracks and forest near Tauranga are closing due to the discovery of kauri disease in the Kaimai Mamaku ranges.

Provisional positive test results have detected Phytophthora agathidicida (PA) – the pathogen responsible for kauri disease – on a track near the Wharawhara entrance of Kaimai Mamaku Conservation Park, near Tauranga.

This means some tracks and forest have been closed immediately.

The tracks and areas closed from July 21 are:

·       Waitengaue Track

·       Waitengaue to Upper Waitawheta Track

·       Upper Waitawheta Track

·       Lindemann to Cashmore’s Clearing Track

·       Lindemann Loop Track

·       Wharawhara Tramway Track

·       North-South Track to Waiorongomai

·       Te Rereatukahia Hut Track

·       Wharawhara Link Track

·       North-South Track (Rereatukahia to Tuahu)

·       Tuahu Track (east)

·       Tuahu Kauri Loop Track

·       North-South Track (Tuahu to Thompsons Track)

·       Sentinel Rock Lookout Track

·       Eliza Mine Loop Track to Thompsons

The test results, found as part of soil sampling on the track, were unexpected and are significant as PA has previously been undetected in the Kaimai Mamaku ranges.

“We are working with iwi to support a rāhui with formal track and forest closures. The closures will allow us time to conduct further testing in the area and to make informed decisions for what might happen next," says a Department of Conservation spokesperson.

“By restricting access, we are trying to limit any further spread of the pathogen that causes the disease, which is carried on as little as a pinhead of soil.”

“We understand how special it is to have Rakau Rangatira such as kauri within the rohe, we all have a role to play in protecting these special giants," says DOC Eastern North Island. Operations Director Jade .Kinghazel.

"Together with Iwi and local communities we are committed to doing what we must to limit further spread of the pathogen – an all-hands-on deck approach to respect the rāhui will be key as we navigate forward over the next while."

A review on the closures will be made after 10 weeks on September 29 September.

The rāhui and closure will allow DOC time to put together an investigation plan and conduct testing in the area to further understand the potential spread of the disease and the risk it presents to kauri within the wider Kaimai landscape.

This will inform whether greater mitigation protection measures are needed. At this stage there are no other known positive sites within the Kaimai Mamaku Conservation Park.

The samples were collected as part of a targeted four-year soil sampling programme led by DOC. Targeted soil sampling has been focused on testing the kauri track mitigations and hygiene measures in place to prevent the spread of PA.

Once claimed to be the ‘most diverse forest ever encountered’ by forest research surveyors, the Kaimai marks the northern limit of plants such as kamahi, alpine flora, red beech and silver beech, and the southern limit of kauri. This combination of plants makes the forest unique and highly valued for its eco-system diversity.

Kauri disease

Phytophthora agathidicida is a fungus-like pathogen which damages the tree’s root system, reducing the tree’s ability to take water and nutrients from the soil. This is sometimes referred to as kauri disease or kauri dieback.

 It is having a devastating effect on New Zealand’s kauri forests.

Kauri forests once covered 1.2 million ha from the far north of Northland to Te Kauri, near Kawhia and were common when the first people arrived around 1,000 years ago.

Significant kauri, like Tane Mahuta and Te Matua Ngahere, are more than just trees, says a DOC spokesperson. 

"They connect us with the past, and with those who have gazed up at them over hundreds of years.

"Kauri provide shelter and nourishment for other species, and are important to the indigenous forests of the upper North Island. A number of plants are found only, or mostly, in association with kauri."

DOC says when kauri disappear, the kauri forest goes too.

"Kauri are a taonga species for Māori and have significant value for our ecosystem, historic heritage, cultural values, tourism industry, and national identity.

"There is no known cure, but we can help reduce its spread by avoiding any movement of soil around the roots of trees. That means making sure we stick to the tracks and have spotlessly clean."

More information on Kauri disease can be found on the DOC website: Kauri disease: Pests and threats