Kauri dieback is caused by a soil and water-borne pathogen (Phytophthora agathidicida) of New Zealand kauri (Agathis australis). The pathogen will eventually cause the death of host kauri trees by damaging the root tissues that distribute nutrients within the tree, effectively creating drought-like conditions. The symptoms of infection include yellowing of the leaves, thinning of the canopy, branch dieback and lesions at the base of the trunk which often encircles the base and produces copious amounts of kauri gum (Dick, M., Bellgard, S, 2010).
Kauri dieback disease is currently incurable and affects kauri of all ages, resulting in kauri now being classified as a threatened species. The Auckland Plan 2050 calls for action to reduce and mitigate the threat of kauri dieback to protect our natural environment, in which our taonga species kauri play such a key part. For the Auckland Council to manage kauri dieback impacts, spread and change over time, it is essential to gain an understanding of kauri dieback distribution. So as part of their commitment to protecting Auckland’s natural environment, and in efforts to better understand the distribution of kauri dieback, Auckland Council has engaged Te Ngahere to undertake kauri surveillance in local parks and private properties across the Auckland region.
We conduct ground surveillance to assess kauri dieback symptomology and collect samples for assessment. When we identify potential kauri dieback during ground surveillance, the team will establish the extent of the kauri dieback infected zone by surveying all kauri in the area until symptoms are no longer visible. We take appropriately located samples to help delimit the infection zone. In doing this, we are assisting the Auckland Council to develop a more up to date map of kauri dieback distribution, which will be to assess its spread over the past and coming years.
The most important aspect of this job is to minimise the spread by regularly undergoing strict decontamination protocols. If you enjoy a walk through New Zealand’s native bush reserves, you can help by doing the same. Ensure that you remove all visible soil from your shoes and other equipment before entering any track and spray with sterigene at provided cleaning stations. The pathogen can survive in and spread from as little as a pinhead of soil, so it is important to be thorough. Remain on the tracks at all times and thoroughly clean equipment again when leaving. You can follow these links to find out more about kauri dieback and about Auckland Councils efforts to protect kauri trees.