Kauri forests, once extensive in the Auckland, Northland and Waikato regions, were decimated by the logging industry of the late 19th and early 20th centuries. Auckland was built on kauri both literally and figuratively – kauri logging provided the materials for physically building the growing city’s infrastructure, and from 1850-1900, kauri gum was Auckland’s main export. It is now estimated that no more than 4% of original kauri forests remain. What little kauri forest we have left is now at risk, but there are things we can do to help protect our precious ngahere (forests). 

Blog by Jane Groufsky, Curator Social History

Kauri Dieback

Kauri Dieback

Recently, the remaining kauri have been under threat from the pathogen Phytophthora agathidicida, known as kauri dieback. The pathogen attacks the tree’s ability to absorb water and nutrients from the soil. Symptoms include root rot, yellowing of leaves then defoliation, bleeding resin, and ultimately death of the tree. Although kauri dieback had been identified in Great Barrier Island in the 1970s, it was first noticed as a condition of concern in 2006 in the Waitakere Ranges. Since then, scientists have been desperately researching the disease to understand it and how kauri can be treated. Although dieback affects all kauri in New Zealand, Auckland has been the centre of this research, with Dr Nick Waipara and the late Dr Ross Beever important contributors in this field. 

The pathogen can spread on just a pinhead of soil, making humans one of the biggest spreaders of the disease. Approaches to stop the spread have included track closures and an emphasis on getting track users to clean their footwear. One important aspect is raising public awareness and understanding of the disease. Kauri are a keystone species – many other species have evolved around them, so their loss would significantly change the ecosystem. 

Rāhui

Rāhui

In 2017 the Auckland Council released a report showing that kauri dieback in the Waitakere Forest (Te Wao Nui a Tiriwa) had more than doubled in 10 years, with 19% of trees infected. There were public calls to close the whole park but the council instead chose to keep the park open, with targeted closure of certain areas. On 2nd December 2017, Te Kawerau ā Maki placed a rāhui (a temporary ban on human activity) on the Waitakere Ranges to prohibit people from entering the park. Around a hundred people met at the Cascades Falls Park where iwi carried out the ceremony. This was to allow the forest to heal and to protect it for future generations. They also erected signs in the region to inform the public of the rāhui and what it meant. 

While many locals and groups like Forest and Bird, the Tree Council, the Waitakere Ranges Protection Society, and Friends of Regional Parks all supported the rāhui, there were no physical barriers and many still flouted the closures. In early 2018 Auckland Council worked in partnership with the Te Kawerau to physically close all forested areas of the Regional Park. Work continues to make the tracks safe for reopening, and the spread of the disease has slowed down. 

Clean your shoes

Clean your shoes

Due to the tiny size of the pathogen, one of the main ways it is spread is by people with infected soil on their footwear travelling to forested areas with kauri. Those studying the disease have noted that the majority of infected trees are in close proximity to walking tracks, which is why it is very important to stay on the tracks. Another way for the public to help stop spreading the disease is to ensure footwear is thoroughly disinfected. 

The brush and trigger spray bottle shown here were part of the efforts by Keep Kauri Standing (now Tiakina Kauri) to spread awareness of the need to clean footwear. Initially, barrels of disinfectant with brushes and spray guns were installed in popular tracks, but these had limited public uptake. 

The Department of Conservation (DOC) contacted Mike Williams of industrial design firm MWDesign to come up with a solution which would encourage users to engage with the cleaning system. MWDesign developed cleaning stations with a combination of fixed brushes and a pressure-activated pad which mists the foot with the disinfectant solution. Dirt and particles drop below the unit into a reservoir which instantly kill any pathogens. MWDesign is continually evolving the cleaning station design to respond to the needs of DOC and the councils who use the units. In 2022, MWDesign donated one of their 2019 prototypes to Auckland Museum. 

The Kauri Project

The Kauri Project

The Kauri Project was established in 2013 to spread awareness and understanding of kauri dieback through arts-based community engagement. According to the Kauri Project trust, their main object is to “educate and encourage the awareness of the public, in respect of the preservation, protection and conservation of kauri, and it’s associated ecosystem including associated fauna and flora, through engaging with iwi, artists including international artists, indigenous artists and communities, scientists educators and the general public and the development of exhibitions, installations, hui, seminars, symposium, film, music, written word, publication, workshops, alternative media, and, by any other means, in New Zealand and overseas, to advance knowledge and understanding of this taonga in order to facilitate protection of the kauri species and to advance environmental knowledge and understanding generally.” 

The project engages with artists as a way to communicate with and influence the wider public. One of their main visible projects has been three series of limited-edition prints. Artists were commissioned to produce new works relating to the theme. Alongside the print editions, the artworks were printed as free posters for distribution to schools and via Kauri Project exhibitions and events. On the back of the posters there is information on the artist and on kauri dieback. 

The Kauri Project also worked with McCahon House (along with Te Kawerau ā Maki, Auckland Council Biosecurity and Auckland Botanic Gardens) to harvest cones from the top of infected trees. Seeds from the cones have successfully been used to germinate seedlings, which are sold through McCahon House and at Kauri Project exhibitions and events. 

Urban tree protests

Urban tree protests

In addition to the threat posed by kauri dieback, urban kauri on private land can still be chopped down by landowners. Changes in 2015 to the Resource Management Act removed blanket protections for urban trees and the removal of kauri is permitted under the Auckland Unitary Plan. Prior to 2009, native trees over a size threshold were protected by default and needed resource consent to be removed, but there are now very few protections to prevent private landowners from chopping down trees on their property. 

Auckland has an average tree cover of less than 20% so the felling of urban trees continues to decrease this. Erosion of laws to protect urban trees has led to the felling of prominent trees, which has in turn led to protests drawing attention to this issue. Awhiawhi, a 350-year-old kauri in Titirangi, has been threatened by developers since 2015. The tree has survived so far due to vehement public protest, but still has no legal protection. 

Destruction of kauri by urban tree removal and the spread of kauri dieback are human-generated problems, but we can also have a role in actively protecting these taonga. By staying on marked tracks, respecting track closures, and making sure we thoroughly clean our footwear, we can help stop the spread of kauri dieback and ensure these giants of the forest stay standing. 

Images

1. The skeleton of a dead kauri tree stands out among the leaves of healthy trees in the Waitākere Ranges, 2019 © Lawrence Smith, Stuff, All Rights Reserved. 

2. (Left) Kauri Dieback case in Tāmaki Herenga Waka Stories of Auckland gallery.

3. (Right) Rāhui sign design, 2018, Te Kawerau-a-Maki and Chris McBride © Te Kawerau-a-Maki and Chris McBride, All Rights Reserved. 

4. Footwear cleaning unit prototype, 2019, MWDesign. Collection of Auckland Museum, 2023.2.1. Gift of MWDesign.

5. Spray bottle and shoe brush, 2010s, Keep Kauri Standing. Collection of Auckland Museum, 2023.1.1-2. Gift of Chris McBride.

6. Fredrik Hjelm from Biosense harvesting harvest the seeds from sick kauri for The McCahon Kauri Project, a collaboration between The Kauri Project, McCahon House, Te Kawerau-a-Maki, Auckland Council Biosecurity, and Auckland Botanic Gardens, 2019 © Chris McBride, All Rights Reserved.

7. SAVE OUR TREES sign, 2018, Louisa Hollier Collection of Auckland Museum, EPH-PT-1-225. Gift of North Shore Forest and Bird. All Rights Reserved. 

8. Kauri dieback cleaning station, Waitakere Ranges, 2022 © Dee Nicholls, All Rights Reserved.