Mātauranga Māori could stop kauri dieback in its tracks

Research led by Victoria University of Wellington’s Dr Monica Gerth in collaboration with iwi has discovered molecules from New Zealand native plants could hold the solution to kauri dieback.

“Our research has discovered that some compounds found in kānuka cause an immediate loss of motility, or movement, of the infectious spores of the microbe that causes kauri dieback disease,” says Dr Monica Gerth from the University’s Centre for Biodiscovery and School of Biological Sciences. “If the spores can’t swim, they can’t make it to a kauri root to infect. These compounds could stop this pathogen from moving through soil and infecting kauri trees.”

These results came from a new collaboration between scientists and kaitiaki from iwi, Dr Gerth says, after colleague Chris Pairama (Te Taou, Ngati Whaatua, Waimauku) connected the research team with Ian Mitchell (Te Uri Taniwha, Ngāpuhi, Waima).

“Being from the north where kauri is common, Ngāpuhi have extensive knowledge about kauri and how plants interact with the forest, and we hoped that we could combine their mātauranga Māori and our scientific knowledge to address the serious problem of kauri dieback disease.”

She says Ngāpuhi knowledge and experience shows that a healthy forest involves three stages of plants— ‘first wave’ plants that cleanse and prepare the soil, ‘second wave’ plants that encourage fertility and growth, and ‘third wave’ plants, including kauri, that bring permanence and stability.

The research group studied four ‘first wave’ plants—kānuka, karamū, kawakawa, and nīkau—to see if the cleansing activity of these plants was due to anti-microbial properties, Dr Gerth says. In the end, testing showed that kānuka extract was most effective at stopping the pathogen.

Mātauranga Māori and scientific knowledge were combined at every stage of this project and collecting and testing the plants was a collaborative effort, Dr Gerth says.

“This project was about mutual trust and collaboration, and it was very important to us to create an ethical collaboration,” Dr Gerth says. “These plants are taonga to Māori, and therefore the right of mana whenua to practice kaitiakitanga (stewardship) should be acknowledged and respected.”

Dr Gerth and her colleagues hope to continue their search for new compounds, while also exploring how their findings can be applied to protect kauri trees in the field.

“Kauri dieback is one of the biggest crises ever to face New Zealand's forests. If we lose kauri, we lose not only a unique ecosystem, but also a key part of part of New Zealand’s identity, history and culture,” Dr Gerth says.

Kia mate te ngarara o te kauri, kia whakaora te mauri o te ngahere. Kauri ora, mauri ora!

This research was funded by the Ministry of Business, Innovation, and Employment, and published in the Journal of the Royal Society of New Zealand. The manuscript is freely available online at: http://dx.doi.org/10.1080/03036758.2019.1648303.

In addition to Dr Gerth, Mr Mitchell and Mr Pairama, the cross-disciplinary research team included Dr Scott Lawrence from the University of Otago, Professor Nigel Perry and Ms Elaine Burgess from Plant & Food Research, Associate Professor Wayne Patrick from Victoria University of Wellington, and Dr Amanda Black from Lincoln University.