Phytopthora agathidicida: The Problem
The Kauri Project addresses the problem of kauri dieback caused by the microscopic soil-born pathogen Phytopthora agathidicida (previously called Phytopthora taxon agathis or PTA), which enters the trees system through the roots and affects the trees ability to take up and distribute nutrients, causing the ‘dieback’ effect that is the main visible symptom of the disease. Infected trees inevitably die, and with the pathogen able to live dormant for long periods in soil, the threat to kauri as a species is immense.
Already well established by the time it was formally identified (2008), kauri dieback is now a serious issue in most of the major kauri containing forest remnants, particularly noticeable in Waipoua, Trounson, Waitakere and Great Barrier. The severity of the threat to a species that is both biologically and culturally significant is not to be underestimated. (For more information on kauri dieback and current strategies on management see http://www.kauridieback.co.nz)
The effect on the environment of the loss of kauri is potentially catastrophic. The scale to which the Kauri tree can grow, along with its accumulation of a particularly deep leaf litter gives them the potential to be one of the largest absorbers of carbon of any tree in the world. An ancient species, their distinct characteristics affect the forest environment around them in a way that has developed a unique ecosystem, in which many plants and other organisms, including severely threatened species such short-tail bats, rely on kauri for their existence. We are now left with but a small remnant of these forest giants which once grew as far south as Invercargill and are now found only in the Kaimai Ranges, Coromandel, parts of Waikato and Auckland and in the Far North. Intensive milling and forest destruction throughout the late 1800s to the 1920s, for timber and to clear land for farming and gum-digging, decimated the originally rich forest cover of Northern New Zealand. This taonga once grew from the mountains to the sea (kauri ki uta, kauri ki tai). Now approximately 7,455 hectares remain, in scattered fragments. (http://www.teara.govt.nz/en/kauri-forest/page-1)
The consequences of not addressing this problem will be the loss of these last great forests, their rich and unique biodiversity, and one of the key trees to ‘breathe’ life into the people of Aotearoa.
The Human connection
Humans are almost certainly responsible for the accidental introduction of this pathogen to New Zealand, and are the major vector of P. agathadicida, able to transport it without knowing in tiny amounts of soil on shoes and other equipment. This has made communication and engagement with the public of New Zealand, as well as with visitors, a critical part of the response. Because the disease is, at this stage, uncurable and seems difficult, if not impossible, to be eliminated from infected environments, the importance of community engagement and education will remain an ongoing priority.
As a population we must learn to live with and manage this disease, in order to keep it contained. Behaviour change around how we live with kauri and operate within forest areas can only come through sustained education. For this to be effective and lasting, the science of kauri dieback must be well understood, and alongside this the way in which forests operate. Hence the quality and depth of communication, education and engagement are of high priority. The Kauri Project was established to address this need.