The New Zealand Herald By Geoff Cumming, Nov. 30, 2013
Reports of Tane Mahuta's demise may be premature but death could be just a stray boot away. The dieback disease threatening the forest kings of northern New Zealand is as bad as it gets: once the algae-like microbes infiltrate the kauri's root system, there is no cure. By the time symptoms show - leaf yellowing, canopy loss, withered branches, bleeding lesions and collar rot - it is likely too late.
Talk to scientists and agencies beavering away on the response and the messages are at once frightening and encouraging. The disease is a new species of phytophthora, from the Greek for plant destroyer. Different strains have devastated everything from strawberries, tomatoes and potatoes to forest giants like jarrah in Australia, oak trees in Europe and North American chestnuts.
The soil-borne variety attacking our kauri, known for now as PTA, has spread to 11 per cent of kauri stands in the Waitakere Ranges. It has footholds in the Waipoua Forest, home of Tane Mahuta, on Great Barrier Island (where it was first observed in the 1970s but mis-identified), in the Russell Forest and on private bush lots in Auckland and Northland.