Red Alert

What we don’t know

Posted by on January 14th, 2013

 

Phil Twyford Hillary Trail day 1

Phil Twyford, Simon Randall and Ngarimu Blair setting off on the Hillary Trail

Walking the first leg of the Hillary Trail today between Arataki Visitor Centre and Huia, I was struck by how little we know about Phytophthera taxon agathis, the pathogen that is killing kauri trees.

I can recite what we don’t know: we don’t know where it came from, we don’t know when it arrived, we don’t know exactly how it kills trees and we don’t know how to fight it.

A group of half a dozen scientists have been working on the disease for the past few years with funding support from government. A handful of scientists trying to deal with a largely unknown organism that is wiping out one of New Zealand’s most iconic species.

Most of the paltry $6 million spent over the last five years went on putting up signs and encouraging trampers to scrub the bottom of their boots, which is important to do, but if this was a biosecurity threat to our kiwifruit or pine plantations (PSA or painted apple moth) then you can bet ten times that amount would have been invested in the science.

Only science has any chance of saving the kauri.

It is important that we try to understand the disease, and what we can do about it. Plant pathologists like Ian Horner and Ellena Hough were out today in the bush above Huia monitoring whether kauri infected with PTA respond to having phosphite injected into their trunks.

Horner and Hough have day jobs with Plant and Food trying to save the kiwifruit industry from PSA. Saving kauri is a sideline for them, and today they are testing whether the phosphite they injected into 50-100 year old sick kauri a year ago has had any positive effect. It is an approach that works well with avocado trees infected with a similar pathogen to the one that is plaguing kauri.

Early results are inconclusive, but Horner concedes that even in the best case scenario, injecting phosphite is not a fix. Any beneficial effect would be temporary, only as long as the phosphite remained in the tree’s system. It might help save an iconic tree, or one treasured by a private landowner, but it is not going to save our forests.

The research must go on. The Government’s lack of commitment to extending the funding for the kauri dieback work beyond mid-2014 puts a question mark over this vital work. It is only a few million dollars a year. The survival of kauri as a species is at stake.

It has been a great start to the Hillary Trail. We had a send off from friends, park rangers and residents of the Waitakeres, with a karakia by kaumatua Fred Holloway. Thanks to my co-walkers Ngarimu Blair of Ngati Whatua, Ross Duder of Friends of Regional Parks and Simon Randall local body politician who did his Masters on Phytophtheras in the Waitakere Ranges.

Tomorrow we walk to Whatipu.

Hillary Trail send off

Send-off at Arataki

Ian Horner

Scientist Ian Horner injecting phosphite into kauri at Huia


One Response to “What we don’t know”

  1. Harv says:

    How can people outside NZ help?