Hunua ranges safe from kauri dieback disease

23 Aug 2012

New Zealand is home to one of the largest and longest-living trees in the world: the New Zealand kauri (Agathis australis).

These majestic conifers can grow more than 50m tall, with trunks greater than 16m in girth and live for more than 2000 years.

New Zealand may not have castles or pyramids as records of history but we do have these incredibly ancient and beautiful trees.  Kauri are our castles; kauri are our taonga (treasures).

 These giant trees support distinctive ecosystems high above the forest canopy. The branches of a large kauri (with epiphytes and nooks that collect water) provide a home to a range of native birds and many insects and native lizards live their entire lives in the branches of a kauri, never touching the ground.

Kauri forests once covered over a million hectares from Kawhia/Tauranga in the south, up to the far north of Northland. Sadly, logging and land clearance over the last 150 years has left less than 1 per cent of this original forest remaining – often in fragile fragments. 

Some ecologically significant kauri stands still remain tucked away in the South Auckland region.

Unfortunately, these trees now face the further threat of kauri dieback disease, a soil-borne disease killing kauri trees in Auckland and Northland.  Symptoms include bleeding gum at the base of the trunk, yellowing leaves, thinning canopy and dead branches.

Despite kauri dieback disease affecting many trees in Auckland and Northland forest, we still have some healthy kauri forests and one of these is the Hunua Ranges, including Hunua, Waharau and Whakatiwai Regional Parks.

The kauri in the Hunua Ranges  have been confirmed as healthy after extensive aerial and ground surveys and their disease-free status makes them even more precious.

In the Hunua Ranges, cleaning stations for footwear and mountain bikes have been installed and large entrance signs remind visitors that they’re entering a ‘healthy kauri area’ and should make sure they clean their shoes before heading into the forest.

“This disease is spread by soil movement so could be brought into Hunua on visitors’ dirty shoes and equipment,” says Ali Thompson, Senior Ranger Conservation for Southern Parks.

“Everyone working in or visiting kauri forest should make sure their footwear and equipment including bikes is clean of soil when they arrive and clean it again when they leave.

“It doesn’t take much effort to do this and it is the only way we are going to protect the kauri in Hunua from this disease.”

Visitors to parks and reserves should also always keep to the tracks.