Watch: 3D graphic shows how kauri dieback could spread through mighty Tāne Mahuta, as scientists make breakthrough

Scientists hope seedlings taken from trees around Northland and Tauranga could be naturally resistant to kauri dieback disease and help save New Zealand's precious natives.

Kauri dieback is threatening the country's most famous tree, the majestic Tāne Mahuta in Waipoua Forest, Northland.

1 NEWS has created a 3D graphic of the planet's largest living kauri - 51.2 metres tall and estimated to be between 1250 to 2500 years old.

Landcare Research plant pathologist Stanley Bellgard told 1 NEWS scientists have deliberately infected seedlings in a glasshouse, "and we're trying to see which ones are not going to die". 

A pathogen that attaches to kauri roots and starves them from below is killing our forests at speed, but researchers say the response is picking up too.

Infected kauri don't immediately show symptoms and it used to take up to a month to test if the disease is present in the soil.  

But scientists have made a breakthrough.

Pine needles are floated over a flooded soil sample and if the pathogen is present, it swims to the needles. 

The needles are ground up, their DNA is extracted and put in a machine which in 20 minutes shows which are positive for the pathogen.

Knowing where the infections are helps researchers understand how it behaves and where it might go next.

No lab is needed, meaning it can be deployed remotely and in large numbers.

Richard Winkworth from the bio-protection research centre based at Massey University says the the long-term goal is to make it possible for a  Department of Conservation ranger or a landowner to be able to go out, test a soil sample and make management decisions immediately.

The mission is more critical than ever as the disease has been found near sacred Tāne Mahuta. 

And kauri are not the only species under threat.  

"Kauri is the keystone species, but there are many species that rely on that environment. If kauri goes, that's an entire ecosystem gone," Mr Winkworth said. 

It's a bleak thought, but our leading researchers are on it. And they say we haven't lost our forest giants just yet.  

New Zealand’s biggest tree, in Northland’s Waipoua Forest, is under threat from the disease. Source: 1 NEWS