Auckland scientist climbs Kauri to study impact of climate change on giants of the forest

An Auckland scientist is climbing high into the canopy of kauri trees gain a better understanding of what keeps the giants of the forest alive, as climate change and extreme weather events pose a risk to their survival..

Not just dieback, but climate change and extreme weather events are posing a risk to the giant trees' survival. Source: 1 NEWS

Auckland University scientists are gauging how much water kauri trees in west Auckland are using.

"It uses water during the day. It shrinks a bit and overnight it refills again, so we get the shrinking and growing," said Cate Macinnis-Ng, Auckland University ecophysiologist.

She says special instruments put into the trees measure the sap flow - how fast the water is moving up the tree.

"And then we can sort of sum it all together to work out how much water a tree uses in a day, or in a season, or in a whole year."

Ms Macinnis-Ng has been studying how kauri trees adapt to climate change, for seven years.

While kauri dieback is the primary threat to the trees, its shallow root system makes it susceptible to extreme weather events too.

A tarpaulin at the foot of a tree catches the rainfall to dry out the soil and simulate drought-like conditions.

"When it comes to climate change here in New Zealand, it's really the extreme events that are a big problem for forests. 

"So the floods are an issue. Storms are a problem because they can knock over the trees, but droughts are also a really extreme event that impact our forests," Ms Macinnis-Ng said.

The scientists can also measure how much carbon the tree is taking up.

"And that's really important because those things change as the climate changes," she said.

The scientists hope the influences of climate change on kauri can be reduced.