Ancient New Zealand kauri trees tell a climate change story – Vox

Source: Ancient New Zealand kauri trees tell a climate change story – Vox

economics of the biodiversity crisis.

In February 2019, Mark Magee was scraping the bucket of his 45-ton excavator through a hillside when it hit something 30 feet down that wouldn’t budge.

It was high summer in the Southern Hemisphere, and Magee, a construction foreman, was clearing a platform for a new geothermal power plant near Ngāwhā, a tiny community in New Zealand’s Northland region, the long peninsula that stretches from the city of Auckland to the country’s northern tip.

He called in additional digger drivers to help. Gradually, as the machines peeled away the mudstone encasing the obstinate object, they realized it was a tree — and not an ordinary tree. More and more of it appeared, a seemingly endless log. When it lay uncovered, complete with a medusa-like rootball, it measured 65 feet long and 8 feet across, and weighed 65 tons.

It was a kauri tree, a copper-skinned conifer endemic to New Zealand. The indigenous Māori hold the species sacred and use its honey-colored softwood for traditional carvings and ocean-going canoes. Although this kauri tree had clearly been buried for thousands of years, Magee was astonished to see leaves and cones stuck to its underside that were still green.

The power company, Top Energy, called in a local sawmiller named Nelson Parker to examine Magee’s find. Parker, a champion woodchopper with powerful shoulders and a missing finger, had been digging up, processing, and selling kauri logs like this one since the early 1990s. As soon as his chainsaw bit into the bark, he knew from the color of the sawdust (dark yellow) and from the smell (subtle, resiny) that this tree was very old, and worth a lot of money.

Parker also knew that swamp kauri, as the buried trees are known, are worth a lot to science. One this large would be of special interest to a group of scientists who study the information that the ancient trees have coded into their rings. After removing the roots, he cut a four-inch-thick slice from the base of the trunk and sent it to them for analysis.

What he couldn’t know then was that this particular tree held the key to understanding an ancient global catastrophe — and how it may have shaped our collective past.