A conifer with a four-meter-thick trunk known as the Great Grandfather in Chile could be the world’s oldest living tree, defeating the current record holder by over 600 years. Chilean scientist Jonathan Barichivich argues that the tree, a Patagonian cypress (Fitzroya), also known as Alerce Milenario, could be a whopping 5,484 years old.
Barichivich, who works at the Climate and Environmental Sciences Laboratory in Paris, used a combination of computer models and traditional methods to calculate the tree’s age. Based on his estimations, the Great Grandfather would be older than Methuselah, a bristlecone pine in California that holds the record for the oldest tree at 4,853 years old.
The finding hasn’t yet been published in a journal as Barichivich hasn’t done a full count of the tree growth rings – something the scientist hopes to do in the coming months. Harald Bugmann, a dendrochronologist at ETH Zürich, told Science he “fully trust” the analysis by Barichivich and that it sounds like “a very smart approach.”
A remarkable tree
The Patagonian cypress is native to Chile and Argentina and belongs to the same family as giant sequoias and redwoods. They grow slowly and can reach heights of up to 45 meters. It was declared a national monument in Chile, yet nevertheless, it has suffered from over-exploitation due to its highly prized wood, as well as forest fires and land-use change.
The Great Grandfather grows in Chile’s Alerce Costero National Park, where it receives thousands of visitors every year. There’s a platform surrounding the tree’s roots, Barichivich said, but it’s not well guarded or signed so people climb over the roots. The problem is the tree is already very vulnerable, with only 28% of it actually alive.
Barichivich said his grandfather discovered the tree around 1972 when working in the area as a ranger. In 2020, before the pandemic hit, the researcher cored part of the Alerce Milenario with an increment borer, a drill to excise cylinders of wood without harming the tree. But the borer couldn’t reach the three’s center, Barichivich said.
That’s why he ended up using statistical modeling to determine the tree’s full age. He used completed cores from other trees and data on how environmental factors affect tree growth to calibrate a model that estimated the tree’s age. The model estimated an overall age of 5,484 years old for the Great Grandfather.
“My method is verified by studying other trees that you can obtain the full growth rings of, and it follows a biological law of growth-longevity trade-offs. The alerce is where it should be on the exponential growth curve: it grows slower than the bristlecone pine, the oldest known tree, which indicates it should live longer,” Barichivich told Newsweek.
The researcher hopes his findings will lead Chile’s government to better protect the tree. Speaking with Science, Pablo Cunazza Mardones, head of the Protected Wildlife Areas Department at Chile’s National Forest Corporation, which oversees the country’s national parks, said the agency has recently increased protections for the tree exponentially.
This article was originally published in May 2022.