‘It’s a miracle’: Gran Abuelo in Chile could be world’s oldest living tree

John Bartlett

100ft alerce has estimated age of 5,484, more than 600 years older than Methuselah in California. In a secluded valley in southern Chile, a lone alerce tree stands above the canopy of an ancient forest. Green shoots sprout from the crevices in its thick, dark trunks, huddled like the pipes of a great cathedral organ, and water streams down its lichen-streaked bark on to the forest floor from bulbous knots in the wood.

Photograph: Krystyna Szulecka Photography/Alamy

“It was like a waterfall of green, a great presence before me,” remembers the climate scientist Jonathan Barichivich, 41, of the first time he encountered the Gran Abuelo, or “great-grandfather”, tree as a child.

Barichivich grew up in Alerce Costero national park, 500 miles (800km) south of the capital, Santiago. It is home to hundreds of alerces, Fitzroya cupressoides, slow-growing conifers native to the cold, wet valleys of the southern Andes.

“I never thought about how old the Gran Abuelo could be,” he said. “Records don’t really interest me.” However, Barichivich’s groundbreaking study has shown the 100ft (30-metre) giant could be the world’s oldest living tree. In January 2020, he visited the Gran Abuelo with his mentor and friend, the dendrochronologist Antonio Lara, to take a core sample from the trunk. They were able to reach only 40% into the tree as its centre is likely to be rotten, making a complete core unattainable. Yet that sample yielded a finding of about 2,400 years.

Undeterred, Barichivich set about devising a model that could estimate the Gran Abuelo’s age. Taking the known ages of other alerces in the forest and factoring in climate and natural variation, he calibrated a model that simulated a range of possible ages, producing an astounding estimate of 5,484 years old.

That would make it more than six centuries senior to Methuselah, a bristlecone pine in eastern California recognised as the world’s oldest non-clonal tree – a plant that does not share a common root system. Some clonal trees live longer, such as Norway’s Old Tjikko, thought to be 9,558 years old.

arichivich believes there is an 80% chance the tree has lived for more than 5,000 years – but some colleagues have poured scorn on the findings. They assert that complete, countable tree ring cores are the only true way of determining age. The climate scientist hopes to publish his research early next year. He will continue to refine his model but waves away the “colonialism” present in the field.

“Some colleagues are sceptical and cannot understand why we have revealed the finding before formally publishing it,” he said. “But this is post-normal science. We have very little time to act – we cannot wait one or two years, it could already be too late.” Barichivich believes ancient trees may help experts understand how forests interact with the climate.

“The Gran Abuelo isn’t just old, it’s a time capsule with a message about the future,” he said. “We have a 5,000-year record of life in this tree alone, and we can see the response of an ancient being to the changes we have made to the planet.” In January, Barichivich, who works at the Laboratory for Climate and Environment Sciences and Environment in Paris, won a €1.5m European Research Council starting grant he describes as the “holy grail” for a scientist. He has embarked on a five-year project to assess the future capacity of forests to capture carbon, hoping to add tree-ring data from thousands of sites around the world into climate simulations for the first time.

More than a third of the planet’s vegetated surface is covered by forests, capturing carbon dioxide during photosynthesis, but current models are only able to make estimates for 20 or 30 years into the future.
By adding data for xylogenesis, the formation of wood, Barichivich believes he could provide 100-year predictions for climate change – and revolutionise our ability to understand and mitigate its effects.

“If tree rings are a book, then for 40 years everyone’s just been looking at the cover,” he said….