From a young age, the scientist Jonathan Barichivich listened to a family tale about a remarkable tree in Los Ríos, southern Chile. Known as the great grandpa, the alere tree endured with a quiet grandeur that drew generations of caretakers. Now, more than three decades later, researchers believe it may be the oldest tree on the planet, aged around 5,500 years.
The discovery came almost by accident during a study on how climate change affects larches, a conifer native to Patagonia that faces threats from fire, logging, and drought.
In the moment of discovery, a small sample enabled experts to estimate the tree’s age, though that was not the study’s original aim. The team was astonished to find an age far beyond their expectations, earlier thought to be between 3,500 and 4,000 years old.
Situated in Alenen Costero National Park, about 800 kilometers south of Santiago, the tree appeared to surpass the venerable Methuselah pine of California, which holds the record at 4,853 years.
Researchers Antonio Lara of the University of Chile, and his colleagues, noted that the specimen is not connected to other trees by a shared root system. Uncloned trees like this one are rare because they tend to live longer when connected, a contrast to other older candidates such as the Norway spruce known as the Stale cikko, which is estimated to be around 9,550 years old. The team observes that uncloned trees often have shorter lifespans, making this finding particularly unusual.
Although the final results are expected to be published in the coming months, a recent issue of Science highlighted the potential impact of this kind of discovery in the scientific community.
an unusual method
Dendrochronology, the science that studies tree ages through growth rings, is central to this work. Traditionally, researchers drill near the center of the trunk and extract a narrow core to count the rings. That method was used in the past to estimate the age of ancient trees such as Methuselah.
In the case of the Millennium Larch, the trunk’s enormous diameter—more than four meters—prevented access to the center with standard tools. The researchers faced a practical challenge that required adaptation and careful statistical thinking.
“Great Grandfather” has become a symbol in the landscape of Valdivian forests, a reminder of the long, patient history written in wood. The park’s protected status helped shield it from logging and fires, yet the tree remains vulnerable to environmental stress.
“We’ve only reached 40 percent of the total radius. In our small sample, we counted about 2,400 years, but the remaining radius could hold many more centuries. The math isn’t a simple addition”, Barichivich notes. He now conducts research at the Climate and Environmental Sciences Laboratory in Paris.
To minimize risk, a larger drill would be unsafe for the tree. Instead, a statistical model that uses data from hundreds of other larches within the park helps estimate the remaining age with a high degree of confidence, suggesting an 80 percent probability that the tree is older than the celebrated Methuselah.
Barichivich acknowledges that his approach may invite debate within the scientific community, describing skepticism as a natural part of scientific progress.
“This isn’t about setting records. The value of this tree lies in what it can teach us about climate history and ecological resilience,” Lara adds.
Three generations of “protectors”
The great grandpa has long been tied to the family’s story in the region. The elders who kept watch over the forest area were forest rangers, beginning with Aníbal Henriquez in the 1970s. His grandson, the researcher, and now the next generation continue the legacy, saying, “It has become part of our lives, and perhaps we have become part of the tree’s life as well.”
Despite its sheltered location in a valley with few nearby larches, the tree remains vulnerable to illicit logging and fire. Today, only about 30 percent of its vitality remains, underscoring the fragility of such ancient life.
Climate change poses a major threat, and tourism has surged recently. Handling both challenges requires careful planning. The park’s protection authority temporarily closed Alenen Costero National Park while new strategies are devised to allow visitors without endangering the sample.
“Tourism and conservation can work together, but access must be regulated,” says a representative from the responsible agency. The great grandpa closes with a message carved in its rings for future generations: a call to protect and preserve it so its story continues to speak across time.