About 5400 years ago, when man invented writing, a Chilean cypress (fitzroya cupressoides) may have begun to grow in the coastal mountains of today's Chile In a cool and humid Canyon, it avoided fire and logging, which had taken away many other similar trees, and it grew into a gray giant - more than 4 meters wide.
Most of the trunks died, some of the crowns fell off, and the trees were covered with moss, lichens, and even other trees that took root in their gaps.
Now, the tree -- known as the alerce MILENARIO or Gran Abuelo (great grandfather) tree -- may claim a new and extraordinary Title: the oldest living individual on earth.
Jonathan barichivich, a Chilean environmental scientist working at the climate and Environmental Sciences Laboratory in Paris, used computer models and traditional methods to calculate the age of trees to estimate the age of alerce MILENARIO - possibly over 5000 years old. This will make it at least a century older than the current record holder.
Many tree age experts may be skeptical of barichivich's statement because it does not involve comprehensive statistics of tree growth rings, which has not yet been published. But at least some experts are open to this possibility. Harald bugmann, a tree age scientist at the Federal Institute of technology in Zurich, said: "I fully believe Jonathan's analysis. It sounds like a very clever method."
Chilean cypress is a coniferous plant belonging to the same botanical family as Giant Sequoia and redwood. From a distance, they can be like those giants. Antonio Lara of austral university in Valdivia, Chile, proved in the 1990s that Chilean cypresses can grow to extreme ages. In a 1993 study, Lara and a colleague reported on a Chilean cypress stump in southern Chile with 3622 growth rings. This makes it the oldest species after foxtail pine, surpassing Sequoia.
But the study does not include alerce MILENARIO, which is separated from other ancient trees in the rain forest west of La munion. Barichivich said his grandfather discovered the tree around 1972. His grandfather and mother worked as Rangers in the park where the tree was located. He suspected that he was one of the first children to see the tree. "This is a tree very, very close to our hearts," he said.
In 2020, just before the new crown pandemic, barichivich and Lara drilled a part of alerce MILENARIO with an incremental drill, a T-shaped drill that scientists used to cut narrow cylindrical wood without damaging trees. Barichivich pointed out that "to some extent, the tree called me and said it was time" to take the core. The wood produced about 2400 closely spaced growth rings.
Since barichivich's rig could not reach the center of the tree, he turned to a statistical model to determine the full age of alerce MILENARIO. He used the complete cores of other Chilean cypresses and information about how environmental factors and random changes affect tree growth to calibrate a model. It is reported that the model simulates the age range that trees may reach at the beginning of the period covered by some tree cores and the probability of each age. The overall age estimated by this method is 5484 years old, and the probability of the tree living for more than 5000 years is 80%.
"It's amazing," barichivich speculated that the tree is about 4000 years old.
Barichivich presented his findings at the meeting and wrote a short informal report on his approach. Some people in this field are very interested in it. "The prospect is certainly exciting," said Nathan Stephenson, an honorary scientist at the U.S. Geological Survey who reviewed the report. "But he won't judge until he sees more information. As a scientist, you want a peer-reviewed publication that includes all the details."
Tree age scientists traditionally believe that the counting of actual rings is the gold standard for determining tree age. Ed cook, founding director of the tree ring laboratory at Columbia University, wrote in an email: "the only way to really determine the age of a tree is to calculate the tree rings through tree aging, which requires all tree rings to exist or be counted." Ramzi touchan of the tree ring Research Laboratory at the University of Arizona added that inferring the growth rate of trees when they are young may be problematic because young trees may have less competition and grow faster than in later years.
Barichivich said his approach considered this possibility. He plans to submit a paper to the journal in the coming months.
At the same time, he said that even if alerce MILENARIO could become the record holder, the Chilean government should be stimulated to better protect it. At present, visitors can climb down from an observation platform in the park and walk around the tree. Barichivich says this behavior will hurt the roots and compact the surrounding soil. In addition, as the climate becomes drier, it will be more difficult for roots to absorb water and put pressure on trees. "People are killing it. It urgently needs our protection," he said.
Pablo cunazza mardones, head of the Wildlife Reserve Department of the Chilean National Forest company, which oversees Chilean National Parks, also believes that the tree is very fragile. He pointed out that budget constraints hampered conservation efforts, but added that the agency had "doubled" its protection of the tree and increased the number of forest rangers from one to five.
Whether or not alerce MILENARIO is accepted as the world's oldest tree, the finding highlights that some trees can live longer than most of their peers. Bugmann table so: "some species do things we think should be impossible. (but) there are still mysterious things in the forest."