About 5400 years ago, when man invented the word, a cedar tree (Chilean cypress) may have grown in the coastal mountains of Chile today It hid in the cool and humid Valley, escaped fire and logging, and now has grown into a gray giant with a diameter of more than 4 meters. Most of the trunk of the tree has withered, some of the crown has fallen off, the tree is also covered with moss and lichens, and other trees have even taken root in its cracks.
The oldest known tree in the world. Image source: Gabriel Popkin
Now, this tree, called alerce MILENARIO or Gran Abuelo, may have a new and unusual title: the oldest living individual on earth.
According to the estimation of Jonathan barichivich, a Chilean environmental scientist working at the climate and Environmental Science Laboratory in Paris, the tree may be over 5000 years old, at least a century older than the current record holder, a foxtail pine in eastern California. There are 4853 rings under its rough bark.
Chilean cypress is an evergreen tree. From a distance, they are similar to giant fir and Sequoia. Antonio Lara of the Southern University of Chile in Valdivia proved in the 1990s that Chilean cypresses can grow to extreme ages. In a 1993 study, Lara and colleagues reported that a Chilean cypress in southern Chile had 3622 growth rings. This makes it the second oldest species after foxtail pine, surpassing Sequoia.
In 2020, barichivich and Lara took cores with an increasing diameter drill (a T-type drill, which scientists use to cut narrow cylindrical wood without damaging trees). There were about 2400 tree rings in the core samples taken. Because the tools used at that time could not reach the center of the tree, barichivich turned to a statistical model to determine the complete age of the Chilean cypress. Using computer models and sampling data, he estimated that the tree was about 5484 years old.
"This is amazing. I thought this tree was about 4000 years old." Barichivich also wrote a brief informal report. However, many scientists have questioned this.
Tree ring experts believe that the actual number of rings is the gold standard for determining the age of trees. 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 by the age of tree rings, which requires that all tree rings exist or be explained clearly."
In this regard, barichivich said that his method explained this possibility. He plans to submit a paper to a magazine in the coming months.
Barichivich said that whether the tree is recognized as the oldest tree in the world or not, the Chilean government should better protect it. At present, the tree is located in the park. Visitors can climb down from the observation deck and walk around the tree, which will damage the root of the tree and compress the surrounding soil. At the same time, as the climate becomes drier and drier, it is more difficult for tree roots to absorb water, causing pressure on trees.
Pablo cunazza mardones, head of the wildlife protection department of the Chilean National Forest company, also believes that the tree is fragile. He said that budget constraints hindered the protection work, but the agency still "doubled" the protection of the tree and increased the number of forest rangers at the site from one to five.