“This method tells us that 80% of all possible growth trajectories give us an age of this living tree greater than 5,000 years. There is only a 20% chance that the tree is younger.”- Jonathan Barichivich, Scientist
Here’s yet another reason to visit Chile. Science reports that Chile now holds the distinction of the country with the world’s oldest tree. Named the Alerce Milenario or Gran Abuelo tree, it is estimated to be around 5484 years old. The tree is situated at the Alerce Costero National Park, which became a national park in 2012. If it’s confirmed by the scientific community, it would surpass Methuselah, a bristlecone pine in eastern California, which is 4853 years old.
The study was conducted by Jonathan Barichivich, who is a Chilean environmental scientist that is employed by the Climate and Environmental Sciences Laboratory in Paris. Usually, scientists use a process called dendrochronology, which is when a t-shape borer determines the age of the tree by finding the number of growth rings that it has. Due to the inability to reach the center of the tree with the borer, Barichvich switched to the following method:
“Barichivich turned to statistical modeling to determine the Alerce Milenario’s full age. He used complete cores from other alerce trees and information on how environmental factors and random variation affect tree growth to calibrate a model that simulated a range of possible ages the tree had reached by the beginning of the period covered by the partial core, along with a probability for each age. The method yielded an overall age estimate of 5484 years old, with an 80% chance that the tree has lived for more than 5000 years.”
The findings are facing their fair share of skepticism though. Dendrochronologists are likely to be skeptical of it due to the scientists not conducting a full count of tree growth rings. Additionally, Ramzi Touchan of the University of Arizona’s Laboratory of Tree-Ring Research said that “inferring growth rates during a tree’s youth can be fraught…because the young tree may have had less competition and grown faster than in later years.” Some scientists are saying that they are waiting for a peer-reviewed study to support the findings. Barichivich has gone to various conferences and published an informal brief on his findings, and he is expecting to submit a paper in a scientific journal in the coming months.
Jonathan Barichivich is hoping these findings will help provide additional protection to the tree, as visitors are allowed to walk directly up to the tree. While there is an observation platform in place to protect it, many still walk around it and touch the tree, which harms the roots of the tree and compacts the soil. With Barichivich estimating that only 28% of the tree is still alive, time is of the essence to make sure it can be around for decades to come.