What Is the Oldest Tree in the World?

To see the world's oldest tree, or one of the front-runners for world's oldest tree, one must travel to a mountaintop in Sweden where a spruce tree has kept its tenacious hold on life for nearly 10,000 years.

The spruce tree, which took root at the end of the world's last ice age in about 7542 B.C.E., was discovered by scientists surveying tree species on Fulufjället (Fulu for short) Mountain in Dalarna province in 2004. Carbon dating confirmed its age in 2008.

The type of tree — and its age — came as a surprise to Leif Kullmann, professor of Physical Geography at Sweden's Umeaa University. Kullmann led a team of researchers to a spot near the summit of Fulu Mountain, where they found a cluster of spruce trees over 8,000 years old and, among them, evidence that a single tree had existed for 9,550 years. (Kullman named the tree Old Tjikko, in honor of his late dog.)

Kullman believes that people immigrating across a land mass close to shrinking glaciers may have introduced the spruces. The discovery of the mountain spruce is not without controversy, however.

The tree's remarkable age is attributed to a single root system, which has been alive for at least four generations; the visible part of the tree — the trunk, branches, cones and needles — only lives for about 600 years. When individual tree trunks die, a cloned stem takes root to replace it.

The ability to replace a new trunk from the tree's root system has been key to its lengthy survival, say researchers.

Is a long-living clone growing from a generation-spanning root system still the same tree? It's a question scientists and researchers (and record-book publishers) will need to debate.

One thing, though, is certain: If you consider that all the world's oldest trees have lived anywhere from 5,000 to nearly 10,000 years, they are each a living example of nature's ingenuity.

While even the shortest-lived trees (like most fruit trees) can survive for 50 years, some species (like pine trees) grow so slowly that even at the age of 40, they may only be 6 inches (15 centimeters) tall. This "slow and steady wins the race" strategy appears to be a winning one, at least when trees are young, but that changes as trees age.

A study published in the journal Nature reports that the older a tree is, the faster it will grow. Previously, the prevailing thought was that tree growth slowed with age. Now researchers know that the largest and oldest trees can increase their wood, bark and leaf mass by 1,300 pounds (about 600 kilograms) each year.

And, unlike most living creatures whose cells change and break down with each day that passes, many trees don't have an age limit. While trees can succumb to being cut down, or to fire, insect infestations, diseases or natural occurrences like lightning, some trees could technically live indefinitely.

Before the Egyptians had even started constructing the famed pyramids of Giza, there was a tiny tree putting down roots in the White Mountains of eastern California.

This tree, a bristlecone pine dubbed Methuselah, is still growing in the Inyo National Forest of California's Great Basin and was once believed to be the world's oldest non-clonal tree.

Tree-ring data from a core sample of its trunk estimates its age at 4,853 years old. The Forest Service keeps Methuselah's exact location secret, but it lives somewhere along the Methuselah Trail in the Ancient Bristlecone Pine Forest.

In 2022, a Patagonian cypress in Chile, known as Gran Abuelo (great-grandfather) or Alerce Milenario, was discovered and is thought to be a new candidate for world's oldest tree.

This particular tree, found growing in a ravine in Chile's Alerce Costero National Park, is estimated at 5,484 years old, which is more than 600 years older than Methuselah.

Chilean environmental scientist Jonathan Barichivich found and studied the tree and has been presenting the findings at conferences. However, because Barichivich estimated the tree's age based on a partial sample of the core, there is some controversy surrounding the estimate's accuracy.

Whatever their age, the world's oldest trees are vital — not only to the health of their respective environments, but as a measure of climate change. By studying the trees' core samples, scientists are able to see the impact of environmental changes on the trees and their surroundings.