00:45 Tree Older Than Christianity Discovered in North Carolina Scientists make a shocking find in southeastern North Carolina -- one of the oldest living trees on earth.

At a Glance A bald cypress in North Carolina was recently determined to be more than 2,600 years old

The find makes it one of the oldest trees in the world.

Researchers say the rings of ancient trees provide a historical record of climate change. A bald cypress tree in North Carolina has been dated to the year 605 BC, making it one of the oldest known trees alive on earth.

Scientists studied the tree's growth rings and used radiocarbon dating to determine that it is at least 2,624 years old, putting it at fifth-oldest in the world, the study says. The tree was one of 110 sampled along North Carolina's 65-mile-long Black River. Another of the trees was found to be 2,088 years old.

“This is one of the great old-growth forests left in the world,” lead researcher David Stahle, a professor of geosciences at the University of Arkansas, told the Charlotte Observer.

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The stand of bald cypress is on property owned by the Nature Conservancy in an area known as Three Sisters Swamp. The cypress there are the oldest known living trees in the U.S. outside of California, and the oldest known wetland tree species in the world, according to the study. The oldest known living tree in the world is a Great Basin bristlecone pine in California that dates to 5,066 years ago.

“It is exceedingly unusual to see an old-growth stand of trees along the whole length of a river like this,” Stahle said in an article published by the University of Arkansas. “Bald cypress are valuable for timber and they have been heavily logged. Way less than 1 percent of the original virgin bald cypress forests have survived.”

Stahle is an expert in dendrochronology, the study of tree rings, and has been studying the Black River bald cypress since 1985. He previously recorded a 1,700-year-old tree in the same area.

<img class="styles__noscript__2rw2y" src="https://s.w-x.co/util/image/w/AncientCypress.jpg?v=at&w=485&h=273" srcset="https://s.w-x.co/util/image/w/AncientCypress.jpg?v=at&w=485&h=273 400w, https://s.w-x.co/util/image/w/AncientCypress.jpg?v=ap&w=980&h=551 800w" > Scientist David Stahle and a team of researchers discovered a tree more than 2,600 years old among this stand of bald cypress along the Black River in North Carolina. (University of Arkansas)

Besides the science involved in dating them, ancient trees are a valuable resource in studying climate change. Their rings provide a chronological road map to help reconstruct extended periods of flooding and drought.

In fact, Stahle originally began dating the trees as part of a study on climate change in the region that revealed extended periods of drought hundreds of years ago.

"It's an amazing coincidence that the oldest known living trees in eastern North America also have the strongest climate signal ever detected anywhere on Earth," Stahle told Smithsonian Magazine. "The best correlations we've ever seen are with these trees. Why that is I don't know. They're incredibly old and extremely sensitive to climate, especially rainfall."

Dave Meko, a researcher at the University of Arizona's Laboratory of Tree-Ring Research who was not associated with Stahle's work, told Smithsonian it's rare to find trees old enough to provide such a long view of climate change.

"We don't have many spots where we can sample tree rings to pick up variations over 2,000 years of climate," Stahle said. "So where we can, we try to take advantage of them. Bald cypress is definitely a gold mine of climate information from the Southeast."

Stahle thinks the find may just be the start of something even bigger.

“There are surely multiple trees over 2,000-year-old trees at Black River,” he told the Charlotte Observer. “It’s my belief there are some approaching, if not exceeding, 3,000 years old.”