Bald cypress trees (Taxodium distichum) over 2,000 years old grow in the forested wetlands along Black River south of Raleigh, North Carolina. One of the trees is at least 2,624-years old, making the bald cypress the oldest-known wetland tree species, the oldest living trees in eastern North America, and the fifth oldest known non-clonal tree species on Earth.
“Living trees over 2,000-years old are extremely rare worldwide,” said University of Arkansas Professor David Stahle and colleagues.
“Many living bald cypress trees at Black River are over 1,000-years old and our research demonstrates that some are over 2,000-years old, making these trees the oldest in eastern North America and as a species the fifth oldest sexually reproducing non-clonal tree taxa on Earth.”
“Only individual trees of Sierra juniper (Juniperus occidentalis) at 2,675-years, giant sequoia (Sequoiadendron giganteum) at 3,266, alerce (Fitzroya cuppressoides) at 3,622, and Great Basin bristlecone pine (Pinus longaeva) at 5,066-years old are known to live longer than Black River bald cypress.”
The scientists documented the age of the trees using dendrochronology, the study of tree rings, and radio carbon dating.
“The oldest known Black River bald cypress has an inner ring date of 605 BCE, based on crossdating with other trees at Black River back to as early as 70 BCE, but with four radii from just this one old tree from 70 to 605 BCE,” they said.
“This means that the specimen is at least 2,624-years old in 2018.”
In addition to their age, the trees are a scientifically valuable means of reconstructing ancient climate conditions.
The oldest trees in the preserve extend the paleoclimate record in the southeast United States by 900 years, and show evidence of droughts and flooding during colonial and pre-colonial times that exceed any measured in modern times.
“It is exceedingly unusual to see an old-growth stand of trees along the whole length of a river like this,” Professor Stahle said.
“Bald cypress are valuable for timber and they have been heavily logged. Way less than 1% of the original virgin bald cypress forests have survived.”
The study was published in the journal Environmental Research Communications.
D.W. Stahle et al. 2019. Longevity, climate sensitivity, and conservation status of wetland trees at Black River, North Carolina. Environ. Res. Commun 1: 041002; doi: 10.1088/2515-7620/ab0c4a