Oldest hardwood tree ever

The African baobab (Adansonia digitata) is the only non-conifer ever recorded to reach in excess of 2,000 years old. As they do not produce wood with crossdatable rings, they can only be dated through the use of radiocarbon dating. The Panke Baobab in Zimbabwe, which had a circumference of 25.5 m (83 ft 7.9 in) and had nearly 400 m3 (14,126 cu ft) of wood and bark, was at least 2,450 (±40) years old when it collapsed and died in 2011. This not only makes it the oldest hardwood tree to be accurately measured but also the oldest known angiosperm (flowering plant). Several other individuals of this species have been dated to more than 1,500 years old.

The oldest known (individual) tree species overall is the intermountain bristlecone pine (Pinus longaeva). They are native to the Great Basin, which spans the length and breadth of Nevada and beyond, and just enters easternmost California, USA. There are several dozen small mountain ranges in the Great Basin, and bristlecone pines can be found on nearly every one that has peaks in excess of 3,300 m (10,827 ft). Among the largest of these are the White Mountains, which lie mostly in California and are strongly influenced by the dramatic rain shadow created by the nearby Sierra Nevada Mountains. The trees are largely found at 3,000 m (9,843 ft) elevation or above – often in single-species woodlands growing on bare rock. The harsh environment all but eliminates the three main sources of death with pines – fire, insects, and disease – allowing the trees to survive for millennia. Longevity in this environment often results in bizarre and fanciful tree shapes which are quite popular with photographers. The trees also get quite large – the largest known is in the Spring Mountains near Las Vegas and has a trunk diameter of 368 cm (12 ft), making it the largest diameter known for any pine species.

Much of the credit for discovering the oldest trees goes to Edmund P Schulman, who himself was a student of A.E. Douglass at the University of Arizona (father of modern dendrochronology), who used patterns in tree rings to learn about previous climatic conditions. During the 1940s and 50s, Schulman spent nearly every Summer trying to find the oldest tree. When he died in 1958 at just 49 years old, he had just found a living tree which would later be named Methuselah. The samples were crossdated by Tom Harlan of the Laboratory of Tree-Ring Research at U of A, and became the oldest known tree – currently 4,852 years old as of 2020. Another tree sampled by Schulman in the White Mountains before he died was also crossdated by Tom Harlan, but not until 2009. This sample was also from a living tree, so the tree is aged 5,070 years as of 2020. This unnamed tree is currently the oldest verified living tree in the world.

While many trees >4,000 years had been discovered in the White Mountains, it is not the only location for old trees. Some 380 km (236 mi) to the north-east across the other side of the Great Basin, on the slopes of Wheeler Peak, Nevada, a tree was cut down in 1964 which had a crossdated age of 4,844 years. Now named Prometheus, the circumstances surrounding the cutting of this ancient tree are still controversial. The tree would have been 4,900 years old in 2020.