Pinus aristata |
The bristlecone pines are a small group of pine trees (Family Pinaceae, genus Pinus, subsection Balfourianae) that can reach an age far greater than that of any other living thing known - up to nearly 5,000 years. There are three closely related species:
- Rocky Mountain Bristlecone Pine Pinus aristata in Colorado, New Mexico and Arizona
- Great Basin Bristlecone Pine Pinus longaeva in Utah, Nevada and eastern California
- Foxtail Pine Pinus balfouriana in California
A bristlecone older than "Methuselah" was cut down in 1964 by a geography graduate student performing research in an area now protected by Great Basin National Park in Nevada. The tree, posthumously named "Prometheus", was found to be about 4,900 years old by ring counting (not an easy task, because the trunks are very twisted and distorted). The inexperienced student who cut the tree had no idea of its age. "Prometheus" did not die in vain, however; the carbon content of the wood from its various rings was analyzed, providing an important calibration for radiocarbon dating.
The other two species are also long-lived, though not to the extreme extent of P. longaeva; specimens of both have been measured or estimated to be up to 3,000 years old.
Bristlecone pines grow in isolated groves at and just below tree-line. Between cold temperatures, high winds, and short growing seasons, the trees grow very slowly. The wood is very dense and resinous, and thus resistant to invasion by insects, fungi, and other potential pests. As the tree ages, much of its bark may die; in very old specimens often leaving only a narrow strip of living tissue to connect the roots to the handful of live branches.