Thursday, May 26, 2005

Bristlecone Pines - The oldest known living species on earth

The bristlecone pines are a small group of pine trees under the Pinaceae family (genus Pinus, subsection Balfourianae) that can live up to nearly 5,000 years, an age which far exceeds any other living thing known.

There are three closely related bristlecone pines species and they are:
1. Rocky Mountains Bristlecone Pine (Pinus aristata) species which can be found in Colorado, New Mexico and Arizona;
2. Great Basin Bristlecone Pine (Pinus longaeva) species which can be found in in Utah, Nevada and eastern California; and
3. Foxtail Pine (Pinus balfouriana) species which can be found in California.

The oldest living specimen of bristlecone pines that is currently known is an individual of Great Basin Bristlecone Pine nicknamed "Methuselah" after the reportedly longest-lived Biblical patriarch. Methuselah is located between 10,000 and 11,000 feet in the lnyo National Forest within the White Mountains, east of the Sierra Nevada. The core samples of Methuselah indicted the age of the bristlecone pine to be in excess of 4,700 years old, which is 1,500 years more than the age of their nearest competitor, being the Giant Sequoia. And quite possibly, there may be even older specimens may exist elsewhere in the White Mountains and in other remote parts of Nevada.

A bristlecone pine 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.

The other two species, being the Rocky Mountains Bristlecone Pine and the Foxtail Pine, are also long-lived, though not to the extreme extent of Great Basin Bristlecone Pine. Specimens of both types of bristlecone pine 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. Young bristlecone pines are densely clad with glistening needle-covered branches that sway like foxtails in the wind. With their bristled cones dripping pine scented resin on a warm afternoon, the bristlecone pines exude all the freshness of youth. As centuries pass and the bristlecone pines are battered by the elements, they become sculpted into astonishingly beautiful shapes and forms.

The trees manage to survive in the poorly nourished, alkaline soil with a minimum of moisture and a forty-five day growing season. In fact, the trees longevity is linked to these inhospitable conditions. Between cold temperatures, high winds, and short growing seasons, the bristlecone pines grow very slowly, adding as little as an inch in girth in a hundred years. Those bristlecone pines that grow the slowest produce very dense, highly resinous wood, and it is the dense and resinous wood that enables the bristlecone pines to be highly resistant to invasion by insects, fungi, and other potential pests.

As the tree ages, much of its bark may die. However, while most of its wood is dead, growth barely continues through a narrow strip of living tissue to connect the roots to the handful of live branches. When all life finally ceases, the snags of the bristlecone pines stand for a thousand years or more. The bristlecone pines then continue to be polished by wind driven ice and sand and the dense wood becomes slowly eroded away rather than decayed.

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