The Oldest Trees in the World – Bristlecone Pines
9 Aug 2017

Do you feel you’re getting old if you’re 70, 80, or 90 years of age? Think again. Some years ago I had the opportunity to hike the Spectra Trail in Utah’s Cedar Breaks National Monument on an exposed, precipitous, windblown ridge at about 10,300 feet elevation. The one-mile hike is only moderately difficult and invigorating. But the air there is a tad thinner than here in East Texas. (Gasp! Pant!) But the effort was worth it. Like the ancient of ancients they are, a modest colony of bristlecone pines clings tenaciously to the white dolomite soil of the ridge. Their gnarled, twisted limbs rise almost in supplication, steadfastly skyward in silent declaration of their amazing age status, while the wind-polished roots spread over the barren surface of the landscape. Bristlecones are the oldest living trees on the earth, although those in Cedar Breaks are relative youngsters, the oldest being a mere 1700 years of age.

Bristlecones exist high in the mountains of six western states, and the patriarchs, found in the White Mountains of California, are over 4000 years old. Methuselah, one of the bristlecones there, was thought to be the oldest tree in the world at 4,848 years of age. Then in 2012, another one in the same area was found to be 5,066 years old! The pyramids of Egypt were constructed from 2589 to 2504 BC. That gives “old” a whole new meaning! The seed from which this unique old-timer formed would have sprouted in 3050 BC.

These amazing trees grow only in high mountains under some of the most difficult conditions imaginable. With low temperatures of minus 26 degrees Fahrenheit and 12 inches or less of annual precipitation, mostly as snow, they survive in areas with growing seasons of 45 days or less. In this high, windswept location, much of the snow blows away, leaving very little life-sustaining moisture.

Deep green clusters of short needles, and cones dripping resin from their bristle-tipped scales, the trees require a minimum of energy, and evaporative moisture loss is very limited. Needles remain on the trees for 30-40 years before being replaced, much longer than is typical of other pines.

The wood of bristlecones is so dense and resinous that it is virtually impervious to insect damage or disease, an important contributing factor enabling these trees to reach their advanced age. Fire occasionally threatens them, but the edges of heat damaged growth tissue quickly seal off following the burn, and although some parts of a tree may be killed, other branches cling to life and go on with healthy growth processes. Some very large bristlecones have only a single strip a few inches wide of life-providing tissue, but the remaining live branches continue to thrive, and likely will for hundreds or even thousands more years.

Slow growers, bristlecones only expand their diameter by about 1/100th of an inch per year, with each passing 12 months marked by a single new, almost microscopic, growth ring. The age of trees is typically determined using a hollow, threaded steel drill called an increment borer, that is screwed into the tree trunk. The wood core is removed from the hollow bit and the borer removed from the tree. Then the growth rings are patiently counted. One, two, three… one hundred one, one hundred two… one thousand one, one thousand two, etc. I grow older just thinking about that.

Imagine! A living organism that was a youth during the reign of the Egyptian pharaohs, and still steadfastly grows today, with the potential of reaching 8,000 years of age or more.

My sojourn in that harshly beautiful environment was deeply moving, and to touch one of those truly ancient living organisms was a thrilling and humbling experience. I could almost feel the years receding into the dim past of that ancient habitat of our fields and forests.

Dr. Risk is a professor emeritus in the College of Forestry and Agriculture at Stephen F. Austin State University in Nacogdoches, Texas. Content © Paul H. Risk, Ph.D. All rights reserved, except where otherwise noted. Click to send questions, comments, or request permission for use.