Bristlecones

Underpriviledged Trees Live Longest

At once it became evident that precisely under such difficult living conditions trees not only showed the expected high sensitivity to rainfall, but were able to live far beyond the normal life span of more "fortunately" located individuals of the species.

An 860-year ponderosa pine in Bryce Canyon National Park, a 975-year pinon pine in Central Utah, and other grand veterans gave us continuous tree-ring histories of annual rainfall much longer than we had once thought possible. After many years of sampling old trees throughout the West, it seemed that we were approaching the age limits for rain-sensitive dwarf trees in this region.

During the summer field season of 1952, an unexpected find opened up new possibilities. Sampling a stand of old Douglas firs above Sun Valley, Idaho, we found an alpine-type limber pine with one side completely dead. The core from this tree could not reach center but seemed to have an unusual number of rings.

That night at our camp below, I examined our sample more closely and was astonished to find that the 16-inch core contained some 1,400 years of datable growth rings. later we found that this limber pine was almost 1,650 years old.

But it was in the 1953 field season that the dazzling possibilities of new and fantastically long records or year-by-year rainfall in alpine trees became apparent. Prof. Frits W. Went, of the Earhart Plant Research Laboratory at the California Institute of Technology, joined me on another visit to the unusually old pines of Sun Valley, and we spent most of one day in cutting down, for detailed laboratory analysis, the 1,650-year pine discovered the preceding year. The next day we piled much of it into our truck and took off for Pasadena, where I was working at Caltech on a year's leave from the University of Arizona.

On our homeward drive we detoured into the White Mountains of California, to check on a rumor that old trees existed there. Often such rumors had turned out to be unfounded. But not this one!

| The story continues.... |

Written By: Dr. Edmund Shulman
Dendrochronologist, Laboratory of Tree-Ring Research
Associate Professor of Dendrochronology, University of Arizona, Tucson

Information received from: USDA Forest Service, Inyo National Forest