Ancient trees live best in harsh places

by Brenda Porter

High winds, extreme cold, and intense solar radiation are the ideal locations for the longest living species in the Southern Rockies. Bristlecone pine trees, Pinus arista, have been dated to 2,400 years old in Colorado, while closely related species are older in other places. Even the needles are long-lived, photosynthesizing for ten to fifteen years. The oldest Colorado trees grow in the Windy Ridge ­Bristlecone Pine Scenic Area in Pike National Forest, but there are small stands of bristlecone throughout the state, often interspersed with limber pines on windy sites as low as 6,800 feet and up to timberline.

These squat, ancient trees are well-adapted to the windy landscapes in which they live. In fact, they do not live as long in hospitable climates with ample water and less wind. Their twisted trucks give the trees great stabilityÑjust as a twisted rope is stronger than a straight rope of the same diameter. Because they grow so slowly, their wood is extremely dense and strong. The annual growth rings are narrow bands that illustrate the short growing season. Bristlecone pines are rare among trees in that they can remain standing in their harsh environment hundreds of years after they have died, again demonstrating their great stability. Next time you see a bristlecone pine that looks dead, search for any sign of life; often layers of dead wood protect a ribbon of life deep within.

Bristlecone Pine i.d.

The trees are usually widely spaced, growing up to thirty feet with a broad-topped, windswept look. The branches resemble “bottlebrushes” because the needles grow around the branches in a dense arrangement, with five needles per bundle growing from the branches. Remember “pines grow in packets” of two, three, or five needles, as in the case of bristlecone pines. This mnemonic helps to distinguish pine trees from spruce and fir, whose needles grow individually from their branches. The short bristlecone needles are less than two inches long and are dotted with white spots of resin. Like other pines, bristlecones have two types of cones: the woody female cones produce seeds and at maturity are prickly with bristles that make it difficult to pick up a cone with bare hands, hence the species name. The pollen producing male cones are smaller and clustered at the tips of branches. P