Bristlecone Pines

¦Identifying Bristlecone Pines ¦Groves in the Park¦

¦ The "Prometheus" Story ¦

Great Basin Bristlecone pines (Pinus longaeva) are remarkable for their great age and their ability to survive adverse growing conditions. In fact, it seems one secret to their longevity is the harsh environment in which most bristlecone pines grow.

Bristlecone pines in Great Basin National Park grow in isolated groves just below treeline. Conditions are harsh, with cold temperatures, a short growing season, and high winds. Bristlecone pines in these high-elevation environments grow very slowly, and in some years don't even add a ring of growth. This slow growth makes their wood very dense and resistant to insects, fungi, rot, and erosion. Vegetation is very sparse, limiting the role of fire. Bristlecone pine seeds are occassionally cached by birds at lower elevations. Bristlecone pines grow more rapidly in more "favorable" environments at lower elevations. They do not achieve their legendary age or fascinating twisted shapes.

While bristlecone pines are the longest-living tree, scientists debate what is truly the oldest living thing. The creosote bush that grows in the Mojave Desert may be older. The cresote achieves its age by "cloning" new bushes from its root system. Yet bristlecone pines surely deserve our respect for not only surviving harsh conditions, but thriving in harsh conditions.

Identifying Bristlecone Pines

Bristlecone pines are often confused with limber pines. They can be found growing together at the same elevations. They are affected by the same erosional processes, and may look very similar with dead and twisted wood exposed.

A bristlecone's needles are about one inch long, and grow in packets of five. The needles completely surround the branches. The tightly-bunched tufts of needles may extend back a foot or more along the branch, giving the branch the appearance of a bottle brush. The developing cones are a deep purple color, which helps to absorb heat, and mature after two years at which time they turn a brown color. The tree gets its name from the cones whose scales are each tipped with a claw-like bristle.

Limber pine trees, on the other hand, have needles in packets of five that are 1 1/2 to 3 inches long, and grow only towards the ends of the branches. Also, the cones of the limber pine do not have bristles.

 

Groves in Great Basin National Park

Wheeler Peak Grove

The Wheeler Peak bristlecone pine grove, the most accessible grove in the park, is located on the northeast side of Wheeler Peak. It is unusual in that it grows on a glacial moraine consisting of quartzite boulders. Most groves grow on limestone or dolomite. The northeastern exposure of the Wheeler Peak grove is also unusual as most other groves have a generally southern or western exposure. The Wheeler Peak grove is reached by a 1.5 mile (3 miles round trip) trail from Wheeler Peak Campground. A short self-guided nature trail passes through a portion of the grove. During the summer, the park offers ranger-led interpretive walks in this grove. Check at the visitor center for a schedule.

Mount Washington Grove

The largest grove of bristlecone pines in the park is on Mt. Washington. Located in the west central portion of the park, access is difficult. No developed trails exist in the grove. Some sections of this grove have relatively tall (over 40 feet) bristlecone pines that resemble high-elevation spruce or limber pine more than the typical gnarled treeline bristlecone pines. Unlike the Wheeler Peak grove, the trees on Mt. Washington grow exclusively on limestone. In fact, nearby quartzite areas are notable for their lack of bristlecones.



Eagle Peak Grove

The third grove in the park is near Eagle Peak (Peak 10,842) on the ridge between the Snake Creek and Baker Creek drainages. The terrain is steep and access is difficult. These bristlecones also grow exclusively on limestone soils, while granitic soils in the area lack bristlecones.

Please remember that everything in a national park is protected. Some bristlecone pine wood on the ground may be thousands of years old and important scientifically. Please leave all down bristlecone pine wood in place.

 

The "Prometheus" Story In 1964, a scientist was granted permission by the United States Forest Service to study some of the bristlecone pines growing in a grove beneath Wheeler Peak. The researcher was very excited to start studying the lessons preserved in the rings inside these ancient trees. Many lessons were to be learned from one tree in particular, named "Prometheus."

Bristlecone pines, like most trees, add a ring for each year of growth. Scientists can study the variation in width to determine patterns of good and bad growing seasons in past years. The trees literally record the seasons of their lives in their rings. This is very valuable for the study of climate change. Dendrochronology is the branch of science that studies tree rings. Dead bristlecone wood is as valuable to scientists as a living tree, since it extends the continuous climate record even farther into the past by overlapping patterns of identical ring growths in different trees.

Tree ring information can also help date archeological sites that contain wooden beams. This has been particularly useful in the Southwest. Radiocarbon dating (carbon-14) is a very common tool in archeology. Bristlecone pine wood has helped calibrate radiocarbon dates that are up to about 10,000 years old. Sea coral is now used to calibrate even older radiocarbon dates.

The Forest Service granted permission for the researcher to take core samples from several old-looking bristlecone pines and to cut one down. Bristlecone pines often grow in a twisted fashion. Also, one section of the tree may die off even a couple thousand years before another part. This means it can be very difficult to capture the oldest part of the tree in a core sample. The tree that was cut down in 1964--while still living--has since become know to some as "Prometheus."

Counting revealed that Prometheus contained about 4,900 growth rings. This made it the oldest known tree. Currently the oldest known living tree, about 4,600 years old, is in the White Mountains of California. Chances are good that there are other, older, bristlecones that have not been dated.

According to ancient Greek myths, Prometheus was an immortal who brought fire (symbolic of knowledge) to humans. Prometheus the bristlecone pine also imparted much knowledge to humans. Information gained by studying this significant tree added to the knowledge of carbon dating (which is valuable to archeologists and paleontologists) and climate data. Perhaps we have not learned all that we can from bristlecone pines. These ancient trees are protected on federal lands so that we will not lose the lessons we may have yet to learn.

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