A common evergreen tree found on the grounds of the zip line, and throughout the Southwest and Colorado Plateau for that matter, is the pinyon pine tree. These trees are fairly short with typical heights of 10 to 30 feet, with some reaching as high as 35 feet tall. The tree has a round to flat top, may have a twisted or crooked trunk, and produces cones. Cones do not mature until September of the second year of the tree’s life. Inside the cones can be found the much coveted and nutritionally robust pine nut.
This perennial is the state tree of New Mexico. In Colorado, it is found on the lower slopes of the Colorado Plateau, usually at elevations of 4500 to 7500 feet (higher elevations, perhaps reaching 9,000 or more feet, along southern-facing slopes). The typical “forest” that includes the pinyon pine tree is also comprised of sagebrush, juniper trees, and rabbit brush.
The pinyon pine tree is drought-resistant and grows in arid regions where rainfall ranges from 10-18 inches per year. Clearly, it is well suited for the dry, rocky soil at the zip line and in this Colorado region. To maximize its potential, the pinyon pine tree has an extensive lateral root system. Still, it is a slow grower–trees with trunk sizes of only 4 to 6 inches may in fact be hundreds of years old.
Approximately every 4 to 7 years, the tree produces a bumper crop of pine seeds. These seeds are high in fat and contain Vitamin A, thiamine, riboflavin, and iron. Pine nuts contain around 20 amino acids and 3,000 calories/pound of seed. Seeds are used for baking as well as candle-making. Native American Indians ate pine seeds in their raw form, roasted them or ground them into flour. They also steeped the needles from the tree for tea. In times of severe food shortages, they ate the inner bark of the tree.
A resin is produced by the pinyon pine, pine gum. American Indians use this sticky resin to waterproof their hand-woven baskets and also in making turquoise jewelry. The Anasazi Indians (Ancestral Puebloans) used pinyon tree poles as door headers in their homes.
Even more uses than described above have been found for the pinyon tree and its various parts. Incense is made from crushed cones; and the wood, when burned, is very fragrant. Besides its use as a fuel, wood from the pinyon tree is sometimes used as fence post. And then of course, some pinyon pine trees end up as Christmas trees in people’s homes.
The pine nuts from the tree serve as an important food source for many animals, including various songbirds, quail, black bears, squirrels, mule deer, and packrats. Cattle that graze in areas where there are pinyon trees usually steer clear of these trees as a food source. Unless there are mitigating circumstances such as severe drought or no suitable alternatives. At times like this, they may chew on the pinyon tree needles. This is problematic for cattle that are pregnant since toxins in the needles–labdane resins such as isocupressic acid–can cause abortions. These toxins have also been found to cause abortions in pregnant buffalo as well, although other similarly-sized animals have not been shown to suffer these consequences. There is no antidote or treatment for such poisoning.
Don’t be surprised if you hear an uproarious clatter and chatter from flocks of the indigenous pinyon jays during your visit with Captain Zipline. These birds are very common in the region and use the zip line grounds as their “hunting grounds” for the scrumptious pinyon tree seeds. Zip line guests have been witness to flocks of pinyon jays descending on a harvest of fresh pinyon tree nuts, creating quite a commotion in their wake. These birds will gorge themselves will pine nuts; as many as 40 pine nuts can be packed into their esophagus in one feeding session! Pinyon jays also store these seeds in the ground for later use. Surprisingly, they seem to have a pretty good memory of where most of these seeds were stashed.
The jays have the ability to determine which pine seeds are mature and thus edible. They distinguish the seeds by color–normal seeds are dark brown in color whereas those that do not develop are tan colored.
Clark’s Nutcrackers, another bird you may see while zipping with Captain Zipline, also tend to store pine nuts by burying them in the ground. The forgotten seeds serve as a source of future trees.
While the tough-beaked jays have an easy time getting through the sturdy outer coat of the pinyon nuts, humans have great difficulty. The laborious task of peeling away the seed’s outer coat can be time-consuming and challenging. One alternative is to toss the pinyon pine cones into an open fire…and watch them pop open like popcorn.
Although hardy and drought-resistant, there are extremes beyond which the pinyon tree cannot survive. University of Arizona researchers documented a massive die-off of these trees in areas throughout Arizona, New Mexico, Colorado, and Utah during 2002-2003: 40-80% of the pinyon trees in various sites throughout these states died, having initially been subjected to high temperatures and drought, followed by a final and deadly blow of infestation with bark beetles. Die-offs like this place the involved area in jeopardy of forest fires. It is a cycle that is repeated over an over again, and it is part of the natural history of the pinyon tree. Growth…drought and temperature extremes…attack by pests and insects…and then fire. When these fires sweep through pinyon tree stands, ironically they also disrupt the caches of seeds stored by the pinyon jays for leaner times. And once again a cycle of life and death is completed.