Plant of the Month
Pinyon Pine by Malcolm Morrison
Pinyon pines are a short (30 feet tall or less), glacially slow-growing, rather unattractive pine tree usually codominant with a juniper species in the pinyon-juniper woodlands of the semidesert southwest between 4500-7000 feet in elevation. For humans, their only true value is as firewood, though local residents will harvest the nuts (It takes an hour to gather a pound.) and use older trees as fence posts for barbed wire. A five year old tree is about one foot tall. A fifty year old tree provides a good four foot tall fence post from its trunk. At 25-100 years of age a pinyon begins to produce nuts if it is not a fence post. At 500 years of age, it is probably dead. As you can guess, pinyons are neither a commercial nor a nursery tree.
But where they grow, if you are not human the odds are high that either you eat pinyon nuts or you eat those that do. If one year there are no pinyon nuts due to a failure of the crop, then you can pretty well bet there will soon be no you. Unfortunately, pinyon nut (seed) crops are anything but uniform, thus it is hard for such an interlocked grouping of species in their range to maintain a stable population number.
Pinyon pines must have certain birds to survive. Pinyon pines and four seed-eating birds have evolved coadaptive traits that enhance the survival of both. No birds, no pinyons. No pinions, well, the birds can fly away and try elsewhere; but obviously their mortality rate would be hideous. Pinyon seeds (nuts) are only effectively dispersed by four corvid species of birds - Clark's nutcracker, Steller's jay, scrub jay, and pinyon jay. The nuts are not adapted to wind dissemination, nor to dissemination and subsequent germination by rodents. Pinyon jays can carry 50+ seeds in an expandable esophagus. These they bury one per hole in the ground, perfect for germination if the seed is not later eaten. A single pair of pinyon jays can "plant" more than 20,000 seeds per season. Flocks of 50-500 jays can plant millions of seeds in a season, 1-2 tons worth. Many of these are never found again, and some of those become new trees.
For additional information on these trees and the ecosystem they anchor, see the following sites and books.
http://www.cirrusimage.com/tree_pinyon_pine.htm
USDA Forest Service Silvics Manual Conifers - Pinus edulis
The Pinon Pine by Ronald Lanner University of Nevada, 1981 (for recipes)
http://www.fs.fed.us/database/feis/plants/tree/pinedu/all.html
Plant of the Month Archives
December 2008 - Witch Hazel
January 2009 - Winterberry
March 2009 - Desert Ironwood
April 2009 - Marsh Marigold
May 2009 - Serviceberry
June 2009 - Choke Cherry
July 2009 - Northern Bush Honeysuckle
August 2009 - Butterfly-weed
September 2009 - Firecracker bush
October 2009 - Black Swallow-wort
November 2009 - Cranberries
December 2009 - Dogwood
January 2010 - Pinyon Pine