A Study of Pinon Pine

Abstract

No other tree species of the southern portion of the Rocky Mountain region presents more difficult problems in maintaining and reproducing the natural stands than does the pifion pine (Pinus edulis). It ranges from northern Mexico to eastern Utah, and Colorado Springs, Colorado. In an east-and-west direction it extends from the hills of western Texas to California. Along the northern and eastern borders of its range it is shrublike and of botanical importance only. In southern Colorado, Arizona, and New Mexico, it has a great economic and silvicultural importance, which will steadily decrease unless measures are taken to prevent excessive utilization. It is commonly found in mixture with the one-seeded juniper (Juniperus monosperma) in the northern part of its range and with the alligator juniper (Juniperus pachyphloea) and one-seeded juniper in the south. Throughout its distribution it is associated with western yellow pine (Pinus ponderosa) and the scrub oaks (Quercus Gambeiii and Quertcus acuminala), often forming with these species a transition belt between stands of juniper and western yellow pine. Occasionally it is found with stunted Douglas fir (Pseudolsuga taxifolia). In association with the junipers, it forms the distinct woodland type so characteristic of New Mexico and Arizona, which in this region covers a more extensive area than any other forest type, and in which the pifion is decidedly the most important tree. It is occasionally seen in pure stands over small areas, but this is rare.