Pinyon–juniper woodland
[3] Historically, pinyon-juniper woodland provided a vital source of fuel and food (particularly piñon nuts) for indigenous peoples of the American Southwest.
[4] As of the early 2020s,[update] pinyon-juniper ecosystems have been under pressure from heavy natural gas extraction in southern Colorado and New Mexico.
[5] They have also been historically destroyed by land managers in the United States in favor of livestock pasture, due to a lack of perceived economic value.
[6] In some areas of New Mexico; more than 90% of piñon pines in a woodland have died due to long-term drought and insect attacks.
[5] The seeds produced by the pinyon pines in mast cycles are the primary influence on population growth in the habitat; in lean years some animals move away in a nomadic fashion.
[8] These birds are the only species capable of re-establishing pinyon pines after major disruptions like fires and beetle infestations, and according to Audubon are critical to the ecosystem's survival.
[1] However, it serves as important habitat for a number of endangered species, including Woodhouse's scrub jay and the gray vireo.
Persistent woodland sites are usually unproductive, with thin soils and sparse ground or shrub cover, often occurring on rocky or rugged terrain.
[2] The woodland's range includes the Mogollon Rim in the south, to its northern extent in the Snake River Plain.
[11] Due to its temperature tolerance, pinyon generally does not naturally grow north of northern Utah, as well as some portions of southern Wyoming and Idaho.
[1] Usually, the habitat experiences freezing temperatures 150 or more days a year, with 6 to 20 in (150 to 510 mm) of annual precipitation, mostly falling as snow.
[17] In the steppes adjoining the Mojave Desert, this vegetation type can be found in areas receiving 12 to 20 in (300 to 510 mm) inches of annual precipitation, and between 4,500 to 8,000 ft (1,400 to 2,400 m).
[5] Alkaline regions at lower elevations include alkali sacaton (Sporobolus airoides), Indian ricegrass (Oryzopsis hymenoides), needled grasses (Stipa spp.
[5] In the D-36 (Southwestern Plateaus, Mesas, and Foothills) region, pinyon-juniper woodland appears in a mosaic gradient with other ecosystems based on elevation.
[5] Trees and shrubs associated with the ecosystem include Mexican blue oak (Quercus oblongifolia), New Mexico locust (Robinia neomexicana), buckbrush (Ceanothus cuneatus), and manzanita (Arctostaphylos spp.).
[5] In the E-49 (Southern Rocky Mountain Foothills) region, pinyon-juniper woodlands are found exclusively in lower elevations in the south.
