Pinyon-Juniper Woodland (Upper Sonoran Life Zone)

Non-technical description: A forest of short (usually less than 20-feet tall) evergreen trees mixed with a variety of desert and upland shrubs or open grasslands on the lower slopes of mountains.

The Pinyon-Juniper Woodland association is found in mountains ranges at elevations of about 5,500 to 7,500 feet where average precipitation exceeds 8 inches. The vegetation in this life zone is dominated by two species of conifers: pinyon pine trees (Pinus spp.) and juniper trees (Juniperus spp.). In the Las Vegas region, there are two species of Pinyon Pine and several species of Juniper.

In the mountains immediately around Las Vegas, the only pinyon is Singleleaf Pinyon Pine (Pinus monophylla). In the Zion and Grand Canyon region, the pinyon is Two-needle Pinyon Pine (Pinus edulis).

In the mountains immediately around Las Vegas, there are several species of juniper. The most common species around Las Vegas is Utah juniper (Juniperus osteosperma). Rocky Mountain Juniper (Juniperus scopulorum) can be found in the Spring Mountains (Mt. Charleston), Sheep Range, and the Virgin Mountains. California Juniper (Juniperus californica) occurs in some of the mountain ranges south of Las Vegas (Newberry and South McCullough mountains) and east of Las Vegas in the Virgin Mountains, and One-Seed Juniper (Juniperus monosperma) can be found north of Las Vegas.

Common shrubs in Pinyon-Juniper Woodland include Blackbrush (Coleogyne ramossissima), bitterbrush (Purshia tridentata), Rabbitbrush (Chrysothamnus spp.), Cliffrose (Cowania mexicana), Shrub Live Oak (Quercus turbinella), Curlleaf Mountain Mahogany (Cercocarpus ledifolius), and Manzanita (Arctostaphylos spp.). At higher elevations, Sagebrush (Artemisia spp.) becomes common. Bunchgrasses can be common.

Several types of cactus are common Pinyon-Juniper Woodland. Cholla (Opuntia spp.) and Pricklypear (Opuntia spp.) can be quite common, Hedgehog Cactus (Echinocereus spp.) can also be locally abundant, and tiny Pincushion Cactus (Escobaria) can be found occasionally.