• GENERAL DISTRIBUTION
• ECOSYSTEMS
• STATES
• BLM PHYSIOGRAPHIC REGIONS
• KUCHLER PLANT ASSOCIATIONS
• SAF COVER TYPES
• SRM (RANGELAND) COVER TYPES
• HABITAT TYPES AND PLANT COMMUNITIES

GENERAL DISTRIBUTION:

The distribution of singleleaf pinyon has undergone many changes in both prehistoric and historic times [35], and Everett [59] points out that any assessment of pinyon and juniper woodland distribution is only a snapshot of a woodland in motion. Historic changes in distribution are reported by several authors [79,172,199,244]. Much has been written on the evolutionary distribution of singleleaf pinyon [7,121,128,138,161,194,198,207,213,219,220,231] and pinyon in general [10,11,57], and may provide information pertinent to predicting potential changes in distribution resulting from climate change.

Hybrids of Colorado and singleleaf pinyon occur in 3 geographical zones along the margin where their distributions overlap. The most extensive zone is that along the eastern margin of the Great Basin in central Utah. Another zone is in the canyons of the Colorado River in southern Utah, and a 3rd zone is among the scattered pine groves south of the Mogollon Rim in central Arizona [75,119]. Hybrids of Parry pinyon and singleleaf pinyon are reported in southern and Baja California [246,247]. Hybrids of singleleaf pinyon and Sierra Juarez piñon are found in scattered places in northern Baja [118].

ECOSYSTEMS [76]:

STATES:

BLM PHYSIOGRAPHIC REGIONS [9]:

KUCHLER [116] PLANT ASSOCIATIONS:

SAF COVER TYPES [70]:

SRM (RANGELAND) COVER TYPES [181]:

HABITAT TYPES AND PLANT COMMUNITIES:

In the Great Basin, singleleaf pinyon is found primarily with Utah juniper (J. osteosperma), sagebrush (Artemisia spp.), rabbitbrush (Chrysothamnus spp.), Arizona joint-fir (Ephedra fasciculata), antelope bitterbrush (Purshia tridentata), granite pricklygilia (Leptodactylon pungens), and a variety of other shrubs, herbs, and cryptobiotic or cryptogamic crusts [78,88,122,164,199,235]. The pinyon-juniper type lies between desert shrub or grassland below and ponderosa pine (Pinus ponderosa) associations above, with broad ecotones [57]. Utah juniper is absent from some singleleaf pinyon stands in extreme western and southern Nevada and adjacent California [57,235]. In southern Nevada, singleleaf pinyon shares a broad lower ecotone with blackbrush (Coleogyne ramosissima), where creosotebush (Larrea tridentata) and white bursage (Ambrosia dumosa) occupy the lower slopes and valley floors, and an upper ecotone with ponderosa pine communities with white fir (Abies concolor), limber pine (P. flexilis) and quaking aspen (Populus tremuloides) [130,131]. Curlleaf mountain-mahogany (Cercocarpus ledifolius) is associated with singleleaf pinyon in many areas, particularly near its upper elevational limit [57].

Codominants of singleleaf pinyon found throughout the Great Basin include mountain big sagebrush (Artemisia tridentata ssp. vaseyana), Wyoming big sagebrush (A. t. ssp. wyomingensis), low sagebrush (A. arbuscula), blackbrush, antelope bitterbrush, desert bitterbrush (P. glandulosa), curlleaf mountain-mahogany, desert snowberry (Symphoricarpos longiflorus), Utah snowberry (S. oreophilus var. utahensis), rubber rabbitbrush (Chrysothamnus nauseosus), low rabbitbrush (C. viscidiflorus), pale serviceberry (Amelanchier pallida), greenleaf manzanita (Arctostaphylos patula), Gambel oak (Quercus gambelii), shadscale (Atriplex confertifolia), green ephedra (E. viridus), bluebunch wheatgrass (Pseudoroegneria spicata), Idaho fescue (Festuca idahoensis), Thurber needlegrass (Achnatherum thurberianum), desert needlegrass (A. speciosum), Indian ricegrass (A. hymenoides), Sandberg bluegrass (Poa secunda), mutton grass (P. fendleriana), blue grama (Bouteloua gracilis), bottlebrush squirreltail (Elymus elymoides), bullgrass (Elymus simplex), arrowleaf balsamroot (Balsamorhiza sagittata), and cheatgrass (Bromus tectorum) [14,16,17,18,19,59,106,132]. Singleleaf pinyon reaches the northern extent of its range at the northern end of the Great Basin, in southern Idaho, where it occurs in rare communities with the following species: Utah juniper, curlleaf mountain mahogany, mountain big sagebrush, black sagebrush (Artemisia nova), Sandberg bluegrass, and bluebunch wheatgrass [175]. Singleleaf pinyon is codominant with narrowleaf cottonwood (Populus angustifolia), big sagebrush, red-osier dogwood (Cornus sericea), narrowleaf willow (Salix exigua), and rabbitbrush species in some of the riparian ecosystems in Great Basin National Park, Nevada [184].

Everett and Koniak [62] describe several other important understory species found with singleleaf pinyon in the Great Basin of Nevada, and note that annual forbs are best adapted to coexist with the singleleaf pinyon and associated juniper species in fully stocked stands. Because of the ephemeral nature of this group, understory cover tends to be variable and response to disturbance less predictable. Understory vegetation varies with microsites, being most abundant in the transition zone between the duff under the tree canopies and the space between trees. Goodrich and others [77] describe endemic and endangered plants of pinyon-juniper communities in Utah.

In the Inyo and White mountains of eastern California, Utah juniper occurs with singleleaf pinyon primarily at lower elevations, with Utah juniper density decreasing at upper elevations. The shrub layer is sparse and composed primarily of big sagebrush, antelope bitterbrush and desert bitterbrush, intermixed with Ephedra spp., rubber and low rabbitbrush, and cactus (Opuntia and Echinocereus spp.). Singleleaf pinyon is bordered by Great Basin bristlecone pine (P. longaeva) and limber pine at higher elevation [157]. Singleleaf pinyon is also found with Great Basin bristlecone pine on several mountain ranges in Nevada, and in the San Francisco Mountains of southwestern Utah [142]. On the eastern slopes of the Sierra Nevada singleleaf pinyon is found with western juniper (J. occidentalis), Utah juniper, Jeffrey pine (P. jeffreyi), ponderosa pine, big sagebrush, curlleaf mountain-mahogany, rubber rabbitbrush, antelope bitterbrush, desert bitterbrush, bluebunch wheatgrass, Idaho fescue, and bottlebrush squirreltail [43,93,142,224]. Singleleaf pinyon may also be found with bigcone Douglas-fir (Pseudotsuga macrocarpa) at upper elevations in southern California [140].

In southern California, singleleaf pinyon is a common component of the desert montane landscape on arid slopes [187], and is most commonly found with California juniper (J. californica) [124,142]. In the Mojave Desert mountain ranges, it intergrades at higher elevations with white fir or Great Basin bristlecone pine forest, and at lower elevations with California juniper and Joshua tree (Yucca brevifolia) woodland with creosotebush and white bursage. Here it occurs with big sagebrush, curlleaf mountain-mahogany, blackbrush, Stansbury cliffrose (Purshia mexicana var. stansburiana), Nevada ephedra (Ephedra nevadensis), shrub live oak (Quercus turbinella), rubber rabbitbrush, low rabbitbrush, blue sage (Salvia pachyphylla), Wright buckwheat (Eriogonum wrightii var. trachygonum), hollyleaf gilia (Gilia latiflora), and cheatgrass [87,93]. In the San Bernardino Mountains singleleaf pinyon occurs primarily with California and western juniper, curlleaf mountain-mahogany, and big sagebrush [94,150]. Singleleaf pinyon may also be found in redshanks (Adenostoma sparsifolium) chaparral communities with desert ceanothus (Ceanothus greggii) [135]. In the Sierra Juárez in northern Baja, singleleaf pinyon forms extensive forests in association with California juniper, sugar sumac (Rhus ovata), Palmer oak (Quercus dunnii), Muller oak (Q. cornelius-mulleri), redberry buckthorn (Rhamnus crocea), Mojave yucca (Yucca schidigera), and chaparral yucca (Y. whipplei), with Parry pinyon dominant on the wetter western margin and singleleaf pinyon dominant on the eastern rim [151]. Singleleaf pinyon may also be found with Jeffrey pine and peninsular oak (Quercus peninsurlaris) [120,156]. On the eastern flank of the Sierra San Pedro Mártir, singleleaf pinyon forms extensive forests with desert chaparral understory dominated by peninsular manzanita (Arctostaphylos peninsularis) and peninsular oak and bordered by Parry pinyon at upper elevations. Elsewhere in Northern Baja, near the southern end of its distribution, singleleaf pinyon occurs in scattered patches on high ridges and northern aspects [151].

In the southern Arizona and southwestern New Mexico, singleleaf pinyon occurs at mid-elevations with ponderosa pine above and oak woodlands below. In the Hualapai Mountains of western Arizona, singleleaf pinyon is dominant at upper elevations with occasional occurrence of Utah juniper and ponderosa pine, and is codominant with Utah juniper at lower elevations. Understory plants include green ephedra, red barberry (Mahonia haematocarpa), broom snakeweed (Gutierrezia sarothrae), turpentine bush (Ericameria laricifolia), kingcup cactus (Echinocereus triglochidiatus var. melanacanthus), greenflower nipple cactus (Mammillaria viridiflorus), prickly-pear (Opuntia spp.), shrub live oak, ceanothus (Ceanothus spp.), skunkbush sumac (Rhus aromatica var. trilobata), banana yucca (Y. baccata), yerba de pasmo (Baccharis pteronioides), and perennial grasses including grama (Bouteloua spp.), fringed brome (Bromus ciliatus), California brome (B. carinatus), New Mexico feathergrass (Hesperostipa neomexicana), and purple threeawn (Aristida purpurea) [30]. In Arizona and New Mexico singleleaf pinyon is codominant with shrub live oak, Emory oak (Q. emoryi), pointleaf manzanita (A. pungens), blue grama, crucifixion thorn (Canotia holacantha), and banana yucca, and also occurs with Utah juniper, alligator juniper (J. deppeana), mimosa (Mimosa aculeaticarpa var. biuncifera), sumac (Rhus spp.), silktassel (Garrya spp.), curlymesquite (Hilaria belangeri), and prairie junegrass (Koeleria macrantha) [154,190].

Related categories for SPECIES: Pinus monophylla | Singleleaf Pinyon