Pinus monophylla - (Juniperus osteosperma) Woodland Alliance
Singleleaf pinyon - Utah juniper woodlands

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation1000-2900 m
  • State RarityS4
  • Global RarityG5
  • DistributionUSA: CA, ID, NV, UT, WY (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added1995/11/01

Characteristic Species

Pinus monophylla is dominant or co-dominant in the tree canopy with Juniperus californica, Juniperus grandis, Juniperus osteosperma, Pinus jeffreyi or Quercus chrysolepis. Shrubs include Artemisia arbuscula, Artemisia nova, Artemisia tridentata, Chrysothamnus viscidiflorus, Ephedra viridis, Ericameria nauseosa, Grayia spinosa, Opuntia polyacantha var. erinacea, Purshia stansburiana, Purshia tridentata, Quercus cornelius-mulleri, Quercus john-tuckeri or Yucca baccata.

Vegetation Layers

Trees < 15 m; canopy is open to intermittent. Shrub layer is intermittent to continuous. Herbaceous layer is sparse or grassy.

Membership Rules

  • Pinus monophylla > 25% absolute cover in the tree canopy; shrub cover is less than tree cover (Thomas et al. 2004).
  • Pinus monophylla > 5% absolute cover in the tree canopy (Keeler-Wolf et al. 1998b).
  • Pinus monophylla ≥ 1% but less than 25% cover. Juniperus osteosperma or J. californica present. P. monophylla occurs over a sparse to relatively dense cover of shrubs (Thomas et al. 2004).
  • Pinus monophylla > 50% relative cover in the tree canopy, or > 30% relative cover with Juniperus spp. and/or Quercus turbinella in stands (Evens et. al 2014).


Alluvial fans, pediments, slopes, ridges, canyons, and ravines. Soils are commonly well drained.

Other Habitat, Alliance and Community Groupings

MCV (1995) Singleleaf pinyon series, Singleleaf pinyon-Utah juniper series
NVCS (2009) Pinus monophylla wooded tall herbaceous alliance, Pinus monophylla-(Juniperus osteosperma) woodland alliance
Calveg Ultramafic mixed conifer, Singleleaf pinyon pine
Holland Great Basin piñon-juniper woodland, Great Basin piñon woodland, Mojavean piñon woodland, Peninsular piñon woodland
Munz Pinyon-juniper woodland
WHR Pinyon-juniper
CDFW CA Code 87.040.00

National Vegetation Classification Hierarchy

Formation Class Mesomorphic Tree Vegetation (Forest and Woodland)
Formation Subclass Temperate Forest
Formation Cool Temperate Forest
Division North American Intermountain Basins Scrub Woodland
Macro Group Intermountain Basins Pinyon-Juniper Woodland
Group Western Great Basin montane conifer woodland