Pinus edulis Woodland Alliance
Two-needle pinyon stands

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation1300-2000 m
  • State RarityS2?
  • Global RarityG4
  • DistributionUSA: AZ, CA, CO, NM, NV, OK, TX, UT, WY (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added1995/11/01

Characteristic Species

Pinus edulis is dominant in the tree canopy with Juniperus osteosperma or Quercus chrysolepis. Or it is emergent above the shrub canopy with Arctostaphylos pungens, Artemisia bigelovii, Artemisia nova, Ceanothus greggii, Ephedra viridis, Eriogonum wrightii, Fallugia paradoxa, Garrya flavescens, Gutierrezia californica, Quercus turbinella, Rhus trilobata, Symphoricarpos longiflorus or Yucca baccata. Herbs characteristically present include Artemisia ludoviciana, Bromus rubens, Elymus elymoides or Poa fendleriana.

Vegetation Layers

Trees < 15 m; canopy is open. Shrubs are intermittent to continuous. Herbaceous layer is sparse.

Membership Rules

  • Pinus edulis > 50% relative cover, or> 30% relative cover with Juniperus osteosperma and/or Quercus turbinella (Evens et al. 2014).


Limestone substrates.

Other Habitat, Alliance and Community Groupings

MCV (1995) Two-leaf pinyon unique stands
NVCS (2009) Pinus edulis-(Juniperus spp.) woodland alliance, Pinus monophylla-(Juniperus osteosperma) woodland alliance
Calveg Singleleaf pinyon pine
Holland Great Basin piñon-juniper woodland, Great Basin piñon woodland
Munz Pinyon-juniper woodland
WHR Pinyon-juniper
CDFW CA Code 87.050.00

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