Pinus quadrifolia Woodland Alliance
Parry pinyon woodland

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation900-1800 m
  • State RarityS2
  • Global RarityG3
  • DistributionUSA: CA. Mexico (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added1995/11/01

Characteristic Species

Pinus quadrifolia is dominant in the tree canopy with Juniperus californica, Pinus jeffreyi, Pinus monophylla and Quercus chrysolepis. Or it is emergent above the shrub canopy with Adenostoma fasciculatum, Adenostoma sparsifolium, Arctostaphylos glandulosa, Arctostaphylos glauca, Ceanothus greggii, Cercocarpus montanus, Eriogonum fasciculatum, Hesperoyucca whipplei, Quercus cornelius-mulleri, Rhus ovata or Yucca schidigera.

Vegetation Layers

Trees < 15 m; canopy is open or intermittent. Shrub layer is usually intermittent. Herbaceous layer is sparse.

Membership Rules

  • Pinus quadrifolia > 3% absolute cover of trees over chaparral shrubs with scattered Quercus chrysolepis (Keeler-Wolf et al. 1998b).
  • Pinus quadrifolia is > 50% relative cover and > 10% absolute cover in the tree canopy (Klein and Evens 2005).


Slopes with north-facing aspects, ridges. Soils are well drained.

Other Habitat, Alliance and Community Groupings

MCV (1995) Parry pinyon series
NVCS (2009) Pinus quadrifolia woodland alliance
Calveg Four-needle pinyon pine
Holland Peninsular piñon woodland, Peninsular juniper woodland and scrub
Munz Pinyon-juniper woodland
WHR Pinyon-juniper
CDFW CA Code 87.030.00

National Vegetation Classification Hierarchy

Formation Class Mesomorphic Tree Vegetation (Forest and Woodland)
Formation Subclass Temperate Forest
Formation Warm Temperate Forest
Division Madrean Forest and Woodland
Macro Group California Forest and Woodland
Group Californian evergreen coniferous forest and woodland