Quercus garryana (tree) Forest & Woodland Alliance
Oregon white oak woodland and forest

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation60-1800 m
  • State RarityS3
  • Global RarityG4
  • DistributionCAN: BC. USA: CA, OR, WA (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added1995/11/01

Characteristic Species

Quercus garryana var. garryana is dominant or co-dominant in the tree canopy with Juniperus occidentalis, Pinus jeffreyi, Pinus ponderosa, Pinus sabiniana, Pseudotsuga menziesii, Quercus chrysolepis, Quercus kelloggii and Umbellularia californica.

Vegetation Layers

Trees < 30 m; canopy is open to continuous. Shrub layer is usually open. Herbaceous layer is open to intermittent and mostly grassy.

Membership Rules

  • Quercus garryana > 30% relative cover in the tree canopy; > 25% absolute cover, and lacking an appreciable conifer cover (NatureServe 2007).


Raised stream benches, terraces, slopes, and ridges of all aspects. The USFWS Wetland Inventory (1996 national list) recognizes Quercus garryana as a UPL plant.

Other Habitat, Alliance and Community Groupings

MCV (1995) Oregon white oak series
NVCS (2009) Quercus garryana forest alliance, Quercus garryana wooded herbaceous alliance, Quercus garryana woodland alliance
Calveg Coastal mixed hardwood, Oregon white oak
Holland Oregon oak woodland, Mixed north cismontane woodland
Munz Northern oak woodland
WHR Montane hardwood
CDFW CA Code 71.030.00

National Vegetation Classification Hierarchy

Formation Class Mesomorphic Tree Vegetation (Forest and Woodland)
Formation Subclass Temperate Forest
Formation Cool Temperate Forest
Division Western North America Cool Temperate Forest
Macro Group Californian-Vancouverian Montane and Foothill Forest
Group Vancouverian evergreen broadleaf and mixed forest