Quercus kelloggii Forest & Woodland Alliance
California black oak forest and woodland

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation60-2500 m
  • State RarityS4
  • Global RarityG4
  • DistributionUSA: CA, OR?. Baja California, Mexico? (NatureServe) (TJM2)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsYes
  • Date Added1995/11/01

Characteristic Species

Quercus kelloggii is dominant or co-dominant in the tree canopy with Abies concolor, Arbutus menziesii, Calocedrus decurrens, Pinus attenuata, Pinus ponderosa, Pseudotsuga menziesii, Quercus agrifolia, Quercus chrysolepis, Quercus garryana, Quercus lobata and Umbellularia californica.

Vegetation Layers

Trees < 40 m; canopy is open to continuous, or savanna-like. Shrub layer is open to intermittent. Herbaceous layer is sparse or grassy.

Membership Rules

  • Quercus kelloggii > 50% relative cover in overstory, and conifers are not conspicuous; or Q. kelloggii > 30% relative cover in the overstory and Pinus ponderosa may co-dominate (Klein et al. 2007).
  • Quercus kelloggii > 50% relative cover in the tree canopy; emergent conifers < 10% relative cover (Keeler-Wolf et al. 2003b, Evens and San 2005).
  • Quercus kelloggii and Pinus ponderosa 30-60% relative cover in the overstory (cf. Keeler-Wolf et al. 2003b).


All aspects and topographic settings. Soils are moderately to excessively drained.

Other Habitat, Alliance and Community Groupings

MCV (1995) Black oak series
NVCS (2009) Quercus kelloggii forest alliance, Quercus kelloggii temporarily flooded woodland alliance
Calveg California black oak
Holland Black oak woodland, Black oak forest
Munz Mixed evergreen forest
WHR Montane hardwood
CDFW CA Code 71.010.00

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 broadleaf forest and woodland