Pseudotsuga menziesii - Calocedrus decurrens Forest & Woodland Alliance
Douglas fir - incense cedar forest and woodland

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation700-1500 m
  • State RarityS3
  • Global RarityG3
  • DistributionUSA: CA, OR. Mexico (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsYes
  • Date Added2009/09/01

Characteristic Species

Calocedrus decurrens and Pseudotsuga menziesii are co-dominant in the tree canopy with Abies concolor, Pinus jeffreyi, Pinus lambertiana, Pinus monticola, Pinus ponderosa and Umbellularia californica.

Vegetation Layers

Trees < 75 m; canopy is intermittent or continuous. Shrubs are infrequent or common. Herbaceous layer is sparse or abundant.

Membership Rules

  • Pseudotsuga menziesii > 30% relative cover, Calocedrus decurrens present as overstory trees and reproduction layer with at least 30% relative cover; Abies concolor and Notholithocarpus densiflorus absent or unimportant though Pinus jeffreyi may be present and codominant (cf. Jimerson et al. 1995).


Raised stream benches, terraces, slopes, and ridges of all aspects. Soils are deep and well drained, often on serpentine or other ultramafics. The USFWS Wetland Inventory (1996 national list) recognizes Pseudotsuga menziesii as a FACU plant.

Other Habitat, Alliance and Community Groupings

MCV (1995) Douglas fir series
NVCS (2009) Calocedrus decurrens-Pseudotsuga menziesii forest alliance
Calveg Pacific Douglas-fir, Klamath mixed conifer, Mixed conifer-Pine
Holland Coast range mixed coniferous forest, Sierran mixed coniferous forest
Munz Yellow pine forest
WHR Sierran mixed conifer
CDFW CA Code 82.600.00

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 Upland Vancouverian mixed woodland and forest