Pseudotsuga menziesii Forest & Woodland Alliance
Douglas fir forest and woodland

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation700-1400 m
  • State RarityS4
  • Global RarityG5
  • DistributionCAN: AB, BC. USA: AZ, CA, CO, ID, MT, NM, OR, TX, UT, WA, WY. Mexico (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added1995/11/01

Characteristic Species

Pseudotsuga menziesii is dominant or co-dominant with hardwoods in the tree canopy with Abies concolor, Acer macrophyllum, Alnus rhombifolia, Arbutus menziesii, Calocedrus decurrens, Chamaecyparis lawsoniana, Chrysolepis chrysophylla, Cornus nuttallii, Pinus contorta, Pinus jeffreyi, Pinus lambertiana, Quercus agrifolia, Quercus chrysolepis, Quercus garryana, Quercus kelloggii and Sequoia sempervirens.

Vegetation Layers

Trees < 75 m; canopy is intermittent to continuous, and it may be two tiered. Shrubs are infrequent or common. Herbaceous layer is sparse or abundant.

Membership Rules

  • Pseudotsuga menziesii > 50% relative cover in the tree canopy and reproducing successfully, though hardwoods may dominate or co-dominate in the subcanopy and regeneration layer; Abies concolor, Chamaecyparis lawsoniana, Pinus contorta, P. ponderosa, and Sequoia sempervirens <20% relative cover; and Notholithocarpus densiflorus <10% relative cover in the tree canopy (Jimerson et al. 1996).

Habitats

All topographic positions and aspects. Substrates various, including serpentine. The USFWS Wetland Inventory (1996 national list) recognizes Pseudotsuga menziesii as FACU plant.

Other Habitat, Alliance and Community Groupings

MCV (1995) Douglas fir series
NVCS (2009) Pseudotsuga menziesii forest alliance
Calveg Pacific Douglas-fir
Holland Upland douglas-fir forest, Coast range mixed coniferous forest
Munz Douglas fir forest
WHR Douglas fir
CDFW CA Code 82.200.00

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