Abies amabilis Forest Alliance
Pacific silver fir forest

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation1700-2100 m
  • State RarityS1
  • Global RarityG5
  • DistributionCAN: BC. USA: AK, CA, OR, WA (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsNo
  • Date Added1995/11/01

Characteristic Species

Abies amabilis is dominant or co-dominant in the tree canopy with Abies concolor, Abies ×shastensis, Calocedrus decurrens, Picea breweriana, Pinus contorta ssp. murrayana, Pinus jeffreyi, Pinus lambertiana, Pinus monticola, Pseudotsuga menziesii and Tsuga mertensiana.

Vegetation Layers

Trees < 75 m; canopy is continuous. Shrub layer is sparse to intermittent. Herbaceous layer is sparse.

Membership Rules

  • Abies amabilis > 30% relative cover in the tree canopy (NatureServe 2007).


Moraines of rocks and boulders, north-facing upper slopes. Soils are granitic and well drained. The USFWS Wetland Inventory (1996 national list) recognizes Abies amabilis as a FACU plant.

Other Habitat, Alliance and Community Groupings

MCV (1995) Silver fir unique stands
NVCS (2009) Abies amabilis giant forest alliance, Abies amabilis seasonally flooded forest alliance
Calveg Klamath mixed conifer
Holland Siskiyou enriched coniferous forest, Salmon-Scott enriched coniferous forest
Munz Subalpine forest
WHR Klamath mixed conifer
CDFW CA Code 88.800.00

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 Vancouverian Subalpine Forest
Group Vancouverian mesic montane coniferous forest and woodland