Chamaecyparis lawsoniana Forest & Woodland Alliance
Port Orford cedar forest and woodland

USDA Ecological Section Map

Summary Information

  • Primary Life FormTree
  • Elevation800-1400 m
  • State RarityS3.1
  • Global RarityG3
  • DistributionUSA: CA, OR (NatureServe)
  • Endemic to CaliforniaNo
  • Endemic to California Floristic Province and DesertsYes
  • Date Added1995/11/01

Characteristic Species

Chamaecyparis lawsoniana is dominant or co-dominant in the tree canopy with Abies concolor, Abies procera, Abies ×shastensis, Alnus rhombifolia, Calocedrus decurrens, Pinus jeffreyi, Pinus lambertiana, Pinus monticola and Pseudotsuga menziesii.

Vegetation Layers

Trees < 60 m; canopy is open to continuous. Shrub layer is sparse to continuous. Herbaceous layer is sparse or grassy.

Membership Rules

  • Chamaecyparis lawsoniana > 50% relative cover in tree canopy (Jimerson et al. 1995).


Low-gradient depositions along rivers, concave slopes, raised stream benches, and terraces with perched water tables. Soils are typically a mixture of alluvial or colluvial material, including serpentine substrates. The USFWS Wetland Inventory (1996 national list) recognizes Chamaecyparis lawsoniana as a FACU plant.

Other Habitat, Alliance and Community Groupings

MCV (1995) Port Orford cedar series
NVCS (2009) Chamaecyparis lawsoniana forest alliance, Chamaecyparis lawsoniana temporarily flooded forest alliance
Calveg Port Orford-cedar
Holland Port Orford cedar forest
Munz North Coast coniferous forest
WHR Douglas fir
CDFW CA Code 81.100.00

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 Rainforest
Group Vancouverian hypermaritime lowland rainforest