Abies grandis Forest Alliance
Grand fir forest
Grand fir forest
USDA Ecological Section Map
Summary Information
- Primary Life FormTree
- Elevation0-50 m
- State RarityS2.1
- Global RarityG4
- DistributionCAN: BC. USA: CA, ID, MT, OR, WA, WY (NatureServe) (USDA Plants)
- Endemic to CaliforniaNo
- Endemic to California Floristic Province and DesertsNo
- Date Added1995/11/01
Characteristic Species
Abies grandis is dominant or co-dominant in the tree canopy with Alnus rubra, Picea sitchensis, Pinus muricata, Sequoia sempervirens and Tsuga heterophylla.
Vegetation Layers
Trees < 70 m; canopy is continuous. Shrub layer is sparse to intermittent. Herbaceous layer is open to abundant.
Membership Rules
- Abies grandis > 60% cover in the tree canopy (Nature-Serve 2007).
Habitats
Maritime terraces, coastline slopes, and bluffs. The USFWS Wetland Inventory (1996 national list) recognizes Abies grandis as a FACU+ plant.
Other Habitat, Alliance and Community Groupings
| MCV (1995) | Grand fir series |
| NVCS (2009) | Abies grandis forest alliance |
| Calveg | Douglas-fir-Grand fir, Grand fir |
| Holland | Sitka spruce-grand fir forest |
| Munz | North Coast coniferous forest |
| WHR | Redwood |
| CDFW CA Code | 88.100.00 |
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 |
Remarks
Abies grandis is a conifer that attains a height of 60 m and an age of 250-300 years. Cone and seed production begin at about 20 years of age with large crops every two to three years. Seed germination is best on mineral soil, but they can establish on duff as well. Seedlings are relatively resistant to drought. Plants are shade tolerant, but less than other species with which it grows (Foiles et al. 1990, Howard and Aleksoff 2000).
The alliance is common in the Pacific Northwest; the southern limit of species is in Sonoma Co. (Griffin and Critchfield 1972). Infrequent in California, the alliance is limited to the north coastal strip, where logging has removed virtually all old-growth stands (Sawyer 2006, 2007). The few inventoried stands in Mendocino and Humboldt Cos. are generally less than 20 ha in size (CNDDB). The alliance does not involve stands with Abies grandis x concolor hybrids found at montane elevations in northern Coast Ranges and western Klamath Mountains (Hunt 1993, Sawyer 2006, 2007); we include them in the Abies concolor alliance.
Stands in California appear mostly seaward of the Sequoia sempervirens belt. The alliance’s proximity to the coast with its maritime temperatures and summer fog are similar to those of the Picea sitchensis alliance. However, unlike P. sitchensis stands, those of A. grandis occupy only upland settings, typically on mesic slopes above creeks and river mouths
The alliance is common in the Pacific Northwest; the southern limit of species is in Sonoma Co. (Griffin and Critchfield 1972). Infrequent in California, the alliance is limited to the north coastal strip, where logging has removed virtually all old-growth stands (Sawyer 2006, 2007). The few inventoried stands in Mendocino and Humboldt Cos. are generally less than 20 ha in size (CNDDB). The alliance does not involve stands with Abies grandis x concolor hybrids found at montane elevations in northern Coast Ranges and western Klamath Mountains (Hunt 1993, Sawyer 2006, 2007); we include them in the Abies concolor alliance.
Stands in California appear mostly seaward of the Sequoia sempervirens belt. The alliance’s proximity to the coast with its maritime temperatures and summer fog are similar to those of the Picea sitchensis alliance. However, unlike P. sitchensis stands, those of A. grandis occupy only upland settings, typically on mesic slopes above creeks and river mouths
Life History Traits of the Principal Species
| Abies grandis | |
|---|---|
| Life forms | Tree; evergreen |
| Seed storage | Transient |
| Seed longevity | Short |
| Mode of dispersal | Gravity; wind |
| Germination agents | Stratification—winter |
| Mode of sprouting | None |
| Survivability after fire/disturbance | Small trees: fire-sensitive; high flammability; no/low sprouter; canopy architecture susceptible. Large trees: relatively fire-hardy; thick epidermis |
| Disturbance-stimulated flowering | No |
| Reproductive range | 20-300 years |
| Recruitment | Low |
| Regional variation | Low in California |
Fire Characteristics
Abies grandis has thin bark, and fire easily kills young trees. At maturity, the bark is more developed, and trees are moderately resistant to fire. However, heart-and root-decaying fungi often kill trees that survive fires because they do not produce heavy pitch or have wood with decay-inhibiting properties (Howard and Aleksoff 2000).
More fire-resistant conifer and hardwood alliances associated with Abies grandis, such as Chamaecyparis lawsoniana, Pseudotsuga menziesii-Notholithocarpus densiflorus, and Quercus garryana alliances, are characterized by more frequently occurring fires (Stuart and Stephens 2006). Usually in mesic settings, A. grandis is a seral tree adapted to long fire intervals (e.g., > 100 years). After fires, seedlings of A. grandis commonly establish in open conditions and they continue to establish as tree canopies close because the species is shade tolerant (Howard and Aleksoff 2000).
| Fire return interval | Long |
| Seasonality | Summer-early fall |
| Size/extent | Small in California |
| Complexity | Moderate |
| Intensity | Moderate |
| Severity | Moderate to high |
| Type | Passive-active crown fire |
| Regional knowledge | North Coast |
Regional Status
- Northern California Coast (263Aa-b, Ad-e, Ag-i). Stands occur from Del Norte to Sonoma Counties in this section. Stands occur on the bluffs in Del Norte Redwoods State Park, in the Bear and Mattole River drainages near Cape Mendocino, on the headlands near Point Cabrillo, and near Fort Ross (Sawyer 2006, 2007). CNDDB has plot data on file for stands in Mendocino Co. and along the Mad River in Humboldt Co. (CNDDB 2023)
Management Considerations
Although Abies grandis is not economically valuable, when it grows with Picea sitchensis, Pseudotsuga menziesii, and Sequoia sempervirens, managers often intentionally remove it to make way for other more desirable timber species. Several recent housing developments have caused impacts on stands in Mendocino Co. This is a rare forest alliance in California.
Associations
- Abies grandis - Picea sitchensis / Gaultheria shallon / Polystichum munitum [2]
- Abies grandis - Tsuga heterophylla / Polystichum munitum [1]
References
- [1] CNDDB (California Natural Diversity Database), 2008+
- [2] California State Parks, 1995
- Boyd, R.J. 1980a
- Foiles, M.W.;Graham, R.T.;Olson, D.F. 1990
- Franklin, J.F. 1980a
- Franklin, J.F. 1988
- Franklin, J.F.;Emmingham, W. 1983
- Griffin, J.R.;Critchfield, W.B. 1972
- Howard, J.L.;Aleksoff, K.C. 2000
- Klein, A.;Keeler-Wolf, T.;Evens, J. 2015
- Lenihan, J.M. 1990
- Minore, D. 1980
- Minore, D. 1990
- NatureServe, 2007
- Sawyer, J.O. 2006
- Sawyer, J.O. 2007
- Steinhoff, R.J. 1978
- Stuart, J.D.;Stephens, S.I. 2006
- Zinke, P.J. 1977