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CEGL002669 Abies grandis - Thuja plicata / Achlys triphylla Forest
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Grand Fir - Western Red-cedar / Sweet After Death Forest
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This is a conifer forest association with a rich forb undergrowth. It is located near stream bottoms in the eastern Cascades near the Columbia River Gorge. These sites are generally found between 730 and 1010 m (2400-3300 feet) and sites are generally free of prolonged snow accumulation. The existing vegetation is characterized by Pseudotsuga menziesii and Abies grandis trees codominating the tree canopy, with Thuja plicata also frequent in the canopy and in regeneration layers. The shrub layer is fairly sparse with patches of tall Acer circinatum and shorter Rosa gymnocarpa, Mahonia nervosa, and Symphoricarpos mollis. The herbaceous layer is patchy with Trientalis borealis ssp. latifolia, Achlys triphylla, and other moist forest forbs.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: No Data Available
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This is an evergreen needle-leaved forest dominated by Pseudotsuga menziesii, Abies grandis, and with abundant Thuja plicata in both the canopy and as seedlings or saplings in the understory. Mature individuals of Tsuga heterophylla are found in most stands, with cover averaging 8%, and seedlings of this species are common in the understory. Cover of the tree canopy is typically between 50 and 80%. Both the shrub and herbaceous layers are generally sparse, but species-rich. Patches of the tall broad-leaved deciduous shrub Acer circinatum are occasionally present. The low-shrub layer consists of scattered broad-leaved shrubs such as Rosa gymnocarpa, Symphoricarpos mollis, and Mahonia nervosa (= Berberis nervosa). The herbaceous layer is patchy with Trientalis borealis ssp. latifolia (= Trientalis latifolia), Achlys triphylla, and other moist forest forbs. Total cover of both tall- and low-shrub layers is about 25%; 15 shrub species were encountered in four stands. Herbaceous cover is equally sparse and consists entirely of perennial forbs, with 23 species encountered in four stands. No grass species occur in this association.
Dynamics: Mature stands of this association are structurally complex, providing excellent wildlife habitat, including winter range. Most stands have large snag trees which provide cavity nesting and foraging opportunities, particularly valuable because the snags are often close to streams. Thick litter and duff and woody debris are also important characteristics of this association. Most stands have probably been logged for large, old trees of Pseudotsuga, Abies grandis and Thuja.
Environmental Description: This association occurs on the eastern slope of the central Cascades, a region with a steep precipitation gradient from west to east due to the rainshadow effect of the Cascade crest. Annual precipitation varies from 147 to 218 cm (58-86 inches), from south to north, with much of it occurring from October through March. Summers are relatively dry. The association is found on warm, mesic sites on lower slopes and in valley bottoms of north- to east-facing drainages at relatively low elevations of 730 to 1000 m (2400-3300 feet). Snow may accumulate, but most sites typically are snow-free most of the year. Parent materials are basalts, with substantial amounts of aerially deposited ash and loess. Soils are moderately deep, have little rock in the profile, and have surface horizons of weathered ash. Textures are coarse sandy loam, loam or silt loam. Some sites have high water tables due to proximity to streams.
Geographic Range: Restricted to the east Cascades of Oregon and Washington in the vicinity of the Columbia River Gorge.
Nations: US
States/Provinces: OR, WA
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.685023
Confidence Level: Low
Confidence Level Comments: No Data Available
Grank: G2
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 1 Forest & Woodland Class | C01 | 1 |
| Subclass | 1.B Temperate & Boreal Forest & Woodland Subclass | S15 | 1.B |
| Formation | 1.B.2 Cool Temperate Forest & Woodland Formation | F008 | 1.B.2 |
| Division | 1.B.2.Nb Rocky Mountain Forest & Woodland Division | D194 | 1.B.2.Nb |
| Macrogroup | 1.B.2.Nb.3 Western Hemlock - Grand Fir - Western Larch Mesic Lower Montane Forest Macrogroup | M500 | 1.B.2.Nb.3 |
| Group | 1.B.2.Nb.3.c Grand Fir - Douglas-fir East Cascades Forest Group | G212 | 1.B.2.Nb.3.c |
| Alliance | A3582 Western Hemlock - Grand Fir Cascadian Mesic Cove Forest Alliance | A3582 | 1.B.2.Nb.3.c |
| Association | CEGL002669 Grand Fir - Western Red-cedar / Sweet After Death Forest | CEGL002669 | 1.B.2.Nb.3.c |
Concept Lineage: THPL/ACTR & ABGR-THPL/ACTR were lumped because review of the data sources for each indicate very similar floristics & site characteristics (Kagan/Crawford, pers comm). Both types are rare & restricted in distribution.
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Thuja plicata - Abies grandis / Achlys triphylla (Topik et al. 1988) [(p.115)]
- Bourgeron, P. S., and L. D. Engelking, editors. 1994. A preliminary vegetation classification of the western United States. Unpublished report. The Nature Conservancy, Western Heritage Task Force, Boulder, CO. 175 pp. plus appendix.
- Kagan, J. S., J. A. Christy, M. P. Murray, and J. A. Titus. 2004. Classification of native vegetation of Oregon. January 2004. Oregon Natural Heritage Information Center, Portland. 52 pp.
- Topik, C. 1989. Plant associations and management guide for the Abies grandis zone Gifford Pinchot National Forest. R6-ECOL-TP-006-88. USDA Forest Service, Pacific Northwest Region, Portland, OR. 110 pp.
- Topik, C., N. M. Halverson, and T. High. 1988. Plant associations and management guide of the ponderosa pine, Douglas-fir, and grand fir zone, Mt. Hood National Forest. R6-ECOL-TP-004-88. USDA Forest Service, Pacific Northwest Region, Portland, OR. 136 pp.
- WNHP [Washington Natural Heritage Program]. 2018. Unpublished data files. Washington Natural Heritage Program, Department of Natural Resources, Olympia, WA.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.