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CEGL000475 Thuja plicata / Gaultheria shallon Forest
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Western Red-cedar / Salal Forest
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This association occurs primarily on north-facing slopes of the San Juan Islands, and on easterly slopes of the Olympics. Elevations are less than 215 m. In these sheltered sites, winds are slight, temperatures are cooler, and summer soil moisture is higher. This is an evergreen needle-leaved tall forest dominated by Thuja plicata, Abies grandis, and/or Pseudotsuga menziesii. Abies grandis is present in 83% of stands, and Thuja plicata in 61% of stands. When Tsuga heterophylla is present, it has less than 5% cover. The broad-leaved deciduous tree Salix scouleriana is often present in the lower canopy with low cover, along with the needle-leaved evergreen Taxus brevifolia. Tree regeneration is dominated by Thuja plicata or Abies grandis. The dense shade of the canopy results in a patchy and sometimes open understory typically lacking an herbaceous layer. The low broad-leaved evergreen shrub Gaultheria shallon dominates the understory, and the taller Holodiscus discolor may be codominant in some stands. Other shrubs may be present, such as the low evergreen Mahonia nervosa.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This association (CEGL000475) could potentially be merged with ~Pseudotsuga menziesii - (Abies grandis, Thuja plicata) / Mahonia nervosa - Gaultheria shallon Forest (CEGL002845)$$, but there currently is not sufficient information to support that.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This is an evergreen needle-leaved tall forest dominated by Thuja plicata, Abies grandis, and/or Pseudotsuga menziesii. Abies grandis is present in 83% of stands, and Thuja plicata in 61% of stands. If the conifer Tsuga heterophylla is present, it has less than 5% cover. The broad-leaved deciduous tree Salix scouleriana is often present in the lower canopy with low cover, along with the needle-leaved evergreen Taxus brevifolia. Tree regeneration is dominated by Thuja plicata or Abies grandis. The dense shade of the canopy results in a patchy and sometimes open understory typically lacking an herbaceous layer. The low broad-leaved evergreen shrub Gaultheria shallon dominates the understory averaging 48% cover. The tall broad-leaved deciduous shrub Holodiscus discolor may be codominant in some stands, and averages 11% cover. Other shrubs may be present, such as the low evergreen Mahonia nervosa.
Dynamics: No Data Available
Environmental Description: This association occurs primarily in the Puget Sound basin, an area in the rainshadow of the Olympic Mountains. It is also found on the eastern slopes of the Olympic Peninsula. The climate in this rainshadow is drier than surrounding coastal mountain areas, with average annual precipitation ranging from as low as 46 cm in the San Juan Islands to 75 cm in the Puget lowlands, with a pronounced summer dry season. Temperatures are strongly moderated by oceanic influence. Geologically, the Puget Trough includes the Puget Sound basin and extends into the Willamette Valley of north-central Oregon. The Puget Sound basin is a depressed, glaciated region which is now partially submerged. This basin slopes gently towards Puget Sound and contains many lakes and poorly drained depressions underlain by glacial drift.
This association occurs primarily on north-facing slopes of the San Juan Islands, and on easterly slopes of the Olympics. Elevations are less than 215 m. In these sheltered sites, winds are slight, temperatures are cooler, and summer soil moisture is higher. Soils are derived from deep glacial deposits, well-drained, and texturally are loamy sands to sandy loams, with weakly developed profiles. Recent data collected by the Washington Natural Heritage Program indicate that the environmental conditions supporting this association are broader than those reported here. However, these recent data have not been thoroughly evaluated and are not available at the time of this writing.
This association occurs primarily on north-facing slopes of the San Juan Islands, and on easterly slopes of the Olympics. Elevations are less than 215 m. In these sheltered sites, winds are slight, temperatures are cooler, and summer soil moisture is higher. Soils are derived from deep glacial deposits, well-drained, and texturally are loamy sands to sandy loams, with weakly developed profiles. Recent data collected by the Washington Natural Heritage Program indicate that the environmental conditions supporting this association are broader than those reported here. However, these recent data have not been thoroughly evaluated and are not available at the time of this writing.
Geographic Range: Found almost exclusively in the San Juan Islands and vicinity (San Juan, Skagit, Island, and Clallam counties) and into adjacent British Columbia. Rare disjunct occurrences further south in the Puget Lowland.
Nations: CA,US
States/Provinces: BC, WA
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.687058
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G1G2
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.Nd Vancouverian Forest & Woodland Division | D192 | 1.B.2.Nd |
| Macrogroup | 1.B.2.Nd.3 Western Hemlock - Sitka Spruce - Redwood Rainforest Macrogroup | M024 | 1.B.2.Nd.3 |
| Group | 1.B.2.Nd.3.f Western Hemlock - Sitka Spruce North-Central Pacific Rainforest Group | G751 | 1.B.2.Nd.3.f |
| Alliance | A3610 Western Hemlock - Western Red-cedar / Deer Fern Rich Mesic Forest Alliance | A3610 | 1.B.2.Nd.3.f |
| Association | CEGL000475 Western Red-cedar / Salal Forest | CEGL000475 | 1.B.2.Nd.3.f |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: >< Pseudotsuga menziesii - Abies grandis - Tsuga heterophylla / Gaultheria shallon - Holodiscus discolor (Agee 1987)
= Pseudotsuga menziesii - Thuja plicata - (Abies grandis) / Gaultheria shallon (Chappell 2006b) [29 plots]
= Pseudotsuga menziesii - Thuja plicata / Gaultheria shallon - Holodiscus discolor (Chappell 1997)
= Pseudotsuga menziesii - Thuja plicata / Gaultheria shallon (Fonda and Bernardi 1976)
= Thuja plicata / Gaultheria shallon Forest Association (Rocchio et al. 2012)
= Pseudotsuga menziesii - Thuja plicata - (Abies grandis) / Gaultheria shallon (Chappell 2006b) [29 plots]
= Pseudotsuga menziesii - Thuja plicata / Gaultheria shallon - Holodiscus discolor (Chappell 1997)
= Pseudotsuga menziesii - Thuja plicata / Gaultheria shallon (Fonda and Bernardi 1976)
= Thuja plicata / Gaultheria shallon Forest Association (Rocchio et al. 2012)
- Agee, J. K. 1987. The forest of San Juan Island National Historic Park. Unpublished report prepared by the University of Washington for the USDA National Park Service. Report CPSU/UW 88-1. 83 pp.
- 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.
- Chappell, C. B. 1997. Terrestrial forested plant associations of the Puget Lowland. Draft report. Washington Natural Heritage Program, Washington Department of Natural Resources, Olympia. 36 pp.
- Chappell, C. B. 2006b. Upland plant associations of the Puget Trough ecoregion, Washington. Natural Heritage Report 2006-01. Washington Department of Natural Resources, Natural Heritage Program, Olympia, WA. [http://www.dnr.wa.gov/nhp/refdesk/communities/pdf/intro.pdf]
- Fonda, R. W., and J. A. Bernardi. 1976. Vegetation of Sucia Island in Puget Sound, Washington. Bulletin of the Torrey Botanical Club 103(3):99-109.
- Franklin, J. F., and C. T. Dyrness. 1973. Natural vegetation of Oregon and Washington. General Technical Report PNW-8. USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Portland, OR. 417 pp.
- Henderson, J. A., D. A. Peter, and R. Lesher. 1986. Preliminary plant associations of the Olympic National Forest. USDA Forest Service, Pacific Northwest Region. 136 pp.
- Rocchio, F. J., R. C. Crawford, and C. C. Thompson. 2012. San Juan Island National Historical Park vegetation classification and mapping project. Natural Resource Report NPS/NCCN/NRR--2012/603. National Park Service, Fort Collins, CO. 188 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.