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A3611 Tsuga heterophylla - Thuja plicata / Vaccinium ovalifolium Forest Alliance
Type Concept Sentence: This alliance consists of forests of the Pacific Northwest dominated by Tsuga heterophylla and Thuja plicata on well-drained and nutrient-poor sites. Understory species are indicators of nutrient-poor soils.
Common (Translated Scientific) Name: Western Hemlock - Western Red-cedar / Oval-leaf Blueberry Forest Alliance
Colloquial Name: Western Hemlock - Western Red-cedar / Oval-leaf Blueberry Forest
Hierarchy Level: Alliance
Type Concept: This alliance covers forests dominated by Tsuga heterophylla and Thuja plicata on well-drained and nutrient-poor sites. Understory species are indicators of nutrient-poor soils. These forests occur in the maritime-influenced regions of the Pacific Northwest, from the central coast of British Columbia to the Kenai Peninsula in Alaska. Throughout the range of this alliance, much of the annual precipitation occurs as rain. Where snow does occur, it can generally be melted by rain during warm winter storms. In all settings, this type occurs where environmental conditions are moderated by the marine influence, with moderate drought and frost. Stands of the alliance generally occur on all slopes and aspects, except for wet bottomland sites. It occurs on a wide variety of soil types across its range, but growth of Tsuga heterophylla is decreased on heavy soils, or soils with poor drainage. The geographic and environmental range of this type is wide, and associated vegetation is correspondingly diverse.
Diagnostic Characteristics: Tsuga heterophylla and Thuja plicata dominate the overstory canopy with sparse understory.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: These forests are found on nutrient-poor and often depauperate sites.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This alliance is characterized by a moderately dense, open canopy of needle-leaved evergreen trees from 20-35 m in height with a subcanopy 2-20 m tall. The shrub layer is moderately dense and is dominated by evergreen and deciduous broad-leaved shrubs. The dwarf-shrub layer is sparse to moderately dense and dominated by broad-leaved evergreen plants. The herbaceous layer is sparse and dominated by perennial forbs and ferns.
Floristics: This section needs to be developed from Canadian plot data.
Dynamics: No Data Available
Environmental Description: This section needs to be developed from Canadian plot data.
Geographic Range: This alliance occurs from the central coast of British Columbia to the Kenai Peninsula in Alaska.
Nations: CA,US
States/Provinces: AK, BC
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899669
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
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 | A3611 Western Hemlock - Western Red-cedar / Oval-leaf Blueberry Forest Alliance | A3611 | 1.B.2.Nd.3.f |
| Association | CEGL003222 Western Hemlock - Western Red-cedar / (Alaska Blueberry, Oval-leaf Blueberry) Forest | CEGL003222 | 1.B.2.Nd.3.f |
| Association | CEGL003224 Western Hemlock - Western Red-cedar / Oval-leaf Blueberry / Threeleaf Foamflower Forest | CEGL003224 | 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: >< Western Hemlock: 224 (Eyre 1980)
>< Western Needleleaf Forests: 13: Cedar-Hemlock-Pine Forest (Thuja-Tsuga-Pinus) (Küchler 1964)
>< Western Needleleaf Forests: 2: Cedar-Hemlock-Douglas Fir Forest (Thuja-Tsuga-Pseudotsuga) (Küchler 1964)
>< Western Redcedar - Western Hemlock: 227 (Eyre 1980)
>< Western Needleleaf Forests: 13: Cedar-Hemlock-Pine Forest (Thuja-Tsuga-Pinus) (Küchler 1964)
>< Western Needleleaf Forests: 2: Cedar-Hemlock-Douglas Fir Forest (Thuja-Tsuga-Pseudotsuga) (Küchler 1964)
>< Western Redcedar - Western Hemlock: 227 (Eyre 1980)
- Burns, R. M., and B. H. Honkala, technical coordinators. 1990a. Silvics of North America: Volume 1. Conifers. Agriculture Handbook 654. USDA Forest Service, Washington, DC. 675 pp.
- DeMeo, T., J. Martin, and R. A. West. 1992. Forest plant association management guide, Ketchikan Area, Tongass National Forest. R10-MB-210. USDA Forest Service, Alaska Region. 405 pp.
- Eyre, F. H., editor. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 pp.
- Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
- Küchler, A. W. 1964. Potential natural vegetation of the conterminous United States. American Geographic Society Special Publication 36. New York, NY. 116 pp.
- Martin, R. R., S. J. Trull, W. W. Brady, R. A. West, and J. M. Downs. 1995. Forest plant association management guide, Chatham Area, Tongass National Forest. R10-RP-57. USDA Forest Service, Alaska Region.
- Pawuk, W. H., and E. J. Kissinger. 1989. Preliminary forest plant associations of the Stikine Area, Tongass National Forest. Technical Publication R10-TP-72. USDA Forest Service, Alaska Region, Juneau, AK. 126 pp.
- Shephard, M. E. 1995. Plant community ecology and classification of the Yakutat Foreland, Alaska. R10-TP-56. USDA Forest Service, Alaska Region. 213 pp. plus appendices.