Print Report
CEGL000488 Tsuga heterophylla / Aralia nudicaulis Forest
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Western Hemlock / Wild Sarsaparilla Forest
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This forested association occurs on warm, moist locations, some of the warmest locations in the Interior Northwest for Tsuga heterophylla communities. It occurs primarily on gentle stream benches, lower valley sideslopes and toeslopes, alluvial terraces and valley bottoms, 640 to 1219 m (2100-4000 feet) in elevation. Soils are typically well-drained, fine-textured with an ash layer, loam to silty loam, moist but never boggy. Parent materials range from glacial till, coarse alluvium to colluvium. This association is heavily forested. Total tree canopy cover ranges from 70-95%. Tsuga heterophylla is always present with 20-75% cover. Thuja plicata is often present with 10-40% average cover. Other trees are always present, but not in any consistent combination. Other tree species include Abies grandis, Betula papyrifera, Larix occidentalis, Pseudotsuga menziesii, and Pinus monticola. The shrub layer is relatively sparse with less than 10% total cover. Typical species include Paxistima myrsinites, Cornus sericea, Lonicera spp., Acer spp., and Linnaea borealis. The herbaceous layer is relatively lush, with 10-80% cover and floristically rich, but only Aralia nudicaulis, Clintonia uniflora, and Maianthemum stellatum have more than 5% cover. Aralia nudicaulis is not present in every stand in the literature, but it is expressed as the forb with the highest constancy and highest cover value within all sampled stands.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This association is defined as a PNV vegetation type. If it were renamed as a dominance type the species would include Thuja plicata, Tsuga heterophylla, and Abies grandis.
In Idaho, occurrences now included in this association have previously been classified as ~Tsuga heterophylla / Clintonia uniflora Forest (CEGL000493)$$; stands representing the Aralia nudicaulis phase of this type are now included here. The difference between Tsuga and Thuja dominance of the upper canopy in this association (and its analogue, ~Thuja plicata / Aralia nudicaulis Forest (CEGL000471)$$) is quite probably related to historical accident, past disturbance events and subsequent successional patterns. Despite the very long fire-return intervals (200-500 years for stand-replacing fire), the longevity of both species, especially Thuja, argues for considering the dual designation (Thuja plicata - Tsuga heterophylla) as appropriate (i.e., combining these two associations into one); if one or the other species responds to disturbance by attaining canopy dominance it is unlikely the non-dominant species will become dominant in the average fire-free interval. Others have recognized that quite probably a dominance continuum exists between these two species by naming at least 8 plant associations with the dual designation (Tsuga heterophylla - Thuja plicata /_).
Arguing against this approach is the approach being taken by the USNVC placing emphasis on existing vegetation composition, and it is indisputable that either climax tree species can be strongly dominant with the other species occurring only in the reproductive layers, if at all. In northern Idaho, where these species are sympatric over an extensive range, there are drainages where one or the other species is present and its complement is not (Daubenmire and Daubenmire 1968); this phenomenon has never been satisfactorily explained and again argues for recognizing separate Thuja plicata and Tsuga heterophylla types.
In Idaho, occurrences now included in this association have previously been classified as ~Tsuga heterophylla / Clintonia uniflora Forest (CEGL000493)$$; stands representing the Aralia nudicaulis phase of this type are now included here. The difference between Tsuga and Thuja dominance of the upper canopy in this association (and its analogue, ~Thuja plicata / Aralia nudicaulis Forest (CEGL000471)$$) is quite probably related to historical accident, past disturbance events and subsequent successional patterns. Despite the very long fire-return intervals (200-500 years for stand-replacing fire), the longevity of both species, especially Thuja, argues for considering the dual designation (Thuja plicata - Tsuga heterophylla) as appropriate (i.e., combining these two associations into one); if one or the other species responds to disturbance by attaining canopy dominance it is unlikely the non-dominant species will become dominant in the average fire-free interval. Others have recognized that quite probably a dominance continuum exists between these two species by naming at least 8 plant associations with the dual designation (Tsuga heterophylla - Thuja plicata /_).
Arguing against this approach is the approach being taken by the USNVC placing emphasis on existing vegetation composition, and it is indisputable that either climax tree species can be strongly dominant with the other species occurring only in the reproductive layers, if at all. In northern Idaho, where these species are sympatric over an extensive range, there are drainages where one or the other species is present and its complement is not (Daubenmire and Daubenmire 1968); this phenomenon has never been satisfactorily explained and again argues for recognizing separate Thuja plicata and Tsuga heterophylla types.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: This association is heavily forested. Total tree canopy cover ranges from 70-95%. Tsuga heterophylla is always present with 20-75% cover. Thuja plicata is often present with 10-40% average cover. Other trees are always present, but not in any consistent combination. Other tree species include Abies grandis, Betula papyrifera, Larix occidentalis, Pseudotsuga menziesii, and Pinus monticola. Deciduous tree presence may be an indication of recent fires. The shrub layer is relatively sparse with less than 10% total cover. Typical species include Paxistima myrsinites, Cornus sericea, Lonicera spp., Acer spp., and Linnaea borealis. The herbaceous layer is relatively lush, with 10-80% cover and floristically rich, however, only Aralia nudicaulis, Clintonia uniflora, and Maianthemum stellatum have more than 5% cover. Aralia nudicaulis is not present in every stand in the literature, but it is expressed as the forb with the highest constancy and highest cover value within all sampled stands.
Dynamics: No Data Available
Environmental Description: This forested association occurs on gentle slopes along valley bottoms in warm, moist locations, some of the warmest for Tsuga heterophylla communities. It occurs primarily on stream benches, lower valley sideslopes and toeslopes, alluvial terraces and valley bottoms at 640 to 1220 m (2100-4000 feet) in elevation. Soils are typically well-drained, occasionally somewhat poorly drained, fine-textured with an ash layer, loam to silty loam, moist but never boggy, and are relatively deep. Parent materials range from glacial till, coarse alluvium or colluvium.
Geographic Range: This association in known from central and northeastern Washington, northern Idaho, north of the Coeur d''Alene River, and in Montana on the west side of Glacier National Park.
Nations: CA?,US
States/Provinces: BC?, ID, MT, WA
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.684211
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G3
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.b Western Red-cedar - Western Hemlock Central Rocky Mountain Forest Group | G217 | 1.B.2.Nb.3.b |
| Alliance | A3613 Western Hemlock - Western Red-cedar Warm-Mesic Central Rocky Mountain Forest & Woodland Alliance | A3613 | 1.B.2.Nb.3.b |
| Association | CEGL000488 Western Hemlock / Wild Sarsaparilla Forest | CEGL000488 | 1.B.2.Nb.3.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Tsuga heterophylla / Aralia nudicaulis Plant Association (Williams et al. 1995)
= Tsuga heterophylla / Aralia nudicaulis association (Kovalchik 1993) [(p.38)]
>< Tsuga heterophylla / Asarum caudatum Habitat Type, Aralia nudicaulis Phase (Cooper et al. 1987) [(p.21)]
= Tsuga heterophylla / Clintonia uniflora Habitat Type, Aralia nudicaulis Phase (Pfister et al. 1977)
= Tsuga heterophylla / Clintonia uniflora Habitat Type, Aralia nudicaulis Phase (Cooper et al. 1987) [(p.23)]
= Tsuga heterophylla / Aralia nudicaulis association (Kovalchik 1993) [(p.38)]
>< Tsuga heterophylla / Asarum caudatum Habitat Type, Aralia nudicaulis Phase (Cooper et al. 1987) [(p.21)]
= Tsuga heterophylla / Clintonia uniflora Habitat Type, Aralia nudicaulis Phase (Pfister et al. 1977)
= Tsuga heterophylla / Clintonia uniflora Habitat Type, Aralia nudicaulis Phase (Cooper et al. 1987) [(p.23)]
- 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.
- Cooper, S. V., K. E. Neiman, R. Steele, and D. W. Roberts. 1987. Forest habitat types of northern Idaho: A second approximation. General Technical Report INT-236.USDA Forest Service, Intermountain Research Station, Ogden, UT. 135 pp. [reprinted in 1991]
- Daubenmire, R. F., and J. B. Daubenmire. 1968. Forest vegetation of eastern Washington and northern Idaho. Washington State University Agricultural Experiment Station Technical Bulletin No. 60. 104 pp.
- Hop, K., M. Reid, J. Dieck, S. Lubinski, and S. Cooper. 2007. U.S. Geological Survey-National Park Service Vegetation Mapping Program: Waterton-Glacier International Peace Park. U.S. Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, WI. 131 pp. plus Appendices A-L.
- Kovalchik, B. L. 1993. Riparian plant associations on the national forests of eastern Washington - Draft version 1. USDA Forest Service, Colville National Forest, Colville, WA. 203 pp.
- Pfister, R. D., B. L. Kovalchik, S. F. Arno, and R. C. Presby. 1977. Forest habitat types of Montana. General Technical Report INT-34. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, UT. 174 pp.
- Reid, M. S., S. V. Cooper, and G. Kittel. 2004. Vegetation classification of Waterton-Glacier International Peace Park. Final report for USGS-NPS Vegetation Mapping Program, International Peace Park Mapping Project. NatureServe, Arlington VA.
- 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.
- Williams, C. K., B. F. Kelly, B. G. Smith, and T. R. Lillybridge. 1995. Forest plant associations of the Colville National Forest. General Technical Report PNW-GTR-360. USDA Forest Service, Pacific Northwest Region, Portland, OR. 140 pp.
- Williams, C. K., T. R. Lillybridge, and B. G. Smith. 1990b. Forested plant associations of the Colville National Forest. Report prepared for USDA Forest Service, Colville National Forest, Colville, WA. 133 pp.