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CEGL000511 Tsuga mertensiana / Streptopus amplexifolius Swamp Forest
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Mountain Hemlock / Clasping Twisted-stalk Swamp Forest
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This plant association is described from sites located primarily in the upper Clearwater River drainage, within the central region of the Bitterroot Mountains ecoregional section, in Idaho. The plant association occurs in a mountainous region characterized by a Pacific maritime climatic regime. Sites are cool, wet, north-facing toeslopes or narrow stringers of streamside terraces at 1525 to nearly 1830 m (5000-6000 feet) elevation. At the lower elevation range stands are characterized by earlier snowmelt and runoff. At the higher elevation range (described as the Luzula glabrata var. hitchcockii phase) snowpacks are often deep and persistent. Parent materials are metamorphic rocks. Soils are seasonally saturated, with high gravel content throughout the profile. Textures range from sandy loams, silt loams to silts. The evergreen needle-leaved forest association is dominated by a variable composition of Tsuga mertensiana, Abies lasiocarpa and Picea engelmannii. All three of these species are capable of rapidly recolonizing following disturbance. Several other conifer species can occur as seral components in younger stands. The understory has a well-developed deciduous shrub layer, less than 2 m tall, dominated by Menziesia ferruginea and lesser amounts of Vaccinium membranaceum. The herbaceous layer is characterized by a variable assemblage of forbs indicative of wet sites, including Streptopus amplexifolius, Senecio triangularis, Mitella breweri, Ligusticum canbyi, Trautvetteria caroliniensis and Veratrum viride. Total herbaceous cover varies from 30-40%. On sites above 1710 m (5600 feet), a phase is recognized where the perennial graminoid Luzula glabrata var. hitchcockii is abundant (24% cover), and overall forb cover and richness are significantly less than in the lower elevation stands.
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 association dominated by a variable composition of Tsuga mertensiana, Abies lasiocarpa and Picea engelmannii. All three of these species are capable of rapidly recolonizing following disturbance. Several other conifer species can occur as seral components in younger stands. Other conifers may include Larix occidentalis, Pinus contorta, Pinus albicaulis, and Pinus monticola. The understory has a well-developed deciduous shrub layer, less than 2 m tall, dominated by Menziesia ferruginea and lesser amounts of Vaccinium membranaceum (= Vaccinium globulare). The herbaceous layer is characterized by a variable assemblage of forbs indicative of wet sites, including Streptopus amplexifolius, Senecio triangularis, Mitella breweri, Ligusticum canbyi, Trautvetteria caroliniensis, and Veratrum viride. Total herbaceous cover varies from 30-40%. On sites above 1710 m (5600 feet) elevation, a phase is recognized where the perennial graminoid Luzula glabrata var. hitchcockii is abundant (24% cover), and overall forb cover and richness are significantly less than in the lower-elevation stands.
Dynamics: No Data Available
Environmental Description: This association occurs in a mountainous region of inland maritime climate, characterized by mild, moderate winters with prolonged gentle rains, deep snow accumulations at higher altitudes and abundant clouds, fog and high humidity. Summers are very dry (<1 inch precipitation/month). Elevations range from 1525 to nearly 1830 m (5000-6000 feet) (subalpine), and sites are cold, wet toeslopes or narrow ''stringers'' of streamside terraces. Aspects are generally northern, and the lower elevation stands are characterized by earlier snowmelt and runoff. In the Luzula glabrata var. hitchcockii phase at higher elevations, snowpacks are often deep and persistent. Parent materials are metamorphic rocks. Soils are seasonally saturated, with high gravel content throughout the profile. Textures range from sandy loams, silt loams to silts.
Geographic Range: The regional endemic occurs in the central region of the Bitterroot Mountains ecoregional section.
Nations: US
States/Provinces: ID
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.686219
Confidence Level: Moderate
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.3 Temperate Flooded & Swamp Forest Formation | F026 | 1.B.3 |
| Division | 1.B.3.Nc Rocky Mountain-Great Basin Montane Flooded & Swamp Forest Division | D195 | 1.B.3.Nc |
| Macrogroup | 1.B.3.Nc.1 Engelmann Spruce - Narrowleaf Cottonwood / Red-osier Dogwood Riparian & Swamp Forest Macrogroup | M034 | 1.B.3.Nc.1 |
| Group | 1.B.3.Nc.1.a Engelmann Spruce - Blue Spruce - Narrowleaf Cottonwood Riparian & Swamp Forest Group | G506 | 1.B.3.Nc.1.a |
| Alliance | A3757 Subalpine Fir - Engelmann Spruce Swamp Forest Alliance | A3757 | 1.B.3.Nc.1.a |
| Association | CEGL000511 Mountain Hemlock / Clasping Twisted-stalk Swamp Forest | CEGL000511 | 1.B.3.Nc.1.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Tsuga mertensiana / Streptopus amplexifolius Habitat Type (Cooper et al. 1987)
- 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]
- IDCDC [Idaho Conservation Data Center]. 2005. Wetland and riparian plant associations in Idaho. Idaho Conservation Data Center, Idaho Department of Fish and Game, Boise. [http://fishandgame.idaho.gov/tech/CDC/ecology/wetland_riparian_assoc.cfm] (accessed 14 June 2005).
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.