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CEGL005927 Picea engelmannii / Equisetum arvense Swamp Forest

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Engelmann Spruce / Field Horsetail Swamp Forest

Colloquial Name: No Data Available

Hierarchy Level:  Association

Type Concept: This spruce-dominated riparian forest association is widely distributed in the upper montane and subalpine zones of the central and northern Rocky Mountains. It occurs on gently sloping stream terraces, wet benches, flat, poorly drained sites, and sidehill seeps, from 1000 to 2880 m (3300-9440 feet) in elevation. It occurs on sites too cold or too wet for Abies lasiocarpa to be abundant. It can occur adjacent to the wet forest margins of lakes, fens or bogs, and is often associated with the margins of wet basins or subirrigated terraces and toeslopes. Soils are Mollisols, or Histosols, sandy loam to clay in texture, often with a mucky organic surface layer and usually over coarse alluvial or glacial material. The upper canopy is dominated by Picea engelmannii or Picea x albertiana, with 20-70% cover. Other conifers typically present are Pinus contorta and Abies lasiocarpa. Other tree species occasionally present, depending on geographic location, are Picea pungens, Populus tremuloides, Populus angustifolia, and Populus balsamifera ssp. trichocarpa. Shrub cover is generally low (<5%), but has been reported as high as 50%. Typical species include Alnus incana, Lonicera involucrata, Cornus sericea, Vaccinium scoparium, Ribes spp., and Salix spp. Herbaceous species diversity is high and extremely variable between stands. However, herbaceous undergrowth is dominated by Equisetum arvense, which generally is the most abundant species, with average cover 30-40%, although it can have less than 10% cover. Other forbs and grasses present are mesic or hydric. Typical species include Calamagrostis canadensis, Glyceria spp., Caltha leptosepala, Gymnocarpium dryopteris, Athyrium filix-femina, Osmorhiza berteroi, Senecio triangularis, Cardamine cordifolia, Streptopus amplexifolius, and Maianthemum stellatum, among many others. Disturbance from flooding is necessary to maintain this community.

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 Picea engelmannii and Abronia latifolia (ABLA2). This association now includes the former Picea (engelmannii x glauca, engelmannii) / Equisetum arvense Forest (CEGL000408), originally identified by Pfister et al. (1977) from throughout western Montana. Picea engelmannii and/or Picea x albertiana (= Picea engelmannii x glauca) (hybrids) are the diagnostic overstory species in this plant association. Stands can include pure Picea engelmannii and PPicea x albertiana hybrid, or both. Hansen et al. (1995) explained that the frequent absence of mature cones, similar morphology, and ecological amplitudes led them to lump Picea engelmannii and Picea glauca (hybrids) into a single type, as did Pfister et al. (1977).

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: This forested association is dominated by Picea engelmannii or Picea x albertiana (= Picea engelmannii x glauca) hybrids, with 20-70% cover. Other conifers typically present are Pinus contorta and Abies lasiocarpa. Other tree species occasionally present, depending on geographic location are Picea pungens, Populus tremuloides, Populus angustifolia, and Populus balsamifera ssp. trichocarpa. Picea engelmannii is typically successfully reproducing in the understory, with shrub-sized trees well-represented. Tall-shrub cover is highly variable and quite diverse, as is the short-shrub layer. Total shrub cover is generally low (<5%), but has been reported as high as 50%. Typical species include Alnus incana, Cornus sericea, Lonicera involucrata, Vaccinium scoparium, Ribes spp., Rubus spp., and Salix spp. The herbaceous undergrowth is dominated by Equisetum arvense, which generally is the most abundant species, with average cover 30-40%, although it can have less than 10% cover. Other forbs and grasses present are mesic or hydric. Typical species include Calamagrostis canadensis, Glyceria spp., Caltha leptosepala, Gymnocarpium dryopteris, Athyrium filix-femina, Osmorhiza berteroi (= Osmorhiza chilensis), Senecio triangularis, Cardamine cordifolia, Streptopus amplexifolius, and Maianthemum stellatum (= Smilacina stellata), among many others. Occasionally stands may support Viola glabella, Tiarella trifoliata, or Gymnocarpium dryopteris with canopy cover of 20-25%.

Dynamics:  No Data Available
Environmental Description:  This forested association occurs on gently sloping stream terraces, wet benches, flat, poorly drained sites, and sidehill seeps, from 1000 to 2880 m (3300-9440 feet) in elevation. It occurs in sites too cold or too wet for Abies lasiocarpa to be abundant. It can occur adjacent to the wet forest margins of lakes, fens or bogs, and is often associated with the margins of wet basins or subirrigated terraces and toeslopes. Soils are Mollisols, or Histosols, sandy loam to clay textures, often with a mucky organic surface layer and usually occur over coarse alluvial or glacial material.
Geographic Range: This association occurs in the mountains of southeastern Oregon, eastern Washington, central and eastern Idaho, eastern Montana, western Wyoming, south into the Wasatch Range in Utah and into northern Colorado. It also is found in Alberta, Canada, and may occur in the Rocky Mountains of British Columbia.

Nations: CA,US

States/Provinces:  AB, CO, ID, MT, OR, UT, WA, WY


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: G4

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 CEGL005927 Engelmann Spruce / Field Horsetail Swamp Forest CEGL005927 1.B.3.Nc.1.a
Concept Lineage: CEGL000408 and CEGL000363 merged, and expanded in concept to include both P. engelmannii and P. engelmannii x glauca hybrids.

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Abies lasiocarpa - Picea engelmannii / Equisetum arvense (Kittel et al. 1999b)
= Abies lasiocarpa - Picea engelmannii / Equisetum arvense Forest (Carsey et al. 2003a)
< Picea / Equisetum arvense Community Type (Youngblood et al. 1985b) [(p.18) Includes stands dominated by Picea pungens or Picea engelmannii.]
< Picea / Equisetum arvense Habitat Type (Hansen et al. 1995) [(p.144) No distinction between Picea engelmannii and Picea glauca as the dominant species.]
= Picea engelmannii / Equisetum arvense - Streptopus (Kovalchik 1987) [(p.57)]
= Picea engelmannii / Equisetum arvense (Crowe and Clausnitzer 1997) [(p.46)]
= Picea engelmannii / Equisetum arvense Association (Crowe et al. 2004)
= Picea engelmannii / Equisetum arvense Association (Kovalchik 1993) [(p.52)]
= Picea engelmannii / Equisetum arvense Community (Huckaby and Moir 1998)
= Picea engelmannii / Equisetum arvense Forest (Hop et al. 2007)
< Picea engelmannii / Equisetum arvense Habitat Type (Steele et al. 1981) [(p. 49)]
< Picea engelmannii / Equisetum arvense Habitat Type (Mauk and Henderson 1984) [(p.36)]
< Picea engelmannii / Equisetum arvense Habitat Type (Steele et al. 1983) [(p.36)]
= Picea engelmannii / Equisetum Association (Williams et al. 1995)
= Picea engelmannii / Equisetum Plant Association (Williams and Lillybridge 1983)
= Picea engelmannii / Equisetum spp. Association (Kovalchik 1993) [(p.52)]
= Picea engelmannii/Equisetum arvense Forest (Crawford et al. 2009)
= Picea pungens - Picea engelmannii / Equisetum arvense Plant Association (Johnston 1987)
>< C78: Picea engelmannii / Equisetum arvense Vegetation Type (Achuff et al. 2002)
< Conifer / Equisetum arvense Community Type (Padgett et al. 1989) [(p. 29) Includes stands dominated by Picea pungens or Picea engelmannii.]
Concept Author(s): Hop et al. (2007)

Author of Description: G. Kittel and S.L. Neid

Acknowledgements: No Data Available

Version Date: 07-14-05
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