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G505 Thuja plicata - Picea engelmannii / Lysichiton americanus Swamp Forest Group
Type Concept Sentence: This group is dominated by conifers such as Thuja plicata and/or Picea engelmannii with an obligate wetland herbaceous understory such as Lysichiton americanus, that generally occurs only on very poorly drained soils that are saturated year-round or may have seasonal flooding in the spring. It occurs in the northern Rocky Mountains from northwestern Wyoming north into the Canadian Rockies and west into eastern Oregon and Washington.
Common (Translated Scientific) Name: Western Red-cedar - Engelmann Spruce / American Skunk-cabbage Swamp Forest Group
Colloquial Name: Rocky Mountain-Great Basin Swamp Forest
Hierarchy Level: Group
Type Concept: This forested wetland/swamp group occurs in the northern Rocky Mountains from northwestern Wyoming north into the Canadian Rockies and west into eastern Oregon and Washington. It is dominated by conifers with diagnostic hydric undergrowth vegetation. Dominant conifers include Abies grandis, Abies lasiocarpa, Picea engelmannii, Picea glauca (and their hybrid), Pinus contorta, Pseudotsuga menziesii, Thuja plicata, and/or Tsuga heterophylla. Aquatic obligate herbs include Alopecurus aequalis, Calamagrostis canadensis, Carex disperma, Carex vesicaria, Dryopteris spp., Eleocharis palustris, Lysichiton americanus, Mitella breweri, Mitella pentandra, Phalaris arundinacea, Senecio triangularis, and/or Streptopus amplexifolius. Typical wetland shrubs such as Alnus incana, Cornus sericea, Rhamnus alnifolia, and Salix spp. may also be present. These occur on poorly drained soils that are saturated year-round or may have seasonal flooding in the spring. These are primarily on flat to gently sloping lowlands, but also occur up to near the lower limits of continuous forest (below the subalpine parkland), and can occur on steeper slopes where soils are shallow over unfractured bedrock (aka on seeps). This group is indicative of poorly drained, mucky areas, and areas are often bathed in a mosaic of moving and stagnant water. It can also occur around vernal ponds (usually <1 m but can be as much as 2 m deep) that usually fill with water over the fall, winter and early spring, but then at least partially dry up towards the end of the growing season. Trees that ring these ponds shade the water and influence the hydrology of the ponds themselves. Soils can be woody peat, muck or mineral but tend toward mineral. Stands generally occupy sites on benches, toeslopes or valley bottoms along mountain streams. Stands are usually dominated by conifers, but can have hardwoods mixed or dominant. These wetland types are generally distinguishable from other upland forests and woodlands by shallow water tables.
Diagnostic Characteristics: This group is dominated by conifers with obligate wetland herbaceous understory on poorly drained soils that are saturated year-round or may have seasonal flooding in the spring.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This is named and described as a conifer-dominated wetland, but it is noted that deciduous trees can be present and may solely dominate some stands. However, to date, there is no documentation or verification of deciduous-dominated swamps.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Wetlands dominated by tall conifer trees, tall deciduous hardwood trees or both, often surrounding a perennial or ephemeral water body. Herbaceous undergrowth is often very dense and ranges from 0.1-1.5 m in height.
Floristics: Abundant conifer tree species include Abies grandis, Abies lasiocarpa, Picea engelmannii, Picea glauca, Pinus contorta, Pseudotsuga menziesii, Thuja plicata, and or Tsuga heterophylla. Deciduous broadleaf trees may also be present or dominant (but swamps dominated by deciduous trees have not yet been documented) such as Betula papyrifera, Fraxinus latifolia, Larix occidentalis, Populus balsamifera ssp. trichocarpa (= Populus trichocarpa), and/or Populus tremuloides. These wetland types are generally distinguishable from other upland forests and woodlands by shallow water table indicator, mesic or hydric undergrowth vegetation; some of the most typical herbaceous species include Alopecurus aequalis, Athyrium filix-femina, Calamagrostis canadensis, Callitriche heterophylla, Carex disperma, Carex vesicaria, Dryopteris spp., Eleocharis palustris, Equisetum arvense, Lysichiton americanus, Mitella breweri, Mitella pentandra, Phalaris arundinacea, Senecio triangularis, and Streptopus amplexifolius. Common shrubs include Alnus incana, Cornus sericea (= Cornus stolonifera), Rhamnus alnifolia, and Salix spp. Floristic descriptions are compiled from Crowe and Clausnitzer (1997), Canadian Rockies Ecoregional Plan (2002), MacKenzie and Moran (2004), and Mincemoyer (2005).
Dynamics: These forests have permanently saturated soils that rarely dry out.
Environmental Description: Climate: Temperate cool. Soil/substrate/hydrology: This group is dominated by conifers on poorly drained soils that are saturated year-round or may have seasonal flooding in the spring. These are primarily on flat to gently sloping lowlands, but also occur up to near the lower limits of continuous forest (below the subalpine parkland). It can occur on steeper slopes where soils are shallow over unfractured bedrock. This group is indicative of poorly drained, mucky areas, and areas are often a mosaic of moving and stagnant water. These wetland types are generally distinguishable from other upland forests and woodlands by shallow water tables and mesic or hydric undergrowth vegetation. It can also occur around vernal ponds (usually <1 m but can be as much as 2 m deep) that usually fill with water over the fall, winter and early spring, but then at least partially dry up towards the end of the growing season. Trees that ring these ponds shade the water and influence the hydrology of the ponds themselves. Soils can be woody peat, muck or mineral but tend toward mineral. Stands generally occupy sites on benches, toeslopes or valley bottoms along mountain streams. Environmental descriptions are compiled from Crowe and Clausnitzer (1997), NCC (2002), MacKenzie and Moran (2004), and Mincemoyer (2005).
Geographic Range: This group occurs in the northern Rocky Mountains from northwestern Wyoming and central Montana, north into the Canadian Rockies of Alberta and British Columbia and west into Idaho, eastern Oregon and Washington.
Nations: CA,US
States/Provinces: AB, BC, CO?, ID, MT, OR, WA, WY
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.849242
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.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.b Western Red-cedar - Engelmann Spruce / American Skunk-cabbage Swamp Forest Group | G505 | 1.B.3.Nc.1.b |
| Alliance | A3775 Engelmann Spruce Swamp Forest Alliance | A3775 | 1.B.3.Nc.1.b |
| Alliance | A3776 Western Red-cedar - Western Hemlock Rocky Mountain Swamp Forest Alliance | A3776 | 1.B.3.Nc.1.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: No Data Available
- Crowe, E. A., and R. R. Clausnitzer. 1997. Mid-montane wetland plant associations of the Malheur, Umatilla, and Wallowa-Whitman national forests. Technical Paper R6-NR-ECOL-TP-22-97. USDA Forest Service, Pacific Northwest Region, Portland, OR.
- 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, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- MacKenzie, W. H., and J. R. Moran. 2004. Wetlands of British Columbia: A guide to identification. Land Management Handbook No. 52. Research Branch, British Columbia Ministry of Forests and Lands, Victoria, BC. 287 pp.
- Mincemoyer, S. 2005. Range-wide status assessment of Howellia aquatilis (water howellia). Revised December 2005. Report to the U.S. Fish and Wildlife Service. Montana Natural Heritage Program, Helena. 21 pp. plus appendices.
- NCC [The Nature Conservancy of Canada]. 2002. Canadian Rockies ecoregional plan. The Nature Conservancy of Canada, Victoria, BC.
- National Wetlands Working Group. 1988. Wetlands of Canada. Ecological Land Classification Series, No. 24. Sustainable Development Branch, Environment Canada, Ottawa, Ontario, and Polyscience Publications Inc., Montreal, Quebec. 452 pp.
- Shaw, S., and C. G. Fredine. 1971. Wetlands of the United States. Circular 39. U.S. Department of the Interior, U.S. Fish and Wildlife Service, Washington, DC. 67 pp.
- Warner, B. G., and C. D. A. Rubec, editors. 1997. The Canadian wetland classification system. Second revised edition. Wetlands Research Centre, University of Waterloo, ON. 68 pp.