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CEGL001061 Acer glabrum Avalanche Chute Shrubland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Rocky Mountain Maple Avalanche Chute Shrubland
Colloquial Name: No Data Available
Hierarchy Level: Association
Type Concept: This deciduous shrubland has been described from subalpine avalanche paths in the northern Rocky Mountains. Elevations range from 950 to 2306 m (3100-7600 feet). Stands are located in avalanche tracks and runout zones, on slopes ranging from 15-60%. These communities can occur on any aspect, but are more common where unstable snowpack conditions frequently occur. Soils are rapidly to well-drained loamy sands, sandy loams, or silt loams. They tend to be dark, weakly developed soils on colluvial and glacio-fluvial landforms with high gravel and rock content. Sites are often mesic because avalanche paths are often in stream gullies. Stands have a moderately dense woody canopy characterized by flexible, deciduous small trees and shrubs, dominated by Acer glabrum. Other common woody plants include Paxistima myrsinites, Sorbus scopulina, Alnus viridis ssp. sinuata, Alnus incana, Rubus parviflorus, Prunus virginiana, Symphoricarpos albus, Symphoricarpos oreophilus, Salix planifolia, Salix scouleriana, and Crataegus douglasii. In addition to shrub species, several trees are usually present, these rarely attaining heights above that of the shrubs due to the frequent disturbance. Tree species are those from the surrounding forested slopes and include Picea engelmannii, Abies lasiocarpa, Populus tremuloides, Populus balsamifera ssp. trichocarpa, Pseudotsuga menziesii, and Betula papyrifera. The ground cover is moderately dense to dense and composed of many graminoids and forbs. Chamerion angustifolium and Thalictrum occidentale are common. Other species include Lomatium dissectum, Heracleum maximum, Xerophyllum tenax, Carex geyeri, Castilleja spp., Agastache urticifolia, Eucephalus engelmannii, Erythronium grandiflorum, Myosotis asiatica, Veratrum viride, and Xerophyllum tenax. Mosses and ferns are often present.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This association is the product of disturbance by avalanche.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: Stands have a moderately dense woody canopy characterized by flexible, deciduous small trees and shrubs, dominated by Acer glabrum. Other common woody plants include Paxistima myrsinites, Sorbus scopulina, Alnus viridis ssp. sinuata, Alnus incana, Rubus parviflorus, Prunus virginiana, Symphoricarpos albus, Symphoricarpos oreophilus, Salix planifolia, Salix scouleriana, and Crataegus douglasii. In addition to shrub species, several trees are usually present, these rarely attaining heights above that of the shrubs due to the frequent disturbance. Tree species are those from the surrounding forested slopes and include Picea engelmannii, Abies lasiocarpa, Populus tremuloides, Populus balsamifera ssp. trichocarpa, Pseudotsuga menziesii, and Betula papyrifera. The ground cover is moderately dense to dense and composed of many graminoids and forbs. Chamerion angustifolium and Thalictrum occidentale are common. Other species include Lomatium dissectum, Heracleum maximum, Xerophyllum tenax, Carex geyeri, Castilleja spp., Agastache urticifolia, Eucephalus engelmannii, Erythronium grandiflorum, Myosotis asiatica (= Myosotis alpestris), and Veratrum viride. Mosses and ferns are often present.
Dynamics: Disturbance by avalanches prevents tall forests from growing on these sites. Flexible-stemmed deciduous trees and shrubs are more tolerant of this snow movement than conifers. Where avalanches are frequent, stands develop that are dominated by dwarfed conifers (less than 4 m tall). Where avalanches occur annually or more often, only brushy deciduous trees and shrubs are present.
Environmental Description: These shrublands have been described from subalpine avalanche paths in the Rocky Mountains. Elevations range from 950-2306 m (3100-7600 feet). Climate is temperate with extremely cold winters and cool summers. Mean annual precipitation ranges from 50-70 cm and occurs mostly as snow. Stands are located in avalanche tracks and runout zones. Slopes range from 15-60%. These communities can occur on any aspect, but are more common where unstable snowpack conditions frequently occur, such as southeast aspects where snow cornices develop because of prevailing northwesterly winds, and south- to southwest-facing slopes because of suncrust formation. Sites are often mesic because avalanche paths are often in stream gullies. Soils are rapidly to well-drained loamy sands, sandy loams, or silt loams. They tend to be dark, weakly developed soils on colluvial and glacio-fluvial landforms with high gravel and rock content. Substrate is variable depending on parent materials but is typically shallow and rocky. Adjacent vegetation may include subalpine forests dominated by Abies lasiocarpa, Picea engelmannii, or Pseudotsuga menziesii, and subalpine meadows.
Geographic Range: This shrubland has been described from subalpine avalanche chutes in northwestern Montana and northwestern Wyoming.
Nations: US
States/Provinces: MT, WY
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.684004
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: G5
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.B Temperate & Boreal Grassland & Shrubland Subclass | S18 | 2.B |
| Formation | 2.B.2 Temperate Grassland & Shrubland Formation | F012 | 2.B.2 |
| Division | 2.B.2.Nf Western North American Grassland & Shrubland Division | D022 | 2.B.2.Nf |
| Macrogroup | 2.B.2.Nf.2 Saskatoon Serviceberry / Idaho Fescue - Bluebunch Wheatgrass Grassland & Shrubland Macrogroup | M048 | 2.B.2.Nf.2 |
| Group | 2.B.2.Nf.2.d Blueberry species - Rusty Menziesia / Common Beargrass Central Rocky Mountain-Vancouverian Mesic Shrubland Group | G305 | 2.B.2.Nf.2.d |
| Alliance | A3968 Subalpine Fir - Quaking Aspen / Rocky Mountain Maple Central Rocky Mountain Avalanche Chute Shrubland Alliance | A3968 | 2.B.2.Nf.2.d |
| Association | CEGL001061 Rocky Mountain Maple Avalanche Chute Shrubland | CEGL001061 | 2.B.2.Nf.2.d |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Acer glabrum - Alnus spp. (Butler 1979)
- 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.
- Butler, D. R. 1979. Snow avalanche path terrain and vegetation, Glacier National Park, Montana. Arctic and Alpine Research 11:17-32.
- Cogan, D., K. Varga, and G. Kittel. 2005. USGS-NPS Vegetation Mapping Program: Grand Teton National Park and John D. Rockefeller, Jr. Memorial Parkway. Final Project Report 2002-2005 Vegetation Mapping Project. Technical Memorandum 8260-06-02. USDI Bureau of Reclamation, Denver, CO. 87 pp. plus Appendixes A-F.
- 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.
- MTNHP [Montana Natural Heritage Program]. 2002b. List of ecological communities for Montana. Montana Natural Heritage Program, Montana State Library, Helena, MT.
- 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.
- Western Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boulder, CO.