Print Report
A3771 Alnus incana - Alnus viridis Wet Shrubland Alliance
Type Concept Sentence: Vegetation types within this riparian tall (>1.5 m) shrubland alliance typically occur adjacent to streams and in mountain meadows at moderate to high-elevation (1200-3000 m) riparian habitats of the northern Rocky Mountains and Cascade Range where deep snow accumulations are common. Landforms associated with this alliance are streambanks, alluvial bars, and floodplains. Alnus incana or Alnus viridis ssp. sinuata forms a dense canopy with at least 90% cover. Acer circinatum may be codominant in the tall-shrub layer in some stands.
Common (Translated Scientific) Name: Gray Alder - Green Alder Wet Shrubland Alliance
Colloquial Name: Western Alder Wet Shrubland
Hierarchy Level: Alliance
Type Concept: Alnus incana or Alnus viridis ssp. sinuata forms a dense canopy with at least 90% cover. Acer circinatum may be codominant in the tall-shrub layer in some stands. The diverse understory shrub layer may include Acer glabrum, Ribes lacustre, and Sorbus scopulina. In the northern Rocky Mountains, Abies lasiocarpa colonizes these communities, and scattered seedlings or saplings may be present. Low cold-deciduous or ericaceous shrubs may be abundant, including Betula occidentalis, Cornus sericea, Oplopanax horridus, Paxistima myrsinites, Ribes hudsonianum, Rubus parviflorus, Rubus spectabilis, Salix drummondiana, Sambucus racemosa, Symphoricarpos albus, and Vaccinium spp. The forb layer is sparse and may include Achillea millefolium, Aconitum columbianum, Canadanthus modestus, Galium triflorum, Heracleum maximum, Osmorhiza berteroi, Polystichum munitum, Senecio triangularis, Symphyotrichum spathulatum, Thalictrum occidentale, Urtica dioica, and Veratrum viride. The graminoid layer is usually dominated by 1 or 2 species that include Agrostis stolonifera and Calamagrostis canadensis. The fern and fern allies layer is generally dense with at least 40% cover. The dominant species typically are Gymnocarpium dryopteris and Athyrium filix-femina. This alliance is found in the Rocky Mountains, the highlands of Arizona, intermountain ranges of Nevada, and montane areas of California. Stands occur adjacent to streams and in mountain meadows at moderate to high-elevation (1200-3000 m) riparian habitats. Landforms associated with this alliance are streambanks, alluvial bars, and floodplains. Soils are shallow, skeletal alluvium over water-worked cobbles and gravels.
Diagnostic Characteristics: Tall (>1.5 m) shrublands dominated by Alnus incana, Alnus viridis ssp. sinuata, Alnus oblongifolia, and/or Acer glabrum.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Alder- and maple-dominated riparian and wetland shrublands.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Vegetation included in this alliance is dominated by a relatively dense tall-shrub layer that is 2-15 m tall, that may or may not have a short-shrub layer that is <2 m tall. The herbaceous layer is dominated by perennial forbs with some perennial graminoids.
Floristics: Alnus incana, Alnus viridis ssp. sinuata, Alnus oblongifolia, and/or Acer glabrum form a dense canopy layer. Acer circinatum may be codominant in the tall-shrub layer in some stands. The diverse understory shrub layer may include Ribes lacustre, and Sorbus scopulina. In the northern Rocky Mountains, Abies lasiocarpa may colonize these communities, and scattered seedlings or saplings may be present. Low cold-deciduous or ericaceous shrubs may be abundant, including Cornus sericea, Betula occidentalis, Oplopanax horridus, Paxistima myrsinites, Ribes hudsonianum, Rubus parviflorus, Rubus spectabilis, Sambucus racemosa, Salix drummondiana, Symphoricarpos albus, and Vaccinium spp. The forb layer is sparse and may include Achillea millefolium, Aconitum columbianum, Canadanthus modestus (= Aster modestus), Galium triflorum, Heracleum maximum (= Heracleum lanatum), Osmorhiza berteroi (= Osmorhiza chilensis), Polystichum munitum, Senecio triangularis, Symphyotrichum spathulatum (= Aster occidentalis), Thalictrum occidentale, Urtica dioica, and Veratrum viride. The graminoid layer is usually dominated by 1 or 2 species that include Agrostis stolonifera and Calamagrostis canadensis. The fern and fern allies layer is generally dense with at least 40% cover. The dominant species typically are Gymnocarpium dryopteris and Athyrium filix-femina.
Dynamics: No Data Available
Environmental Description: Vegetation types within this riparian tall (>1.5 m) shrubland alliance typically occur adjacent to streams and in mountain meadows at moderate to high-elevation (1200-3000 m) riparian habitats of the northern Rocky Mountains and Cascade Range where deep snow accumulations are common. Landforms associated with this alliance are streambanks, alluvial bars, and floodplains. Sites are young, active channel shelves that lie between active and flood-stage streambanks along second-order and larger streams in moderately graded (3-5%) valleys. Soils are shallow, skeletal alluvium over water-worked cobbles and gravels. Active channel shelves have surface soil textures that are loamy sands, while older sites are silts and loam. Available water-holding capacity is low; surface water is present briefly during the growing season. The water table usually lies well below the ground surface.
Geographic Range: This alliance is found in the Rocky Mountains of eastern Oregon, Washington, Idaho, Montana, British Columbia, Alberta, Wyoming, Colorado, Utah, and New Mexico, the highlands of Arizona, intermountain ranges of Nevada, and montane areas of California.
Nations: CA,US
States/Provinces: AB, AZ, BC, CA, CO, ID, MT, NM, NV, OR, UT, WA, WY
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899823
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: ? Alnus incana (Mountain alder thicket) Alliance (Sawyer et al. 2009) [63.210.00]
? Alnus viridis (Sitka alder thickets) Provisional Alliance (Sawyer et al. 2009) [63.220.00]
? Alnus viridis (Sitka alder thickets) Provisional Alliance (Sawyer et al. 2009) [63.220.00]
- Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
- Sawyer, J. O., T. Keeler-Wolf, and J. Evens. 2009. A manual of California vegetation. Second edition. California Native Plant Society, Sacramento CA. 1300 pp.