Name:
Salix arctica - (Salix petrophila, Salix nivalis) / Polygonum bistortoides Dwarf-shrubland
Reference:
NatureServe Biotics 2019
Description:
This dwarf-shrub alpine association is known from the Rocky Mountains of Alberta, Montana and Wyoming. It occurs primarily as small patches, from the uppermost subalpine to the highest alpine elevations, from 1980 to 3231 m (6495-10,600 feet). It is mainly associated with receiving positions, toeslopes and lower to midslopes of gentle terrain. It occurs in mesic areas with slopes that range from flat to moderate (up to 50% grade), with all aspects represented. The type occurs predominantly in small, visually salient patches that appear as a continuous blanket of green due to high coverage of both the vascular and bryophyte components. The dwarf-shrub layer is commonly dominated by <i>Salix arctica, Salix petrophila</i>, or <i>Salix nivalis</i>. <i>Dryas octopetala</i> may be present or absent in the dwarf-shrub layer with up to 20% cover. Graminoids are present in all stands but are neither diverse nor in high quantities. Common species include <i>Poa alpina</i> and moist-site <i>Carex</i> spp. (<i>Carex albonigra, Carex phaeocephala</i>, and <i>Carex nova</i>). The herbaceous layer is dominated by forbs, most notably <i>Polygonum bistortoides</i>, but other forbs, including <i>Polygonum viviparum, Geum rossii, Potentilla diversifolia, Oreostemma alpigenum, Solidago multiradiata</i>, and <i>Claytonia lanceolata</i>, are often codominant. Other common species include <i>Astragalus kentrophyta, Phlox pulvinata, Tetraneuris grandiflora, Arenaria congesta, Oxytropis deflexa</i>, and <i>Castilleja</i> spp. <i>Picea engelmannii</i> seedlings may be present. This association most often grades to moist turf types or unequivocal snowbed communities (e.g., <i>~Carex nigricans</i> Wet Meadow (CEGL001816)$$) or wet meadows (e.g., <i>~Deschampsia cespitosa - Caltha leptosepala</i> Wet Meadow (CEGL001882)$$). Most other dwarf-shrub <i>Salix</i> spp.-dominated types occur on yet wetter sites; therefore, they should be recognized first in working keys.
Accession Code:
urn:lsid:vegbank.org:commConcept:30340-{DB2978D5-E603-4D98-A8B2-AEC3EB1CCD9B}
Plot-observations of this Community Concept:
2
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