Name:
Carex paysonis - Sibbaldia procumbens Alpine Snowbed
Reference:
NatureServe Biotics 2019
Description:
This is a small-patch herbaceous association found in Glacier National Park, Montana, and Grand Teton National Park, Wyoming. It occurs on relatively exposed alpine ridgelines and flats from 2180 to 3120 m (7150-10,236 feet) elevation. Surface relief is smooth to moderately rolling with slopes not exceeding 18% and no particular slope aspect being preferred; however, sites are apparently aligned with microtopographic depressions, such as lee slopes, otherwise disposed to accumulate deep snowdrifts. Despite the high to very high wind exposure of the landscape, the drifted snow has a moderately long duration into summer. Meltwaters create an early-season soil saturation which is rapidly dried out due to well-drained soils and desiccating winds. This community is found on red and green argillite and quartzite. The ground surface is blanketed by a dense cover of mosses (10-50% cover) and lichens (10-35% cover) with the remainder being litter. Being relatively stressful sites, the vascular cover is relatively low, ranging from 15 to 45%. <i>Salix arctica</i> and <i>Salix petrophila</i> are dwarf-shrubs present. <i>Carex paysonis</i>, ranging in cover from 10 to 25%, is the dominant herb; other graminoids of high constancy include <i>Carex phaeocephala, Carex pyrenaica, Agrostis variabilis, Juncus parryi, Luzula piperi</i>, and <i>Luzula spicata</i>. The forb component is relatively depauperate in species richness and cover; those with greater than 50% constancy include the chionophilous (snow-loving) species <i>Antennaria umbrinella, Arenaria capillaris, Sibbaldia procumbens</i>, and <i>Antennaria alpina</i>, and the high-elevation generalists <i>Erigeron peregrinus, Hieracium gracile</i>, and <i>Polygonum bistortoides</i>. Moss cover, ranging up to 45%, is important for soil formation and is dominated by <i>Polytrichum piliferum</i> followed by <i>Polytrichastrum alpinum</i> and <i>Tortula ruralis</i>. Snow cover persisting long into summer favors lichen development (10-30% cover), among which are the circumpolar species <i>Cladonia ecmocyna</i> and <i>Cladonia borealis</i>, and <i>Solorina crocea</i>, a colorful foliose soil lichen.
Accession Code:
urn:lsid:vegbank.org:commConcept:34519-{0A1B7E83-4472-4426-BE69-DE3F5D04BF64}
Plot-observations of this Community Concept:
0
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