Name:
Dryas integrifolia - Dryas octopetala - Arctostaphylos uva-ursi Rocky Mountain Fell-field Dwarf-shrubland Alliance
Reference:
NatureServe Biotics 2019
Description:
This Rocky Mountain alpine alliance is characterized by an open to dense, often patchy dwarf-shrub layer dominated by <i>Dryas octopetala</i> mats or, less commonly, <i>Dryas integrifolia</i> or <i>Arctostaphylos uva-ursi</i> that may extend down subalpine slopes. Dwarf <i>Salix</i> spp. can be present to codominant. Scattered <i>Dasiphora fruticosa ssp. floribunda</i> and <i>Juniperus communis</i> may also be present. The herbaceous layer is variable, ranging from sparse to moderate cover, sometimes forming a patchy turf. Species diversity ranges from depauperate to diverse, dominated by graminoids or forbs. <i>Carex</i> species are often dominant, especially <i>Carex elynoides</i> and <i>Carex rupestris</i>, but also <i>Carex albonigra, Carex nardina</i>, and <i>Carex scirpoidea</i>. Other graminoids include <i>Danthonia intermedia, Festuca brachyphylla, Kobresia myosuroides, Luzula spicata, Poa alpina</i>, and <i>Trisetum spicatum</i>. Cushion plants such as <i>Minuartia obtusiloba, Oxytropis borealis var. viscida, Oxytropis campestris, Oxytropis sericea</i>, or <i>Polygonum viviparum</i> are common on drier sites. Moss and lichen cover is high on some plots (>50%). This alliance has been reported from alpine habitats throughout the Rocky Mountain cordillera and alpine areas of high plateaus and ranges in Colorado Plateau and Great Basin. Stands occur well above upper treeline on mountain ridges, fell-fields and other gentle to steep exposed slopes where snow blows off or melts relatively early. Elevations vary greatly with latitude, ranging from 2300 to 3900 m and extending down to 1700 m on dry ridges in northwestern Montana. Stands occur on all aspects. Soils are poorly developed, well- to rapidly drained and skeletal with a gravelly surface because of the windswept, exposed nature of these sites.
Accession Code:
urn:lsid:vegbank.org:commConcept:38466-{7E8849E4-5C69-41F1-88F0-41B8DA663C05}
Plot-observations of this Community Concept:
0
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