Name:
Minuartia obtusiloba - Paronychia pulvinata - Silene acaulis Alpine Fell-field Alliance
Reference:
NatureServe Biotics 2019
Description:
This Rocky Mountain alpine alliance is composed of sparse to moderate plant cover, which ranges from 10-50%, with exposed gravel and rock making up the rest of the cover. The herbaceous layer is characterized by a sparse to moderate herbaceous layer dominated by cushion plants with lesser cover of graminoids. Diagnostic and often dominant species are <i>Aquilegia scopulorum, Carex albonigra, Carex arapahoensis, Eriogonum caespitosum, Eriogonum holmgrenii, Geum rossii, Ivesia gordonii, Minuartia obtusiloba, Myosotis asiatica, Paronychia pulvinata, Phlox pulvinata, Potentilla ovina, Potentilla sierrae-blancae, Silene acaulis, Sphaeromeria argentea, Trifolium dasyphyllum</i>, and <i>Trifolium nanum</i>. These plants are adapted to harsh conditions with their cushioned or matted, frequently succulent, flat-to-the-ground rosettes, and are often densely haired and thickly cutinized. Widespread alpine turf species such as <i>Carex rupestris</i> or <i>Geum rossii</i> may be present but usually with low cover. Great Basin alpine areas tend to be drier and include some lower elevation species common in desert scrub such as <i>Poa secunda</i>. The moss <i>Selaginella densa</i> is often present. This alliance occurs in higher elevation alpine zone above upper treeline throughout the Rocky Mountain cordillera and alpine areas of high plateaus and ranges in the Colorado Plateau and Great Basin. It includes wind-scoured fell-fields and stabilized scree and talus fields that are typically free of snow during the winter as they are found on ridgetops, upper slopes or exposed saddles. Stands are usually located on flat to gently sloping ridges and summits in the upper alpine zone between 1900 and 3865 m elevation depending on latitude. The ridgetops are subject to extremely high winds and are blown free of snow in winter. The ground is covered with rocks that have been stabilized for a long period of time, often forming a gravelly pavement. The sites are called fell-fields and differ from talus or scree which are located on steeper slopes and are unstable and often moving. The soils are poorly developed and have little organic matter.
Accession Code:
urn:lsid:vegbank.org:commConcept:38442-{58BCB88B-5F7F-4108-A05D-B11A0AC1E595}
Plot-observations of this Community Concept:
0
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