Name:
Vaccinium uliginosum - Rhododendron lapponicum / Juncus trifidus Dwarf-shrubland
Reference:
NatureServe Biotics 2019
Description:
Alpine meadows of matted shrubs, sedges, and rushes are the dominant vegetation above treeline on the highest peaks of the northern Appalachian Mountains. Typically they occur above 1370 m (4500 feet) (occasionally lower) on exposed mountain summits, ridges, and bedrock-dominated tablelands. The substrate ranges from gravelly flats to jumbled rocks to stone pavements, with limited soils: basically well-drained gravels and stones with shallow organic accumulation. Protected spots may have continuous atmospheric moisture. The short snow-free season, frequent fog, cutting winds, and intense solar radiation are hallmarks of this environment. The vegetation is often patchy, with some areas shrub-dominated and other patches graminoid-dominated, but overall, dwarf-shrubs predominate. Shrub cover is usually 40-60%; herb cover is typically less, but may be up to 50% in some spots. Tree species may be present in shrub form in scattered, somewhat sheltered pockets. Bryophytes are very limited, but lichens may be abundant. Characteristic dwarf-shrubs are <i>Vaccinium uliginosum</i>, ubiquitous in this association, with <i>Vaccinium vitis-idaea, Vaccinium boreale, Betula glandulosa, Empetrum nigrum, Empetrum eamesii ssp. atropurpureum, Rhododendron lapponicum, Diapensia lapponica, Salix uva-ursi</i>, and <i>Arctostaphylos uva-ursi</i>. Graminoids scattered among the shrubs, and in places codominant, are primarily <i>Juncus trifidus</i> and <i>Carex bigelowii</i>. <i>Sibbaldiopsis tridentata</i> is a common forb, as is <i>Minuartia groenlandica</i>, which typically grows in the more gravelly substrates, often along trails. Herbs that are not abundant, but characteristic, include <i>Solidago multiradiata, Anthoxanthum monticola ssp. alpinum, Agrostis mertensii, Prenanthes boottii</i>, and <i>Huperzia appalachiana</i>. The combination of alpine heath shrubs in a mosaic with alpine graminoids is diagnostic. This is the above-treeline "matrix" type in which other, more limited and specialized alpine associations found on the more extensive summits are embedded. These include ~<i>Diapensia lapponica</i> Dwarf-shrubland (CEGL006322)$$, ~<i>Vaccinium uliginosum - Harrimanella hypnoides - Loiseleuria procumbens</i> Dwarf-shrubland (CEGL006155)$$, ~<i>Carex bigelowii</i> Alpine Meadow (CEGL006081)$$ and ~<i>Empetrum nigrum - Vaccinium uliginosum - Vaccinium oxycoccos / Rubus chamaemorus</i> Dwarf-shrubland (CEGL006140)$$.
Accession Code:
urn:lsid:vegbank.org:commConcept:34945-{877E82C3-7EE2-4CCE-8A43-3ACE825D0EC2}
Plot-observations of this Community Concept:
0
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