Name:
Phyllodoce empetriformis - Cassiope mertensiana - Vaccinium deliciosum Alpine Dwarf-shrubland Alliance
Reference:
NatureServe Biotics 2019
Description:
Within these communities, dwarf-shrub is often the dominant lifeform, but they also occur with a mosaic of very low subshrub-like perennials- and herbaceous-dominated communities. <i>Cassiope mertensiana, Luetkea pectinata, Phyllodoce empetriformis, Phyllodoce glanduliflora</i>, or <i>Vaccinium deliciosum</i> may be the dominant. <i>Kalmia microphylla, Ledum glandulosum, Salix cascadensis, Vaccinium membranaceum</i>, and <i>Vaccinium scoparium</i> may also be shrub associates. The herbaceous layer is usually a lush mix of forbs and graminoids, especially sedges, including, <i>Antennaria lanata, Arenaria capillaris, Carex breweri, Carex nigricans, Carex phaeocephala, Carex scirpoidea, Carex spectabilis, Castilleja parviflora, Claytonia lanceolata, Deschampsia cespitosa, Erigeron</i> spp., <i>Erythronium</i> spp., <i>Festuca brachyphylla, Festuca viridula, Hieracium gracile, Juncus parryi, Juncus drummondii, Ligusticum grayi, Luetkea pectinata, Lupinus sellulus var. lobbii, Luzula piperi, Minuartia obtusiloba, Oreostemma alpigenum, Pedicularis ornithorhyncha, Polygonum bistortoides, Potentilla flabellifolia, Ranunculus eschscholtzii, Saxifraga tolmiei</i> (which can be codominant with the dwarf-shrub layer), <i>Sibbaldia procumbens, Tauschia stricklandii</i> (a forb that can be the dominant in mosaic meadow patch), <i>Valeriana sitchensis</i>, and <i>Veronica cusickii</i>. Moss and lichen cover can be high in spaces between vascular plants (70-80%). These communities usually grade into herbaceous meadows dominated by <i>Carex</i> spp. at their wetter margin and, in stands below treeline, into woodlands of <i>Tsuga mertensiana, Abies lasiocarpa</i>, and/or <i>Pinus albicaulis</i> at their drier margins, and alpine fell-fields, rock, or ice on higher elevation alpine slopes. Such changes are generally related to only minor changes in microelevation, and woodland, dwarf-shrubland, and herbaceous meadow communities may be strongly intermingled. These dwarf-shrubland and herbaceous communities are typically located in subalpine or low alpine habitats on high mountains of the Pacific Northwest, often in association with subalpine parkland. Some of these dwarf-shrublands form part of a subalpine parkland mosaic just below the upper treeline. The climate is cold and snowy with annual precipitation exceeding 150 cm and a snow-free period of only 3-4 months. These habitats receive abundant (100-250 cm) precipitation and accumulate very heavy snowpacks in winter. These sites are subirrigated by snowmelt during most of the short growing season, although some meadows have soils that dry out by summer's end. Elevations typically range from 1400-2500 m. These communities occur in areas of level or concave to very steep slopes (over 100%) on hills and ridges of glacial topography, with late-lying snow, and subirrigation from surrounding slopes. In exceptionally wet areas, they may occur on convex slopes with better drainage. Soils are moist, but well-drained, strongly acidic, and often with substantial peat layers. Some stands are found on the base of a lobe of soil formed by solifluction. Other are found on deep deposits of volcanic ash, such as thick accumulations of pumice parent material; some occur on andesite.
Accession Code:
urn:lsid:vegbank.org:commConcept:38618-{924BECB5-4D1E-43F5-8FC7-DA0511D1483C}
Plot-observations of this Community Concept:
0
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