Name:
Empetrum nigrum - Vaccinium uliginosum - Vaccinium oxycoccos / Rubus chamaemorus Dwarf-shrubland
Reference:
NatureServe Biotics 2019
Description:
These heath-sedge bogs occur in alpine and subalpine depressions in the montane regions of the northeastern United States. Found at elevations above 1067 m (3500 feet), these peatlands form where bedrock basins retain water (or ice) through all or most of the year. The bog vegetation covers the flat portion of the basin and may also creep upslope on the margins. The bogs may receive small amounts of runoff from upslope bedrock, but conditions are extremely nutrient-poor. Combined with the cold temperatures and frequent clouds and fog, this creates conditions suitable for only a limited number of subalpine and boreal species. The substrate is acidic, permanently saturated organic soil, where lenses of peat beneath the surface may remain frozen through much of the growing season. Trees are generally absent, although a few small islands of stunted <i>Picea mariana</i> and <i>Abies balsamea</i> may occur. Dwarf-shrubs are the dominant vascular layer, with coverage of up to about 50%. Among the dwarf-shrubs, herbs (primarily sedges) are scattered, with up to 20% cover. Bryoids are generally more extensive than the vascular vegetation, approaching 100% cover. The dwarf-shrub cover is generally a mixture of <i>Vaccinium uliginosum, Empetrum nigrum, Chamaedaphne calyculata, Ledum groenlandicum, Kalmia polifolia, Kalmia angustifolia</i>, and <i>Vaccinium oxycoccos</i>. <i>Eriophorum vaginatum var. spissum</i> and <i>Trichophorum cespitosum</i> are typically the most abundant graminoids; <i>Carex magellanica ssp. irrigua, Carex canescens</i>, and <i>Carex pauciflora</i> may be present in lower abundance. <i>Rubus chamaemorus</i> is a diagnostic herb, although it may not always be present. <i>Sphagnum</i> spp. are the most abundant bryophytes, particularly <i>Sphagnum capillifolium, Sphagnum fuscum, Sphagnum fallax</i>, and <i>Sphagnum magellanicum</i>. The combination of subalpine species such as <i>Vaccinium uliginosum</i> and bog species such as <i>Eriophorum vaginatum var. spissum</i> is diagnostic. This community is related to, and may be adjacent to, ~<i>(Picea mariana, Abies balsamea) / Kalmia angustifolia - Ledum groenlandicum</i> Dwarf-shrubland (CEGL006031)$$; that association is less wet and lacks the true bog species such as <i>Eriophorum vaginatum var. spissum, Chamaedaphne calyculata</i>, and <i>Sphagnum</i> spp. It is also related to ~<i>Kalmia angustifolia - Chamaedaphne calyculata / Rubus chamaemorus / Cladonia</i> spp. Dwarf-shrubland (CEGL006425)$$, but that type is not constantly saturated and occurs on subalpine or alpine slopes rather than basins.
Accession Code:
urn:lsid:vegbank.org:commConcept:34788-{C34ECDBF-FB14-4967-BC28-D3723EA7E48E}
Plot-observations of this Community Concept:
0
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