Name:
Chamaedaphne calyculata / Eriophorum virginicum / Sphagnum rubellum Dwarf-shrubland
Reference:
Eastern Ecology Working Group of...
Description:
These nutrient-poor fens are found across the glaciated northeastern United States and likely adjacent Canada. Physiognomy is that of a dwarf-shrubland of variable cover over a bryophyte carpet. They occur as floating or quaking mats in peat-accumulating basins, either closed basins or, if in open basins, with very restricted water movement. Kettleholes in glacial deposits are a classic setting. Conditions are acidic, with pH averaging about 4.0, and nutrient availability is very limited. Often referred to as "bogs," these are technically fens since the vegetation is in contact with groundwater. Trees and tall shrubs, if present, are sparse, and the vegetation is dominated by bryophytes and the dwarf-shrub layer, the latter typically with 40-80% cover. Herb cover is variable, but is less than the dwarf-shrub cover. The bryophyte layer is essentially continuous. Chamaedaphne calyculata dominates the dwarf-shrub layer; Andromeda polifolia var. glaucophylla (= Andromeda glaucophylla) is usually present, a good indicator, and may occasionally approach codominance. Myrica gale, Kalmia polifolia, Ledum groenlandicum, and Kalmia angustifolia are frequent, although not at high cover. Scattered tall shrubs (usually near the upland margin) and stunted trees may include Gaylussacia baccata, Lyonia ligustrina, Picea mariana, and Larix laricina. Prominent sedges are Eriophorum vaginatum ssp. spissum (on hummocks), Eriophorum virginicum, and Rhynchospora alba (on Sphagnum mats), and, under the wettest conditions, Eriophorum angustifolium. Carex oligosperma, Carex utriculata, or Carex pauciflora may also be present. Vaccinium oxycoccos grows as a trailing shrub on the Sphagnum mats, where Sphagnum rubellum (= Sphagnum capillifolium var. tenellum) and/or Sphagnum magellanicum usually dominate. Other common Sphagnum spp. include Sphagnum fallax and Sphagnum angustifolium. Diagnostic characteristics include the dominance of Chamaedaphne calyculata and presence of Vaccinium oxycoccos in a setting that is not a raised bog, with lower abundance of graminoids than shrubs, and without species of somewhat southerly affinity such as Decodon verticillatus and Peltandra virginica.
Accession Code:
VB.CC.21222.CHAMAEDAPHNECAL
Plot-observations of this Community Concept:
0
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