Name:
Kalmia angustifolia - Chamaedaphne calyculata - (Picea mariana) / Cladina spp. Dwarf-shrubland
Reference:
Eastern Ecology Working Group of...
Description:
These are the true ombrotrophic dwarf-shrub bogs of northern New England and Canada, occurring on the raised and relatively well-drained portions of raised peatlands. Peat accumulation has caused plant growth to be raised above the water table, and virtually all nutrients come from precipitation and deposition. The peat is typically saturated with water throughout the growing season, although standing water is often not apparent. Conditions are highly acidic, pH usually between 3.8-4.8. The classic vegetation pattern is drier hummocks and wet hollows across the peatland surface. Dwarf-shrubs dominate the vegetation, with overall heights usually 0.3-0.6 m. Trees are sparse and stunted; tall shrubs, if present, are usually confined to pockets near the peatland's upland border. Herb cover is low, usually <25%. The bryoid layer is very well-developed and forms the substrate for the vascular plants. <i>Kalmia angustifolia</i> is a constant and usually dominant shrub; <i>Gaylussacia baccata</i> may be important in some peatlands. Other important dwarf-shrubs include <i>Ledum groenlandicum, Rhododendron canadense</i>, and <i>Chamaedaphne calyculata</i>. <i>Kalmia polifolia, Vaccinium angustifolium</i>, and <i>Vaccinium oxycoccos</i> are often present but less abundant. Scattered stunted trees of <i>Picea mariana</i> (or, less commonly, <i>Larix laricina</i> or <i>Pinus strobus</i>) may be present, and there are often circular islands of shrub-form <i>Picea mariana</i> that has reproduced by layering. Frequent herbs include <i>Sarracenia purpurea, Drosera rotundifolia, Carex trisperma</i>, and <i>Eriophorum vaginatum var. spissum</i>. <i>Calopogon tuberosus (= Calopogon pulchellus)</i> is a typical orchid. <i>Sphagnum fuscum</i> is the diagnostic and usually dominant moss; others include <i>Sphagnum magellanicum</i> and <i>Sphagnum capillifolium</i>. <i>Polytrichum strictum</i> is common on the hummocks. In the drier portions of the raised heath, fruticose lichens may be important, including <i>Cladina rangiferina, Cladina mitis</i>, and <i>Cladonia</i> spp. (<i>Cladonia crispata, Cladonia cristatella, Cladonia cervicornis ssp. verticillata (= Cladonia verticillata), Cladonia uncialis</i>, and others). This association is distinguished from other dwarf-shrub bog associations by the raised bog setting, greater importance of <i>Kalmia angustifolia</i> compared to <i>Chamaedaphne</i>, and usual absence of maritime indicators such as <i>Rubus chamaemorus</i> and <i>Gaylussacia dumosa</i>.
Accession Code:
VB.CC.31329.CEGL006225
Plot-observations of this Community Concept:
0
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