Name:
Chamaedaphne calyculata - Vaccinium oxycoccos - Carex oligosperma Bog & Acidic Fen Macrogroup
Reference:
NatureServe Biotics 2019
Description:
This macrogroup extends across the boreal regions of North America, extending south into subboreal regions of the Pacific Maritime and Rocky Mountain divisions, Great Lakes region and northeastern U.S. It occurs where sufficiently cold climatic conditions allow the rate of peat accumulation to exceed its decomposition, resulting in ombrotrophic and acidic peatlands in which the bog surface is raised above the water table. Stands are dominated by a continuous layer of <i>Sphagnum</i> mosses (sometimes submerged in bog pools) and ericaceous dwarf-shrubs and thin-leaved graminoids. Scrub trees <2 m may be common, but trees >5 m are <10% cover. Dominant shrubs include <i>Andromeda polifolia, Betula nana, Chamaedaphne calyculata, Empetrum nigrum, Gaultheria hispidula, Kalmia polifolia, Ledum palustre ssp. decumbens, Ledum groenlandicum, Rubus chamaemorus, Vaccinium macrocarpon</i> (east), <i>Vaccinium oxycoccos, Vaccinium vitis-idaea</i>, and <i>Vaccinium uliginosum</i>. The herbaceous layer is typically graminoid-dominated. Species include <i>Carex aquatilis, Carex lasiocarpa, Carex livida, Carex membranacea, Carex microglochin, Carex oligosperma</i> (more eastern), <i>Carex pauciflora, Carex pluriflora, Carex rariflora</i> (more eastern), <i>Carex rotundata</i> (more eastern), <i>Carex stylosa, Eriophorum angustifolium, Eriophorum brachyantherum</i>, and <i>Eriophorum virginicum</i>. Graminoids common to both poorer and richer fens include <i>Carex chordorrhiza, Carex lasiocarpa</i>, and <i>Carex limosa</i> Insectivorous plants are common features of bogs and may include <i>Drosera intermedia, Drosera rotundifolia, Sarracenia purpurea</i>, and <i>Utricularia intermedia</i>. Trees include <i>Picea mariana, Picea glauca</i>, and <i>Larix laricina</i>.<br /><br />Acidic peatlands range from strictly ombrotrophic bog (isolated from groundwater, precipitation-fed) to weakly minerotrophic poor fen. The surface morphology of a bog may be more-or-less level, domed, or eccentric, but typically is above the water table. As peat accumulates, ridges may form, which can be relatively dry compared to the flat areas. Secondary bog pools (schlenke) may be present in the raised portions of the peatlands. Peat deposits are composed primarily of partially decomposed <i>Sphagnum</i> mosses, and depth of peat exceeds 40 cm, separating this from similar wetlands that are non-peatlands. The water table is at or just above the surface, although the surface of some bogs is raised above the surrounding terrain.<br /><br />In the eastern U.S., acidic peatlands extend southward through the Great Lakes and Northeast. Here <i>Sphagnum</i> and shrub peatlands occur in basins south through the Laurentian-Acadian region down to near the glacial boundary in the northeastern and north-central U.S. Unlike the true raised bogs of boreal regions, the vegetation is not raised above the groundwater level. The nutrient-poor substrate and the reduced throughflow of water create oligotrophic conditions fostering the development of <i>Sphagnum</i> peat and the growth of peatland vegetation. Although these peatlands are often called bogs, in most cases they are technically "poor fens," as the vegetation remains in contact with the weakly minerotrophic (nutrient-poor) groundwater.<br /><br />In the Atlantic region, from Labrador to Downeast Maine, acidic peatlands take a somewhat different form. In basins, they develop raised plateaus with undulating sedge and dwarf-shrub vegetation. <i>Trichophorum cespitosum</i> may form sedge lawns on the raised plateau. The system may also occur as "blanket bogs" over a sloping rocky substrate in extreme maritime settings; here, dwarf-shrubs and <i>Sphagnum</i> are the dominant cover. Species characteristic of this maritime setting include <i>Empetrum nigrum</i> and <i>Rubus chamaemorus</i>. Typical bog heaths such as <i>Gaylussacia dumosa, Gaylussacia baccata, Kalmia angustifolia, Kalmia polifolia</i>, and <i>Ledum groenlandicum</i> are also present. Morphological characteristics and certain coastal species distinguish these from more inland acidic peatlands.
Accession Code:
urn:lsid:vegbank.org:commConcept:41097-{1B636250-FD59-4D79-93B0-C3E232FD3E00}
Plot-observations of this Community Concept:
0
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