Name:
Dasiphora fruticosa - Carex lasiocarpa / Campylium stellatum Alkaline Fen Macrogroup
Reference:
NatureServe Biotics 2019
Description:
This alkaline fen vegetation contains a mossy peat layer with depths typically exceeding 40 cm, and extends across the boreal regions of North America, extending south into subboreal regions of Alaska and the Yukon Territory, the Rocky Mountains, Great Lakes, and northeastern and north-central U.S. The vegetation may be graminoid-dominated, shrub-dominated, or a patchwork of the two, with broad-leaved non-ericaceous shrubs typically dominant. There is a discontinuous to absent layer of <i>Sphagnum</i> peatmoss, with brown mosses (<i>Calliergon, Campylium, Drepanocladus, Tomentypnum, Scorpidium scorpioides</i>) present to dominant. Broad-leaved non-ericaceous shrubs such as <i>Alnus incana, Betula glandulosa, Betula pumila, Dasiphora fruticosa ssp. floribunda, Myrica gale, Rhamnus alnifolia, Salix barclayi</i> (west), <i>Salix candida, Salix maccalliana</i> (west), and other <i>Salix</i> spp. exceed the cover of ericaceous shrubs, although some shore fens may be dominated by <i>Chamaedaphne calyculata</i>. Thin-leaved graminoids include especially <i>Carex lasiocarpa</i>, as well as <i>Carex aquatilis</i> (on peat), <i>Carex diandra, Carex interior, Carex limosa, Carex livida, Eriophorum viridicarinatum, Muhlenbergia glomerata, Rhynchospora alba</i>, and <i>Trichophorum alpinum</i>. A wide diversity of herbs is found, especially <i>Equisetum fluviatile, Menyanthes trifoliata, Sarracenia purpurea, Solidago uliginosa</i> (east), <i>Triantha glutinosa</i>, and <i>Triglochin maritima</i>. Other herbs include <i>Comarum palustre</i> and <i>Calla palustris</i>.<br /><br />These fens develop in open basins where lateral groundwater flows through circumneutral to calcareous parent materials or causes calcareous upwellings, creating moderately to strongly alkaline conditions. They are found on level to gently sloping surfaces, or in closed wet depressions (sometimes as floating mats), and along wetland margins and lake- and rivershores. The shore fens are occasionally flooded, and so are included here because flooding tends to create moderately alkaline conditions. Peat deposits are composed primarily of partially decomposed brown mosses and sedges. 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.<br /><br />In the subboreal regions of southeastern Canada and the northeastern United States, this macrogroup is typically found in glaciated settings, in pitted outwash or in kettle lakes associated with kettle-kame-moraine topography. The characteristic species include the shrubs <i>Cornus amomum, Cornus racemosa, Cornus sericea, Dasiphora fruticosa ssp. floribunda</i>, prairie grasses such as <i>Andropogon gerardii</i> and <i>Spartina pectinata</i>, sedges including <i>Carex flava, Carex sterilis, Carex prairea</i>, and other graminoids such as <i>Trichophorum alpinum</i>, and forbs such as <i>Packera aurea, Symplocarpus foetidus, Triantha glutinosa</i>, and <i>Lobelia kalmii</i>. Less commonly, <i>Cladium mariscoides</i> may be a dominant.<br /><br />In the western boreal regions of North America, this macrogroup occurs in shallow depressions and basins, pond margins, and thermokarst pits with an open hydrologic regime. Fens are nutrient-rich and have a thick peat layer that may be floating or submerged. Standing water is usually present. They are most abundant in areas of limestone bedrock, and widely scattered in areas where calcareous substrates are scarce.
Accession Code:
urn:lsid:vegbank.org:commConcept:41098-{711E3DFC-CC19-4CDC-8C21-813D3C9B3C46}
Plot-observations of this Community Concept:
0
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