Name:
Alnus incana ssp. rugosa - Nemopanthus mucronatus / Sphagnum spp. Shrubland
Reference:
Eastern Ecology Working Group of...
Description:
This alder-dominated community is associated with peatlands across northern New England and adjacent Canada. It is most often found at the landward edge of acidic peat mats (i.e., the lagg), where it receives slightly more enriched waters than those of the adjacent oligotrophic or ombrotrophic peatland. Nitrogen levels are higher than in other peatland communities, presumably as a result of nitrogen fixing by the alders. Occasionally, it occurs in a montane setting (>730 m [2400 feet]) on thin organic soils over coarse cryic soils. Tall shrubs are the dominant physiognomy, with at least 50% cover; trees may be present but are sparse. Herb cover varies from sparse to extensive depending on the shrub cover. The bryophyte layer is well-developed, usually with at least 50% cover. <i>Alnus incana ssp. rugosa (= Alnus rugosa)</i> is the dominant or characteristic tall shrub; <i>Ilex verticillata</i> or <i>Nemopanthus mucronatus</i> are often present and sometimes abundant. Other shrubs include <i>Alnus viridis, Viburnum nudum var. cassinoides (= Viburnum cassinoides), Vaccinium corymbosum</i>, or <i>Spiraea tomentosa</i>. A tree canopy is lacking, but there may be scattered trees of <i>Acer rubrum, Picea mariana, Thuja occidentalis</i>, or <i>Abies balsamea</i>. Dwarf-shrub cover is variable, with <i>Rhododendron canadense</i> and <i>Chamaedaphne calyculata</i> the most typical, and <i>Kalmia angustifolia, Gaylussacia baccata</i>, and <i>Ledum groenlandicum</i> often also present. (<i>Nemopanthus mucronatus, Picea mariana, Thuja occidentalis, Abies balsamea</i>, and <i>Ledum groenlandicum</i> drop out at the southern extent of the range.) The most characteristic herbs are <i>Carex trisperma, Calla palustris</i>, and <i>Osmunda cinnamomea</i>; other species include <i>Triadenum virginicum, Carex intumescens, Carex magellanica ssp. irrigua (= Carex paupercula), Doellingeria umbellata (= Aster umbellatus), Iris versicolor, Gaultheria hispidula, Lysimachia terrestris, Maianthemum trifolium, Onoclea sensibilis, Sarracenia purpurea, Thalictrum pubescens</i>, and <i>Trientalis borealis</i>. The bryoid layer consists of <i>Sphagnum</i> spp., including <i>Sphagnum recurvum, Sphagnum palustre, Sphagnum fallax</i>, and <i>Sphagnum magellanicum</i>. The combination of <i>Alnus incana</i> dominance with <i>Nemopanthus mucronatus</i> and understory plants characteristic of peatlands is diagnostic.
Accession Code:
VB.CC.31402.CEGL006158
Plot-observations of this Community Concept:
0
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