Common (Translated Scientific) Name: Leatherleaf / Tawny Cottongrass / Red Peatmoss Acidic Peatland

Colloquial Name: Acadian-Appalachian Leatherleaf Poor Fen

Hierarchy Level:  Association

Type Concept: 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 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 var. 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 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.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This northeastern type appears very similar to the Midwest''s ~Chamaedaphne calyculata / Carex oligosperma - Eriophorum virginicum Acidic Peatland (CEGL005092)$$, but additional data from the Canadian range of these boggy fens is needed, followed by a rangewide review to determine if the two should be combined. In the Northeast, this type is related to the dwarf-shrub bog types ~Rhododendron canadense - Chamaedaphne calyculata Acidic Peatland (CEGL006514)$$ and ~Kalmia angustifolia - Chamaedaphne calyculata - (Picea mariana) / Cladonia spp. Acidic Peatland (CEGL006225)$$, both of which can feature Chamaedaphne calyculata but are in more ombrotrophic (raised bog) settings; it is also related to the more minerotrophic ~Carex (oligosperma, exilis) - Chamaedaphne calyculata Shrub Acidic Peatland (CEGL006524)$$, which differs in having graminoids more abundant than dwarf-shrubs. Similar quaking "bogs" in more southerly portions of the glaciated Northeast are placed in ~Chamaedaphne calyculata - (Gaylussacia dumosa) - Decodon verticillatus / Woodwardia virginica Acidic Peatland (CEGL006008)$$, and have species of somewhat more southern affinity such as Decodon verticillatus and Peltandra virginica.

Similar NVC Types: No Data Available

note: No Data Available