Classification of Vegetation Communities of Maryland: First Iteration
A Subset of the International Classification of Ecological
Concept: This alliance is characterized by a canopy of abundant Chamaecyparis thyoides, but because other hardwoods are often present in quantity, this vegetation is placed within a mixed alliance. Nearly pure stands do occur, but their floristic composition is similar enough to warrant their placement within this alliance. Associated canopy trees include Acer rubrum, Magnolia virginiana, Betula alleghaniensis, Pinus strobus, Pinus rigida, Pinus serotina, and Nyssa sylvatica. Common shrubs include Vaccinium corymbosum, Ilex glabra, Leucothoe racemosa, Lyonia lucida, Rhododendron viscosum, Clethra alnifolia, and Gaylussacia frondosa. Common herbaceous species of this alliance include Osmunda cinnamomea, Woodwardia virginica, Smilax rotundifolia, Smilax laurifolia, Trientalis borealis, Arundinaria gigantea, Maianthemum canadense, and Aralia nudicaulis. Sphagnum hummocks are usually characteristic of this vegetation. Schizaea pusilla is apparently restricted to this vegetation, where it grows at the bases of cedar trees. Other species found in this alliance on the Delmarva peninsula include Orontium aquaticum and Alnus maritima. Communities of this alliance are commonly associated with pine barrens vegetation in New Jersey; Long Island, New York; and Cape Cod, Massachusetts. Isolated communities also occur in poorly drained depressions inland of the coastal plain in Massachusetts, New York and New Jersey. Waters are generally acidic, and soils are usually thick peat deposits in basin wetlands, or mucks overlying mineral soils along water courses. Atlantic white-cedar grows in basins and along streams in the pine barrens; it is much more common in this habitat in Delaware than it is in basins not influenced by stream flooding or seepage. White-cedar reaches its greatest abundance on artificial habitats in Delaware, headwaters of dammed mill ponds (Clancy 1993b). As a commercially important species, Atlantic white-cedar has been cut extensively throughout its range, and very few virgin or old-growth stands are known. Classification of this vegetation is complicated by this fact, although much research has been done on the impacts of fire in this vegetation. Although Atlantic white-cedar trees are fire-sensitive, many stands were initiated following fire. Low-intensity fires that did not burn the forest floor foster the growth of dense seedlings. Seedling mortality is high, but even mature stands initiated in this way are quite dense (McCormick 1979.)
Comments: White-cedar swamps of the New Jersey Pine Barrens are described by Little (1951), who lists Pogonia ophioglossoides, Sarracenia purpurea, Bartonia paniculata, and Drosera rotundifolia as more characteristic of cedar swamps than of hardwood swamps in the pine barrens. Harshberger (1916) describes the "cedar swamp formation" of the New Jersey Pine Barrens and lists essentially the same species. Other orchid species apparently confined to cedar swamps in the pine barrens noted by Harshberger include Arethusa bulbosa, Platanthera blephariglottis, and Platanthera clavellata. Other associates include Carex collinsii, Kalmia angustifolia, Chamaedaphne calyculata, and Helonias bullata. Olsson (1979) describes similar white cedar vegetation. This alliance is also described from Cape May, New Jersey, by Bernard (1963) as the "Chamaecyparis thyoides - Acer rubrum type."
Range: This alliance occurs in southern New England, New York, New Jersey, Maryland, Delaware, and Virginia. It also occurs in the Southeastern Region. The range of this alliance is essentially coincident with the range of Chamaecyparis thyoides, from southern Maine along the coastal plain to northern South Carolina. This alliance also occurs in small areas inland in New York, Massachusetts and New Jersey. Chamaecyparis thyoides also occurs along the coastal plain of the Gulf of Mexico, but these forests may be better placed in a separate alliance.
States/Provinces: DE MD NJ
TNC Ecoregions: 61:C, 62:C
USFS Ecoregions: 212Dc:PPP, 221Aa:CCP, 221Ab:CCC, 221Ac:CCC, 221Ad:CCC, 221Ae:CCP, 221Af:CCP, 221Ag:CCP, 221Ah:CCP, 221Ai:CCP, 221Aj:CCP, 221Ak:CCC, 221Al:CCP, 221Am:CCP, 221Bc:CPP, 221Bd:CPP, 232Aa:CCC, 232Ac:CCC, 232Ba:CPP, 232Bc:CPP, 232Br:CPP, 232Bt:CPP, 232Ch:CPP, M212Bb:PPP
Synonymy: Atlantic White-Cedar: 97 (Eyre 1980); Chamaecyparis thyoides - Acer rubrum type. described from Cape May, New Jersey (Bernard 1963)
References: Bernard 1963, Clancy 1993b, Eyre 1980, Laderman 1989, McCormick 1979, Motzkin 1990
Authors: ECS, East Identifier: A.448
CHAMAECYPARIS THYOIDES - ACER RUBRUM - MAGNOLIA VIRGINIANA FOREST
Atlantic White-cedar - Red Maple - Sweetbay Forest
Coastal Plain Atlantic White-cedar - Red Maple Swamp G? (97-12-01)
Ecological Group (SCS;MCS): Southeastern Coastal Plain
Concept: Mixed Atlantic white-cedar - red maple swamp of New Jersey, Delaware, and Maryland. In addition to Chamaecyparis thyoides and Acer rubrum, other canopy associates include Nyssa sylvatica, Magnolia virginiana. The shrub layer is characterized by Vaccinium corymbosum or Vaccinium formosum, Clethra alnifolia, Ilex glabra, Gaylussacia frondosa, Rhododendron viscosum. The herbaceous layer may be sparse to moderate cover and includes species such as Mitchella repens, Sarracenia purpurea, Triadenum virginicum, Pogonia ophioglossoides. In canopy openings, Peltandra virginica, Orontium aquaticum, Iris versicolor may also occur. Sphagnum mosses form a moderately dense to dense bryophyte layer; species include Sphagnum magellanicum, Sphagnum pulchrum, Sphagnum flavicomans, Sphagnum recurvum, and Sphagnum fallax.
Range: This association is found in New Jersey, Delaware, and Maryland.
States/Provinces: DE:S?, MD:S?, NJ:S4
TNC Ecoregions: 61:?, 62:C
USFS Ecoregions: 232Ac:CCC, 232Bt:CPP, 232C:CP
Synonymy: Coastal Plain Atlantic White Cedar Swamp (Breden 1989) B
References: Breden 1989, Breden et al. 2001, Clancy 1996, Karlin 1988, Olsson 1979
Authors: ECS Confidence: 2 Identifier: CEGL006078
- Maryland Vegetation Classification Subset Report I.C. Mixed evergreen-deciduous forest
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