Department of Conservation and Recreation

THE NATURAL COMMUNITIES OF VIRGINIA
CLASSIFICATION OF ECOLOGICAL COMMUNITY GROUPS

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Second Approximation (Version 2.5)
Information current as of February, 2012

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Basic Mesic Forests

This group is represented by forests occurring in fertile, mesic, low-elevation habitats of the Coastal Plain, Piedmont and valleys of the Central Appalachian region. Typical sites are deep ravines, sheltered north- or east-facing slopes subtending large streams and rivers, and occasionally well-drained floodplain terraces. Soils are usually weathered from carbonate or mafic bedrock, or from calcareous, shell-rich deposits in the Coastal Plain. The term "basic," as applied by DCR-DNH ecologists, refers high levels of base cation saturation rather than to soil pH, which analysis has proven to be a less reliable indicator of fertility and parent material.

Dominant trees include the species of Rich Cove and Slope Forests, as well as chinkapin oak (Quercus muhlenbergii), black maple (Acer nigrum), southern sugar maple (Acer barbatum), American beech (Fagus grandifolia), bitternut hickory (Carya cordiformis), and black walnut (Juglans nigra). Shrub and herb layers contain a number of species that are atypical of mountain slopes, such as paw-paw (Asimina triloba), painted buckeye (Aesculus sylvatica), twinleaf (Jeffersonia diphylla), harbinger-of-spring (Erigenia bulbosa), lowland brittle fern (Cystopteris protrusa), and toadshade (Trillium sessile). Widespread herbs include species such as maidenhair fern (Adiantum pedatum), hog-peanut (Amphicarpaea bracteata), puttyroot (Aplectrum hyemaleArisaema triphyllum ssp. triphyllum), wild ginger (Asarum canadense var. canadense), black bugbane (Cimicifuga racemosa), large yellow lady's-slipper (Cypripedium parviflorum var. pubescens), silvery spleenwort (Deparia acrostichoides), squirrel-corn (Dicentra canadensis), Dutchman's breeches (Dicentra cucullaria), showy orchid (Galearis spectabilis), round-lobed hepatica (Hepatica americana), green violet (Hybanthus concolor), Virginia pennywort (Obolaria virginica), aniseroot (Osmorhiza longistylis), broad beech fern (Phegopteris hexagonoptera), may-apple (Podophyllum peltatum), bloodroot (Sanguinaria canadensis), small-flower baby-blue-eyes (Nemophila aphylla), and foamflower (Tiarella cordifolia var. collina).

Five community types classified to date are segregated by geography and associated substrates. Slopes subtending streams cutting through limestone and other calcium-rich substrates of the mountain valleys and Piedmont support a distinctive community type characterized by lush growth of twinleaf, dwarf larkspur (Delphinium tricorne), broad-leaved waterleaf (Hydrophyllum canadense), and other spring ephemerals. Coastal Plain ravines that have downcut into Tertiary shell deposits in James City and York Counties and the City of Suffolk support an endemic community type with abundant southern sugar maple and many noteworthy mountain disjuncts.

Basic Mesic Forests are the low-elevation analogues of Rich Cove and Slope Forests. Excepting stands in the northwestern Virginia mountain valleys, they occur in non-montane settings and contain a substantial number of species that are confined to low elevations in Virginia. The extent and viability of basic mesic forests has been much reduced by repeated logging and invasive introduced weeds.

References: Fleming (1999), Fleming (2002a), Fleming (2002b), Fleming et al. (2007), Fleming and Coulling (2001), Fleming and Patterson (2004), Rawinski et al. (1996), Vanderhorst (2000), Walton et al. (2001), Ware and Ware (1992).

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Click on the images below to open a larger image in a separate window.

	Toad-shade (Trillium sessile) and squirrel-corn (Dicentra canadensis) carpet the floor of a basic mesic forest on bluffs bordering the Potomac River in Fairfax County (Scotts Run Nature Preserve). Gary P. Fleming / © DCR Natural Heritage.
	Basic Mesic Forest on a fertile slope bordering the Potomac River in Turkey Run Park, Fairfax County. Blue cohosh (Caulophyllum thalictroides) and harbinger-of-spring (Erigenia bulbosa) are abundant in the herb layer. Gary P. Fleming / © DCR Natural Heritage.
	Basic Mesic Forest in a northern Coastal Plain ravine that has down-cut into calcareous limesands near Accokeek Creek, Stafford County. Glade fern (Diplazium pycnocarpon) and silvery spleenwort (Deparia acrostichoides) dominate the herb layer. Gary P. Fleming / © DCR Natural Heritage.
	Southern sugar maple (Acer barbatum) and may-apple (Podophyllum peltatum) dominate a basic mesic forest in the southern Virginia Piedmont. Hogan Creek Wildlife Management Area (John H. Kerr Reservoir), Charlotte County. Gary P. Fleming / © DCR Natural Heritage.

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REPRESENTATIVE COMMUNITY TYPES:
Data have been collected from 130 plots representing this group (map) and supporting the classified types in several regional analyses. Additional sampling of some of the currently classified units is needed to fill geographic gaps, aid in determining within-type variation, and refine community-type names. Click on any highlighted CEGL code below to view the global USNVC description provided by NatureServe Explorer.

• Fagus grandifolia - Acer barbatum - Quercus muhlenbergii / Sanguinaria canadensis Forest
  Coastal Plain Calcareous Ravine Forest
  USNVC: = CEGL007181
  Global/State Ranks: G2?/S2
  
  
• Fagus grandifolia - Liriodendron tulipifera - Carya cordiformis / Lindera benzoin / Podophyllum peltatum Forest
  Coastal Plain / Outer Piedmont Basic Mesic Forest
  USNVC: = CEGL006055
  Global/State Ranks: G4?/S3
  
  
• Liriodendron tulipifera - Quercus rubra - Fraxinus americana / Asimina triloba / Cimicifuga racemosa - Uvularia perfoliata Forest
  Inner Piedmont / Lower Blue Ridge Basic Mesic Forest
  USNVC: = CEGL006186
  Global/State Ranks: G4?/S4
  
  
• Acer (nigrum, saccharum) - Tilia americana / Asimina triloba / Jeffersonia diphylla - Caulophyllum thalictroides Forest
  Central Appalachian / Piedmont Basic Mesic Forest (Twinleaf - Blue Cohosh Type)
  USNVC: = CEGL008412
  Global/State Ranks: G4G5/S4
  
  
• Acer barbatum - Fagus grandifolia - Carya cordiformis / Aesculus sylvatica / Cimicifuga racemosa Forest
  Southern Piedmont Basic Mesic Forest
  USNVC: = CEGL008466
  Global/State Ranks: G3G4/S3
  

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