Title: Classification of Vegetation Communities of Maryland

Classification of Vegetation Communities of Maryland: First Iteration

A Subset of the International Classification of Ecological
Communities: Terrestrial Vegetation of the United States
March 2004

V. HERBACEOUS VEGETATION
V.A.6.N.q. Bedrock temperate or subpolar grassland with a sparse tree layer
V.A.6.N.q.103. (PINUS RIGIDA) / SCHIZACHYRIUM SCOPARIUM WOODED HERBACEOUS ALLIANCE
(Pitch Pine) / Little Bluestem Wooded Herbaceous Alliance


Concept: Schizachyrium scoparium-dominated grasslands with scattered Pinus rigida. This alliance includes ultramafic outcrop barrens of Virginia and serpentine barrens of the mid-Atlantic Piedmont region. This latter vegetation consists of open, herb-dominated grasslands on serpentine, which contain Schizachyrium scoparium and Scleria pauciflora under scattered Pinus rigida. The Piedmont examples in Virginia actually do not contain Pinus rigida, but instead are adjacent to areas with Pinus virginiana.

Range: This alliance occurs in Maryland, New York, Pennsylvania, and Virginia.

States/Provinces: MD NY PA VA

TNC Ecoregions: 52:C, 61:C

USFS Ecoregions: 221D:CC, 231Ak:CCC, 232A:CC

Synonymy: Red-cedar - pine serpentine shrubland (Fike 1999); Serpentine grassland (Fike 1999); Eastern Serpentine Barren, in part (Smith 1991)

References: Fike 1999, Smith 1991

Authors: ECS, MP, East Identifier: A.1921

PINUS RIGIDA / SCHIZACHYRIUM SCOPARIUM - SCLERIA PAUCIFLORA WOODED HERBACEOUS VEGETATION
Pitch Pine / Little Bluestem - Papillose Nutrush Wooded Herbaceous Vegetation
Eastern Serpentine Barren                                                                             G2 (98-07-24)

Concept: This serpentine grassland community is essentially restricted to a 97-km chain of large serpentine outcrops in Maryland and Pennsylvania. This community occurs on thin Alfisols or Mollisols developed over serpentinite or similar ultra-mafic rock. Soils generally have a low calcium to magnesium ratio, and they are stony and shallow with a low moisture-holding capacity. Some form of disturbance is necessary to prevent extensive soil development, generally burning or grazing. This community occurs as herbaceous grassland openings with scattered trees. Typically it occurs as part of a woodland/grassland complex with the specific canopy composition shifting between Pinus rigida, Pinus virginiana, and Juniperus virginiana. Quercus marilandica and Quercus stellata may also be present. The actual species composition of the canopy probably reflects site history and available seed sources. The herbaceous layer is generally dominated by Schizachyrium scoparium but is characteristically rich in other herbaceous species such as Sorghastrum nutans, Dichanthelium depauperatum, Dichanthelium linearifolium, Dichanthelium oligosanthes, Dichanthelium sphaerocarpon, Dichanthelium villosissimum, Panicum philadelphicum, Cerastium arvense ssp. velutinum, Sporobolus heterolepis, Viola sagittata, Sisyrinchium mucronatum, Saxifraga virginiensis, Fimbristylis annua, Juncus secundus, Oenothera fruticosa, Arabis lyrata, Aristida purpurascens, Asclepias verticillata, Asclepias viridiflora, Polygonum tenue, Scleria pauciflora, Packera anonyma (= Senecio anonymus), Talinum teretifolium, Symphyotrichum depauperatum (= Aster depauperatus), Lobelia spicata, Polygala verticillata, and Andropogon gerardii. In eastern North America, outcrops of serpentine occur in a broken chain from Quebec to Alabama. Most outcrops, however, are small and do not develop this community. Distinct but closely related communities occur in western North Carolina, Virginia and Georgia. In addition, there are four small, degraded occurrences (17 ha) in New York, and several other degraded remnants were documented in Delaware, but any remaining vegetation is deemed too degraded to be considered a community, and so are regarded as extirpated (W. McAvoy, Delaware Natural Heritage Program, pers. comm.).

Comments: Physiognomically this community may occasionally occur as a treeless prairie. Some researchers recognize both a prairie and savanna type. However, as they are virtually identical in floristic composition and as the presence of at least a few trees is generally the rule (except after a severe fire or in microsites of solid bedrock), they have been combined here. Somewhat related serpentine outcrop communities, which are extremely small and patchy, are described separately.

Range: This community occurs on serpentine outcrops primarily in Maryland and southeastern Pennsylvania, with a few small, degraded remnants on Staten Island in New York.

States/Provinces: MD:S?, NY:S1, PA:S?,S?

TNC Ecoregions: 61:C

USFS Ecoregions: 221D:CC, 232A:CC

References: Brooks 1987, Edinger et al. 2002, Fike 1999, Grossman et al. 1994, Jones 1956, Lapham and McKague 1964, Latham 1983, Latham 1993, Marye 1920, Marye 1955a, Marye 1955b, Marye 1955c, Miller 1977, Miller 1981, Montferrante 1973, Pennell 1910, Pennell 1912, Pennell 1929, Reed 1986, Reschke 1990, Smith n.d. (a), Tyndall 1992a, Tyndall 1992b, Tyndall and Farr 1989, Tyndall and Farr 1990, Wherry 1963

Authors: M. Anderson, ECS Confidence: 2 Identifier: CEGL006159

- Maryland Vegetation Classification Subset Report V.A. Perennial graminoid vegetation
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