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.5.N.n. Tidal temperate or subpolar grassland
V.A.5.N.n.6. PANICUM VIRGATUM TIDAL HERBACEOUS ALLIANCE
Switchgrass Tidal Herbaceous Alliance
 

Concept: This alliance consists of brackish to oligohaline tidal marshes dominated by Panicum virgatum. Hydrology of this alliance is irregularly tidally inundated, usually occurring above Juncus roemerianus and other tidal marshes, and at the conceptual edge of tidal and upland communities. Associated species in the northern part of the alliance's range include Spartina pectinata, Agrostis stolonifera, Cladium mariscoides, Schoenoplectus americanus (= Scirpus americanus), Solidago sempervirens, Baccharis halimifolia, and Tripsacum dactyloides. Associates in the southern portion of the range include Cladium mariscus ssp. jamaicense, Sagittaria lancifolia, and Spartina cynosuroides.

Comments: This vegetation typically intergrades with the Baccharis halimifolia - Iva frutescens Tidal Shrubland Alliance (A.1023); its status as a distinct alliance may require further study. More information is needed on its expression and extent in the southeastern U.S.

Range: This alliance is found in Alabama, Mississippi, Connecticut, Delaware, Massachusetts, Maryland, New Jersey, New York, Rhode Island, and Virginia, and possibly in Florida (?) and Louisiana (?).

States/Provinces: AL CT DE FL? LA? MA MD MS NJ NY RI VA

TNC Ecoregions: 53:C, 55:P, 56:P, 57:P, 58:C, 61:C, 62:C

USFS Ecoregions: 221Aa:CCP, 221Ab:CCC, 221Ac:CCC, 221Ad:CCC, 221Ae:CC?, 221Ak:CCC, 232Aa:CCC, 232Ab:CCC, 232Ac:CCC, 232Ad:CCC, 232Bc:CCP, 232Bd:CC?, 232Bx:CCC, 232Bz:CCC, 232Cb:CCP, 232Ce:CCP, 232Ch:CC?, 232Ci:CCP, 232Cj:CC?, 232Dc:CCC

Federal Lands: NPS (Assateague Island, Fire Island)

Synonymy: Estuarine Intertidal: Salt Marsh (Swain and Kearsley 2001); Estuarine Intertidal: Brackish Tidal Marsh (Swain and Kearsley 2001)

References: Sneddon et al. 1994, Swain and Kearsley 2001

Authors: ECS, JT, East Identifier: A.1476

PANICUM VIRGATUM - SPARTINA PATENS HERBACEOUS VEGETATION
Switchgrass - Saltmeadow Cordgrass Herbaceous Vegetation
Brackish Meadow                                                                                          G? (97-12-01)
Ecological Group (SCS;MCS):   Atlantic and Gulf Coast High Tidal Marsh Grasslands (202-45; n/a) 172

Concept: This brackish meadow of the northern Atlantic coast occurs at the upland border of high salt marshes. It occurs on freely drained, shallow, sandy peat that is moist from upland seepage and brackish from irregular tidal flooding. Vegetation is dominated by Panicum virgatum and occasionally codominated by Spartina patens. Common associates can include Schoenoplectus americanus, Solidago sempervirens, Teucrium canadense, Distichlis spicata, Carex silicea, and Juncus spp. (Juncus gerardii in the north, Juncus roemerianus in the south). Additional species can include Kosteletzkya virginica, Hibiscus moscheutos, Amaranthus cannabinus, and Typha spp., especially in oligohaline situations. Shrubs may occur sporadically, especially Baccharis halimifolia, Morella pensylvanica (= Myrica pensylvanica), Prunus maritima, and Iva frutescens. Vegetation can be quite diverse and is a mixture of freshwater and brackish species. This association is best developed in salt marshes with a gradual elevation gradient that lends itself to vegetation zonation. The diagnostic species of this association is Panicum virgatum in brackish settings near upland-marsh borders.

Comments: This association is similar in species composition to the herbaceous component of Baccharis halimifolia - Iva frutescens / Spartina patens Shrubland (CEGL003921). This association is less developed in the northern edge of its range (New Hampshire).

Range: This association occurs from New Hampshire to Delaware.

States/Provinces: CT:S?, DE:S3?, MA:S3,S1, MD:S?, NJ:S2S3, NY:S1S2, RI:S?, VA:S?

TNC Ecoregions: 58:C, 61:C, 62:C

USFS Ecoregions: 221Ab:CCC, 221Ac:CCC, 221Ad:CCC, 221Ak:CCC, 232Aa:CCC, 232Ab:CCC, 232Ac:CCC, 232Ad:CCC, 232Bx:CCC, 232Bz:CCC

Federal Lands: NPS (Assateague Island, Fire Island)

Synonymy: Salt marsh complex, upland border (Breden 1989), Panicum virgatum upland border (Nixon 1982), Salt Marsh (Rawinski 1984). formerly Southern New England and Gulf of Maine Salt Marshes., Brackish Tidal Marsh (Rawinski 1984). formerly Southern New England and Gulf of Maine., Fresh marsh (Hill 1986) B. Assateague Island., Mesic shrub community (Higgins et al. 1971) B. Assateague Island., Freshwater marsh (Fender 1937) B. New Jersey., Panicum virgatum Wetland Association (Heckscher et al. 1995) B. Delaware.

References: Bowman 2000, Breden 1989, Breden et al. 2001, Edinger et al. 2002, Enser 1999, Fender 1937, Harrison 2001, Heckscher et al. 1995, Higgins et al. 1971, Hill 1986, Hunt 2000, Lundgren et al. 2000, Metzler and Barrett 2001, Nixon 1982, Rawinski 1984, Sperduto 2000b, Swain and Kearsley 2001

Authors: S.L. Neid, ECS Confidence: 2 Identifier: CEGL006150

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