Classification of Vegetation Communities of Maryland: First Iteration

V. HERBACEOUS VEGETATION
V.A.5.N.n. Tidal temperate or subpolar grassland
V.A.5.N.n.1. SPARTINA ALTERNIFLORA TIDAL HERBACEOUS ALLIANCE
Saltmarsh Cordgrass Tidal Herbaceous Alliance

Concept: This alliance includes various tidal marshes dominated by Spartina alterniflora. The hydrology is usually regularly tidally flooded. In the northern part of its range, southern Maine to Cape Hatteras, North Carolina, this alliance is generally limited to the zone between mean sea level and the mean high water level. The habitat occurs in protected inlets behind barrier beaches or in drowned river valleys. Peat depth ranges from a few feet, if the community formed over a mud flat, to 80 feet in drowned river valleys. Spartina alterniflora is limited to the low marsh zone by moderate salinity; it can withstand longer submergence than other salt marsh grasses, but still requires periodic exposure of the substrate. It also requires moderately high levels of iron (7-15 ppm). This community is commonly known as the 'low salt marsh,' occurring as a tall grassland strongly dominated by Spartina alterniflora. There is little variation in vascular plant species composition across the range. It occurs in nearly pure stands, with occasional low growing species such as Spergularia salina (= Spergularia marina), Salicornia spp., Suaeda maritima, and seaweeds such as Ulva lactuca and other algae such as Fucus vesiculosus and Ascophyllum nodosum, which grow at the bases of the Spartina plants. Herbs of Salicornia virginica and Salicornia bigelovii can be quite common mixed in with the Spartina, often becoming more apparent later in the growing season. Limonium carolinianum is another characteristic herb, but only as scattered individuals. More detailed information is needed on the variability of the alliance in the southern parts of its range.

Range: This alliance is found in Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Texas, Connecticut, Delaware, Massachusetts, Maine, Maryland, New Hampshire, New Jersey, Rhode Island, and Virginia.

States/Provinces: AL CT DE FL GA LA MA MD ME MS NB NC NH NJ NS NY RI SC TX VA

TNC Ecoregions: 30:P, 31:C, 41:P, 53:C, 54:P, 55:P, 56:C, 57:C, 58:C, 62:C, 63:C

USFS Ecoregions: 212Cb:CCC, 212Db:CCC, 212Dc:CCC, 221Aa:CCP, 221Ab:CCC, 221Ac:CCC, 221Ad:CCC, 221Ae:CCC, 221Aj:CCP, 221Ak:CCC, 221Dc:CPP, 231Fb:CCC, 232Aa:CCC, 232Ab:CCC, 232Ac:CCC, 232Ad:CCC, 232Ae:CCC, 232Bb:CCP, 232Bc:CCP, 232Bd:CCP, 232Br:CCC, 232Bt:CCC, 232Bx:CCC, 232Bz:CCC, 232Cb:CCC, 232Ce:CCC, 232Ch:CCC, 232Ci:CCC, 232Cj:CCC, 232Db:CCP, 232Dc:CCC, 232Dd:CCC, 232De:CCP, 232Eb:CCC, 232Ed:CCC, 232Ee:CCC, 232Gb:CPP, 255Da:CC?, 255Dc:CCC

Federal Lands: NPS (Acadia, Assateague Island, Cape Hatteras, Cape Lookout, Fire Island, Fort Pulaski); USFS (Croatan); USFWS (Anahuac?, Aransas?, Big Boggy, Bon Secour, Brazoria, Matagorda Island, McFaddin, San Bernard, Texas Point)

Synonymy: Tidal Marsh, in part (FNAI 1992a); Saline Marsh, in part (Wieland 1994a); Saline Marsh, in part (Wieland 1994b); Salt Marsh (Schafale and Weakley 1990); Salt Marsh (Smith 1996a); Salt Marsh (Nelson 1986); Brackish Marsh, in part (Nelson 1986); Smooth Cordgrass Series, in part (Diamond 1993); Smooth Cordgrass Marsh (Wharton 1978); Estuarine Intertidal: Salt Marsh (Swain and Kearsley 2001); Estuarine Intertidal: Brackish Tidal Marsh (Swain and Kearsley 2001)

References: Cowardin et al. 1979, Diamond 1993, Eleuterius 1972, FNAI 1992a, Kurz and Wagner 1957, Montague and Wiegert 1990, Nelson 1986, Odum 1988, Schafale and Weakley 1990, Smith 1996a, Swain and Kearsley 2001, Tiner 1977, Wharton 1978, Wieland 1994a, Wieland 1994b

Authors: D.J. ALLARD, JT, East Identifier: A.1471

Concept: This oligohaline brackish marsh occurs in the mid-tidal range of tidal rivers in Delaware and Maryland. The dominant species are Spartina alterniflora and Amaranthus cannabinus, with other associates, such as robustus (= Scirpus robustus), Spartina patens, and Atriplex prostrata, occurring infrequently. The shrub Baccharis halimifolia sometimes occurs at low cover.

Comments: This association contains perennials with Spartina alterniflora as a strong component, whereas Amaranthus cannabinus Tidal Herbaceous Vegetation (CEGL006080) is dominated by annuals. However, the types may reflect seasonal variation within freshwater tidal marsh systems and be similar enough to warrant merging. Spartina alterniflora - Lilaeopsis chinensis Herbaceous Vegetation (CEGL004193) occurs along oligo- to mesohaline reaches of large tidal rivers (Delaware River, Connecticut River), whereas this association occurs along smaller tidal rivers and creeks.

Range: Currently described from Maryland and Delaware.

States/Provinces: DE:S?, MD:S?

TNC Ecoregions: 58:C

USFS Ecoregions: 232Bt:CCC

References: Bowman 2000

Authors: P. Bowman, ECS Confidence: 2 Identifier: CEGL006417

Concept: This oligohaline to mesohaline marsh occurs in silty mud along meanders in tidal rivers and creeks where there is significant freshwater seepage. It is often adjacent to uplands. The taxonomic relationship of this type has not been fully assessed. The vegetation is diverse and is codominated by Spartina alterniflora, Ptilimnium capillaceum, and Polygonum punctatum. Other associates include Pluchea odorata, Bidens coronata, Kosteletzkya virginica, Eleocharis parvula, Cyperus filicinus, Hibiscus moscheutos, Amaranthus cannabinus, Eleocharis palustris, Asclepias incarnata, Sium suave, Schoenoplectus tabernaemontani (= Scirpus tabernaemontani), Schoenoplectus americanus (= Scirpus americanus), Schoenoplectus robustus (= Scirpus robustus), Echinochloa walteri, Typha angustifolia, Peltandra virginica, Pontederia cordata, Lobelia cardinalis, and Sagittaria latifolia.

Comments: The taxonomic relationship of this type has not been fully assessed. It differs from Spartina alterniflora - Lilaeopsis chinensis Herbaceous Vegetation (CEGL004193) and Spartina alterniflora - Amaranthus cannabinus Herbaceous Vegetation (CEGL006417) by having greater species diversity presumably from the freshwater seepage input.

Range: Currently described from Delaware and Maryland.

States/Provinces: DE:S?, MD:S?

TNC Ecoregions: 58:C

USFS Ecoregions: 232Bt:CCC, 232Bx:CCC

References: Bowman 2000

Authors: P. Bowman, ECS Confidence: 3 Identifier: CEGL006418

Concept: This tall grassland dominated by Spartina alterniflora forms the low salt marsh of the north and mid-Atlantic coast. It is diurnally flooded by tides, occurring in the intertidal zone between mean high tide and mean sea level in protected inlets behind barrier beaches or in the seaward reaches of drowned river valleys. It forms a coarse peat over sandy substrate. The low salt marsh occurs elevationally between high marsh that occurs landward and subtidal communities that occur seaward. Spartina alterniflora is limited to the low marsh zone by interspecific competition and by moderate salinity; it can withstand longer submergence than other salt marsh grasses but still requires periodic exposure of the substrate. Spartina alterniflora forms nearly monotypic stands with little variation across the geographic range of the community.Tall form Spartina alterniflora occurs adjacent landward. Associated species occur in low abundance and commonly include Limonium carolinianum, Salicornia virginica, Salicornia bigelovii, Spergularia maritima, Spergularia canadensis, and Suaeda maritima. Brown algae can form extensive mats at the bases of the grass culms, especially Ascophyllum nodosum, Fucus vesiculosus, Enteromorpha spp., and Ulva spp. Macroalgae associates may be sparse or absent at the southern edge of the range. This community occurs from Nova Scotia to Cape Hatteras, North Carolina. Low marshes at the northern edge of the geographic range are far less extensive in size than those farther south due to differences in geomorphology and time since last glaciation.

Comments: The northern limit of this type occurs where there is a slower accumulation of silt and corresponding absence of algal species (Chapman 1937). The southern limit corresponds with the southern limit of the Virginian province of the American Atlantic Temperate Region, a transitional area harboring animal species of both southern and northern affinities (Gosner 1979, Cowardin 1979). Southern occurrences, where Ascophyllum nodosum may be sparse or absent, are placed within this type because of the associated characteristic faunal assemblage, including Uca pugnax, Littorina saxatilis, Littorina obtusata, and Brachidontes demissus. Analogous low salt marsh associations in other geographic areas include Spartina alterniflora Carolinian Zone Herbaceous Vegetation (CEGL004191) and Spartina alterniflora - Juncus roemerianus - Distichlis spicata Louisianian Zone Salt Tidal Herbaceous Vegetation (CEGL004190) for the Atlantic Coast of the southeastern U.S. (Cape Hatteras, North Carolina, to Florida) and the Gulf Coast (Florida to Texas), respectively (see Cowardin 1979 for regional boundaries). Spartina alterniflora - Lilaeopsis chinensis Herbaceous Vegetation (CEGL004193) is a Spartina alterniflora-dominated association occurring in the mid-tidal range of tidal rivers that have a minimum tidal range of one meter.

Range: This association occurs along the Atlantic coastline from Nova Scotia and New Brunswick south to Cape Hatteras, North Carolina.

States/Provinces: CT:S?, DE:S5, MA:S3, MD:S5, ME:S4, NB:S?, NC:S5, NH:S?, NJ:S5, NS:S?, NY:S3S4, RI:S?, VA:S?

TNC Ecoregions: 57:C, 58:C, 62:C, 63:C

USFS Ecoregions: 212Cb:CCC, 212Db:CCC, 212Dc:CCC, 221Ab:CCC, 221Ac:CCC, 221Ad:CCC, 221Ak:CCC, 232Aa:CCC, 232Ab:CCC, 232Ac:CCC, 232Ad:CCC, 232Ae:CCC, 232Br:CCC, 232Bt:CCC, 232Bx:CCC, 232Bz:CCC, 232Ch:CCC, 232Ci:CCC

Federal Lands: NPS (Acadia, Assateague Island, Fire Island)

Synonymy: Salt marsh (Higgins et al. 1971) B. Assateague Island., Salt marsh community (Hill 1986) B. Assateague Island., Salt marsh complex, low marsh (Breden 1989). New Jersey., Spartina alterniflora salt marsh (Clancy 1993b). Delaware., Low salt marsh (Reschke 1990). New York., Cordgrass saltmarsh community (MENHP 1991). Maine., Low salt marsh (Enser 1993). Rhode Island., Low salt marsh community (Sperduto 1994). New Hampshire., Salt Marsh (Virginian Subtype) (Schafale 2000), Salt Marsh (Rawinski 1984). formerly Southern New England and Gulf of Maine Salt Marshes., Spartina alterniflora community (Metzler and Barrett 1992). Connecticut.

References: Adams 1963, Bertness 1988, Bowman 2000, Breden 1989, Breden et al. 2001, Chapman 1937, Clancy 1993b, Cowardin et al. 1979, Edinger et al. 2002, Enser 1993, Enser 1999, Fleming et al. 2001, Gawler 2001, Gawler 2002, Gosner 1979, Higgins et al. 1971, Hill 1986, MENHP 1991, Metzler and Barrett 1992, Metzler and Barrett 2001, Moul 1973, Rawinski 1984, Reschke 1990, Schafale 2000, Schafale and Weakley 1990, Sperduto 1994, Sperduto 2000b, Swain and Kearsley 2001, Teal 1986

Authors: S.L. Neid, ECS Confidence: 1 Identifier: CEGL004192

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

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