Name:
Spartina patens - (Distichlis spicata) Tidal Herbaceous Alliance
Reference:
Eastern Ecology Working Group of...
Description:
This alliance comprises "high salt marsh" vegetation dominated or codominated by Spartina patens along the Gulf and Atlantic coasts from Maine to Texas. The high salt marsh is irregularly flooded by tides and forms at slightly higher elevations than regularly flooded low marshes; they establish where peat accumulation raises the marsh surface above mean high tide. Landward the vegetation can transition to brackish marsh or upland vegetation. Vegetation of this alliance also occurs in mesohaline zones along lower reaches of tidal rivers. Variation in codominant species occurs across the geographic range. From the Canadian maritime provinces south to Delaware (discontinuously south to Virginia), this alliance is characterized by the dominance of Spartina patens, Distichlis spicata, and Juncus gerardii and the presence of more northerly distributed marsh species such as Puccinellia fasciculata, Plantago maritima, and Triglochin maritima. In brackish reaches of tidal rivers, this alliance includes Spartina patens-dominated vegetation that may also be characterized by the presence of Agrostis stolonifera, Festuca rubra, Symphyotrichum novi-belgii (= Aster novi-belgii), Hierochloe odorata, Carex paleacea, or Spartina pectinata. From Delaware south to Florida, this high salt marsh coastal community is dominated by Spartina patens, forming meadows at slightly higher elevations in relation to the adjacent Spartina alterniflora Tidal Herbaceous Alliance (A.1471). Diagnostic species for this community are Spartina patens, Distichlis spicata, Borrichia frutescens, Kosteletzkya virginica, and Pluchea odorata. Shrub seedlings such as Baccharis halimifolia and Morella cerifera (= Myrica cerifera) may also be present. The associated Juncus roemerianus Tidal Herbaceous Alliance (A.1475) often occurs as discrete patches which may reach substantial size. This alliance also includes mesohaline to oligohaline marshes of the Gulf Coast of Texas and Louisiana. In these associations, Spartina patens may strongly dominate, Distichlis spicata, Spartina alterniflora, and Spartina patens may codominate, Distichlis spicata may form pure stands, Paspalum vaginatum may strongly dominate, or Spartina patens and Vigna luteola may codominate. Other characteristic species include Juncus roemerianus, Spartina spartinae, Spartina cynosuroides (within its range), Schoenoplectus robustus, Schoenoplectus americanus, Sagittaria lancifolia, Phragmites australis, and Eragrostis spp. Here, this alliance forms mosaics with Spartina spartinae and Spartina alterniflora marshes and saline herbaceous vegetation. Western states have a different alliance for inland situations dominated by Distichlis spicata, the Distichlis spicata Intermittently Flooded Herbaceous Alliance (A.1332).
Accession Code:
VB.CC.18053.SPARTINAPATENSD
Plot-observations of this Community Concept:
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