Figure 3, Upper zone of saltmeadow cordgrass (foreground) and 

 lower zone of smooth cordgrass (background) (Maine). 



Marshes in the mid-Atlantic region undergo subtle changes from the north 

 Atlantic type on Long Island to the south Atlantic type at the Virginia Capes . 

 To the north there are relatively limited areas of smooth cordgrass with the 

 greatest area covered by saltmeadow cordgrass. Localized high salinity 

 patches are dominated by pickleweed {Saliaormia spp.). Big cordgrass 

 {Spavtina aynosuvoides) and several rushes (So'tvpus spp.) occur along creeks 

 and tidal stream mouths where the freshwater influence is greater. Black 

 needle rush increases in importance near the mouth of the Chesapeake Bay. The 

 tall form of smooth cordgrass appears along creek banks. 



South of the Chesapeake Bay, the south Atlantic marshes typically form 

 behind barrier beaches and in estuaries where rivers deposit heavy silt 

 burdens. Smooth cordgrass occupies vast areas of mostly soft sediments between 

 mean sea level (MSL) and mean high water (MHW) . Large areas of high marsh, 

 primarily black needle rush, occur where astronomical tides are restricted and 

 wind setup predominates, e.g., in Pamlico Sound, North Carolina. South of 

 Daytona Beach, Florida, (peninsular Florida), the typical south Atlantic 

 marshes are largely replaced by mangrove trees that form the tropical and 

 subtropical equivalent of salt marshes. Marshes of the south Atlantic type 

 occur on the gulf coast with the largest expanses on the Mississippi River 

 delta. Smooth cordgrass occupies the areas regularly flooded by saltwater 

 with a brackish marsh of saltmeadow cordgrass, big cordgrass, saltgrass, and 

 black needle rush covering vast areas. Gulf cordgrass (Spavtina spavtinae) 

 replaces saltmeadow cordgrass above MHW on fine-textured soils along the 

 coasts of Texas and southwestern Louisiana. Hypersaline conditions in the 

 Laguna Madre (Corpus Christi to Brownsville, Texas), due to limited rainfall 

 and high temperatures, largely exclude coastal marshes from the south Texas 



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