TM_Tidal MarshTM-Tidal Marsh.
This land type is on the nearly level flats between the coastal dunes and the interior uplands and along
the Cape Fear River near Wilmington. Many areas are flooded daily by tides. Further inland the seawater
is diluted with freshwater. Some areas are protected from the seawater by long expanses of sand dunes
that do not have inlets from the ocean. The water table is at or above the surface most of the time. Most
of the acreage is used as natural habitat for shore and water birds, and some areas are used for shellfish
gardens. Many areas are being dredged, filled, and converted to summer cottage sites and recreational
areas. The dominant vegetation in areas that are flooded daily by saltwater is smooth cordgrass. Further
inland, in areas that are flooded by seawater that has been diluted by freshwater, the vegetation is a
mixture of smooth cordgrass and black rush.
Typically, the surface layer is black clay loam about 18 inches thick. The underlying layer is very dark gray
and black silty clay loam to a depth of more than 60 inches.
Included with these soils in mapping are areas along the Intracoastal Waterway that are sandy because
of the deep dredging.
The organic-matter content of the surface layer is high. Reaction is neutral to mildly alkaline. In the areas
flooded by saltwater, sulfur content is 80 to 130 parts per million and salt content is 1 or 2 percent.
Capability subclass Vlllw; woodland group not assigned.