Estuarine Intertidal Organic: Partly Enclosed, Backshore, Polyhaline (Marsh)

This habitat is intermediate between true low and high marsh. Salinities as high as 28 ppt have been measured. It can occur as a band between high and low marsh, along the edges of tidal sloughs, or in slight depressions in the high marsh.

Diagnostic Species

Two commonly occurring marsh communities in this habitat are:  (1) Deschampsia caespitosa-Distichlis spicata, and (2) Deschampsia caespitosa-Distichlis spicata-Salicornia virginica.  The first community appears to occur at slightly lower salinities and higher elevations than does the second.  Some infrequently occurring assemblages also fall into this intermediate habitat: (3) Potentilla pacifica, (4) Grindelia integrifolia, and (5) Juncus gerardii dominated areas.

Common Associates

Deschampsia caespitosa-Distichlis spicata community can have no associates or any of the following: Atriplex patula, Triglochin maritimum, Juncus balticus, Hordeum spp.

Deschampsia caespitosa-Distichlis spicata-Salicornia virginica has several associates: Carex lyngbyei, Glaux maritima, Grindelia integrifolia, Jaumea carnosa, Triglochin maritimum, Juncus balticus, Juncus gerardii, Atriplex patula and Potentilla pacifica.

Sites Surveyed

Pysht River, Salt Creek, Lynch Cove, Nisqually River Delta, Skookum Inlet.


Kunze, 1984; Kunze and Cornelius, 1982; Burg, 1980; Frenkel, Boss and Schuller, 1978; Jefferson, 1975.