Wetland Classification and Mapping of Seward, Alaska     Map Unit Descriptions   Ecosystem: Tidal   Map Unit: T65   Seward Area Extent: 2 wetland polygons; 42.0 acres

T6 is represented by the dense, uniform Lyngbye sedge stand in the foreground of this photo, and T5 by the pools behind.  Taken at the head of Resurrection Bay.

Wetland Indicators Type: Tidal Average depth to water table: Varies with tidal stage Organic layer thickness: not measured Average depth to redoximorphic features: not measured Common Soils: probably Oxyaquic Cryofluvents and Typic Cryaquents Common Plant communities: Lyngbye's sedge (Carex lyngbyei) Open water pools Ramensk's sedge (Carex ramenskii)

 

Both T65 wetlands are large areas where Lyngbye Sedge and open water pools are mixed together at a scale too fine to map separately at the scale of 1:25,000.  They are both found on the Resurrection River delta, at the head of Resurrection Bay.

 

T6 wetlands are dominated by Lyngbye's sedge (Carex lyngbyei).  They are found in the upper sedge marsh zone in the upper reaches of estuaries.  Monotypic stands are common.  T6 corresponds with Vince and Snow's (1984) 'Inner Sedge Marsh Zone 7', estimated to be inundated on only the highest spring tides, or an average of 2 times per summer on the Susitna Flats (with a range of 0-5 times per summer), in upper Cook Inlet, Alaska.  Vince and Snow found that water was retained for greater than 5 days per inundation. 

 

T5 corresponds with Vince and Snow's (1984) 'Outer Sedge Marsh Zone 3', estimated to be inundated on only the highest spring tides, or an average of 3 times per summer on the Susitna Flats (with a range of 0-5 times per summer), in upper Cook Inlet, Alaska.  Vince and Snow also found that water was retained for 2-3 days per inundation.  Pools with common mare's tail (Hippuris vulgairs) and saltmarsh starwort (Stellaria humifusa) are frequently encountered within this zone; and between it and the landward Lyngbye's sedge (Carex lyngbyei) zone (T6).  The rare plant, Kamchatka spikerush (Eleocharis kamchatica) is sometimes encountered in the T5 zone around Cook Inlet.  In the more restricted tidal range of Resurrection Bay (compared to Cook Inlet), open mudflats are usually found seaward.