Wetland Classification and Mapping of the Kenai Lowland, Alaska
Map Unit Descriptions
Ecosystem: Tidal
Map Unit: T74; T74d
Extent:
T74: 1 wetland polygon; 24.0 ha; 0.02% of wetland area; 0.01% of wetland polygons.
T74d: 1 wetland polygon; 0.3 ha; 0.00% of wetland area; 0.01% of wetland polygons.
 The T74 wetland, near the mouth of the Kasilof River (polygon 22861).
The T74d wetland, on fill near the barge basin on the Homer Spit (polygon (50718). |
Wetland Indicators Type: Tidal Average depth to water table: T7: 22 cm; n=1 T4: 114 cm; n=4 Organic layer thickness: T7: n/a T4: 25.5 cm; n=2 Average depth to redoximorphic features: T7: 0 cm; n=1 T4: 0.2 cm; n=5 Common Soils: CLUNIE Common Plant communities: T4 Component:
T7 Component: |
T74 wetlands are beach berms dominated by beachrye (Lemus mollis ssp. mollis) (T7) and alkaligrass (Puccinellia spp.) (T4). Only two of these wetlands have been mapped, one near the mouth of the Kasilof river and the other on a human-disturbed berm near the barge basin on the Homer Spit. Both are berms dominated by beachrye, with smaller amounts of alkaligrass mixed in and around the lower fringes of the berm.
Beachrye (T7, Leymus mollis ssp. mollis) is found on coastal storm berms and higher riverbank levees. Vince and Snow (1984) describe 'Riverbank Levees' dominated by other grasses, and that "Still higher levees featured [Beachrye] and large forbs..." Their lower elevation riverbank levees flood an average of 1 time per summer; probably higher T7 beachrye berms or levees flood only when storms correspond with the highest spring tides.
T4 loosely corresponds with Vince and Snow's (1984) 'Outer Mudflats Zone 2', estimated to be inundated on higher spring tides, or an average of 15 times per summer on the Susitna Flats (with a range of 10-20 times per summer), in upper Cook Inlet, Alaska. Vince and Snow found that water was retained for 2-5 days per inundation.
