Wetland Classification and Mapping of the Kenai Lowland, Alaska
Map Unit Descriptions
Ecosystem: Tidal
Map Unit: T2-4; T42; T23; T32
Extent:
T2-4: 2 wetland polygons; 10.5 ha; 0.01% of wetland area; 0.01% of wetland polygons.
T42: 2 wetland polygons; 5.9 ha; 0.00% of wetland area; 0.01% of wetland polygons.
T23: 2 wetland polygons; 1.5 ha; 0.00% of wetland area; 0.01% of wetland polygons.
T32: 2 wetland polygons; 1.5 ha; 0.00% of wetland area; 0.01% of wetland polygons.
 A T2-4 wetland at the base of the Homer Spit (polygon 50600).
A T42 wetland along the northeast side of the Homer Spit (polygon 50706).
A T23 wetland in Mariner Lagoon, at the base of the Homer Spit (polygon 50617). |
Wetland Indicators Type: Tidal Average depth to water table: T2: n/a T3: at least 150 cm; n=1 T4: 114 cm; n=4 Organic layer thickness: T2: n/a T3: 23.5; n=2 T4: 25.5; n=2 Average depth to redoximorphic features: T2: n/a T3: 0.0; n=2 T4: 0.2 cm; n=5 Common Soils: CLUNIE Common Plant communities: T2 Component: T3 Component: Marsh arrowgrass – Seaside arrowgrass T4 Component: |
These uncommon lower tidal wetlands primarily occur adjacent to the Homer Spit. A single T2-4 complex occurs near the mouth of the Kasilof River. These complexes are composed of the lower vegetated Tidal Ecosystem map components from mud flats with creeping alkaligrass (T2), to goosetongue edges (T3), to Hultén's and Nootka alkaligrass (Puccinellia hulténii and P. nukaënsis) on broad, low levees (T4).
Individual plants often segregate according to tidal flooding frequency and duration. Intermediate zones are occasionally encountered, and a mix of plants is found in these locations. When all three components are found, the complex is named T2-4, otherwise complexes are named according to which plants dominate.
The goosetongue and arrowgrass components (T3) often occur adjacent to tidal guts, and flood frequently (8 times per summer- retaining water for 2-3 hours per inundation on the Susitna Flats (Vince and Snow, 1984)); while alkaligrass components (T4) flood somewhat more frequently (15 times per summer), and retain water longer (2-5 days). The creeping alkaligrass (T2) component floods frequently (34 times per summer) and retains water for 4-5 hours per inundation.
Although Vince and Snow list Nutka alkaligrass in a position that floods more frequently and retains water longer than goosetongue and arrowgrass, when these plants occur together in protected estuaries on the Kenai Lowlands, Nutka alkali grass occupies a higher position.
