Map Unit Descriptions
Geomorphic Component: Discharge Slope
Map Units: SAC; SCA; SCAd
Extent:
SAC: 19 wetland polygons; 151.5 ha; 0.11% of wetland area; 0.12% of wetland polygons.
SCA: 19 wetland polygon; 115.1 ha; 0.08% of wetland area; 0.12% of wetland polygons.
 A wetland mapped as SCA east of Homer (polygon 33164).
A wetland mapped as SAC in the lower Fox River Valley, at the head of Kachemak Bay (polygon (32193). |
Wetland Indicators Type: Mineral or Peat Average depth to water table: SA: 24.2 cm; n=5 SC: 39.1 cm; n=7 Organic layer thickness: SA: 105.3 cm; n=6 SC: 39.1 cm; n=7 Average depth to redoximorphic features: SA: 30.8 cm; n=4 SC: 17.2 cm; n=6 Common Soils: SA: STARICHKOF, SPENARD, NIKOLAI, BELUGA SC: BELUGA, NIKOLAI, KALIFONSKY Common Plant communities: SA component:
SC component: |
Accuracy assessment: 2 polygons interpreted as SAC on aerial photographs were field checked. They both remained SAC. 2 polygons interpreted as SCA on aerial photographs were field checked. They both remained SCA. |
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Wetlands mapped as SCA and SAC are where alder (Alnus incana ssp tenuifolia) and bluejoint reedgrass (Calamagrostis canadensis) occur mixed together at toeslope landscape positions over areas receiving discharging groundwater. When bluejoint grass is in the understory of a alder stand the unit is named SA. To be named SAC or SCA, a segregated mosaic of alder and bluejoint is present at a scale too fine to map each component separately at the mapping scale. These wetlands are found almost exclusively at the foot- and toe-slopes of the bluffs along the north shore of Kachemak Bay. Alder and bluejoint in these wetlands are probably maintained by chronic natural soil disturbance supplied by the eroding bluffs (colluvial processes). If an organic layer is present it is usually not greater than 1 meter thick.
In Homer, the name SCAd refers to wetlands that were SCA but are now disturbed.
