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Wetland Classification and Mapping of the Kenai Lowland, Alaska
Map Unit Descriptions Ecosystem: Relict Glacial Drainageway Map Unit: DW32; DW23
Extent: DW32: 152 wetland polygons; 1092.9 ha; 0.77% of wetland area; 0.92% of wetland polygons. DW23: 135 wetland polygons; 1281.0 ha; 0.90% of wetland area; 0.82% of wetland polygons. |
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Polygon 8137, a DW23 unit northeast of the City of Kenai.
A DW32 unit in a large peatland complex near Cohoe Loop Road (polygon 887). |
Wetland Indicators Type: Peat Average depth to water table: DW2: 14.9 cm; n=25 DW3: 32.1 cm; n=36
Organic layer thickness:
DW2: 132.3 cm; n=25 DW3: 102.2 cm; n=40 Average depth to redoximorphic features: DW2: 97.0 cm at the single site measured DW3: 67.8 cm; n=6
Common Soils:
DW2: SALAMATOF, STARICHKOF DW3: STARICHKOF, NIKOLAI, DOROSHIN Common Plant communities: DW2 component: Water sedge / Marsh fivefinger Sphagnum moss - Creeping sedge
DW3 component:
Sweetgale – Dwarf birch / Water horsetail Barclay's willow / Bluejoint / Marsh fivefinger |
| Accuracy assessment: 26 polygons interpreted as DW32 on aerial photographs were field checked. 10 remained DW32, 5 were revised to DW2, 2 each were revised to DW4 and DW23, and 1 each was revised to: DW3, DW3-5, DW35A, DW52, DW55A, K2 and LB2-4. 24 polygons interpreted as DW23 on aerial photographs were filed checked. 16 remained DW23; 1 each was revised to: DW12, DW2, DW3, DW5, DW52, K32, LB21 and Rea. | |
DW23 complexes are common and widespread. They occur in Relict Glacial Drainageway Ecosystems dominated by sedges and shrubby hummocks, either intermixed or as separate more or less parallel linear features. The water table is close to the surface, and the microtopography is well-developed. These units are found in a variety of locales, from the margins of the upper reaches of major streams to shorter relict drainageways linking kettles on the northern lowlands. They also flow along the treads of the terraced moraines fronting the western Caribou Hills.
When sedges dominate, with the water table more uniformly close to the surface, the unit is named DW23; where the heterogeneous, hummocky, but still wet DW3 component is more abundant, the wetland is assigned DW32.
Where the two components are intermixed, the sedges are found in microtopographic-low spots frequently with ample standing water, and the shrubs on micro-highs. Where the two units are parallel, a complex with a wetter medial linear feature is fringed by parallel shrubby components.
