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Wetland Classification and Mapping of the Kenai Lowland, Alaska
Map Unit Descriptions Ecosystem: Relict Glacial Drainageway Map Unit: DW34; DW43
Extent: DW34: 15 wetland polygons; 88.5 ha; 0.06% of wetland area; 0.09% of wetland polygons. DW43: 6 wetland polygons; 49.1 ha; 0.03% of wetland area; 0.04% of wetland polygons. |
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A segregated DW34 unit neat the Kasilof River (polygon 9232).
A mixed DW43 unit in the city of Kenai (polygon 8412). |
Wetland Indicators Type: Peat Average depth to water table: DW3: 32.1 cm; n=36 DW4: 53.3 cm; n=4 Organic layer thickness: DW3: 102.2 cm; n=40 DW4: 68.6 cm; n=4 Average depth to redoximorphic features: DW3: 67.8 cm; n=6 DW4: 70.0 cm at the single site measured Common Soils: DW3: STARICHKOF, NIKOLAI, DOROSHIN, SLIKOK, COAL CREEK DW4: STARICHKOF, NIKOLAI Common Plant communities: DW3 component: Sweetgale – Dwarf birch / Water horsetail Barclay's willow / Bluejoint / Marsh fivefinger Sweetgale – Shrubby cinquefoil DW4 component: |
| Accuracy assessment: The single polygon interpreted as DW43 on aerial photographs that was filed checked was revised to DW32. None of the polygons interpreted as DW34 on aerial photographs were field checked. | |
These uncommon map units are in Relict Glacial Drainageway Ecosystems dominated by bluejoint grass (Calamagrostis canadensis) (DW4) and shrubby hummocks (DW3), either intermixed or as separate more or less parallel linear features. The water table is close to the surface, and the microtopography is usually well-developed.
Where the components are intermixed, bluejoint tussocks are interspersed between shrubby hummocks. Where the units are segregated, a linear wetter medial shrub dominated component (usually the sweetgale- dwarf birch / water horsetail plant community) parallels a distal bluejoint band, which, in turn borders either an upland valley wall, or a broader forested unit (DW5A or discharge slope).
The bluejoint component (DW4) is not very common, and either indicates human disturbance or a mineral soil or shallow organic layer.
