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Wetland Classification and Mapping of the Kenai Lowland, Alaska
Map Unit Descriptions Ecosystem: Relict Glacial Drainageway Map Units: DW2-5A; DW5A2; DW2-5; DW25; DW25A; DW52 (DW2-5A complexes)
Extent: DW2-5A: 23 wetland polygons; 257.6 ha; 0.18% of wetland area; 0.14% of wetland polygons. DW5A2: 20 wetland polygons; 228.3 ha; 0.16% of wetland area; 0.12% of wetland polygons. DW2-5: 12 wetland polygons; 96.7 ha; 0.07% of wetland area; 0.07% of wetland polygons. DW25: 10 wetland polygons; 107.9 ha; 0.06% of wetland area; 0.08% of wetland polygons. DW25A: 9 wetland polygons; 61.5 ha; 0.04% of wetland area; 0.05% of wetland polygons. DW52: 5 wetland polygons; 49.2 ha; 0.03% of wetland area; 0.03% of wetland polygons. |
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 A mixed DW2-5 unit north of Happy Valley (polygon 2209).
A segregated DW25 unit near Kasilof (polygon 9829).
A mixed DW2-5A unit near Ninilchik (polygon 2208). |
Wetland Indicators Type: Primarily Peat, occasionally with mineral soil at the margins Average depth to water table: DW2: 14.9; n=25 DW3: 32.1 cm; n=36 DW4: 53.3 cm; n=4 DW5: 37.4 cm; n=14 DW5A: 38.8 cm; n=24 Organic layer thickness: DW2: 132.2 cm; n=25 DW3: 102.2 cm; n=40 DW4: 68.6 cm; n=4 DW5: 78.2 cm; n=14 DW5A: 46.3 cm; n=24 Average depth to redoximorphic features: DW2: 97.0 cm at the single site measured DW3: 67.8 cm; n=6 DW4: 70.0 cm at the single site measured DW5: 135.0 cm at the single site measured DW5A: 60.7 cm; n=3 Common Soils: DW2: SALAMATOF, STARICHKOF DW3: STARICHKOF, NIKOLAI, DOROSHIN, SLIKOK, COAL CREEK DW4: STARICHKOF, NIKOLAI, KALIFONSKY DW5: NIKOLAI, STARICHKOF, TRUULI DW5A: TRUULI, NIKOLAI, STARICHKOF, 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 Sweetgale – Shrubby cinquefoil DW4 component:
DW5 component: Sphagnum moss - Ericaceous shrub Lutz spruce / Barclay's willow / Field horsetail / Crowberry DW5A component: Lutz spruce / Barclay's willow / Field horsetail / Crowberry |
| Accuracy
assessment: 3 polygons interpreted as DW5A2 on aerial photographs were
field checked. 1 remained DW5A2, 2 were revised to DW2-5A.
3 polygons interpreted as DW2-5A on aerial photographs were field checked. 2 remained DW2-5A, one was revised to DWR. The single polygon interpreted as DW2-5 on aerial photographs that was field checked remained DW2-5. The single polygon interpreted as DW25A on aerial photographs that was field checked was revised to DWR. 2 polygons interpreted as DW25 on aerial photographs were visited, 1 was revised to DW2-5A, the other to DW2. 3 polygons interpreted as DW52 on aerial photographs were field checked. None of them remained DW52. 1 each was revised to: DW35, LB2-4 and LB46. |
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These uncommon complexes are composed of either of two types: 1) nearly all the Relict Glacial Drainageway components except the wettest component (DW1), which contains standing, flowing water, and, in some complexes, the forested component (DW5A) segregated into roughly parallel bands, or 2) as a microtopographically diverse mix of a wet sedge component (DW2) with a drier component, either in the understory of a forest (DW5A) or with a shrubby deep sphagnum mat (DW5).
The first is most typically found on narrower drainageways where the components occur together on a scale too small to delineate, the second can occupy narrow or broad drainageways.
Anywhere, the components can be intermixed or segregated in roughly parallel bands. Typically they are mixed when the wetlands are encountered along modern 'underfit' streams, and segregated when found along relict features. Relict drainageway features with these map components are more common north of Clam Gulch.
