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Classification and Mapping of the Kenai Lowland, Alaska
Map Unit Descriptions Ecosystem: Depression Map Unit: D1-4; D14
Extent: D1-4: 35 wetland polygons; 87.3 ha; 0.06% of wetland area; 0.21% of wetland polygons. D14: 2 wetland polygons; 3.9 ha; 0.00% of wetland area; 0.01% of wetland polygons. |
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 A segregated, concentric D1-4 depression with a central pool (D1) ringed by a sweetgale - sedge community (D2), then a sphagnum moss - round sedge plant community (D3), and a black spruce forest (background, D4) near Soldotna (polygon 623). |
Wetland Indicators Type: Peat or mineral soil Average depth to water table: D1: open water D2: 6.8 cm; n=5 D3: 10.0 cm n=1 D4: 55.5cm, n=11 Organic layer thickness: D1: open water D2: 6.8 cm; n=5 D3: 10.0 cm n=1 D4: 85.8cm; n=17 Average depth to redoximorphic features: D1-3: n/a D4: 24.3 cm; n=3 Common Soils: STARICHKOF, TRUULI, SPENARD, NIKOLAI, DOROSHIN Common Plant communities: D1 component: Sphagnum moss - Creeping sedge D2 component: Tall cottongrass - Livid sedge Beaked sedge – Water horsetail D3 component: D4 component: Black spruce / Woodland horsetail - Labrador tea |
| Accuracy assessment: None of the polygons interpreted as D1-4 or D41 on aerial photographs were field checked. | |
D1-4 wetlands are small and uncommon, and primarily occur north of Clam Gulch. They inconspicuous on the range map above. They are a combination of all the Depression map components from open water emergent (D1) through sedge communities (D2) and shrub communities (D3) to forests / woodlands (D4). The components are almost always arranged in concentric rings, with a pond or pool in the center surrounded by the sedge, then shrub (or bluejoint), then forested components transitioning to upland.
The single, unvisited, D14 unit, near Kasilof, has an open forest on a short terrace ringing a pond. Often, the forested transition from the edge of the depression to upland is rapid and steep, thus too small to map at 1:25,000. Depressions are most common on younger glacial surfaces, such as the moraine between Nikiski and Sterling, and also east of Sterling.
