Discharge Slope Ecosystem Map Component SC

Wetland Classification and Mapping of the Kenai Lowland, Alaska

Map Unit Descriptions

Ecosystem: Discharge Slope

Map Component: SC; SCd

Extent: 31 wetland polygons; 192.2 ha; 0.14% of wetland area; 0.19% of wetland polygons.

An SC wetland near the Village of Nikolaevsk (polygon 7214).

Wetland Indicators

Type: Mineral or Peat

Average depth to water table: 54.8 cm; n=5

Organic layer thickness: 39.1 cm; n=7

Average depth to redoximorphic features: 17.2 cm; n=6

Common Soils: BELUGA, NIKOLAI, KALIFONSKY

Common Plant communities:

Bluejoint - Field horsetail

Bluejoint streamside

Barclay willow / Rich

NWI: PEM1Bn,g

HGM: Terrene Slope groundwater-dominated Throughflow

Accuracy assessment: 3 polygons interpreted as SC on aerial photographs were field checked. They all remained SC.

SC is a Discharge Slope Ecosystem map component dominated by a bluejoint grass (Calamagrostis canadensis). SC units are uncommon, although many of the bluejoint grass fields on the foot and toeslopes of the Homer Bench are SC wetlands. Bluejoint may or may not indicate disturbance, and usually indicates a mineral soil, rather than peat, or groundwater in recent contact with a mineral source.

A slope covered with bluejoint grass can be upland, or very wet. The presence of field horsetail (Equisetum arvense), or marsh horsetail (E. palustre) mixed in with the tall bluejoint, is a good indicator that the site meets the regulatory wetland criteria defined in the 1987 Army Corps of Engineers Delineation Manual.

In Homer, the name SCd refers to a wetland that was SC but is now disturbed.