LOCATION DOROSHIN AK

Established Series
Rev. KMO/JPM/DM
10/2001

DOROSHIN SERIES

The Doroshin series consists of very deep, very poorly drained soils that formed in organic material overlying loamy and gravelly sediments. Doroshin soils are in depressions on drainageways, outwash plains, along lake borders, and on footslopes affected by seepage. Slopes range from 0 to 20 percent. Mean annual temperature is about 32 degrees F., and the average annual precipitation is about 28 inches.

TAXONOMIC CLASS: Loamy, mixed, euic Terric Cryohemists

TYPICAL PEDON: Doroshin peat - at 350 feet elevation under bog vegetation. (All colors are for moist soil)

Oi--0 to 14 inches; dark reddish brown (5YR 3/2) peat; 90 percent fibers unrubbed, 75 percent fibers rubbed; 5 percent thin strata of mineral material; strongly acid, clear smooth boundary.

Oe1--14 to 24 inches; very dark grayish brown (10YR 3/2) mucky peat; 60 percent fibers unrubbed, 25 percent fibers rubbed; 5 percent thin strata of mineral material; strongly acid; clear smooth boundary.

Oe2--24 to 36 inches; very dark brown (10YR 2/2) mucky peat; 30 percent fibers unrubbed, 25 percent fibers rubbed; 10 percent thin strata of mineral material; strongly acid; abrupt smooth boundary.

2Cg--36 to 60 inches; dark greenish gray (5GY 4/1) silt loam; massive; friable; slightly sticky, nonplastic; strongly acid.

TYPE LOCATION: Anchorage Area, Alaska, about 1.2 mile west of Lower Fire Lake; in the NE1/4, SW1/4, Section 25, T.15N., R.2W., Anchorage B7SW Seward Meridian; UTM north 6805376 and UTM east 0363161, zone 6.

RANGE IN CHARACTERISTICS: Depth to mineral material ranges from 16 to 50 inches. The pH of the organic materials is 4.5 or greater (0.01M CaCl2) within some part of the control section. Strata of fibrous peat may occur at any depth. Thin strata of mineral material are common in the organic materials. The mineral substratum is dominantly silt loam lacustrine deposits with occasional strata of volcanic ash, sand, loamy sand, or gravel.

The O horizons have hue of 5YR to 10YR; value of 2 to 5; and chroma of 1 to 4. Reaction is very strongly acid or strongly acid.

The 2C horizon has gleyed hue of 7.5YR to 5Y, value of 3 to 7; and chroma of 1 to 4. Texture is silt loam, loam, loamy sand and sandy loam, modified by 0 to 25 percent gravel. Clay is less than 18 percent.

COMPETING SERIES: These are the Hewitt and Tepete series. Hewitt soils have more than 18 percent clay in the mineral underlying material. Tepete soils have continuous loose sand and gravel in the lower part of the control section.

GEOGRAPHIC SETTING: The Doroshin soils are in depressions on drainageways, outwash plains, along lake borders, and on footslopes affected by seepage. The soils formed in organic material over loamy and gravelly sediments. The climate is transitional with the average annual precipitation ranging from 14 to 29 inches. Mean annual air temperature ranges from 32 to 35 degrees F. Slopes range from 0 to 20 percent.

GEOGRAPHICALLY ASSOCIATED SOILS:

DRAINAGE AND PERMEABILITY: Very poorly drained. Ponded to medium runoff. The water table is at or near the surface from May through September. Permeability is moderately rapid in the organic materials and moderate in the mineral underlying material.

USE AND VEGETATION: The Doroshin soils are used for wildlife habitat and recreation. The native vegetation consists of mosses, sedges, willows, low-growing woody shrubs, and black spruce.

DISTRIBUTION AND EXTENT: Cook Inlet-Susitna Lowlands, Southcentral Alaska. The series is extensive.

MLRA OFFICE RESPONSIBLE: Anchorage, Alaska

SERIES ESTABLISHED: Kenai-Kasilof Area, Alaska, 1960.

REMARKS: Diagnostic horizons and features recognized in this pedon are: hemic material between 14 and 36 inches; continuous loamy material from 36 to 60 inches; pH is greater than 4.5 (0.01M CaCl2) in the control section. The Doroshin series was originally classified as Dysic. 

However, the pH of the organic matter is more than 4.5 (0.01M CaCl2) in at least part of the control section within each pedon.

National Cooperative Soil Survey
U.S.A.

Contact: Mike Gracz Kenai Watershed Forum  PO Box 15301 Fritz Creek, AK  99603 907-235-2218

04 May 2007 10:20