LOCATION WRANGELL                AK

Established Series
Rev. MHC/JPM
02/2022

WRANGELL SERIES

The Wrangell series consists of very poorly drained soils formed in organic materials overlying clayey lacustrine sediments. Permafrost is present at 14 to 38 inches below the organic soil surface. Wrangell soils are in depressional areas on broad lacustrine terraces. Slopes range from 0 to 2 percent. Mean annual temperature is about 26 degrees F., and mean annual precipitation is about 12 inches.

TAXONOMIC CLASS: Mixed, euic, subgelic Terric Hemistels

TYPICAL PEDON: Wrangell peat - on a 0 percent slope under low shrubs, sedges and grasses. When described, the soil was wet throughout. Percent fiber is by field estimate.

Oi--0 to 4 inches; dark reddish brown (5YR 2.5/2, moist) peat consisting of undecomposed sedges, roots and ericaceous shrub fibers; 90 percent fiber unrubbed, 75 percent rubbed; many very fine, fine, and medium roots; moderately acid (pH 6.0); clear irregular boundary. (3 to 10 inches thick)

Oe--4 to 23 inches; dark reddish brown (5YR 2.5/2, moist) mucky peat consisting of partially decomposed sedges, roots and ericaceous shrub fibers; 70 percent fiber unrubbed, 50 percent rubbed; common very fine, fine and medium roots; slightly acid (pH 6.2); abrupt wavy boundary. (4 to 26 inches thick)

Cg1--23 to 30 inches; dark greenish gray (5GY 4/1) silty clay with common medium distinct dark yellowish brown (10YR 4/4) mottles; massive; very sticky and very plastic; slightly alkaline (pH 7.6); gradual smooth boundary. (0 to 14 inches thick)

Cg2--30 to 37 inches; olive gray (5Y 4/2) silty clay with common medium distinct dark greenish gray (5GY 4/1) mottles; massive; very sticky and very plastic; moderately alkaline (pH 8.0); abrupt wavy boundary. (0 to 10 inches thick)

Cf--37 to 47 inches; olive gray (5Y 4/2) silty clay; moderately alkaline (pH 8.0); frozen August 22, 1984.

TYPE LOCATION: Copper River Area, Alaska; about 3 miles SW of Gakona; 600 feet south and 300 feet west of the NW corner of section 6, T.5N., R.1W., Copper River Meridian.

RANGE IN CHARACTERISTICS: The mean annual soil temperature is less than 32 degrees F. The mat of organic material consists of fibrous over partially decomposed moss, sedge and ericaceous shrub fibers 18 to 33 inches thick. Depth to permafrost ranges from 14 to 38 inches below the surface two months after the summer solstice. Saturated conditions typically occur within 8 inches of the surface. Mineral soil textures in the lower part of the control section include clay,silty clay clay loam and silty clay loam. Clay content ranges from 35 to 70 percent. Reaction is medium acid to neutral in the organic horizons and slightly alkaline or moderately alkaline in the underlying mineral horizons.

The O horizons have moist hue of 2.5YR, 5YR, 7.5YR, or 10YR; moist value of 2 or 2.5; and moist chroma of 1 or 2.

The C horizons have moist hue of 2.5Y, 5Y, 5GY, or 5G; moist value from 3 to 5; and moist chroma from 1 to 3. Textures include clay, silty clay, silty clay loam or clay loam. Coarse fragment content ranges from 0 to 20 percent gravel and cobble.

COMPETING SERIES: This is the Bolio series in the same subgroup. Bolio soils have pH less than 4.5 (0.01M CaCl2) in the organic materials within the control section.

GEOGRAPHIC SETTING: Wrangell soils are in depressions on broad lacustrine terraces. Slopes are level or slightly concave with gradients of less than 2 percent.

The climate is subarctic continental with long, cold winters and short, warm summers. Mean annual precipitation ranges from 8 to 17 inches and the mean annual snowfall ranges from 39 to 68 inches. Mean January temperature is minus 10 degrees F., mean July temperature is 56 degrees F., and the mean annual temperature ranges from 23 to 27 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Klawasi soils which are mineral soils on slightly higher positions on broad lacustrine terraces.

DRAINAGE AND PERMEABILITY: Very poorly drained. Runoff is slow. Permeability is moderately rapid in the organic mat, moderately slow in the mineral soil, and impermeable in the permafrost. Typically, free water is present within 8 inches of the surface.

USE AND VEGETATION: Most areas of Wrangell soils are in native vegetation of ericaceous shrubs, sedges, and grasses. Primarily used for wildlife habitat.

DISTRIBUTION AND EXTENT: Copper River Basin, Alaska. The series is of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA

SERIES ESTABLISHED: Copper River Area, Alaska. 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon include: organic materials from 0 to 23 inches with hemic material from 4 to 23 inches; mineral soil in the lower part of the subsurface tier; permafrost at 37 inches with saturated conditions above the permafrost; pH of the organic materials are greater than 4.5 (0.01M CaCl2).

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National Cooperative Soil Survey
U.S.A.