LOCATION STRELNA                 AK

Established Series
Rev. MHC/JPM/DLM
02/2022

STRELNA SERIES

Depth class: shallow, permafrost is in the loess layer within 10 inches of the mineral surface
Drainage class: well drained
Parent material: loess over variable material including glacial till, lacustrine deposits and bedrock
Landform: hill slopes and stable escarpment slopes
Slopes: 7 to 50 percent
Mean annual temperature: 23 to 27 degrees F.
Mean annual precipitation: about 14 inches

TAXONOMIC CLASS:

TYPICAL PEDON: Strelna peat on a 32 percent slope under white spruce forest at 1800 feet elevation. When described, the soil was moist throughout.

Oi--0 to 13 inches; very dark brown (10YR 2/2) peat consisting of slightly decomposed moss, twigs, and root fibers; thin horizontal lenses of weak red (2.5YR 4/2) silt loam; gradual smooth boundary. (6 to 10 inches thick)

Oa/Ajj--13 to 17 inches; black (10YR 2/1) mucky peat consisting of highly decomposed organic material with streaks and patches of very dark brown (10YR 2/2) and dark brown (10YR 3/3) mucky silt loam; weak thin platy structure; very friable, nonsticky and nonplastic; many roots of all sizes; neutral (pH 6.8); clear smooth boundary. (2 to 8 inches thick)

A/Cjj--17 to 27 inches; very dark brown (10YR 2/2) mucky silt loam with streaks and patches of black (10YR 2/1) and dark brown (10YR 3/3); weak medium subangular blocky structure separating horizontally along prominent color bands; very friable, nonsticky and nonplastic; neutral (pH 6.8); abrupt wavy boundary. (0 to 12 inches thick)

A/Cjjf--27 to 57 inches; very dark brown (10YR 2/2) mucky silt loam with streaks and patches of black (10YR 2/1) and dark brown (10YR 3/3); frozen on August 10, 1983.

TYPE LOCATION: Copper River Area, Alaska; 11 miles east of Chitina, 1000 feet north and 400 feet east of the SW corner of section 16, T. 4S., R. 7E., Copper River Meridian.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature is less than 32 degrees F.
Diagnostic: non saturated fibrous moss over partially decomposed moss, twigs, and root fibers and ranges from 0 to 40 inches thick
Depth to permafrost: surface of the mineral soil to 10 inches, two months after the summer solstice
Loess mantle: 16 to over 40 inches thick from mineral soil surface
Particle size control section: less than 18 percent clay and less than 15 percent fine sand or coarser including gravel
Coarse fragments: 0 to 15 percent.
Texture of the material below the control section: silt loam, silt, fine sandy loam, silty clay loam, silty clay, or clay
Reaction in the mineral soil: slightly acid to mildly alkaline
Base saturation: 60 to 95 percent.

O/A horizon:
Matrix color: hue of 7.5YR or 10YR; value of 2 to 4; chroma of 1 to 3.
Texture: highly stratified mineral and highly decomposed organic material, mucky silt, and mucky silt loam in dark organic strata, silt loam, silt; very fine sandy loam in the lighter colored mineral strata
Organic carbon content: greater than 12 percent
Loess strata: typically parallel to the soil surface, often discontinuous, or churned

A/C horizons:
Matrix color: hue of 7.5YR or 10YR; value of 2 to 4; chroma of 1 to 3
Texture: silt loam, mucky silt loam, silt, very fine sandy loam, and occasional decomposed organic material
Loess strata: parallel to the soil surface, may be offset, discontinuous, or churned

COMPETING SERIES: These are the Goldstream, Saulich, Turbellina, and Windy Creek series. Goldstream, Saulich, Turbellina, and Windy Creek soils have gleyed colors and lack mollic epipedons.

GEOGRAPHIC SETTING:
Depth class: shallow, permafrost is in the loess layer within 10 inches of the mineral surface
Drainage class: well drained
Parent material: loess over variable material including glacial till, lacustrine deposits and bedrock.
Landform: hill slopes and stable escarpment slopes
Slopes: 7 to 50 percent
Mean annual temperature: 23 to 27 degrees F.
Mean annual precipitation: about 14 inches
Climate: subarctic continental with long, cold winters and short, warm summers. Snowfall: 39 to 68 inches
Mean January temperature: minus 10 degrees F
Mean July temperature: 56 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Copper River, Narelna(P), and Taral(P) soils. Copper River soils have saturated conditions above the permafrost and are on slopes of less than 20 percent. Narelna and Taral soils are thawed counterparts of Strelna and occur on the same landforms.

DRAINAGE AND PERMEABILITY: well drained runoff is high. Saturated hydraulic conductivity is moderately high or high above the permafrost and very low in the permafrost. Fire or clearing removes the insulating organic mat and results in lowering of the permafrost level. Textural variability in thawed substratums results in extreme variability in permeability rates.

USE AND VEGETATION: Strelna soils have native vegetation of black spruce, white spruce, and paper birch. The successional state of the vegetation in a given area is closely related to the fire history. This soil is used primarily 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 profile include:
Folistic epipedon: 0 to 13 inches
Mollic epipedon: 17 to 57 inches
Permafrost: 27 to 57 inches
Mean annual soil temperature: less than 0 degrees C.
Particle size control section: 10 to 40 inches from the surface of the mineral soil surface and permafrost at 27 inches.

The Narelna and Taral series are recognized for pedons in which the organic mat has been burned or mechanically cleared. In these pedons the permafrost has dropped below the series control section. These series reflect the nature of the substratum materials.

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National Cooperative Soil Survey
U.S.A.