LOCATION HISNA                   AK

Established Series
Rev. MHC-JPM
05/2022

HISNA SERIES

The Hisna series consists of very deep, very poorly drained soils that formed in an organic mat overlying stratified loamy alluvium underlain by very gravelly and cobbly alluvium. Hisna soils are on floodplains. Slopes range from 0 to 6 percent. The mean annual temperature is about 26 degrees F., and the average annual precipitation is about 16 inches.

TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, nonacid Histic Cryaquepts

TYPICAL PEDON: Hisna peat-on a 1 percent slope under willow scrub at 2800 feet elevation. (All colors are for moist soil)

Oi--12 to 3 inches; black (10YR 2/1) peat with occasional lenses and strata of very dark grayish brown (10YR 3/2) sand and silt; many very fine, fine and medium roots; slightly alkaline (pH 7.8); clear smooth boundary. (5 to 9 inches thick)

Oe--3 inches to 0; dark yellowish brown (10YR 3/6) mucky peat; many very fine, fine and medium roots; slightly alkaline (pH 7.8); clear wavy boundary. (0 to 4 inches thick)

Ag--0 to 3 inches; dark greenish gray (5G 4/1 and 5GY 4/1) stratified fine sand through silt with composite texture of fine sandy loam; weak fine granular structure; very friable, nonsticky and nonplastic; many very fine, fine, and medium roots; moderately alkaline (pH 8.0); clear smooth boundary. (2 to 6 inches thick)

Cg--3 to 21 inches; dark greenish gray (5GY 4/1) stratified sand through silt with composite texture of sandy loam; weak medium subangular blocky structure; very friable, nonsticky and nonplastic; common very fine and fine roots; moderately alkaline (pH 8.0); abrupt wavy boundary. (8 to 20 inches thick)

2Cg--21 to 25 inches; dark greenish gray (5GY 4/1) extremely cobbly coarse sand; single grain; loose, nonsticky and nonplastic; 40 percent rounded gravel and 20 percent rounded cobble; few very fine and fine roots; moderately alkaline (pH 8.0); gradual smooth boundary. (0 to 14 inches thick)

2C--25 to 60 inches; variegated extremely cobbly coarse sand; single grain; loose, nonsticky and nonplastic; 40 percent rounded gravel and 20 percent rounded cobble; moderately alkaline (pH 8.0).

TYPE LOCATION: Gulkana River Area, Alaska; about 21 miles (34 kilometers) southwest of Paxson; the NW1/4 of the SE1/4 of section 5, T.13N., R.4W., Copper River Meridian.

RANGE IN CHARACTERISTICS: The organic mat ranges from 7 to 12 inches thick with strata of loamy texture alluvium common. The upper part of the control section consists of stratified sediments that ranges from 10 to 22 inches in thickness and is coarse-loamy upon mixing. A gleyed matrix is present to the surface of the mineral soil. Reaction is neutral to slightly alkaline in the organic horizons and neutral to moderately alkaline in the mineral soil.

The Ag horizon has hue of 5Y, 5GY, 5G or 5BG; value moist of 4, or 5. Texture is stratified and includes sand, fine sandy loam and silt loam.

The Cg horizon has hue of 5Y, 5GY, 5G or 5BG; value moist of 4 or 5; chroma moist of 1 or 2. Texture is stratified and includes sand, fine sandy loam, and silt loam. These horizons have a gleyed matrix .

The 2Cg horizon (when present) has hue of 5Y, 5GY, 5G or 5BG; value moist of 4 or 5; chroma moist of 1 or 2. Texture is sand, loamy sand or loamy coarse sand. Rock fragments range from 35 to 70 percent and include 35 to 70 percent rounded gravel and 0 to 30 percent rounded cobble. These horizons have a gleyed matrix .

The 2C horizons are variegated sand, gravel, and cobble. Texture includes sand or coarse sand. Rock fragments range from 35 to 70 percent and include 35 to 70 percent rounded gravel and 0 to 30 percent rounded cobble. Pockets and strata of sand and silt are common

COMPETING SERIES: These are the Chichagof, Liscum, and Nakwasina series. Chichagof soil are sandy-skeletal throughout the particle size control section. Liscum soils have stratified sandy and silty textures to more than 40 inches. Nakwasina soils are shallow to paralithic glacial till material.

GEOGRAPHIC SETTING: The Hisna soils are on floodplains. Slopes range from 0 to 6 percent. Hisna soils formed in an organic mat 7 to 12 inches thick over stratified loamy alluvium 10 to 22 inches thick, underlain by very gravelly and cobbly sand. The mean annual temperature is about 26 degrees F. and the average annual precipitation is about 16 inches. Elevation ranges from 2550 to 2800 feet.

DRAINAGE AND PERMEABILITY: Very poorly drained. Slow runoff. Moderate rapid permeability in the organic surface, moderate permeability in the loamy alluvial horizons and rapid in the gravelly and cobbly underlying material. Hisna soils are subject to flooding.

USE AND VEGETATION: Mostly sedges, bluejoint reedgrass and low willow. Primary uses of these soils are for recreation and wildlife habitat.

DISTRIBUTION AND EXTENT: Southcentral, Alaska. The soil is of minor extensive.

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

SERIES ESTABLISHED: Gulkana River Area, Alaska. 1999.

REMARKS: Diagnostic features recognized in this profile include: no diagnostic horizons; reduced matrix from 0 to 25 inches; coarse loamy particle size (weighted average) from 0 to 21 inches and sandy skeletal particle size from 21 to 60 inches; cryic temperature regime;

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National Cooperative Soil Survey
U.S.A.