LOCATION CHISANA                 AK

Established Series
SDB/MJS
08/2025

CHISANA SERIES

Depth class: moderately deep to permafrost
Drainage class: poorly drained
Parent material: mossy organic material over gravelly colluvium
Landscape: mountains
Landform: mountain slopes
Slopes: 5 to 35 percent
Mean annual precipitation: about 350 mm (14 in)
Mean annual air temperature: about -3 degrees C. (27 degrees F)
Frost-free period: 40 to 75 days

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, nonacid, subgelic Typic Historthels

TYPICAL PEDON: Chisana peat in a scrub birch willow community on a north facing linear, linear backslope on a slope of 25 percent at an elevation of 1100m (3610 ft).

Oi1--0 to 17 cm (0 to 7 in); peat, 60 percent brown (7.5YR 4/2) broken face and 40 percent light brown (7.5YR 6/4) broken face dry, 60 percent very dark brown (7.5YR 2.5/2) broken face and 40 percent brown (7.5YR 4/4) broken face moist; many very fine and fine, and common medium roots throughout; extremely acid (pH 4.4); clear smooth boundary (10 to 20 cm, 4 to 8 in).

Oi2--17 to 24 cm (7 to 9 in); peat, dark gray (10YR 4/1) broken face dry, black (10YR 2/1) broken face moist; many very fine and fine roots throughout; strongly acid (pH 5.1); abrupt wavy boundary (5 to 15 cm, 2 to 6 in).

Bg--24 to 40 cm (9 to 16 in); stony silt loam, grayish brown (2.5Y 5/2) broken face dry, very dark grayish brown (2.5Y 3/2) broken face moist; weak coarse subangular blocky parts to moderate medium granular structure; slightly hard, friable, slightly sticky, moderately plastic; nonsmeary; many very fine and fine roots throughout; very fine and fine irregular pores; 10 percent subrounded stones by volume, 15 percent subrounded gravel by volume; negative to alpha-alpha dipyridyl measured in matrix; moderately acid (pH 5.8); clear smooth boundary (10 to 25 cm, 4 to 10 in).

Cg--40 to 80 cm (16 to 31 in); very stony loam, gray (2.5Y 6/1) broken face dry, dark gray (2.5Y 4/1) broken face moist; 10 percent fine faint irregular very dark gray (10YR 3/1) mottles; massive; moderately hard, firm, moderately sticky, moderately plastic; nonsmeary; common very fine and fine roots throughout; very fine and fine irregular pores; 10 percent very fine prominent irregular (7.5yr 5/6), moist, masses of oxidized iron; 20 percent subrounded gravel by volume, 30 percent subrounded stones by volume; positive to alpha-alpha dipyridyl measured in matrix; strongly acid (pH 5.5); clear smooth boundary (30 to 50 cm, 12 to 20 in).

Cgf--80 to 150 cm (31 to 59 in); permanently frozen loam, gray (2.5Y 6/1) broken face dry, dark gray (2.5Y 4/1) broken face moist; massive; very rigid, noncoherent; nonsmeary; strongly acid (pH 5.5). (40 to 95 cm, 16 to 37 in).

TYPE LOCATION: North Copper River Soil Survey Area, Alaska; latitude 61.9232, longitude - 147.35525, UTM 6865681.19 north and UTM 481346.19 east, zone 6, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: aquic
Soil temperature regime: gelic
Mean annual soil temperature: -4 to 1 degrees C. (25 to 34 degrees F)
Thickness of epipedon: 15 to 35 cm (6 to 14 in)
Thickness of cambic horizon: 15 to 25 cm (6 to 10 in)
Depth to aquic horizon: 0 to 200 cm (0 to 79 in)
Depth to redoximorphic concentrations: 25 to 60 cm (10 to 24 in)
Depth to redoximorphic depletions: 25 to 60 cm (10 to 24 in)
Depth to permafrost: 55 to 110 cm (22 to 43 in)

Oi, Oe, Oa horizons:
Hue: 7.5YR or 10YR
Value: 2 to 4
Chroma: 1 to 4
Texture: Peat
Organic matter: 60 to 90 percent
Reaction class: extremely acid to strongly acid (pH 3.5 to 5.5)

Bg and Cg horizons:
Hue: 2.5Y or 5Y
Value: 2 to 5
Chroma: 1 to 3
Texture: stony silt loam, very stoney loam
Sand: 5 to 52 percent
Silt: 28 to 80 percent
Clay: 5 to 27 percent
Rock fragments: 15 to 59 percent
Gravels: 10 to 34 percent
Cobbles: 5 to 30 percent
Organic matter: 1 to 13 percent
Reaction class: strongly acid to moderately acid (pH 5.1 to 6.0)

Cf horizons:
Hue: 2.5Y or 5Y
Value: 3 to 5
Chroma: 1 to 2
Texture: loam
Sand: 25 to 52 percent
Silt: 28 to 50 percent
Clay: 10 to 27 percent
Rock fragments: 0
Organic matter: 1 to 3 percent
Reaction class: strongly acid to moderately acid (pH 5.1 to 5.5)

COMPETING SERIES: These are the Cranberryslough soils.
Cranberryslough soils do not have a reduced matrix in the permafrost horizon and occur on hillslopes and saddles at elevations below 300 m (985 ft).

GEOGRAPHIC SETTING:
Elevation: 800 to 1200 meters (2625 to 3935 ft)
Parent material: mossy organic material over gravelly colluvium
Landform: mountain slopes
Slopes: 5 to 35 percent
Mean annual precipitation: 350 to 400 mm (14 to 16 in)
Mean annual air temperature: -4 to -2 degrees C. (25 to 28 degrees F)
Frost free period: 40 to 75 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ahtell, Chakina, and Schleyer soils.
Ahtell soils are well drained, lack permafrost, have folistic and umbric epipedons, and occur on hill tops, and hillside positions.
Chakina soils are somewhat poorly drained, have a cryoturbated horizon, and occur along perennial streams on mountain slopes.
Schleyer soils are somewhat excessively drained, have an albic horizon, and occur in mountain valleys and on fan remnants.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: poorly drained
Saturated Hydraulic Conductivity: high in the O and Cg horizons, is moderately high in the Bg horizon, and low in the Cf horizon
Permeability: Moderately rapid in O and Cg horizons, moderate in the Bg horizon, and very slow in the Cf horizon
Runoff: very high

USE AND VEGETATION:
Use: wildlife habitat, recreation, and subsistence
Native vegetation: Resin birch and crowberry

DISTRIBUTION AND EXTENT: MLRA 228 Interior Alaska mountains.
Extent: limited

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Wasilla, Alaska

SERIES ESTABLISHED: North Copper River Soil Survey, Alaska, 2024.

REMARKS: Diagnostic features and horizons recognized in this profile include:

Particle-size control section: 59 to 124 cm (23 to 49 in)

Histic epipedon: 0 to 24 cm (0 to 9 in) (Oi horizons)

Cambic horizon: 24 to 40 cm (9 to 16 in) (Bg horizon)

Redoximorphic concentrations: 40 to 80 cm (16 to 31 in) (Cg horizon)

Reduced matrix: 40 to 150 cm (16 to 31 in) (Cg and Cgf horizons)

Aquic conditions: 0 to 150 cm (0 to 59 in) (Oi, Bg, Cg, and Cgf horizons)

Permafrost: 80 to 150 cm (31 to 59 in) (Cgf horizon)

ADDITIONAL DATA:

User pedon Id: 2023AK170913

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National Cooperative Soil Survey
U.S.A.