LOCATION BIDARKA AK

Established Series
Rev. CAP
08/2025

BIDARKA SERIES

Depth class: moderately deep
Drainage class: well drained
Parent material: herbaceous organic material over channery medial silty volcanic ash over residuum weathered from graywacke
Landform: mountains, hills, and ridges
Slopes: 3 to 70 percent
Mean annual precipitation: 900 to 2000 mm (35 to 79 in)
Mean annual temperature: -2 to 4 degrees C. (28 to 39 degrees F.)

TAXONOMIC CLASS: Medial-skeletal, amorphic Typic Haplocryands

TYPICAL PEDON: Bidarka channery medial silt loam - on grass herbaceous and shrubby at elevation 115 meters (380 feet). (All colors are for moist soil.)

Oe--0 to 7 centimeters (0 to 3 inches); very dark brown (10YR 2/2), very dark grayish brown (10YR 3/2), dry; moderately decomposed plant material; soft, very friable, nonsticky, nonplastic; many very fine, fine, and common medium roots throughout; 1 percent gravel; strongly acid (pH 5.5); clear smooth boundary. (0 to 13 cm, 0 to 5 in thick)

A--7 to 21 centimeters (3 to 8 inches); very dark gray (7.5YR 3/1), dark gray (7.5YR 4/1), dry; channery medial silt; weak fine granular structure; soft, very friable, nonsticky, nonplastic; many fine and common medium roots throughout; 15 percent gravel; strongly acid (pH 5.4); gradual wavy boundary. (5 to 18 cm, 2 to 7 in thick)

Bw--21 to 60 centimeters (8 to 24 inches); dark brown (7.5YR 3/4) very channery medial silt loam; weak fine granular structure; soft, very friable, nonsticky, nonplastic; many fine and common medium roots throughout; 50 percent gravel and 10 percent cobble; moderately acid (pH 5.7); clear irregular boundary. (40 to 79 cm, 16 to 31 in thick)

2R--60 to 85 centimeters (24 to 34 inches); strongly to indurated graywacke bedrock.

TYPE LOCATION: Kodiak Archipelago Soil Survey Area, Alaska; Latitude 57 degrees 22 minutes 7.00 seconds and Longitude 154 degrees 1 minutes 58.00 seconds west, UTM north 6358890.75 and UTM east 4378836.95, zone 5, Datum WGS84.

RANGE IN CHARACTERISTICS:

Soil moisture regime: Udic
Mean annual soil temperature: -2 to 4 degrees C (28 to 39 degrees F.)
Thickness of organic material: 0 to 13 cm (0 to 5 in)
Depth to andic properties: 0 to 13 cm (0 to 5 in)
Depth to cambic horizon: 5 to 18 cm (2 to 7 in)
Depth to bedrock: 45 to 110 cm (18 to 43 in)

Oa, Oe, Oi horizon:
Hue: 7.5YR to 10 YR
Value: 2 to 5
Chroma: 1 to 4
Texture: slightly, moderately, or highly decomposed plant material
Organic matter: 60 to 90 percent
Reaction class: extremely acid to moderately acid (pH 3.5 to 6.0)

A horizon:
Hue: 7.5YR to 10 YR
Value: 2 to 5
Chroma: 1 to 3
Texture: medial silt loam, silt, loam, and very fine sandy loam
Rock fragments: 0 to 25 percent
Silt: 40 to 90 percent
Clay: 2 to 10 percent
Reaction class: extremely acid to moderately acid (pH 3.5 to 6.0)

Bw horizon:
Hue: 5YR, 7.5YR, or 10YR
Value: 2 or 3
Chroma: 1 to 4
Texture: (medial) silt loam, silt, loam, or very fine sandy loam, or their gravelly analogues
Silt: 40 to 90 percent
Clay: 2 to 12 percent
Rock Fragments: 0 to 30 percent
Reaction Class: extremely acid to moderately acid (pH 3.5 to 6.0)

3R horizon: Strongly to indurated bedrock.

COMPETING SERIES: These are the Battleax (OR), Divers (OR), Highcamp (OR), Holderman (OR), Icecap (OR), Idanha (OR), Oatman )OR), Ohana (WA), Otwin (OR) series.
Battleax soils lack a lithic contact, have mean annual air temperature greater than 4 degrees C. (39 degrees F.), have frost free days greater than 50, and are on similar landform positions.
Divers soils lack a lithic contact, have mean annual air temperature greater than 4 degrees C. (39 degrees F.), have precipitation greater than 3000 mm (98 in), have frost free days greater than 50, and are on similar landform positions.
Highcamp soils have andesite bedrock, have mean annual air temperature greater than 4 degrees C. (39 degrees F.), have frost free days greater than 50, and are on similar landform positions.
Holderman soils have rhyolitic welded tuff bedrock, have mean annual air temperature greater than 4 degrees C. (39 degrees F.), have frost free days greater than 50, and are on similar landform positions.
Icecap soils have andesite bedrock, have mean annual air temperature greater than 4 degrees C. (39 degrees F.), have frost free days greater than 50, and are on similar landform positions.
Idanha soils lack a lithic contact, have mean annual air temperature greater than 4 degrees C. (39 degrees F.), have frost free days greater than 50, and are on similar landform positions.
Oatman soils lack a lithic contact, have mean annual air temperature greater than 4 degrees C. (39 degrees F.), have frost free days greater than 50, and are on similar landform positions.
Ohana soils have densic horizons, have mean annual air temperature greater than 4 degrees C. (39 degrees F.), have frost free days greater than 50, and are on similar landform positions.
Otwin soils have andesite bedrock, have mean annual air temperature greater than 4 degrees C. (39 degrees F.), have frost free days greater than 50, and are on similar landform positions.

GEOGRAPHIC SETTING:
Elevation: 115 to 1210 meters (375 to 4000 feet)
Parent material: herbaceous organic material over channery medial silty volcanic ash over residuum weathered from graywacke
Landform: mountains, hills and ridges
Slopes: 3 to 70 percent
Mean annual precipitation: 900 to 2000 mm (35 to 79 in)
Mean annual temperature: -2 to 4 degrees C. (28 to 39 degrees F.)
Frost free period: 20 to 50 days

GEOGRAPHICALLY ASSOCIATED SOILS: These include Akalura, Ayakulik, Kaguyak, Kodiak, Luchek, Shuyak, Spiridon, Sulua, Terror Lake, Tonki, and Tungalara.
Akalura soils lack bedrock at depths less than 100 cm (40 in), have glacial till substratum, and occur on mountain flanks, and hill or ridge backslopes, footslopes, and toeslopes.
Ayakulik soils lack medial-skeletal particle-sized control sections
and occur on mountain tops and flanks, and hill or ridge summits, shoulders, and backslopes.
Kaguyak soils have bedrock at depths less than 50 cm (20 in), lack glacial till substratum, have skeletal particle-sized control sections, and occur on mountain tops and flanks, and hill or ridge summits, shoulders, and backslopes.
Kodiak soils have spodic horizons and occur on similar landform positions.
Luchek soils have thick organic material over skeletal glacial till and occur on drainageways and depressions on lower sloping mountain flanks and hill or ridge backslopes and toeslopes.
Shuyak soils have bedrock at depths less than 50 cm (20 in), lack glacial till substratum, and occur on mountain tops and flanks, and hill or ridge summits, shoulders, and backslopes.
Spiridon soils have bedrock at depths less than 100 cm (40 in) and occur on mountain tops and flanks, and hill or ridge summits, shoulders, and backslopes.
Sulua soils have thick organic material over skeletal glacial till and occur on drainageways and depressions on lower sloping mountain flanks and hill or ridge backslopes and toeslopes.
Terror Lake soils have aquic features within 41 to 100 cm (16 to 40 in) and occur on drainageways and depressions on lower sloping mountain flanks and hill or ridge backslopes and toeslopes.
Tonki soils have aquic features within 0 to 25 cm (0 to 10 in) and occur on drainageways and depressions on lower sloping mountain flanks and hill or ridge backslopes and toeslopes.
Tungalara soils have skeletal particle-sized control sections and occur on similar positions.

DRAINAGE AND PERMEABILITY:
Drainage class: well drained
Saturated Hydraulic Conductivity: very high in the Oe horizon, moderately high to high in the A, Bw horizons, and very low to low in the 2R.
Permeability: rapid to very rapid in the Oa horizon, moderate to rapid in the A and Bw horizons, and impermeable to very slow in the 2R.
Runoff: high to very high.

USE AND VEGETATION:
On slopes of less than 45 percent, the soils are used as rangeland. The native vegetation is tall grass, dominantly bluejoint reedgrass, and associated plants including fireweed, salmonberry, and alder. A few patches of white spruce, Sitka spruce, and paper birch occur in places.

DISTRIBUTION AND EXTENT: MLRA 225, Kodiak Archipelago, Alaska.
Extent: extensive.

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

SERIES ESTABLISHED: Kodiak Archipelago Soil Survey, Alaska, 2024.

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

Organic material: 0 to 7 cm (0 to 3 in) (highly decomposed hemic plant material) (Oa horizon)

Andic soil properties: 7 to 60 cm (3 to 24 in) (A, Bw horizons)

Cambic horizon: 14 to 60 cm (6 to 24 in) (Bw horizon)

Lithic contact: 60 to 85 cm (24 to 34) (R horizon)

ADDITIONAL DATA:

User pedon Id: 09SS 05403

National Cooperative Soil Survey
U.S.A.