LOCATION BEARCAT CA

Established Series
Rev. SAA/KP
07/2016

BEARCAT SERIES

The Bearcat series consists of very deep, moderately well drained soils formed in colluvium and residuum from mudstone, sandstone, and siltstone. Bearcat soils are on mountains. Slopes range from 9 to 50 percent. The mean annual precipitation is about 1285 millimeters and the mean annual air temperature is about 11 degrees C.

TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Pachic Haploxerolls

TYPICAL PEDON: Bearcat silt loam on a southeast facing linear convex slope of 18 percent on rangeland at 386 meters elevation. (Colors are for dry soil unless otherwise noted. When described on July 10, 2007, the soil was dry throughout.)

A1--0 to 18 centimeters; dark gray (10YR 4/1); silt loam, black (10YR 2/1) moist; moderate very fine subangular blocky structure; very friable, slightly hard, slightly sticky and slightly plastic; many very fine roots throughout; neutral (pH 6.6); abrupt smooth boundary.

A2--18 to 55 centimeters; dark gray (10YR 4/1); silt loam, black (10YR 2/1) moist; moderate fine subangular blocky structure; very friable, slightly hard, slightly sticky and slightly plastic; many very fine roots throughout; 15 percent organoargillans on all faces of peds; neutral (pH 6.6); abrupt smooth boundary. (combined thickness of the A horizons is 50 to 85 centimeters.)

Bt1--55 to 90 centimeters; light brownish gray (10YR 6/2) silty clay loam; dark grayish brown (10YR 4/2) moist; strong medium subangular blocky structure; firm, hard, moderately sticky and very plastic; many very fine roots throughout; 10 percent clay films on all faces of peds and 10 percent organoargillans on all faces of peds; 10 percent distinct dark yellowish brown (10YR 4/6) iron-manganese masses; slightly acid (pH 6.4); clear smooth boundary.

Bt2--90 to 125 centimeters; dark gray (10YR 4/1); silty clay loam, brown (10YR 5/3) moist; strong medium subangular blocky structure; firm, hard, moderately sticky and very plastic; 5 percent organoargillans on all faces of peds and 10 percent clay films on all faces of peds; 5 percent distinct grayish brown (10YR 5/2) iron depletions and 15 percent distinct dark yellowish brown (10YR 4/6) iron-manganese masses; slightly acid (pH 6.2); clear wavy boundary.

Bt3--125 to 155 centimeters; light gray (10YR 7/2); silty clay loam, brown (10YR 5/3), moist; moderate medium subangular blocky structure; firm, hard, moderately sticky and very plastic; 5 percent organoargillans on all faces of peds and 15 percent clay films on all faces of peds; 15 percent distinct dark yellowish brown (10YR 4/6) iron-manganese masses and 15 percent distinct grayish brown (2.5Y 5/2) iron depletions; slightly acid (pH 6.2); clear wavy boundary.

Bt4--155 to 175 centimeters; light gray (10YR 7/2); silty clay loam, brown (10YR 5/3) moist; moderate medium subangular blocky structure; firm, hard, moderately sticky and very plastic; 15 percent clay films on all faces of peds; 15 percent distinct dark yellowish brown (10YR 4/6) iron-manganese masses and 15 percent distinct grayish brown (2.5Y 5/2) iron depletions; slightly acid (pH 6.2); clear wavy boundary. (Combined thickness of the Bt horizons is 100 to 150 centimeters.)

Btg--175 to 200 centimeters; light gray (10YR 7/2); silty clay loam, grayish brown (10YR 5/2) moist; moderate medium subangular blocky structure; firm, hard, moderately sticky and very plastic; 20 percent clay films on all faces of peds; 20 percent prominent strong brown (7.5YR 5/8) iron-manganese masses in matrix; slightly acid (pH 6.2). (Combined thickness of the Btg horizons is 0 to 150 centimeters.)

TYPE LOCATION: Humboldt County, California; About 4 kilometers west of the intersection of Mattole Road and Bear Ridge Road and 300 meters south; WGS84 Decimal degrees latitude 40.5078270, longitude -124.3228178; UTM Zone 10, 387924mE, 4484964mN; NAD83.

RANGE IN CHARACTERISTICS:

Soil moisture: The soil is dry in all parts in the moisture control section from about July 10 to September 20, and is moist in all parts from about October 1 to June 1. The soils have a xeric soil moisture regime.

Soil Temperature: The mean annual soil temperature at 50 centimeters is 10 to 13 degrees C. The difference between mean summer and mean winter soil temperature is more than 6 degrees C. The soils have a mesic soil temperature regime.

Depth to Redoximorphic Features: 50 to 100 centimeters

Particle size control section (weighted average):
Pararock fragments: 0 to 14 percent very weakly cemented mudstone paragravel
Fine sand or coarser: 6 to 14 percent
Clay content: 21 to 32 percent

Some pedons have an Oi horizon (0 to 5 centimeters thick).

A horizon:
Hue: 10YR
Value: 2 or 3, 4 or 5 dry
Chroma: 1 through 3, moist or dry
Texture of fine earth: silt loam
Pararock fragments: 0 to 5 percent paragravel
Clay content: 22 to 26 percent
Reaction: slightly acid to neutral

Upper B horizons:
Hue: 10YR, 2.5Y
Value: 2 through 4, 4 through 6 dry
Chroma: 1 through 3, moist or dry
Texture of fine earth: loam, silt loam, clay loam, silty clay loam
Pararock fragments: 0 to 14 percent paragravel
Clay content: 25 to 30 percent
Reaction: moderately to slightly acid

Bt horizons:
Hue: 10YR, 2.5Y
Value: 4 or 5, 5 through 7 dry
Chroma: 3 or 4, moist or dry
Texture of fine earth: loam, silt loam, clay loam, silty clay loam
Pararock fragments: 0 to 34 percent paragravel
Clay content: 24 to 34 percent
Reaction: moderately to slightly acid

Redoximorphic Features:
fine and medium iron-manganese masses in the matrix
Quantity: few to many
Hue: 7.5YR, 10YR
Value: 4 or 5
Chroma: 4 through 8

Redoximorphic Features: fine and medium iron depletions in the matrix
Quantity: few to many
Hue: 10YR, 2.5Y
Value: 5 or 6
Chroma: 1 or 2

Btg or Cg horizons, when present:

Hue: 10YR, 2.5Y
Value: 4 through 6, 5 through 7 dry
Chroma: 1 through 3, moist or dry
Texture of fine earth: loam, clay loam, silty clay loam
Pararock fragments: 0 to 59 percent paragravel
Clay content: 25 to 34 percent
Reaction: moderately to slightly acid

Redoximorphic Features: fine and medium iron-manganese masses in the matrix
Quantity: none to many
Hue: 7.5YR, 10YR
Value: 4 or 5
Chroma: 4 through 8

Redoximorphic Features: fine and medium iron depletions in the matrix
Quantity: common to many
Hue: 10YR, 2.5Y
Value: 4 through 6
Chroma: 1 or 2

COMPETING SERIES: These are the Athena, La Grande, Tucannon and Wingville soils. Athena soils have redoximorphic features greater than 100 centimeters deep. La Grande soils are 100 to 150 centimeters deep. Tucannon soils are 50 to 100 centimeters to bedrock. Wingville soils have redoximorphic features above 50 centimeters.

GEOGRAPHIC SETTING: Bearcat soils are on mountain summits and gentle to steep slopes. Slopes are 15 to 50 percent. Elevations are 60 to 520 meters. These soils formed in colluvium and residuum from mudstone with minor amounts of siltstone and sandstone. The climate is humid with cool foggy summers and cool wet winters. Mean annual precipitation is 1040 to 1530 millimeters. Mean January temperature is about 9 degrees C, mean July temperature is about 14 degrees C, and the mean annual temperature is 10 to 12 degrees C. Frost free season is about 240 to 330 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ferncat), Darkprairie, Oilcreek, and Sleepyhollow, soils. Ferncat soils have a difference between mean summer and mean winter soil temperature of less than 6 degrees C. Darkprairie, Oilcreek and Sleepyhollow soils lack redoximorphic features within 100 centimeters of the surface. Darkprairie soils are on gently sloping open prairies. Ferncat, Oilcreek and Sleepyhollow soils are on linear to convex positions on ridges and mountain slopes under conifer and hardwood forest.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Moderately well drained, high to very high runoff, moderately high to high saturated hydraulic conductivity.

USE AND VEGETATION: This soil is used for livestock grazing, wildlife habitat, and watershed. Natural vegetation consists of California oatgrass, dogtail grass, foxtail fescue, tall oatgrass, plantain, and annual legumes. Invasion by Sitka spruce, redwood and other forest species occurs primarily in disturbed areas and along forest borders.

DISTRIBUTION AND EXTENT: Coastal Redwood Belt; MLRA 4B. The series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Humboldt County Soil Survey, Central Part, California, 2016; proposed 2010. The name is coined.

REMARKS: The series type location was moved in 2016 to better reflect the series concept.

Diagnostic horizons and features recognized in this pedon are:
1. Mollic epipedon: The zone from 0 to 55 centimeters (A1 and A2 horizon)
2. Cambic horizon: The zone from 55 to 200 centimeters (Bt1, Bt2, Bt3, Bt4, and Btg horizons)
3. Particle-size control section: The zone from 25 to 100 centimeters (A2 Bt1, and Bt2 horizons)
4. Oxyaquic feature: The zone from 55 to 200 centimeters (Bt1, Bt2, Bt3, Bt4, and Bt5 horizons)

ADDITIONAL DATA:

Keys to Soil Taxonomy, 12th edition

NASIS User Pedon ID 07CA600066.

National Cooperative Soil Survey
U.S.A.