LOCATION KIBESILLAH CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, isomesic Ultic Haplustalfs
TYPICAL PEDON: Kibesillah very gravelly loam - on a northwest facing convex slope of 40 percent under redwood canopy, tanoak and Douglas-fir at 1,400 feet elevation. (Colors are for dry soil unless otherwise noted. When described July 19, 1979, the soil was dry throughout.)
Oi--0.5 inch to 0; litter of Douglas fir, redwood and tanoak.
A1--0 to 4 inches; pale brown (10YR 6/3) very gravelly loam, dark brown (10YR 4/3) moist; strong very fine and fine granular structure; slightly hard, friable, nonsticky and slightly plastic; many fine and common very fine and medium roots; many very fine and fine and common medium interstitial pores; 40 percent hard, subangular pebbles (2 to 15 mm); strongly acid (pH 5.5); clear wavy boundary. (3 to 7 inches thick)
A2--4 to 13 inches; pale brown (10YR 6/3) very gravelly loam, dark yellowish brown (10YR 4/4) moist; strong very fine and fine subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; common very fine, medium and coarse and few fine roots; many very fine and fine and common medium interstitial, and common very fine and medium tubular pores; 45 percent hard, subangular pebbles (2 to 15 mm); strongly acid (pH 5.3); clear wavy boundary. (2 to 10 inches thick)
Bt1--13 to 19 inches; very pale brown (10YR 7/3) very gravelly loam, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; common medium and coarse and few very fine and fine roots; common very fine and fine and few medium interstitial, and few fine and medium tubular pores; few thin clay films lining pores and bridging mineral grains; 50 percent hard, subangular pebbles (2 to 25 mm); strongly acid (pH 5.3); gradual wavy boundary. (5 to 12 inches thick)
Bt2--19 to 26 inches; very pale brown (10YR 7/3) extremely gravelly clay loam, yellowish brown (10YR 5/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine, medium and coarse roots; common very fine, few fine and medium interstitial, and few fine tubular pores; many thin clay films on faces of peds and lining pores; 65 percent hard subangular pebbles (2 to 75 mm) and 10 percent hard subangular cobbles (7.5 to 10 cm); strongly acid (pH 5.3); abrupt irregular boundary. (6 to 14 inches thick)
R--26 to 38 inches; hard fractured sandstone; fractures are 1 to 2 mm wide and 5 to 7.5 cm apart; few medium and coarse roots along fractures.
TYPE LOCATION: Mendocino County, California; about 4.15 miles northwest of Branscomb; about 2,000 feet north and 2,000 feet west of SE corner of sec. 13, T. 21 N., R. 17 W., Branscomb 15 minute Quadrangle.
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to a lithic contact is 20 to 40 inches. The mean annual soil temperature ranges from 50 to 56 degrees F. The difference between mean summer and mean winter temperature ranges from 5 to 9 degrees F. The soil between depths of 11 to 34 inches or to a lithic contact, if less than 34 inches deep, is moist in all parts from November 1 to June 1, and is dry in some or all parts from July 1 to October 1 in most years. The particle-size control section averages from 20 to 28 percent clay.
The A horizon is 10YR 5/2, 5/3, 6/3, 6/4, 7/4; or 7.5YR 5/4. Moist color is 10YR 4/2, 4/3, 4/4; 7.5YR 3/4, 4/4 or 4/6. Gravel content is 15 to 50 percent. Reaction is strongly acid through neutral.
The Bt horizon is 10YR 6/3, 6/4, 7/2, 7/3 or 8/2. Moist color is 10YR 4/4, 4/6, 5/3, 5/4, 6/4 or 7.5YR 4/6. It is loam or clay loam and is very or extremely gravelly. Clay content ranges from 20 to 35 percent. Gravel content ranges from 35 to 75 percent. Cobble content is 0 to 20 percent. Reaction is strongly through slightly acid. Base saturation (sum) ranges from 35 to 65 percent.
COMPETING SERIES: This is the Yellowhound (CA) series. Yellowhound soils are 40 to 60 inches deep to a lithic contact.
GEOGRAPHIC SETTING: Kibesillah soils are on hills and mountains. The soils formed in material weathered from sandstone. Slopes are 9 to 99 percent. Elevation ranges from 200 to 2,500 feet. The climate is characterized by cool moist winters and cool foggy summers. A moderate coastal fog influence limits the diurnal and annual range of temperature. Mean annual precipitation varies from 50 to 70 inches. Mean January temperature is 50 degrees F; mean July temperature is 60 degrees F; mean annual temperature is 53 degrees F. The frost-free period is 220 to 320 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Yellowhound soils and the Ornbaun, Zeni and Woodin soils. Ornbaum and Zeni soils are fine-loamy. Woodin soils have a xeric-mesic soil moisture-temperature regime.
DRAINAGE AND PERMEABILITY: Well drained; surface runoff under bare soil conditions is medium to very rapid; moderate permeability.
USE AND VEGETATION: This soil is used for timber production, wildlife habitat and watershed. Vegetation is Douglas-fir, redwood, tanoak, madrone and California huckleberry.
DISTRIBUTION AND EXTENT: Northern coastal California. The series is of moderate extent. MLRA is 4.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Mendocino County, California, Eastern Part, 1985.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the surface layer from 0 to 4 inches
Argillic horizon - the zone from 13 to 26 inches (Bt1, Bt2 horizons)
Lithic contact - the boundary with hard sandstone at 26 inches
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET