LOCATION HILTABIDEL CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, parasesquic, nonacid, mesic Lithic Xerorthents
TYPICAL PEDON: Hiltabidel very stony clay loam - on a southwest facing slope of 58 percent under knobcone pine and manzanita at 3,820 feet elevation. (Colors are for dry soil unless otherwise stated. When described May 22, 1980, the soil was moist throughout.)
Oi--1/2 inch to 0; litter of knobcone pine and manzanita leaves and twigs.
A1--0 to 13 inches; reddish brown (5YR 4/4) very stony clay loam, dark reddish brown (2.5YR 3/4) moist; moderate very fine and fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and common medium roots; many very fine and fine interstitial pores; 30 percent cobbles (8-25cm), 20 percent stones (25-60cm); neutral (pH 6.7); gradual irregular boundary.
A2--13 to 17 inches; reddish brown (5YR 4/4) extremely stony clay loam, dark reddish brown (2.5YR 3/4) moist; moderate very fine granular structure; soft, very friable, slightly sticky and slightly plastic; common fine and medium and few very fine roots; many very fine and fine interstitial pores; 20 percent cobbles (8-25cm), 55 percent stones (25-60cm); neutral (pH 6.7); abrupt irregular boundary.
R--17 inches; variegated reddish yellow (7.5YR 7/8) and gray (5Y 5/1, 6/1) hard, fractured peridotite; many black (N 2/0) manganese stains in randomly oriented in fractures that are 1 to 2mm wide and 3 to 10cm apart.
TYPE LOCATION: Mendocino County California; about 1,600 feet south and 3,200 feet west of the northeast corner sec. 19, T.24N., R.16W., MDBM, Noble Butte quadrangle.
RANGE IN CHARACTERISTICS: Depth to lithic contact is 10 to 20 inches. The mean annual soil temperature ranges from 53 to 57 degrees F. The soil between a depth of 8 inches and bedrock is moist in all parts from November 1 to June 1 and is dry in all parts from July 15 through October 1 in most years. There are 20 to 50 percent cobbles and 10 to 40 percent stones on the soil surface. Base saturation (HACH) ranges from 70 to 95 percent throughout. Reaction is slightly acid or neutral throughout.
The A horizon is 2.5YR 3/4, 4/4; 5YR 4/3 or 4/4. Moist color is 10R 3/4; 2.5YR 3/4 or 4/4. It is very stony or extremely stony clay loam. Clay content ranges from 27 to 35 percent. Cobble content ranges from 15 to 45 percent and stone content ranges from 20 to 55 percent. Total rock fragment content ranges from 35 to 80 percent.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Hiltabidel soils are on mountains. Slopes are 5 to 75 percent. Elevations are 2,000 to 4,100 feet. The soils formed in material weathered from ultrabasic intrusive rocks. The climate is subhumid with hot dry summers and cool moist winters. The mean annual precipitation ranges from 60 to 70 inches with occasional snowfall. Mean January temperature is about 45 degrees F., mean July temperature is about 66 degrees F., and the mean annual temperature is about 55 degrees F. The frost-free period is 150 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dann, Littlered, Casabonne, Hollowtree and Holohan series. The Dann series is 20 to 40 inches deep to a lithic contact. Littlered soils are very deep. Casabonne, Hollowtree and Holohan soils formed from sandstone that surrounds the ultrabasic rocks from which Hiltabidel soils were formed. Casabonne soils are fine-loamy. Hollowtree and Holohan soils have mixed mineralogy and are greater than 20 inches deep.
DRAINAGE AND PERMEABILITY: Well drained; surface runoff under bare soil conditions is medium through very rapid; moderate permeability.
USE AND VEGETATION: This soil is used as wildlife habitat and as watershed. Vegetation consists of knobcone pine, incense cedar, manzanita and ceanothus. Chemical characteristics including a low calcium to magnesium ratio, restrict plant growth and influence species composition.
DISTRIBUTION AND EXTENT: Northern coastal California. The series is not extensive. MLRA 5.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Mendocino County, California, Western part, 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone form 0 to 17 inches (A1, A2)
Lithic contact - the boundary at 17 inches (R layer)
Mineralogy - Oxidic, 10.3 percent dithonite-citrate
extractable Fe clay percentage = 33
Many areas of Hiltabidel soils were mapped as Huse series in the Wildland Soils and Associated Vegetation of the Mendocino County California by the State Cooperative Soil Vegetation Survey 1947-1950.