LOCATION OSITO                   CA

Established Series
REV: TMR/DRG/JGR/DJE/RLR
05/2014

OSITO SERIES

The Osito series consists of shallow, well drained soils formed in material weathered from interbedded sandstone and shale. Osito soils are on uplands and have slopes of 15 to 70 percent. Mean annual precipitation is 432 centimeters (17 inches) and mean annual temperature is 14 degrees C (58 degrees F).

TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Typic Haploxerepts

TYPICAL PEDON: Osito silt loam - on a south facing linear to slightly convex slope of 30 percent under chamise and annual grasses. (Colors are for dry soils unless otherwise stated. When described on 6/1/78 the soil was dry throughout).

A--0 to 5 centimeters (0 to 2 inches); brown (10YR 5/3) silt loam; dark brown (10YR 3/3) moist; moderate very fine and fine subangular blocky structure; hard, friable, sticky and plastic; common very fine roots; many very fine and fine tubular and interstitial pores; neutral (pH 7.3); clear wavy boundary. (5 to 13 cm (2 to 5 inches) thick)

Bw--5 to 38 centimeters (2 to 15 inches); pale brown (10YR 6/3) silt loam, brown (10YR 4/3) moist; moderate fine and medium subangular blocky structure; hard, friable, sticky and very plastic; common very fine and medium roots; many very fine and fine tubular and interstitial pores; neutral (pH 7.0); abrupt wavy boundary. (20 cm to 38 cm (8 to 15 inches) thick)

Cr--38 centimeters (15 inches); light yellowish brown fine grained sandstone, highly fractured with fractures less than l mm wide and greater than 10 cm apart; fragments easily slake in water; easily cut with a spade, no roots.

TYPE LOCATION: Los Angeles County, California; approximately 1.2 miles southeast of Oak Flat Campground in the Angeles National Forest; 2250 feet east and 5 feet south of the NW corner of sec. 29, T. fi N., R. 17 W., SBBM.

RANGE IN CHARACTERISTICS:

Soil Moisture: usually dry below 10 cm (4 inches) for at least 45 consecutive days within the 4 months following the summer solstice.
Mean annual soil temperature: 15 to 21 degrees C (59 to 70 degrees F)

Depth to a paralithic contact: 25 to 50 cm (10 to 20 inches)
Rock fragments: less than 15 percent gravel in the solum
Reaction: neutral or mildly alkaline.
Organic carbon: averages less than 0.6 percent after mixing the upper 18 cm (7 inches)


A horizon:
Dry color: hue of lOYR; value of 3 to 6; chroma of 2 to 4
Moist color: hue of lOYR; value of 3 or 4; chroma of 2 or 3
Texture: loam, silt loam
Structure: weak or moderate granular structure

Bw horizon:
Dry Color: hue of lOYR; value of 5 or 6; chroma of 3 or 4
Moist Color: hue of lOYR; value of 4 or 5; chroma of 3 or 4
Texture: loam, silt loam, or silty clay loam

Cr horizon: weathered sandstone or shale

COMPETING SERIES: These are the Amador, Borreguero, and Wolfey soils. Amador soils are weathered from rhyolitic tuffaceous sediments. Borreguero soils are weathered from marine sandstone. Wolfey soils receive 114 to 150 cm (45 to 60 inches) of precipitation each years.

GEOGRAPHIC SETTING: Osito soils are on uplands and have slopes of 15 to 70 percent. Elevation is 200 to 1200 meters (650 to 4000 feet). They are formed in material weathered from interbedded fine grained sandstone and shale. The climate is dry, subhumid, mesothermal with hot dry summers and cool moist winters. Mean annual precipitation is 330 to 500 mm (13 to 20 inches). Average January temperature is 9 degrees C (48 degrees F); average July temperature is 22 degrees C (72 degrees F); mean annual temperature is 14 degrees C (58 degrees F). Frost-free season is approximately 200 to 320 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Balcom, Calleguas, Millsholm, Modesto, Stonyford, San Andreas, and Trigo soils. Balcom soils have a calcic horizon. Callegues soils are calcareous throught the profile. Millsholm soils have a lithic contact within 20 inches. Modesto and Stonyford soils have an argillic horizon. San Andreas soils have a coarse-loamy particle-size class and a mollic epipedon. Trigo soils lack a cambic horizon.

DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; moderate permeability.

USE AND VEGETATION: Used for watershed, wildlife habitat and recreation. The vegetation is chamise, manzanita, ceonothus, scrub oak, mountain mahogony, black sage, white sage, yerba santa, laurel sumac, buckwheat, and annual grasses.

DISTRIBUTION AND EXTENT: Southern California Mountain and foothills. This soil is moderately extensive.

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

SERIES ESTABLISHED: Los Angeles County (Angeles National Forest Area), California, 1980.

REMARKS: updated English to metric unit conversion, RIC conversion to tabular format, updated competing and geographically associated soils sections (RLR)

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National Cooperative Soil Survey
U.S.A.