LOCATION RUDDER CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, isomesic Typic Haploxerepts
TYPICAL PEDON: Rudder gravelly loam on a mountain side under a cover of Bishop Pines at an elevation of 950 feet (290 meters). (Colors are for dry soil unless otherwise noted).
Oi--0 to 2 inches, (0 to 5 cm); slightly decomposed pine needles and sticks; abrupt smooth boundary. (2 to 4 inches thick, 5 to 10 centimeters)
Oe--2 to 4 inches, (5 to 9 cm); moderately decomposed pine needles; abrupt smooth boundary. (2 to 4 inches thick, 5 to 10 centimeters)
A1--4 to 8 inches, (9 to 20 cm); grayish brown(10YR 5/2) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky; 1 percent 75 to 250 millimeter cobbles and 25 percent 2 to 75 millimeter gravel; very strongly acid (pH 4.6); clear wavy boundary. (2 to 10 inches thick, 55 to 25 centimeters)
A2--8 to 22 inches, (20 to 55 cm); light brownish gray (10YR 6/2) gravelly sandy loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky; 1 percent 75 to 250 millimeter cobbles and 25 percent 2 to 75 millimeter gravel; very strongly acid (pH 4.6); clear wavy boundary. (10 to 20 inches thick, 25 to 50 centimeters)
Bw--22 to 28 inches, (55 to 72 cm); light yellowish brown (10YR 6/4) gravelly sandy loam, yellowish brown (10YR 5/4) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky; 1 percent 75 to 250 millimeter cobbles and 34 percent 2 to 75 millimeter gravel; very strongly acid (pH 4.6); abrupt wavy boundary. (4 to 10 inches thick, 10 to 25 centimeters)
Cr--28 to 32 inches, (72 to 81 cm); rigid volcanic breccia with many fractures less than 2 to 8 cm apart; abrupt wavy boundary. (3 to 40 inches thick, 7 to 102 centimeters)
R--32 inches, (81 to 82 cm); extremely rigid volcanic breccia with fractures greater than 10 cm apart.
TYPE LOCATION: Santa Cruz Island, Santa Barbara County, California, in the Channel Islands Soil Survey Area 34 degrees North latitude, 0 minutes, 1 seconds and 119 degrees, 49 minutes, 18 seconds West longitude, NAD83; U.S.G.S Quad: Santa Cruz Island
RANGE IN CHARACTERISTICS:
The soil moisture control section is dry in all parts from about mid-September to mid-November (about 90 days) and is usually moist the rest of the time.
The mean annual soil temperature at a depth of 50 cm (20 inches) is between than 12 and 15 degrees C (54 and 59 degrees F) and the mean summer and mean winter temperatures vary less than 6 degrees C.
Base saturation by sum of bases ranges from 45 to 75 percent.
Depth to bedrock is 32 to 104 centimeters (13 to 41 inches) but is best represented by 50 to 100 centimeters (20 to 40 inches).
The particle size control section averages 10 to 18 percent clay, and 5 to 35 percent rock fragments.
The A horizon dry color is 10YR 5/2, 6/2, or 6/3. Moist color is 10YR 3/2, 4/2, or 4/3.
The Bw horizon dry color is 10YR 6/3, 6/4 or 5/4. Moist color is 10YR 5/3, 5/4, 4/3 or 4/4.
Textures are gravelly sandy loam or gravelly coarse sandy loam.
Clay films: Very few to few clay films occur in some pedons. These are not argillic horizons.
COMPETING SERIES: There are no competing soils in this family.
GEOGRAPHIC SETTING: Rudder soils are on northerly side slopes of mountains on islands. They formed in breccia, andesite, and basalt. Slopes are 30 to 75 percent. Elevations are 700 to 1600 feet (213 to 488 meters). The climate is characterized by warm, dry summers and cool, moist winters with fog throughout the year. The mean annual precipitation is 13 to 24 inches (330 to 610 mm) the mean annual temperature is 55 to 61 degrees F (13 to 16 degrees C), and the frost free season is 320 to 365 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Spinnaker and Starboard soils. Spinnaker soils are found on convex and linear summits, shoulders and side slopes of mountains, primarily on southern aspects. Starboard soils are located on side slopes of mountains, canyons, valleys, hanging-valleys and draws.
DRAINAGE AND PERMEABILITY: Well drained; very high runoff; moderately slow permeability.
USE AND VEGETATION: Wildlife habitat, recreation and building site development. Vegetation is Bishop Pine woodland.
DISTRIBUTION AND EXTENT: Santa Barbara County, California. The soil is not extensive. MLRA 20.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Los Angeles County, California, 2006.
REMARKS: The series name is coined. Isomesic is determined from data gathered from NRCS Soil Temperature/Soil Moisture climate stations. Diagnostic horizons and features recognized in this pedon:
Ochric epipedon--The zone from the soil surface to a depth of about 22 inches (A horizons).
Cambic horizon--The zone from a depth of 22 inches to a depth of about 28 inches (Bw horizon).
Paralithic material--The zone from a depth of 28 inches to about 32 inches (Cr horizon)