LOCATION DITTMAR CAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, amorphic, frigid Lithic Haploxerands
TYPICAL PEDON: Dittmar, very gravelly ashy sandy loam on a south facing (180 degrees) slope of 28 percent, under a cover of greenleaf manzanita, huckleberry oak, Jeffrey pine at an elevation of 5643 feet, (1720 m). When described on 7/11/07, the soil was dry throughout. (Colors are for dry soil unless otherwise noted).
Oi--0 to 1 inches (0 to 2 cm); slightly decomposed leaves, needles and bark litter; abrupt smooth boundary.
A1--1 to 2 inches (2 to 5 cm); grayish brown (10YR 5/2) very gravelly ashy sandy loam, very dark gray (10YR 3/1) moist; 3 percent clay; weak thin platy structure parting to single grain; loose, nonsticky, nonplastic; many very fine roots; many very fine and fine interstitial pores; 5 percent angular fine gravel, 40 percent angular medium and coarse gravel and 3 percent angular cobbles; strongly acid, pH 5.5 by Hellige-Truog; NaF pH 9.0; abrupt smooth boundary.
A2--2 to 5 inches (5 to 12 cm); grayish brown (10YR 5/2) very gravelly medial sandy loam, very dark gray (10YR 3/1) moist; 3 percent clay; weak fine to coarse granular structure parting to single grain; loose, nonsticky, nonplastic; many very fine and common fine and medium roots; many very fine and fine interstitial and common very fine tubular pores; 12 percent angular fine gravel, 30 percent angular medium and coarse gravel, and 3 percent angular cobbles; slightly acid, pH 6.4 by Hellige-Truog; NaF pH 10.6; abrupt wavy boundary. (Combined thickness of the A horizon is 3 to 6 inches (8 to 15 cm) thick)
Bw1--5 to 7 inches (12 to 19 cm); pale brown (10YR 6/3) very gravelly medial fine sandy loam, dark grayish brown (10YR 4/2) moist; 4 percent clay; weak fine to coarse granular structure parting to single grain; loose, nonsticky, nonplastic; many very fine to very coarse roots; many very fine and fine interstitial and common fine and medium tubular pores; 10 percent angular fine gravel, 18 percent angular medium and coarse gravel, and 8 percent angular cobbles; slightly acid, pH 6.4 by Hellige-Truog; NaF pH 11.5; clear smooth boundary.
Bw2--7 to 15 inches (19 to 37 cm); pale brown (10YR 6/3) extremely stony medial fine sandy loam, dark grayish brown (10YR 4/2) moist; 4 percent clay; weak fine to coarse granular structure parting to single grain; loose, nonsticky, nonplastic; many very fine to very coarse roots; many very fine and fine interstitial and common fine tubular pores; 4 percent angular fine gravel, 8 percent angular medium and coarse gravel, 35 percent angular cobbles, and 35 percent angular stones; slightly acid, pH 6.5 by Hellige-Truog; NaF pH 11.6; clear wavy boundary.
Bw3--15 to 19 inches (37 to 47 cm); brown (10YR 5/3) extremely stony medial fine sandy loam, dark grayish brown (10YR 4/2) moist; 4 percent clay; weak very fine and fine subangular blocky structure parting to single grain; loose, nonsticky, nonplastic; many very fine to very coarse roots; many very fine and fine interstitial pores; 6 percent angular fine gravel, 16 percent angular medium and coarse gravel, 30 percent angular cobbles, and 30 percent angular stones; slightly acid, pH 6.3 by Hellige-Truog; NaF pH 11.6; abrupt wavy boundary. (Combined thickness of the Bw horizon is 12 to 16 inches (30 to 41 cm) thick)
R--19 inches (47 cm); indurated dacite bedrock.
TYPE LOCATION: Plumas County, California, about 0.25 miles northwest of Kelly Camp, approximately 1200 feet east and 600 feet south of the northwest corner of sec 30, T. 30 N., R. 6 E., 40 degrees, 26 minutes, 13 seconds north latitude and 121 degrees, 21 minutes, 40 seconds west longitude, NAD83; USGS Quad: Mount Harkness, California.
RANGE IN CHARACTERISTICS:
Depth to restrictive feature: Lithic contact 10 to 20 inches (25 to 51 cm).
Mean annual soil temperature: 43 to 45 degrees F (6 to 7 degrees C).
Soil moisture control section is dry: July to October (about 90 days).
Particle-size control section (thickest part): 3 to 6 percent clay, and 36 to 86 percent rock fragments.
Surface fragments: 5 to 65 percent gravel, 3 to 45 percent cobbles, 3 to 15 percent stones.
A horizon:
Color dry: 10YR 5/2, 6/2
Color moist: 10YR 3/1, 3/2
Texture: gravelly ashy coarse sandy loam, very gravelly ashy sandy loam, very gravelly medial sandy loam
Clay content: 3 to 4 percent
Rock fragments: 5 to 18 percent fine gravel, 10 to 45 percent medium and coarse gravel, 25 to 55 percent total gravel, 0 to 10 percent cobbles, 25 to 59 percent total rock fragments
Organic matter: 4 to 12 percent
Base saturation by ammonium acetate: 25 to 55 percent
Acid oxalate extractable Al plus 1/2 Fe: 1.20 to 2.00
P retention: 65 to 90 percent
Glass content: 14 to 29 percent
NaF pH: 9.0 to 11.5
Soil reaction: strongly acid to slightly acid
Bw horizon:
Color dry: 10YR 5/3, 6/2, 6/3
Color moist: 10YR 4/2
Texture: very gravelly medial fine sandy loam, extremely stony medial fine sandy loam, extremely stony medial sandy loam, extremely cobbly medial sandy loam
Clay content: 3 to 6 percent
Rock fragments: 5 to 10 percent fine gravel, 5 to 20 percent medium and coarse gravel, 10 to 30 percent total gravel, 5 to 40 percent cobbles, 5 to 40 percent stones, 36 to 82 percent total rock fragments
Organic matter: 3 to 8 percent
Acid oxalate extractable Al plus 1/2 Fe: 2.25 to 5.00
P retention: 85 to 100 percent
Glass content: 4 to 15 percent
NaF pH: 11.5 to 11.6
Soil reaction: slightly acid or neutral
COMPETING SERIES: This is the Woodwest series. The Woodwest soils have an umbric epipedon and have 7 to 12 percent clay in the Bw horizon.
GEOGRAPHIC SETTING: Dittmar soils are on scoured glacial-valley walls in the Southern Cascade mountains. Slopes range from 20 to 80 percent. These soils formed in tephra and residuum from volcanic rocks. Elevation is 5291 to 7406 feet (1613 to 2258 m). The mean annual precipitation is 43 to 91 inches (1092 to 2311 mm). The mean annual temperature is 41 to 43 degrees F (5 to 6 degrees C). Frost free season is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kingsiron, Scoured and Juniperlake soils. The Kingsiron soils are very deep and formed in colluvium on the lower slopes on glacial-valley walls. The Scoured soils are moderately deep to bedrock, and are on glaciated uplands. The Juniperlake soils are deep to dense till, and are on moraines.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; saturated hydraulic conductivity is high.
USE AND VEGETATION: This soil is used for wildlife habitat, recreation, ecosystem management and watershed. Vegetation is greenleaf manzanita, huckleberry oak, bush chinquapin and Jeffrey pine.
DISTRIBUTION AND EXTENT: The soils are inextensive and are mapped in MLRA: 22B Southern Cascade Mountains
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Plumas County California. Source of name from the Dittmar Volcanic Center.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 1 to 5 inches, (2 to 12 cm)
Cambic horizon: 5 to 19 inches, (12 to 47 cm)
Andic soil properties: 2 to 19 inches, (5 to 47 cm)
Particle-size control section: 1 to 19 inches, (2 to 47 cm)
Soil moisture control section: 19 inches, (47 cm)
ADDITIONAL DATA: Classification and properties inferred from lab data from lab pedon number 07N0137 NSSL, Lincoln, NE. NASIS User Pedon ID in Davis, MLRA Office:789305