LOCATION HARDTIL CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Humic Lithic Dystroxerepts
TYPICAL PEDON: Hardtil gravelly loamy coarse sand--forest land. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with 35 percent gravel, 5 percent cobbles, 5 percent stones, and 5 percent boulders.
A1--0 to 3 inches; grayish brown (10YR 5/2) gravelly loamy coarse sand, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; common very fine interstitial and tubular pores; 25 percent gravel and 5 percent stones; slightly acid; clear wavy boundary. (3 to 6 inches thick)
A2--3 to 7 inches; brown (10YR 5/3) very gravelly coarse sandy loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; common very fine interstitial and tubular pores; 45 percent gravel and 10 percent cobbles; slightly acid; clear wavy boundary. (4 to 7 inches thick)
Bw--7 to 18 inches; light yellowish brown (10YR 6/4) very gravelly coarse sandy loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, common fine, and common medium roots; common very fine interstitial and tubular pores; few medium distinct brown (7.5YR 4/4) moist masses of iron accumulation; 55 percent gravel; moderately acid; abrupt wavy boundary. (3 to 11 inches thick)
R--18 inches; hard granitic rock.
TYPE LOCATION: Alpine County, California; on the Toiyabe National Forest about 2,100 feet south of Hope Valley Campground; approximately 1,600 feet north and 800 feet west of the southeast corner of section 7, T. 10 N., R. 19 E.; USGS Carson Pass 7.5 minute topographic quadrangle; 38 degrees 43 minutes 30.1 seconds north latitude and 119 degrees 55 minutes 33.8 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in the moisture control section; moist fall, winter, and spring; usually dry July through early October; saturated within a 3 to 6 inch thick layer directly overlying bedrock for greater than 20 consecutive days during the spring or early summer; Xeric moisture regime.
Mean annual soil temperature - 44 to 47 degrees F.
Mean summer soil temperature - 59 to 62 degrees F.
Umbric epipedon thickness - 7 to 12 inches.
Depth to bedrock - 10 to 20 inches to a lithic contact.
Particle-size control section - Clay content: Averages 8 to 15 percent; Rock fragments: Averages 35 to 60 percent, mainly gravel. Lithology of fragments are mainly granitic rocks such as granodiorite.
A horizons - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 2 to 4 percent.
Reaction: Moderately acid or slightly acid.
Bw horizon - Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 8 to 15 percent.
Rock fragments: 35 to 60 percent.
Reaction: Moderately acid or slightly acid.
Redoximorphic features: Redox concentrations occur as masses of iron accumulation.
Other features: Some pedons lack cambic horizons when the Bw horizon is less than 6 inches thick.
COMPETING SERIES: This is the Woodseye series.
Woodseye soils average more than 18 percent clay in the particle-size control section and have subhorizons with more than 60 percent rock fragments.
GEOGRAPHIC SETTING: Hardtil soils are on mountains. They formed in till derived from mixed rocks and colluvium derived mainly from granitic rocks. Slopes are 8 to 75 percent. Elevations range from 7,000 to 8,000 feet. The climate is subhumid-continental with cold, moist winters and cool, dry summers. The mean annual precipitation is 20 to 45 inches, mean annual temperature is 39 to 45 degrees F., and the frost-free period is 40 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alpineco and Burnlake soils. Alpineco soils are deep to lithic contacts. Burnlake soils are very deep and occur on adjacent moraines.
DRAINAGE AND PERMEABILITY: Moderately well drained; very high surface runoff; rapid permeability (high or very high saturated hydraulic conductivity). Endosaturation is present with an apparent seasonal high water table occurring somewhere between 7 and 17 inches (very shallow or shallow free water occurrence class) from April to June. Cumulative annual duration class is Transitory. The water table only occurs during spring and early summer when the snowpack melts and subsurface water moves laterally above the bedrock.
USE AND VEGETATION: Hardtil soils are used for forest land, recreation, watershed, and wildlife habitat. The native vegetation is mainly a forest canopy of lodgepole pine, Jeffrey pine, and Sierra juniper with an understory of sedge, bluegrass, needlegrass, snowberry, and currant.
DISTRIBUTION AND EXTENT: Eastern California, on the east side of the Sierra Nevada Range. These soils are not extensive with about 3,100 acres of the series mapped to date. MLRA 22A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Alpine County (Toiyabe National Forest Area), California, 2006.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - The zone from the soil surface to 7 inches (A1 and A2 horizons).
Cambic horizon - The zone from 7 to 18 inches (Bw horizon).
Lithic contact - The boundary at 18 inches to underlying hard bedrock (R layer).
Particle-size control section - The zone from 10 to 18 inches (part of the Bw horizon).
ADDITIONAL DATA: The Bw horizon of the typical pedon at the series type location is sampled for the Soil Survey Laboratory (SSL), Lincoln, NE as soil survey sample number S99CA-003-010 (pedon # 00P0473).