LOCATION STEEPSHRUB              NV

Established Series
Rev. DHZ/TM
11/2016

STEEPSHRUB SERIES

The Steepshrub series consists of very deep, well drained soils that formed in colluvium and residuum derived from quartzite. Steepshrub soils are on mountains. Slope ranges from 30 to 75 percent. The mean annual precipitation is about 750 mm and the mean annual temperature is about 2 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Xeric Haplocryolls

TYPICAL PEDON: Steepshrub very gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with 65 percent gravel.

Oe--0 to 1 cm; moderately decomposed plant material. (1 to 2 cm thick)

Oa--1 to 5 cm; very dark brown (10YR 2/2) highly decomposed plant material, black (10YR 2/1) moist; many very fine roots; 65 percent gravel; neutral (pH 6.9); clear smooth boundary. (2 to 5 cm thick)

A1--5 to 15 cm; dark brown (10YR 3/3) very gravelly loam, very dark brown (10YR 2/2) moist; moderate coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine, common fine and medium roots; common very fine, fine, and medium and few coarse tubular and interstitial pores; very few distinct sand coats on bottom surfaces of rock fragments and on faces of peds; 50 percent gravel; neutral (pH 6.8); clear smooth boundary. (3 to 15 cm thick)

A2--15 to 30 cm; dark brown (10YR 3/3) very gravelly loam, very dark brown (10YR 2/2) moist; moderate coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine, common fine and medium roots; common very fine, fine, and medium and few coarse tubular and interstitial pores; very few distinct sand coats on bottom surfaces of rock fragments and on faces of peds; 40 percent gravel; neutral (pH 6.8); clear wavy boundary. (10 to 30 cm thick)

Bw--30 to 60 cm; dark yellowish brown (10YR 4/4) extremely gravelly loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine, fine, medium, and coarse roots; few very fine and fine and common medium and coarse interstitial pores; very few distinct sand coats on bottom surfaces of rock fragments and on faces of peds; 65 percent gravel; neutral (pH 6.8); clear wavy boundary. (15 to 70 cm thick)

C--60 to 152 cm; dark yellowish brown (10YR 4/4) gravel, dark brown (10YR 3/3) moist; loose; common very fine and fine roots; common very fine, fine, medium, and coarse interstitial pores; very few distinct sand coats on bottom surfaces of rock fragments; 90 percent gravel; sloughs readily when excavated; neutral (pH 6.8).

TYPE LOCATION: White Pine County, Nevada; in the Schell Creek Range of the Humboldt-Toiyabe National Forest about 0.9 miles southwest of South Schell Peak; T. 17 N., R. 65 E.; USGS South Schell Peak 7.5 minute topographic quadrangle; latitude 39 degrees 19 minutes 29 seconds N and longitude 114 degrees 36 minutes 31 seconds W; WGS84 Decimal Degrees 39.3247417 latitude, -114.6085000 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter, spring, and early summer, dry in mid-summer and fall, but intermittently moist due to summer convection storms in late August and September; dry in all parts at least 45 consecutive days following the summer solstice. Typic xeric soil moisture regime.
Mean annual soil temperature: 3 to 5 degrees C.
Mean summer soil temperature: 7 to 8 degrees C.
Mean winter soil temperature: 0 to 2 degrees C.
Mollic epipedon thickness: 18 to 40 cm.
Reaction: Slightly acid or neutral.

Particle-size control section - Clay content: Averages 8 to 18 percent;
Rock fragments: 70 to 90 percent, mainly gravel, with 0 to 20 percent cobbles. Lithology of the fragments is quartzite.

O horizons
Texture: Moderately decomposed and highly decomposed plant material derived from mountain big sagebrush leaves and twigs and grass residues.

A horizons
Value: 3 or 4 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Consistence: Soft or slightly hard, dry.

Bw horizon
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 3 or 4 moist.
Clay content: 16 to 24 percent
Rock fragments: 60 to 85 percent, mainly gravel, with 0 to 20 percent cobbles.
Structure: Medium or coarse subangular blocky.
Consistence: Soft or slightly hard, dry.
Concentrations: Faint or distinct sand and silt coats on the bottoms of rock fragments and faces of peds.

C horizon
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 3 or 4 moist.
Texture: Extremely gravelly loam or gravel.
Clay content: 0 to 8 percent.
Rock fragments: 85 to 95 percent, mainly gravel, with 0 to 20 percent cobbles.
Consistence: Loose or soft, dry.
Concentrations: Faint or distinct sand or silt coats on the bottoms of rock fragments.

COMPETING SERIES: These are the Basinpeak, Berrycreek, Decram, Fairydell, Foxmount, Gaia, Klug, Krackle, Lag, Middlehill, Rockabin, Sup, Timmercrek, and Wareagle series.

Basinpeak soils do not have cambic horizons.
Berrycreek soils have 45 to 65 percent rock fragments and 18 to 27 percent clay in the particle-size control section.
Decram soils are moderately deep to lithic contacts.
Fairydell soils have Bk and Bqk horizons.
Foxmount soils formed in tuff and volcanic flow rock and have paralithic contacts at 61 to 100 cm.
Gaia soils do not have cambic horizons.
Klug soils have mean summer soil temperatures of 9.4 to 12.2 degrees C, no O horizons, and 40 to 80 percent rock fragments in the C horizon.
Krackle soils have a lithic contact at 61 to 100 cm and have 27 to 35 percent clay in the control section.
Middlehill soils have a lithic contact at 61 to 100 cm and have Bk horizons.
Rockabin soils have a paralithic contact at 61 to 100 cm.
Sup soils do not have cambic horizons.
Timmercrek soils have lamellae in the C horizons.
Wareagle soils have 40 to 70 rock fragments in the particle size control section.

GEOGRAPHIC SETTING: Steepshrub soils are on mountains. They typically are on backslope and shoulder positions. These soils formed in colluvium and residuum derived from quartzite. Slopes are 30 to 75 percent. Elevations range from 2,600 to 3,350 meters. The climate is subhumid, continental with cold, snowy winters and cool, dry summers. The mean annual precipitation is 600 to 950 mm, mean annual temperature is 1.5 to 4 degrees C., and the frost-free period is 30 to 50 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cobblywheel and Keyole soils and the competing Berrycreek soil. Keyole and Cobblywheel soils do not have mollic epipedons.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Steepshrub soils are used for recreation, livestock grazing, and wildlife habitat. The native vegetation is mainly slender wheatgrass, Letterman's needlegrass, mountain big sagebrush, and gooseberry currant. This pedon is correlated to Ecological Site R028BY104NV, Loamy Slope 20+ P.Z.

DISTRIBUTION AND EXTENT: Eastern Nevada. These soils are not extensive. MLRA 28B.

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

SERIES ESTABLISHED: White Pine County, Humboldt-Toiyabe National Forest, South Part, Nevada, 2013. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 5 to 30 cm (A1 and A2 horizons).
Cambic horizon - The zone from 30 to 60 cm (Bw horizon).
Particle-size control section - The zone from 30 to 105 cm (Bw horizon and upper part of the C horizon; 25 to 100 cm from the mineral soil surface).

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National Cooperative Soil Survey
U.S.A.