LOCATION SWISSRANCH              CA

Established Series
BJM/AJP/TKK/JW
09/2018

SWISSRANCH SERIES

The Swissranch series consists of very deep, well drained soils formed in colluvium derived from tuff over residuum derived from rhyolite or acidic tuff. The Swissranch soils are on the backslopes and footslopes of high hills. Slopes range from 15 to 60 percent. The mean annual precipitation is about 1020 mm and the mean annual air temperature is about 14 degrees C.

TAXONOMIC CLASS: Fine-loamy, isotic, mesic Vitrandic Dystroxerepts

TYPICAL PEDON: Swissranch ashy fine sandy loam on a northwest-facing, 55 percent, linear slope, under interior live oak, manzanita, and chamise at an elevation of 800 meters. (Colors are for dry soils unless otherwise noted. When described on August 13, 2009 the soil was dry throughout.)

A--0 to 15 cm; light gray (2.5Y 7/2) gravelly ashy fine sandy loam, dark gray (10YR 4/1) moist; 12 percent clay; moderate medium granular structure; soft, very friable, slightly sticky, slightly plastic; many very fine and fine roots, and few medium roots throughout; common medium irregular pores; 15 percent angular strongly cemented acidic tuff gravel; slightly acid (pH 6.2); clear smooth boundary. (3 to 25 cm thick)

Bw1--15 to 48 cm; light gray (10YR 7/2) ashy sandy clay loam, grayish brown (10YR 5/2) moist; 23 percent clay; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; many very fine, fine, and medium roots throughout; common medium tubular pores; very strongly acid (pH 5.0); clear smooth boundary.

Bw2--48 to 85 cm; light brownish gray (10YR 6/2) sandy clay loam, grayish brown (10YR 5/2) moist; 24 percent clay; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine and fine roots, and many medium roots throughout; common medium tubular pores; very strongly acid (pH 4.7); clear smooth boundary.

Bw3--85 to 122 cm; light gray (10YR 7/2) sandy clay loam, brown (10YR 5/3) moist; 20 percent clay; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; few very fine to very coarse roots throughout; common medium tubular pores; very strongly acid (pH 4.6); clear smooth boundary. (Combined thickness of Bw horizons is 50 to 150 cm thick)

C--122 to 158 cm; very pale brown (10YR 8/2) sandy loam, grayish brown (10YR 5/2) moist; 15 percent clay; massive; slightly hard, friable, slightly sticky, slightly plastic; few very fine roots throughout; 3 percent angular strongly cemented acidic tuff gravel; extremely acid (pH 4.4); abrupt smooth boundary. (0 to 50 cm thick)

Cr--158 to 200 cm; moderately cemented acidic tuff bedrock, fractured at intervals of 45 to <100 cm; extremely acid (pH 4.4).

TYPE LOCATION: Calaveras County, California, about 6.6 km (4.1 miles) southeast of the community of Railroad Flat, CA; USGS 7.5 minute topographic quadrangle: Fort Mountain, California; WGS84 38.285483 latitude and -120.489678 longitude; UTM Zone 10 719559 meters E 4240472 meters N NAD83.

RANGE IN CHARACTERISTICS:
Soil temperature: The mean annual soil temperature at 50 cm is 8 to 15 degrees C and the difference between mean summer and mean winter soil temperature is greater than 6 degrees C. The soils have a mesic temperature regime.

Soil moisture: The soil moisture control section is dry in all parts from about June to October. The soils have a xeric soil moisture regime.

Diagnostic Feature(s):
Ochric epipedon thickness: 5 to 18 cm
Cambic horizon thickness: 75 to 145 cm
Depth to paralithic contact: 150 to 200 cm

Organic matter: 1 to 6 percent in the epipedon

Reaction: moderately to slightly acid in the epipedon (5.1-6.5) and very strongly to moderately acid in the control section (4.5-6.0).

Base saturation: less than 60 percent in all horizons between 25 and 75 cm (by ammonium acetate)

Volcanic glass: greater than 30 percent in a layer 18 cm or more thick within 75 cm of the mineral soil surface.

Particle size control section weighted average:
Rock fragments: 0 to 35 percent, with 0 to 35 percent gravel and 0 to 5 percent cobbles.
Clay content: averages 18 to 27 percent clay

A horizon
Hue: 2.5Y or 10YR
Value: 5 to 7 dry, 3 to 5 moist
Chroma: 2 or 3 dry, 1 to 3 moist
Texture: sandy loam, fine sandy loam, or loam
Clay content: 10 to 20 percent
Rock fragments: 0 to 35 percent
0 to 35 percent gravel
0 to 35 percent channers

Bw1, Bw2, and Bw3 horizon
Hue: 2.5Y or 10YR
Value: 5 to 7 dry, 4 or 5 moist
Chroma: 2 or 3 dry, 2 to 4 moist
Texture: sandy loam, fine sandy loam, or sandy clay loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 35 percent
0 to 35 percent gravel
0 to 5 percent cobbles
0 to 35 percent channers

C horizon
Hue: 2.5Y or 10YR
Value: 6 to 8 dry, 4 to 6 moist
Chroma: 2 or 3 dry, 2 to 4 moist
Texture: sandy loam, fine sandy loam, or sandy clay loam
Clay content: 12 to 27 percent
Rock fragments: 0 to 35 percent
0 to 35 percent gravel
0 to 5 percent cobbles
0 to 35 percent channers

COMPETING SERIES: There are no other series in this family at this time.

GEOGRAPHIC SETTING: The Swissranch soils are on backslopes and footslopes of high hills. Slopes range from 15 to 60 percent. These soils formed in colluvium over residuum derived from acidic tuff or rhyolite. Elevation is 675 to 975 meters. The climate is Mediterranean with warm, dry summers and cool, moist winters. The mean annual precipitation is 970 to 1190 mm and the mean annual air temperature is 13 to 15 degrees C. The frost free season is 195 to 245 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fuches, Supan, Crozier, McCarthy, and Iron Mountain soils. Fuches soils occupy similar hillslope positions adjacent as Swissranch but are shallow to bedrock. Supan, Iron Mountain, Crozier and McCarthy soils develop on ridges or nearby mountain slopes from basic volcanic rocks including tuff breccia, tuff, or agglomerate. Supan, Crozier, and McCarthy soils are moderately deep to bedrock. Iron Mountain soils are shallow and have a mollic epipedon.

DRAINAGE AND PERMEABILITY: Well drained; moderately high to high saturated hydraulic conductivity throughout the profile. Saturated hydraulic conductivity of the bedrock is very to moderately low.

USE AND VEGETATION: This soil is used for recreation and wildlife habitat. Vegetation is mainly shrubs interspaced with some conifers. Shrub species include manzanita, chamise, live oak, and poison oak.

DISTRIBUTION AND EXTENT: Sierra Nevada Mountains of California; MLRA 22A. This series is not extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES PROPOSED: Calaveras County, California. Source of the name is from a road near the type location.

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric Epipedon 0 to 15 cm (A horizon)
Cambic Horizon 15 to 122 cm (Bw1, Bw2, and Bw3 horizon)
Paralithic Contact 158 to 200 cm
Particle Size Control Section for this pedon: 25 to 100 cm.

ADDITIONAL DATA:
NASIS User Pedon ID: 09BJM095
Pedon Type: OSD pedon
Lab Source ID: SSL
Pedon Purpose: laboratory sampling site
Lab Pedon #: 10N0900

Soil classified using the 12th Edition of the Keys to Soil Taxonomy.

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National Cooperative Soil Survey
U.S.A.