LOCATION CAHOON CA

Established Series
JBB/CES
09/2021

CAHOON SERIES

The Cahoon series consists of very deep, moderately well drained soils formed in outwash over till derived from granitic rocks. The Cahoon soils are on moraines and outwash plains of the Sierra Nevada Mountains. Slopes range from 2 to 20 percent. The mean annual precipitation is about 1000 mm and the mean annual air temperature is about 6 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Vitrandic Humixerepts

TYPICAL PEDON: Cahoon sandy loam on an east-facing (70 degree), 7 percent slope under Sierra lodgepole pine at an elevation of 2631 meters. (Colors are for dry soils unless otherwise noted. When described on August 28, 2014 the soil was dry throughout.)

Oi--0 to 7 cm; slightly decomposed plant material, dark brown (7.5YR 3/3) moist; very strongly acid (pH 4.8); clear smooth boundary. (0 to 10 cm thick)

A1--7 to 27 cm; brown (10YR 4/3) sandy loam, very dark brown (10YR 2/2) moist; 8 percent clay; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common very fine, fine, medium, coarse, and very coarse roots throughout; common very fine and fine dendritic tubular pores; 5 percent subrounded indurated granite gravel, 2 percent subrounded indurated granite cobbles, 2 percent subrounded indurated granite stones, 2 percent subrounded indurated granite boulders; NaF pH 9.5; very strongly acid (pH 5.0); gradual smooth boundary.

A2--27 to 62 cm; brown (10YR 4/3) very bouldery sandy loam, very dark brown (10YR 2/2) moist; 10 percent clay; moderate medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common very fine, fine, medium, and coarse roots throughout; common very fine and fine dendritic tubular, and common medium interstitial pores; 5 percent subrounded indurated granite gravel, 5 percent subrounded indurated granite cobbles, 10 percent subrounded indurated granite stones, 20 percent subrounded indurated granite boulders; NaF pH 10.5; very strongly acid (pH 5.0); gradual smooth boundary. (combined thickness of A horizons is 15 to 55 cm)

2Bw--62 to 101 cm; brown (7.5YR 5/4) extremely bouldery sandy loam, brown (7.5YR 4/4) moist; 11 percent clay; weak medium subangular blocky structure; slightly hard, friable, nonsticky, nonplastic; common fine and medium roots throughout; common very fine and fine dendritic tubular, and common medium interstitial pores; 1 percent fine faint irregular masses of oxidized iron with diffuse boundaries in matrix; 15 percent subrounded indurated granite gravel, 15 percent subrounded indurated granite cobbles, 15 percent subrounded indurated granite stones, 20 percent subrounded indurated granite boulders; NaF pH 10.5; very strongly acid (pH 5.0); clear smooth boundary. (25 to 60 cm thick)

2C--101 to 150 cm; light yellowish brown (2.5Y 6/3) extremely gravelly loamy sand, dark grayish brown (2.5Y 4/2) moist; 5 percent clay; structureless massive; hard, very firm, nonsticky, nonplastic; few fine roots throughout; common fine interstitial pores; 1 percent fine faint irregular masses of oxidized iron with diffuse boundaries in matrix; 40 percent subrounded indurated granite gravel, 5 percent subrounded indurated granite cobbles, 15 percent subrounded indurated granite stones; NaF pH 10.5; very strongly acid (pH 5.0).

TYPE LOCATION: Tulare County, California, 1/2 mi South of Hockett Ranger Station; USGS 7.5 minute topographic quadrangle: Moses Mountain, California; WGS84 36.371392 latitude and -118.655714 longitude; UTM zone 11 4026416 meters N 351471 meters E WGS84.

RANGE IN CHARACTERISTICS:
Soil temperature: The mean annual soil temperature at 50 cm is 5 to 8 degrees C and the difference between mean summer and mean winter soil temperature is greater than 6 degrees C. The soils have a frigid temperature regime.

Soil moisture: The soils have a xeric soil moisture regime. The soil moisture control section is dry in all parts from about August to October (about 90 days).

Diagnostic Feature(s):
Umbric epipedon thickness: 25 to 75 cm
Cambic horizon thickness: 0 to 50 cm

Organic matter: 2 to 6 percent in the epipedon

Base saturation: less than 50 percent (by ammonium acetate)

Acid-oxalate extractable Al plus 1/2 Fe: 0.4 to 1.0 percent (by weight) to a depth of 100 cm

Depth to redoximorphic features: 50 to 75 cm

Volcanic glass: 5 to 30 percent in the 0.02 to 2.0 mm fraction in an 18 cm thick layer within a depth of 75 cm from the mineral soil surface

Particle size control section weighted average:
Rock fragments: 35 to 75 percent, with 5 to 35 percent gravel, 0 to 35 percent cobbles, 0 to 15 percent stones and 0 to 15 percent boulders
Clay content: 5 to 12 percent
NaF pH: 9.0 to 11.0

A horizon(s)
Hue: 7.5YR, 10YR
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Texture: sandy loam, fine sandy loam
Clay content: 6 to 12 percent
Rock fragments: 0 to 40 percent
0 to 15 percent gravel
0 to 15 percent cobbles
0 to 15 percent stones
0 to 20 percent boulders
Reaction: very strongly to strongly acid

Bw horizon(s)
Hue: 7.5YR, 10YR
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Texture: sandy loam, fine sandy loam
Clay content: 6 to 12 percent
Rock fragments: 35 to 75 percent
5 to 35 percent gravel
0 to 35 percent cobbles
0 to 15 percent stones
0 to 20 percent boulders
Reaction: very strongly to moderately acid

C horizon(s)
Hue: 10YR, 2.5Y
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Texture: loamy sand, loamy fine sand, sand, fine sand
Clay content: 1 to 5 percent
Rock fragments: 15 to 60 percent
5 to 40 percent gravel
0 to 15 percent cobbles
0 to 15 percent stones
0 to 15 percent boulders
Reaction: very strongly to moderately acid

COMPETING SERIES: These are the Bindle (MLRA 6) and Mineralking soils. Bindle soils formed in mixed ash, loess, and colluvium from mafic volcanic rocks, and have a lithic contact between 50 and 100 cm. Mineralking soils formed in colluvium from metasedimentary rocks, are well drained, and have subangular or angular fragments.

GEOGRAPHIC SETTING: The Cahoon soils are on linear backslopes and footslopes of moraines and outwash plains on plateaus. Slopes range from 2 to 20 percent. These soils formed in outwash over till derived from granite and granodiorite. Elevation is 2065 to 3175 meters. The climate is Mediterranean with warm, dry summers and cool, moist winters. The mean annual precipitation is 440 to 1345 mm and the mean annual air temperature is 3 to 7 degrees C. The frost free season is 80 to 115 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hockett and Kanawyer soils. The Hockett soils are on linear to concave structural benches of glacial valley-floors, and have a lithic contact between 50 and 100 cm. The Kanawyer soils are on linear to convex moraines and have a densic contact between 100 and 150 cm.

DRAINAGE AND PERMEABILITY: Moderately well drained, low to moderate saturated hydraulic conductivity.

USE AND VEGETATION: This soil is used for recreation, wildlife habitat, and watershed. Vegetation is Sierra lodgepole pine, threadleaf sedge, western needlegrass, squirreltail, and Ross's sedge.

DISTRIBUTION AND EXTENT: Sierra Nevada Mountains of California; MLRA 22A. These soils are of limited extent.

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

SERIES PROPOSED: Tulare County, California in Sequoia and Kings Canyon National Parks. Source of name from Cahoon Meadow near the type location in Sequoia National Park.

REMARKS:
Particle Size Control Section for this pedon: 32 to 107 cm
Diagnostic horizons and features recognized in this pedon are:
Umbric Epipedon 7 to 62 cm
Cambic Horizon 62 to 100 cm
Lithologic Discontinuity 62 cm
Redox Concentrations 62 to 150 cm

ADDITIONAL DATA:
NASIS User Pedon ID: 2014CA7925071

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

National Cooperative Soil Survey
U.S.A.