LOCATION GREENWELL CAEstablished Series
TAXONOMIC CLASS: Medial, amorphic, frigid Humic Haploxerands
TYPICAL PEDON: Greenwell medial sandy loam, on a northwest facing 17 percent slope under a cover of mixed conifers and shrubs at an elevation of 4975 feet, (1516 m). When described on 12/16/1996 the soil was moist throughout. (Colors are for dry soil unless otherwise noted).
Oi--0 to 2 inches, (0 to 5 cm); slightly decomposed needles and twigs; abrupt smooth boundary.
Oe--2 to 3 inches, (5 to 8 cm); moderately decomposed needles and twigs; abrupt smooth boundary.
A1--3 to 5 inches, (8 to 13 cm); brown (10YR 5/3) medial sandy loam, dark brown (7.5YR 3/2) moist; 8 percent clay; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; few fine and common very fine roots; common very fine irregular and few very fine vesicular pores; 5 percent subrounded andesite gravel; slightly acid, pH 6.5 by Hellige-Truog; NaF pH 12.0; abrupt smooth boundary.
A2--5 to 10 inches, (13 to 26 cm); brown (10YR 5/3) medial sandy loam, dark brown (10YR 3/3) moist; 10 percent clay; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; few fine and medium and common very fine roots; common very fine irregular pores; 10 percent subrounded andesite gravel; slightly acid, pH 6.3 by Hellige-Truog; NaF pH 11.7; abrupt smooth boundary. (Combined thickness of the A horizon is 2 to 13 inches, (5 to 33 cm) thick)
Bw--10 to 18 inches, (26 to 46 cm); light yellowish brown (10YR 6/4) gravelly medial sandy loam, dark brown (10YR 3/3) moist; 12 percent clay; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; many fine and medium, few coarse roots and common very fine roots; common very fine irregular pores; 16 percent subrounded andesite gravel; slightly acid, pH 6.3 by Hellige-Truog; NaF pH 11.5; clear smooth boundary. (8 to 33 inches, (20 to 84 cm) thick)
2BC1--18 to 23 inches, (46 to 59 cm); very pale brown (10YR 7/3) medial sandy loam, brown (10YR 4/3) moist; 18 percent clay; weak very fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; common fine and medium and few coarse roots; common very fine irregular pores; 5 percent subrounded andesite cobbles; strongly acid, pH 5.5 by Hellige-Truog; NaF pH 11.0; gradual wavy boundary.
2BC2--23 to 32 inches, (59 to 82 cm); very pale brown (10YR 7/3) very gravelly medial sandy loam, brown (10YR 4/3) moist; 18 percent clay; weak very fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; few fine roots and common medium and coarse roots top of horizon; common very fine irregular pores; 5 percent subangular andesite cobbles and 40 percent subangular andesite gravel; strongly acid, pH 5.5 by Hellige-Truog; NaF pH 10.7; abrupt smooth boundary. (Combined thickness of the 2BC horizon is 0 to 14 inches, (0 to 36 cm) thick)
2Cr--32 inches, (82 cm); moderately cemented volcanic mudflow bedrock imbedded with well rounded andesite gravel and cobbles; few fine roots in cracks greater than 10 inches, (25 cm) apart.
TYPE LOCATION: Plumas County, California, about 2.1 miles south of Camel Peak Lookout, approximately 2050 feet west and 1400 feet north of the southeast corner of Section 8, Township 21 N., Range 8 E., 39 degrees, 41 minutes, 18 seconds North latitude and 121 degrees, 6 minutes, 26 seconds West longitude, NAD83 - U.S.G.S Quad: American House, California.
RANGE IN CHARACTERISTICS: Depth to paralithic bedrock is 20 to 40 inches, (51 to 102 cm). The mean annual soil temperature is 40 to 47 degrees F, (4 to 8 degrees C). The particle-size control section averages 10 to 18 percent clay and 0 to 34 percent rock fragments, mostly gravel. Mineralogy is amorphic. Organic matter ranges from 4 to 35 percent to a depth of 32 inches, (81 cm). Base saturation by ammonium acetate ranges from 10 to 35 percent to a depth of 32 inches, (81 cm). Rock fragments on the surface range from 0 to 5 percent gravel, 0 to 5 percent cobbles, 0 to 5 percent stones and 0 to 5 percent boulders.
The A horizon dry color is 10YR 3/2, 3/3, 4/2, 5/2 or 5/3. Moist color is 10YR 2/1, 3/2, 3/3 or 7.5YR 3/2. Texture is medial sandy loam or gravelly medial sandy loam. Clay content ranges from 8 to 11 percent. Rock fragments range from 0 to 25 percent gravel. NaF pH ranges from 9 to 12. Reaction ranges from very strongly acid to slightly acid.
The Bw horizon dry color is 10YR 4/3, 5/3, 6/3, 6/4, 7.5YR 4/2, 4/3, 5/3 or 6/3. Moist color is 10YR 3/3, 4/3, 7.5YR 3/2, 3/3, 4/2 or 5YR 3/2. Texture is medial sandy loam, gravelly medial sandy loam or gravelly medial coarse sandy loam. Clay content ranges from 10 to 15 percent. Rock fragments range from 0 to 25 percent gravel and 0 to 5 percent cobbles. NaF pH ranges from 11.0 to 11.5. Reaction ranges from very strongly acid to slightly acid.
The 2BC horizon dry color is 10YR 5/4, 7/3, 7.5YR 4/3 or 6/3. Moist color is 10YR 4/3, 7.5YR 3/3 or 4/3. Texture is medial sandy loam, gravelly medial sandy loam, very gravelly medial coarse sandy loam or very gravelly medial sandy loam. Clay content ranges from 12 to 18 percent. Rock fragments range from 0 to 60 percent gravel and 0 to 10 percent cobbles. NaF pH ranges from 10.5 to 11.0. Reaction ranges from very strongly acid to strongly acid.
COMPETING SERIES: This is the Ahart series. Ahart soils have base saturation between 25 and 50 percent throughout the profile. The thickness of the umbric epipedon ranges from 20 to 38 inches (51 to 97 cm).
GEOGRAPHIC SETTING: Greenwell soils are on lahar over narrow basalt plateaus in volcanic Sierra Nevada mountains. Slopes range from 2 to 50 percent. These soils formed in tephra over residuum and colluvium weathered from volcanic mudflow. Elevation is 4800 to 5700 feet, (1463 to 1737 m). Mean annual precipitation is 75 to 80 inches, (1905 to 2032 mm). The mean annual temperature is 48 to 50 degrees F, (9 to 10 degrees C). Frost free season is 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonneyridge, Lavatop, Lewisflat, McNair, Powderhouse, Timberisland, and Shakeridge soils. Bonneyridge soils are very deep, coarse-loamy, have an ochric epipedon, and are formed in colluvium and residuum from quartz diorite. Lavatop soils are moderately deep to lithic basalt bedrock. Lewisflat soils are very deep, fine-loamy, and formed in residuum and colluvium from quartz diorite. McNair soils are deep to paralithic bedrock of volcanic mudflow. Powderhouse soils are medial-skeletal. Timberisland soils are deep to lithic basalt bedrock. Shakeridge soils are very deep.
DRAINAGE AND PERMEABILITY: Well drained; high runoff; moderately rapid saturated hydraulic conductivity in the A, Bw and 2BC horizons.
USE AND VEGETATION: This soil is used for timber production, wildlife habitat and watershed. Vegetation is white fir, sugar pine, incense cedar, Douglas-fir, ponderosa pine, California black oak with an understory of Sierra chinquapin, greenleaf manzanita, Sierra gooseberry, snowberry, currant, scrub oak, and princes pine. Above 5,000 feet, (1524 m) California red fir, Jeffrey pine, and pinemat manzanita occur.
DISTRIBUTION AND EXTENT: Plumas county and are mapped in the upper Batholith and Volcanic Flows subsection of the Sierra Nevada section MLRA: 22A - Sierra Nevada Range. The soils are inextensive
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Plumas County, California 2005. Source of name from Greenwell Saddle near Timberisland.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric Epipedon - zone from 3 to 10 inches, (8 to 26 cm) (A1, A2)
Cambic Horizon - zone from 10 to 32 inches, (26 to 82 cm) (Bw, 2BC1, 2BC2)
Paralithic Contact - 32 inches, (82 cm) (2Cr)
Andic soil properties zone from 3 to 32 inches (8 to 82 cm) assumed from nearby pedon
Particle Size Control Section for this pedon: 3 to 32 inches, (8 to 81 cm) (A1, A2, Bw, 2BC1, 2BC2)
The soil moisture control section 9 to 32 inches, (23 to 81 cm) is dry in all parts from about July to October (about 90 days).