LOCATION SCAATH CA
Established Series
Rev: ACF/JPS/ET
05/2016
SCAATH SERIES
The Scaath series consists of moderately deep, well drained soils formed in colluvium and residuum derived from sandstone, mudstone, and schist. Scaath soils are on mountains and have slopes of 15 to 75 percent. The mean annual precipitation is about 2290 millimeters (90 inches) and the mean annual temperature is about 12 degrees C (52 degrees F).
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, isomesic Ustic Haplohumults
TYPICAL PEDON: Scaath gravelly loam - on a uniform south-facing slope of 56 percent under tanoak, Douglas fir, Pacific madrone, and sparse California huckleberry at 610 meters (2000 feet) elevation. (Colors are for moist soil unless otherwise noted. When described May 4, 1982, the soil was moist throughout.)
Oi--0 to 4 centimeters (0 to 1 inches); slightly decomposed Douglas-fir needles, twigs, cones, and tanoak leaves; very strongly acid (pH 4.5). (0 to 5 centimeters thick)
Oe--4 to 5 centimeters (1 to 2 inches); moderately decomposed leaves, humus, and fungal mycelia; very strongly acid (pH 4.7). (0 to 3 centimeters thick)
A--5 to 29 centimeters (2 to 11 inches); dark brown (10YR 3/3) gravelly loam, brown (10YR 5/3) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium and few coarse roots; common very fine and fine irregular and common very fine and fine tubular pores; 15 percent fine and 5 percent coarse gravel; strongly acid (pH 5.1); clear wavy boundary. (6 to 41 centimeters thick)
AB--29 to 45 centimeters (11 to 18 inches); dark yellowish brown (10YR 3/4) gravelly clay loam, yellowish brown (10YR 5/4) dry; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common fine, medium and coarse roots; common very fine irregular and common very fine, fine and medium tubular pores; 15 percent fine and 8 percent coarse gravel; strongly acid (pH 5.4); abrupt wavy boundary. (0 to 16 centimeters thick)
2BA--45 to 61 centimeters (18 to 24 inches); brown (7.5YR 4/4) very cobbly clay loam, light brown (7.5YR 6/4) dry; weak fine subangular blocky structure; hard, firm, moderately sticky and slightly plastic; few very fine and fine, common medium and few coarse roots; few very fine irregular and few very fine and fine tubular pores; 25 percent fine and 10 percent coarse gravel and 20 percent cobbles; strongly acid (pH 5.4); clear wavy boundary. (0 to 25 centimeters thick)
2Bt1--61 to 83 centimeters (24 to 33 inches); yellowish brown (10YR 5/6) extremely cobbly clay loam, very pale brown (10YR 7/4) dry; weak fine subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; few very fine, fine and coarse, and common medium roots, few very fine tubular pores; common faint clay films on ped faces; 20 percent coarse and 15 percent fine gravel and 50 percent cobbles; strongly acid (pH 5.4); clear broken boundary.
2Bt2--83 to 94 centimeters (33 to 37 inches); dark yellowish brown (10YR 4/4) extremely gravelly clay loam, light yellowish brown (10YR 6/4) dry; weak coarse subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; few fine and medium roots; few very fine tubular pores; common distinct clay films on ped faces; 50 percent fine and 25 percent coarse gravel; strongly acid (pH 5.5); abrupt irregular boundary. (combined thickness of 2Bt horizons is 15 to 85 centimeters)
2R--94 centimeters (37 inches); fractured shale, fractures mostly less than 1 mm across, and greater than 10 centimeters apart. About 1 percent soil material in fractures and pockets; few medium and fine roots; few very fine interstitial pores; common prominent clay films on fracture faces; strongly acid (pH 5.5).
TYPE LOCATION: Redwood National Park, Humboldt County, California; about 18 kilometers east of the town of Trinidad, 0.15 kilometers on W-Line Road from Bald Hills Road and 305 meters west along the ridge from W-Line Road; southwest quarter, southwest quarter, Section 29, T. 10 N., R. 2 E. WGS84 Decimal degrees 41.2246528 latitude and -123.9826917 longitude; HBLM; USGS Bald Hills Quadrangle; UTM Zone 10 417636mE 4564161mN; NAD83.
RANGE IN CHARACTERISTICS:
Soil Moisture: The soil is usually moist in all parts in the soil moisture control section in most years, but becomes nearly dry in the upper part from about July 15 to October 15 in most years. The soils have an Ustic moisture regime.
Soil Temperature: The mean annual soil temperature is 10 to 13 degrees C (50 to 55 degrees F). The difference between mean summer and mean winter temperature is 2 to 4 degrees C.
Depth to a lithic contact: 50 to 100 centimeters.
Organic Matter: There is 12 to 20 Kg per square meter of organic carbon above the lithic contact.
Reaction is moderately to very strongly acid throughout. Base saturation is 15 to 35 percent at the lithic contact.
Particle-Size Control Section (weighted average):
Rock fragments: 35 to 75 percent gravel and 0 to 50 percent cobbles.
Clay content: 25 to 35 percent clay.
O horizon
Hue: 10YR.
Value: 2 through 6 dry and moist.
Chroma: 1 through 4 dry and moist.
Texture: slightly decomposed organic material.
Wood fragments: 0 to 35 percent.
Reaction: moderately to very strongly acid.
A horizon
Hue: 7.5YR or 10YR.
Value: 3 through 5 dry, 2 through 4 moist.
Chroma: 3 or 4 dry, 2 through 4 moist.
Texture of fine earth: loam.
Rock fragments: 15 to 30 percent gravel and 0 to 5 percent cobbles.
Clay content: 23 to 27 percent.
2Bt horizon (Some pedons lack a lithologic discontinuity)
Hue: 7.5YR or 10YR.
Value: 5 through 7 dry, 3 through 5 moist.
Chroma: 4 through 6 dry and moist.
Texture of fine earth: loam or clay loam.
Rock fragments: 30 to 75 percent gravel and 0 to 50 percent cobbles.
Clay content: 25 to 35 percent.
Some pedons have a C horizon.
C horizon
Hue: 7.5YR, 10YR, or 2.5Y.
Value: 5 through 7 dry, 4 or 6 moist.
Chroma: 4 through 6 dry and moist.
Texture of fine earth: loam.
Rock fragments: 35 to 55 percent gravel and 0 to 15 percent cobbles.
Clay content: 20 to 30 percent.
COMPETING SERIES: At this time there are no other series in this family.
GEOGRAPHIC SETTING: Scaath soils are on strongly convex mountain slopes in highly dissected terrain and on narrow ridges. Slopes are 15 to 75 percent. Elevations are 137 to 972 meters (445 to 3185 feet). The soils formed in colluvium and residuum derived from sandstone, mudstone, and schist. The climate is humid with cool, foggy summers and cool, rainy winters. Mean annual precipitation is 1900 to 2550 millimeters (75 to 100 inches). Mean January temperature is about 8 degrees C; mean July temperature is about 14 degrees C; and the mean annual temperature is 10 to 13 degrees C (50 to 55 degrees F). Frost-free season is about 220 to 290 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Ahpah,
Rockysaddle and
Wiregrass soils. Ahpah and Wiregrass soils have less than 35 percent rock fragments in the particle-size control section. Rockysaddle and Wiregrass soils are more than 100 centimeters (40 inches) deep to bedrock. The Ahpah soils are on gentler slopes, softer bedrock, or higher positions than the Scaath soils. The Rockysaddle and Wiregrass soils are on straight to gently concave slopes, often below the Scaath soils.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high to very high runoff; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: This soil has been used for commercial timber, recreation, wildlife, and watershed. Natural vegetation consists of Douglas fir, tanoak, madrone, scattered redwood and evergreen huckleberry.
DISTRIBUTION AND EXTENT: California Coastal Redwood Belt; MLRA 4B. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Humboldt Del Norte area, California 2007. Source of name is Scaath Creek, a creek east of Klamath Glen, CA.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon - the zone from 0 to 29 centimeters (Oi, Oe, & A horizons)
2. Argillic horizon - the zone from 29 to 94 centimeters (ABt, 2BAt, 2Bt1 & 2Bt2 horizons)
3. Lithic contact - the bedrock interface at 94 centimeters
4. Ultisol feature - base saturation of 34 percent at lithic contact
5. Humult feature - 13.35 kg per square meter organic carbon to a depth of 94 centimeters
6. Particle-size control section - the zone from 29 to 79 centimeters, averages 28 percent clay, by weight, and 56 percent rock fragments, by volume. CEC/clay ratio averages 0.53.
ADDITIONAL DATA: Soil profile samples 82-RNP-10 and 83-RNP-14 were collected at the type location and analyzed at the Oregon State University Soil Testing and Soil Physics Laboratories. Soil sample S83-CA-12-05, from the type location, was analyzed at NSSL for clay mineralogy.
NASIS User Pedon ID: 82CA605REDW023
Soil classified using the 12th Edition of the Keys to Soil Taxonomy.
National Cooperative Soil Survey
U.S.A.