LOCATION COUNTSHILL CA

Established Series
Rev: JHP/JPS/ET
07/2016

COUNTSHILL SERIES

The Countshill series consists of moderately deep, well drained soils formed in colluvium and residuum derived from siltstone and sandstone. Countshill soils are on mountains and have slopes of 9 to 50 percent. The mean annual precipitation is about 2290 millimeters (90 inches) and the mean annual temperature is about 11 degrees C (52 degrees F).

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Pachic Humixerepts

TYPICAL PEDON: Countshill loam - on a southwest-facing, gently convex slope of 13 percent under annual and perennial grasses at 732 meters (2400 feet) elevation. (Colors are for dry soil unless otherwise stated. When described October 21, 1983, the soil was moist throughout.)

A1--0 to 19 centimeters (0 to 7 inches); dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium granular and weak subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine, common medium roots; common very fine irregular and common very fine and fine tubular pores; strongly acid (pH 5.5); 3 percent gravel; gradual wavy boundary.

A2--19 to 51 centimeters (7 to 20 inches); dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots; common very fine, fine and medium tubular pores; strongly acid (pH 5.5); 5 percent gravel; abrupt irregular boundary. (Combined thickness of the A1 and A2 horizons is 35 to 80 centimeters)

AC--51 to 72 centimeters (20 to 28 inches); brown (10YR 5/3) and light olive brown (2.5Y 5/4) variegated very gravelly loam, dark yellowish brown (10YR 3/4) moist; massive; soft, very friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine and fine tubular pores; strongly acid (pH 5.5); 35 percent gravel, 15 percent cobbles; abrupt, wavy boundary. (15 to 25 centimeters thick)

Cr--72 to 91 centimeters (28 to 36 inches); saprolitic sandy siltstone, easily dug and crushable in one hand; original rock macrostructure still intact throughout; becomes harder at about 90 centimeters; depth to Cr ranges from 62 to 87 centimeters across pit face.

TYPE LOCATION: Redwood National Park, Humboldt County, California; located on a ridgetop in Counts Hill Prairie; northeast quarter, northwest quarter, Section 10, T. 9 N., R. 2 E.; WGS84 Decimal degrees 41.1900028 latitude and -123.9351972 longitude; HBLM; USGS Bald Hills Quadrangle. UTM Zone 10 421594mE 4560248mN; NAD83.

RANGE IN CHARACTERISTICS:

Soil moisture: The soil is dry in all parts in the moisture control section from about July 10 to September 20, and is moist in all parts from about October 1 to June 1. The soils have a xeric moisture regime.

Soil temperature: The mean annual soil temperature is 10 to 15 degrees C (50 to 59 degrees F). The difference between mean summer and mean winter temperature is 6 to 10 degrees C.

Depth to a paralithic contact: 50 to 100 centimeters.

Depth to lithic contact: 90 to 150 centimeters.

The umbric epipedon is 50 to 100 centimeters thick.

Reaction: strongly or very strongly acid and base saturation, by ammonium acetate, is less than 35 percent throughout.

Particle-Size Control Section (weighted average):

Rock fragments: 5 to 35 percent gravel and 0 to 15 percent cobbles.
Clay content: 18 to 30 percent clay.

Some pedons have a Cambic horizon.

A horizon

Hue: 10YR or 2.5Y.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1 through 3 dry, 1 through 3 moist.

Texture of fine earth: loam.
Rock fragments: 0 to 30 percent gravel and 0 to 5 percent cobbles.
Clay content: 15 to 30 percent clay.

Some pedons have Bw and/or C horizons.

Bw horizon

Hue: 10 YR or 2.5Y.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 3 or 4 dry, 2 through 4 moist.

Texture of fine earth: loam, sandy loam or clay loam.
Rock fragments: 35 to 50 percent gravel and 0 to 5 percent cobbles.
Clay content: 20 to 35 percent clay.

C horizon

Hue: 10 YR or 2.5Y.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 3 or 4 dry, 2 through 4 moist.

Texture of fine earth: loam, sandy loam or clay loam.
Rock fragments: 35 to 50 percent gravel and 0 to 5 percent cobbles.
Clay content: 20 to 35 percent clay.

COMPETING SERIES: These are the Dolason, and Doty series. Dolason soils are greater than 100 centimeters to bedrock. Doty soils have a difference between mean July and mean January soil temperatures of 12 to 18 degrees C.

GEOGRAPHIC SETTING: Countshill soils are on gently convex ridgetops, spur ridges and mountain slopes. Slopes are 9 to 50 percent. Elevations are 153 to 1032 meters (500 to 3390 feet). The soils formed in colluvium and residuum derived from siltstone and sandstone. The climate is humid with cool, foggy summers and cool, rainy winters. Mean annual precipitation is 2160 to 2550 millimeters (85 to 100 inches). Mean January temperature is about 7 degrees C; mean July temperature is about 15 degrees C; and the mean annual temperature is 10 to 15 degrees C (50 to 59 degrees F). Frost-free season is about 200 to 280 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Airstrip and Dolason soils. Airstrip soils have greater than 35 percent rock fragments in the particle-size control section. Dolason soils are greater than 100 centimeters (40 inches) deep to a paralithic contact. The Dolason soils are on smooth sideslopes and in saddles on ridgetops. The Airstrip soils are on strongly convex relief on spur ridges and ridgetops.

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

USE AND VEGETATION: This soil has been used for livestock grazing, recreation, wildlife habitat, and watershed. Natural vegetation consists of California oatgrass, dogtail grass, foxtail fescue, tall oatgrass, plantain, sheep sorrel, hairy cat's ear, and annual legumes. Invasion by Douglas-fir and other forest species occurs primarily in disturbed areas and along forest borders.

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: Redwood National Park portion, Humboldt and Del Norte Area Soil Survey, California, 2001. The source of the name is from Counts Hill Prairie, located in Redwood National Park south of the town of Orick.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

1. Umbric epipedon - the zone from 0 to 51 centimeters (A1 and A2 horizons)(Pachic)
2. Paralithic contact - the bedrock interface at 72 centimeters
3. Humixerepts feature - base saturation of less than 35 percent, by ammonium acetate, in the zone from 25 to 72 centimeters
4. Particle-size control section - the zone from 25 to 72 centimeters, averages 22 percent clay, by field estimate, and 15 percent rock fragments, by volume. CEC/clay ratio averages 0.75.

ADDITIONAL DATA: Soil samples 83-RNP-17 were collected from a similar pedon and analyzed chemically at the Oregon State University Soil Testing Laboratory.

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

NASIS User Pedon ID: 83CA605REDW033

National Cooperative Soil Survey
U.S.A.