LOCATION RODGERPEAK              CA

Established Series
Rev: JHP/JPS/ET
05/2016

RODGERPEAK SERIES

The Rodgerpeak series consists of shallow, well drained soils formed in residuum derived from quartz-mica schist. Rodgerpeak soils are on mountains and have slopes of 0 to 15 percent. The mean annual precipitation is about 2410 millimeters (95 inches) and the mean annual temperature is about 10 degrees C (50 degrees F).

TAXONOMIC CLASS: Loamy, mixed, active, isomesic Lithic Dystrustepts

TYPICAL PEDON: Rodgerpeak gravelly loam - on a uniform, east-facing slope of 1 percent under second-growth Douglas-fir, redwood, tanoak, Pacific madrone, salal, and hairy manzanita at 835 meters (2740 feet); on summit of Rodger's Peak. (When described on October 18, 1985, the soil was slightly moist throughout Colors are for moist soil unless otherwise noted.)

Oi-- 0 to 1 centimeter (0 to 0.5 inch); fresh and slightly decomposed redwood needles, salal leaves twigs, humus and angular pebbles (50 percent gravel pavement); very strongly acid (pH 4.5). (0 to 3 centimeters thick)

A--1 to 19 centimeters (0.5 to 7 inches); dark brown (7.5YR 3/4) gravelly loam, brown (7.5YR 5/4) dry; weak fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; many very fine, fine and medium, and common coarse roots; few very fine irregular, and common very fine and fine tubular pores; 29 percent gravel; strongly acid (pH 5.5); gradual wavy boundary. (9 to 26 centimeters thick)

BA--19 to 30 centimeters (7 to 12 inches); strong brown (7.5YR 4/6) loam, strong brown (7.5YR 5/6) dry; weak medium and coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many very fine, fine and medium, and common coarse roots; common very fine and fine, and few medium tubular pores; 13 percent gravel; strongly acid (pH 5.5); gradual wavy boundary. (10 to 20 centimeters thick)

Bw--30 to 45 centimeters (12 to 18 inches); dark yellowish brown (10YR 4/6) gravelly loam brownish yellow (10YR 6/6) dry; weak medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine, common fine, medium and coarse roots; few very fine and fine tubular pores; krotovina, 15 by 30 centimeters, filled with reddish yellow (5YR 6/6) clay loam, yellowish red (5YR 5/6) moist; 30 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (13 to 20 centimeters thick)

R--45 centimeters (18 inches); hard quartz-mica schist, pieces can only be chipped out with hand tools. Depth to rock in pit ranges from 36 to 50 centimeters (14 to 20 inches).

TYPE LOCATION: Humboldt County, California; located 12 kilometers south of the town of Orick, 33.5 meters NNE from the northern radio tower; northeast quarter, northeast quarter, Section 23, T. 9 N., R. 1 E., HBLM; WGS84 Decimal degrees 41.1579972 latitude, -124.0229833 longitude; HBLM; USGS Rodger's Peak Quadrangle; UTM Zone 10 414171mE 4556801mN; 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: 8 to 12 degrees C (46 to 54 degrees F). The difference between mean summer and mean winter temperature is less than 6 degrees C.

Depth to a lithic contact: 36 to 50 centimeters.

Organic Matter: There is 4 to 8 kg per square meter of organic carbon above the lithic contact.

Reaction: moderately or strongly acid and the base saturation is less than 50 percent throughout.

Surface fragments: 10 to 70 percent gravel.

Particle-Size Control Section (weighted average):

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

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: 5 dry, 3 through 5 moist.
Chroma: 3 through 5 dry, 3 or 4 moist.

Texture of fine earth: loam.
Rock fragments: 15 to 30 gravel, and 0 to 5 percent cobbles.
Clay content: 15 to 27 percent.

Bw horizon

Hue: 7.5YR or 10YR.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 4 or 6 dry, 4 through 8 moist.

Texture of fine earth: loam, clay loam, or silty clay loam.
Rock fragments: 15 to 30 gravel and 0 to 5 percent cobbles.
Clay content: 20 to 30 percent.

COMPETING SERIES: At this time there are no other series in this family.

GEOGRAPHIC SETTING: Rodgerpeak soils occur on broad, gently convex to planar areas on ridges. Slopes are 0 to 15 percent. Elevations are 816 to 848 meters (2675 to 2780 feet). The soils formed in residuum derived from quartz-mica schist. The climate is humid with cool, foggy summers and cool, moist winters. Coastal influence limits the annual and diurnal range in temperature. Mean annual precipitation ranges from 2290 to 2550 millimeters (90 to 100 inches). Mean January temperature is about 8 degrees C; mean July temperature is about 13 degrees C; and the mean annual temperature is 8 to 13 degrees C (46 to 55 degrees F). Frost-free season is 220 to 250 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ahpah , Coppercreek , and Lackscreek soils. The Ahpah and Lackscreek soils are 50 to 100 centimeters deep to a paralithic and lithic contact. The Coppercreek and Lackscreek soils have argillic horizons. Coppercreek soils are on ridge shoulders and bedrock concavities on the ridgetop. Ahpah soils are on rounded main and spur ridges and convex slopes. Lackscreek soils are on bedrock knobs.

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

USE AND VEGETATION: This soil has been used for commercial timber, wildlife, and watershed. Natural vegetation consists of Douglas fir, tanoak, madrone, redwood, a dense shrub layer of huckleberry, salal, hairy manzanita, and rhododendron, and a sparse herb layer.

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 area, California 2007. Source of name is from Rodger's Peak, located 14.5 kilometers south of the town of Orick.

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

1. Ochric epipedon - the zone from 0 to 19 centimeters (Oi & A horizons)
2. Cambic horizon - the zone from 19 to 45 centimeters (BA & Bw horizons)
3. Lithic contact - the bedrock interface at 45 centimeters
4. Dystrustepts feature - base saturation of less than 60 percent, by ammonium acetate, between 25 to 45 centimeters
5. Particle-size control section - the zone from 25 to 45 centimeters, averages 25 percent clay, by weight, and 24 percent gravel, by volume.

ADDITIONAL DATA: The assignment of the active activity class is inferred from lab data from the Lackscreek soil. Soil profile samples 82-RNP-10 and 83-RNP-14. NASIS User Pedon ID: 85CA605REDW011

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

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National Cooperative Soil Survey
U.S.A.