LOCATION WIREGRASS CA

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

WIREGRASS SERIES

The Wiregrass series consists of very deep, well drained soils that formed in colluvium and residuum from schist, sandstone, and mudstone. Wiregrass soils are on mountains and have slopes of 0 to 75 percent. The mean annual precipitation is about 2290 millimeters (90 inches) and the mean annual temperature is about 12 degrees C (54 degrees F).

TAXONOMIC CLASS: Fine-loamy, mixed, semiactive, isomesic Ustic Palehumults

TYPICAL PEDON: Wiregrass very gravelly silt loam - on a uniform northwest-facing slope of 39 percent under tanoak, coast redwood, Douglas fir, Pacific madrone, and California huckleberry at 287 meters (940 feet) elevation. (Colors are for moist soil unless otherwise stated. When described June 13, 1983, the soil was moist throughout.)

Oi--0 to 3 centimeters (0 to 1 inches); slightly decomposed needles, leaves and twigs; very strongly acid (pH 4.5); abrupt smooth boundary. (0 to 12 centimeters (0 to 5 inches) thick)

A--3 to 12 centimeters (1 to 5 inches); dark yellowish brown (10YR 3/4) very gravelly silt loam, pale brown (10YR 6/3) dry; weak fine granular and subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots; common very fine irregular and common very fine and fine tubular pores; 36 percent gravel; strongly acid (pH 5.3); clear smooth boundary. (2 to 40 centimeters thick)

AB--12 to 29 centimeters (5 to 11 inches); dark yellowish brown (10YR 3/4) gravelly silty clay loam, light yellowish brown (10YR 6/4) dry; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine, fine, medium, and coarse roots; common very fine and fine tubular pores; 20 percent gravel and 5 percent cobbles; very strongly acid (pH 5.0); gradual smooth boundary. (0 to 30 centimeters thick)

Bw1--29 to 44 centimeters (11 to 17 inches); dark yellowish brown (10YR 4/4) gravelly silty clay loam, very pale brown (10YR 7/4) dry; weak fine and medium subangular blocky structure; slightly hard, very friable, moderately sticky and slightly plastic; few very fine and fine, common medium and coarse roots; common very fine and fine tubular pores; 14 percent gravel and 10 percent cobbles; very strongly acid (pH 5.0); gradual wavy boundary. (0 to 36 centimeters) thick)

Bw2--44 to 78 centimeters (17 to 31 inches); yellowish brown (10YR 5/4) very gravelly clay loam, pale yellow (2.5Y 7/3) dry; weak medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine, fine, medium and coarse roots; few very fine and fine tubular pores; 38 percent gravel and 5 percent cobbles; strongly acid (pH 5.2); gradual wavy boundary.

Bt1--78 to 103 centimeters (31 to 41 inches); light olive brown (2.5Y 5/4) very gravelly clay loam, pale yellow (2.5Y 8/2) dry; weak coarse subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; few very fine, fine, medium and coarse roots; few very fine and fine tubular pores; few faint clay films on ped faces; 38 percent gravel and 5 percent cobbles; very strongly acid (pH 4.8); gradual smooth boundary.

Bt2--103 to 170 centimeters (41 to 67 inches); light olive brown (2.5Y 5/4) very gravelly clay loam, light gray (2.5Y 7/2) dry; weak coarse subangular blocky structure; slightly hard, firm, moderately sticky and moderately plastic; few very fine, fine, medium and coarse roots; few very fine tubular pores; common faint clay films on ped faces; 43 percent gravel and 5 percent cobbles; strongly acid (pH 5.3). (Combined thickness of the Bt horizons is 50 to 175 centimeters)

TYPE LOCATION: Redwood National Park, Humboldt County, California; located approximately 26 kilometers southeast of the town of Orick, 274 meters NNW of junction between 2005 Road and K&K Road; southeast quarter, southwest quarter, section 15, T. 9 N., R. 2 E., WGS84 Decimal 41.2193861 latitude and -124.0316889 longitude; HBLM, USGS Bald Hills Quadrangle; UTM Zone 10 421413mE 4557610mN; 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 dry in the upper part from about July 15 to October 15. 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.

Organic matter: There is 12 to 20 kg organic carbon per square meter to a
depth of one meter.

Reaction is slightly to very strongly acid throughout. Base saturation is 15 to 35 percent at the critical depth.

Surface fragments: 0 to 75 percent gravel.

Particle-Size Control Section (weighted average):

Rock fragments: 0 to 35 gravel and 0 to 15 percent cobbles.
Clay content: 27 to 35 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: 4 through 7 dry, 3 or 4 moist.
Chroma: 2 through 4 dry and moist.

Texture of fine earth: silt loam or loam.
Rock fragments: 0 to 45 percent gravel and 0 to 5 percent cobbles.
Clay content: 20 to 30 percent

Bt horizon

Hue: 7.5YR, 10YR, or 2.5Y.
Value: 4 through 7 dry, 2 through 6 moist.
Chroma: 2 through 6 dry, 3 through 8 moist.

Texture of fine earth: loam, silty clay loam or clay loam.
Rock fragments: 0 to 45 percent gravel, 0 to 15 percent cobbles
Clay content: 25 to 40 percent.

Some pedons have a C horizon.

C horizon

Hue: 10YR, 2.5Y, or 5Y.
Value: 6 through 8 dry, 4 through 6 moist.
Chroma: 2 through 4 dry, 2 through 8 moist.

Texture of fine earth: loam or clay loam.
Rock fragments: 0 to 50 percent gravel, 0 to 15 percent cobbles and 0 to 10 percent stones.
Clay content: 20 to 40 percent.

COMPETING SERIES: This is the Childshill series. The Childshill soils have sub rounded or rounded rock fragments within the particle size control section.

GEOGRAPHIC SETTING: Wiregrass soils are on mountain slopes and broad ridgetops. Slope gradients are 0 to 75 percent. Elevations are 48 to 972 meters (155 to 3185 feet). These soils formed in colluvium and residuum from schist, sandstone, and mudstone. 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 9 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, Atwell, Devilscreek, Pittplace, Rockysaddle, Scaath, and Trailhead soils. Ahpah and Devilscreek soils lack argillic horizons. Atwell, Pittplace, and Trailhead soils have more than 35 percent clay in their control sections. Rockysaddle and Scaath soils are loamy-skeletal in their control sections. Ahpah and Scaath soils are 50 to 102 centimeters (20 to 40 inches) deep to bedrock. The Atwell and Devilscreek soils are in wet hillslope hollows below the Wiregrass soils. The Ahpah and Scaath soils are on convex slopes or on spur ridges above the Wiregrass soils. The Rockysaddle soils are alongside the Wiregrass soils on very gravelly colluvium. The Pittplace and Trailhead soils are above the Wiregrass soils on gentler slopes.

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

USE AND VEGETATION: This soil has been used for commercial timber production, wildlife, and watershed. Natural vegetation includes Douglas-fir, tanoak, scattered redwood, rhododendron, and evergreen huckleberry.

DISTRIBUTION AND EXTENT: California Coastal Redwood Belt; MLRA 4B. The series is moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Humboldt Del Norte area, California. The source of the name is from Wiregrass Ridge, approximately 15 kilometers northeast of the town of Blue Lake.

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

1. Ochric epipedon - the zone from 0 to 12 centimeters (Oi, and A horizons).
2. Argillic horizon - the zone from 12 to 170 centimeters (AB, Bw1, Bw2, Bt1, & Bt2 horizons).
3. Ultisol feature - base saturation of 20.1 percent, by sum of cations (Bt3 horizon).
4. Humult feature - organic carbon is 1.22 percent or more from 3 to 44 centimeters. (A, AB, & BAt horizons).
5. Palehumult feature - clay maximum is 29.2 percent in BAt and exceeds 23.4 percent in (Bt1, Bt2, & Bt3 horizons).
6. Particle-size control section - the zone from 12 to 62 centimeters, averages 28 percent clay, by weight, and 31 percent rock fragments, by volume. CEC/clay ratio averages 0.36.

ADDITIONAL DATA: Soil sample 83-RNP-12 was collected at the type location and analyzed at the Oregon State University soil-testing laboratory. Soil sample S83-CA-012-06, from the type location, was analyzed by NSSL for clay mineralogy class placement.

NASIS User Pedon ID: 83CA605REDW004

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

National Cooperative Soil Survey
U.S.A.