LOCATION WOCREEK WAEstablished Series
TAXONOMIC CLASS: Ashy, glassy Xeric Vitricryands
TYPICAL PEDON: Wocreek ashy sandy loam, on a southwest-facing 23 percent slope in a forest of subalpine fir, Douglas-fir, and lodgepole pine. (Colors are for dry soil unless otherwise stated. All textures are apparent field textures.)
Oi--0 to 1 inch; slightly decomposed forest litter; abrupt smooth boundary. (1 to 3 inches thick)
A--1 to 8 inches; light gray (10YR 7/2) ashy sandy loam, grayish brown (10YR 5/2) moist; moderate fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and few medium and coarse roots; common very fine and fine irregular pores; 10 percent pumice paragravel and 2 percent gravel; slightly acid (pH 6.5); clear wavy boundary. (2 to 15 inches thick)
Bw--8 to 35 inches; pale brown (10YR 6/3) paragravelly ashy sandy loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and few medium and coarse roots; common very fine and fine irregular pores; 20 percent pumice paragravel and 5 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (20 to 35 inches thick)
BC--35 to 52 inches; pale brown (10YR 6/3) very gravelly ashy loamy coarse sand, grayish brown (10YR 5/2) moist; single grain; soft, loose, nonsticky and nonplastic; common very fine and fine, and few medium roots; common fine and medium irregular pores; 50 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (10 to 25 inches thick)
2C--52 to 61 inches; light gray (10YR 7/2) gravelly sandy loam, brown (10YR 5/3) moist; massive; soft, friable, nonsticky and nonplastic; few very fine and fine roots; few fine irregular pores; 15 percent gravel and 5 percent cobbles; slightly acid (pH 6.4).
TYPE LOCATION: Okanogan County, Washington; about 10 miles southwest of Methow, WA; about 1,500 feet east and 500 feet south of the northwest corner of section 6, T. 29 N., R. 22 E. (Latitude 48 degrees, 02 minutes, 51 seconds N., Longitude 120 degrees, 07 minutes, 59 seconds W.)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 37 to 41 degrees F. These soils are usually moist, but are dry in all parts of the moisture control section for 45 to 60 consecutive days following the summer solstice. The solum (A and Bw horizons) has an estimated moist bulk density of 0.60 to 0.85 g/cc, volcanic glass content of 30 to 60 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 1.0 to 2.0 percent, 15-bar water retention of 5 to 12 percent for air dried samples, and 10 to 40 percent pumice paragravel. The particle-size control section has 0 to 25 percent rock fragments. Reaction is slightly acid to neutral. Depth to loamy or loamy-skeletal 2C horizon is 40 to over 60 inches. Depth to the BC horizon is 30 to 50 inches.
The A horizon has value of 5 to 7 dry, 4 or 5 moist, and chroma of 2 or 3 dry or moist. The texture is ashy sandy loam or ashy coarse sandy loam, and can be paragravelly or very paragravelly. There is 10 to 40 percent pumice and 0 to 10 percent gravel.
The Bw horizon has value of 5 to 7 dry, 4 or 5 moist and chroma of 2 or 3 day and moist. It is ashy sandy loam or ashy coarse sandy loam and is paragravelly or very paragravelly with 15 to 40 percent pumice paragravel.
The BC horizon has value of 6 or 7 dry, 4 or 5 moist and chroma of 2 or 3 dry and moist. It is ashy sandy loam or ashy loamy coarse sand and is gravelly or very gravelly with 25 to 55 percent gravel and 0 to 5 percent cobbles. Moist bulk density and glass content is the same as the A and Bw horizon but the acid oxalate aluminum plus one-half the acid oxalate iron is 0.4 to 1.0 percent.
The 2C horizon has value of 6 or 7 dry, 4 or 5 moist, and chroma of 2 or 3 dry and moist. The texture is sandy loam or coarse sandy loam. It can be very gravelly, very cobbly, gravelly, or cobbly. There is 10 to 30 percent gravel, 0 to 25 percent cobbles, and 0 to 15 percent stones.
COMPETING SERIES: These are the Collier, Goffpeak, Kittleson, Shroyton, Steiger and Sycan series. Collier soils have less than 5 percent clay throughout the profile. Kittleson, Goffpeak and Shroyton soils are 40 to 60 inches deep to bedrock. Steiger soils have less than 5 percent clay throughout the profile, lack a cambic horizon and have 70 to 100 percent glass and have 0.4 to 0.9 percent oxalate values. Sycan soils have redox concentrations below 40 inches.
GEOGRAPHIC SETTING: Wocreek soils are found on backslopes and footslopes of mountains at elevations from 3,800 to 6,500 feet. They form in volcanic ash. Slopes are 15 to 65 percent. The climate is characterized by cool, dry summers and cold, wet winters. Average annual precipitation is 25 to 40 inches. The average January temperature ranges from 18 to 22 degrees F., and the average July temperature is 52 to 58 degrees F. Average annual temperature ranges from 37 to 41 degrees F. The frost-free season is 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coopmont, Fears, Thow, and Vingulch soils. Coopmont soils are on backslopes and have a volcanic ash mantle less than 40 inches thick. Fears soils are on backslopes and have 35 to 80 percent rock fragments throughout the 0 to 40 inch particle-size control section. Thow soils are frigid and are on backslopes. Vingulch soils are frigid and are on ridges and upper backslopes and are 20 to 40 inches to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Used for timber production, livestock grazing, wildlife habitat, watershed, and recreation. Native vegetation is subalpine fir, Douglas-fir, and lodgepole pine with an understory of grouse blueberry, pinegrass, low huckleberry, pachystima, shinyleaf spirea, prince's pine, silky lupine, and longtube twinflower.
DISTRIBUTION AND EXTENT: Northcentral Washington; MLRA 6. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Okanogan National Forest, Okanogan County, Washington, 2005.
REMARKS: Diagnostic horizons and features in this pedon are:
Ochric epipedon
Cambic epipedon - 8 to 35 inches (Bw horizon)
PSCS - zone from 1 to 41 inches (A, Bw, and part of BC horizons)
Andic properties - 1 to 25 inches (A and Bw horizons) The BC horizon meets Vitrandic subgroup criteria.
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.
All pumice fragments are paragravel and are weakly or moderately cemented.