LOCATION BREVCO WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Vitrandic Haploxerepts
TYPICAL PEDON: Brevco gravelly ashy coarse sandy loam, - forestland, on a 40 percent northeast-facing slope at an elevation of 4,240 feet, under a Douglas-fir, lodgepole pine canopy. (Colors are for dry soil unless otherwise stated. When described on July 27, 1992, the soil was dry throughout. All textures are apparent field textures.)
Oi--0 to 1 inch; slightly decomposed organic matter consisting of needles and grasses.
A--1 to 4 inches; very pale brown (10YR 7/3) gravelly ashy coarse sandy loam, brown (10YR 4/3) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many fine and very fine and common medium and coarse roots; common fine irregular pores; 20 percent gravel; neutral (pH 6.6); clear smooth boundary. (2 to 5 inches thick)
Bw--4 to 12 inches; very pale brown (10YR 7/4) gravelly ashy coarse sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many fine and very fine and common medium and coarse roots; common fine irregular pores; 25 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (8 to 11 inches thick)
2C1--12 to 26 inches; very pale brown (10YR 8/3) very gravelly sandy loam, brown (10YR 5/3) moist; massive; soft, very friable, nonsticky and nonplastic; many fine and common medium and coarse roots; 30 percent gravel and 15 percent cobbles; moderately acid (pH 5.8); gradual wavy boundary.
2C2--26 to 39 inches; very pale brown (10YR 7/4) very cobbly coarse sandy loam, light yellowish brown (10YR 6/4) moist; massive; soft, very friable, nonsticky and nonplastic; common fine and medium roots; 25 percent gravel and 30 percent cobbles; moderately acid (pH 5.6); abrupt irregular boundary. (Combined thickness of the C horizon is 10 to 30 inches)
R--39 inches; fractured granite.
TYPE LOCATION: Okanogan County, Washington; about 7 miles north of the town of Winthrop, Washington, and about 1 mile northeast of Ramsey Peak, on the Lewis Butte USGS topographic quadrangle. (Latitude 48 degrees, 34 minutes, 05 seconds N., Longitude 120 degrees, 07 minutes, 37 seconds W.)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 40 to 44 degrees F. These soils are usually moist, but are dry in all parts of the moisture control section for 60 to 75 consecutive days following the summer solstice. Depth to a lithic contact is 20 to 40 inches. The solum is 10 to 14 inches thick and has an estimated moist bulk density of 1.20 to 1.55 g/cc, volcanic glass content of 5 to 20 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 0.2 to 0.6 percent, and 15-bar water retention of 5 to 10 percent for air dried samples. The particle-size control section averages 35 to 60 percent rock fragments.
The A horizon has a value of 5 to 7 dry, 3 to 5 moist and chroma of 2 or 3 dry or moist. Texture is gravelly ashy coarse sandy loam or ashy sandy loam. It has 15 to 30 percent gravel.
An AB horizon is present in some pedons.
The Bw horizon has a value of 6 or 7 dry, 3 to 5 moist, and chroma of 2 to 4 dry or moist. Texture is gravelly ashy coarse sandy loam, very gravelly ashy coarse sandy loam, gravelly ashy sandy loam, or very gravelly ashy sandy loam. It has 15 to 45 percent gravel and 0 to 10 percent cobbles with a total rock fragment content of 15 to 45 percent. Reaction is moderately acid to neutral.
The 2C horizon has hue of 10YR or 2.5Y, value of 6 to 8 dry, 4 to 6 moist and chroma of 2 to 4 dry or moist. It is very gravelly sandy loam, very gravelly coarse sandy loam, very cobbly coarse sandy loam, or extremely gravelly coarse sandy loam. It averages 35 to 75 percent rock fragments, with 25 to 60 percent gravel and 5 to 25 percent cobbles. Reaction ranges from moderately acid to neutral.
A BC horizon is present in some pedons.
COMPETING SERIES: These are the Coxit, Highhorn, Huntrock, Jimbluff, Jumpe, Lekrem, Longort, Ontrail, Radercreek, Redpeak, Santop, Seeburg and Thout series. Coxit, Jimbluff, Lekrem, and Ontrail soils are very deep. Highhorn soils are deep to a lithic contact. Radercreek soils have a lithic contact at 40 to 60 inches. Redpeak soils have hue of 2.5YR or 5YR. Santop soils have soft sandstone fragments and do not have coarse sands in the substratum. Huntrock soils have 27 to 35 percent clay and 60 to 80 percent rock fragments in the particle-size control section. Jumpe and Seeburg soils are very deep to bedrock. Thout soils have an average annual soil temperature of 44 to 46 degrees F. and dominated by rock fragments of basalt and andesite origin. Longort soils have densic material at 20 to 40 inches.
GEOGRAPHIC SETTING: Brevco soils are on shoulder slopes and backslopes of mountains at elevations of 2,400 to 5,500 feet. These soils formed in residuum and colluvium from granitic rock with a minor component of volcanic ash. Slopes are 15 to 65 percent. The climate is characterized by warm, dry summers and cool, moist winters. The mean annual precipitation ranges from 18 to 30 inches. The average January temperature ranges from 22 to 26 degrees F, the average July temperature ranges from 62 to 67 degrees F, and the mean annual temperature ranges from 39 to 45 degrees F. The frost-free season is 85 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Goddard, Bromas, Sitdown, Wapal, and Watony soils. Goddard and Watony soils are on shoulders and backslopes of mountains, and are sandy-skeletal. Bromas soils are on shoulders and backslopes of mountains, and are cryic and are sandy-skeletal. Sitdown soils are on backslopes of mountains, and are cryic and are sandy-skeletal. Wapal soils are on southerly facing backslopes of mountains, and are deeper than 40 inches to bedrock.
DRAINAGE AND PERMEABILITY: Well drained, medium to rapid runoff, moderately rapid permeability.
USE AND VEGETATION: Brevco soils are used for timber production, wildlife habitat, watershed and recreation. Potential natural vegetation is Douglas-fir, ponderosa pine, lodgepole pine, dwarf huckleberry, mallow ninebark, common snowberry, and kinnikinnick.
DISTRIBUTION AND EXTENT: Northcentral and Northeastern, Washington; MLRA 43. Series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Okanogan County, Washington, Okanogan National Forest, 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Cambic horizon - the zone from 4 to 12 inches (Bw horizon)
Vitrandic feature - the zone from 1 to 12 inches (A and Bw horizons)
Lithic contact - at 39 inches (2R horizon)
Particle-size control section - the zone from 11 to 39 inches (part of the Bw, 2C1 and 2C2 horizons)