LOCATION BEARRUN WAEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, frigid Vitrandic Palexeralfs
TYPICAL PEDON: Bearrun ashy sandy loam - forestland, on a 6 percent east-facing toe slope at an elevation of 3,300 feet. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inch; slightly decomposed forest litter mixed with a small amount of 1980 Mt. St. Helens ash; abrupt smooth boundary. (1/2 to 1 inch thick)
A--1 to 7 inches; brown (10YR 5/3) ashy sandy loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, few medium roots; many very fine irregular pores; moderately acid (pH 5.6); NaF pH 8.8; clear smooth boundary. (3 to 7 inches thick)
2Bw1--7 to 14 inches; pale brown (10YR 6/3) ashy loam, brown (10YR 4/3) moist; moderate medium and coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, common fine and medium and few coarse roots; common very fine and fine irregular and few fine tubular pores; moderately acid (pH 5.7); NaF 8.6; clear smooth boundary. (0 to 8 inches thick)
2Bw2--14 to 23 inches; pale brown (10YR 6/3) ashy loam, brown (10YR 4/3) moist; moderate medium and coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium and coarse roots; common fine irregular and common fine tubular pores; 5 percent gravel; moderately acid (pH 6.0); NaF 8.7; abrupt wavy boundary. (7 to 12 inches thick)
3Bt1--23 to 33 inches; pale brown (10YR 6/3) clay, grayish brown (2.5Y 5/2) moist; strong medium prismatic structure, parting to strong medium subangular blocky; very hard, very firm, very sticky and very plastic; few very fine and fine roots; few fine and medium tubular pores; common prominent very dark grayish brown (10YR 3/2) clay films lining pores and on the faces of peds; 5 percent gravel and 5 percent cobbles; moderately acid (pH 5.8); NaF pH 8.5; gradual smooth boundary.
3Bt2--33 to 45 inches; light gray (10YR 7/2) clay, grayish brown (2.5Y 5/2) moist; strong medium and coarse prismatic structure, parting to strong medium subangular blocky; very hard, very firm, very sticky and very plastic; few very fine and fine roots; few fine and medium tubular pores; common prominent olive brown (2.5Y 4/4) clay films lining pores and on the faces of peds; 5 percent gravel and 5 percent cobbles; moderately acid (pH 5.9); gradual smooth boundary.
3Bt3--45 to 55 inches; light yellowish brown (10YR 6/4) gravelly clay loam, brown (10YR 5/3) moist; moderate medium and coarse subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine and medium roots; common fine irregular and few fine tubular pores; common distinct brown (10YR 4/3) clay films lining pores and on faces of peds; 15 percent gravel and 5 percent cobbles; moderately acid (pH 6.0); clear smooth boundary.
3Bt4--55 to 61 inches; light yellowish brown (10YR 6/4) very gravelly clay loam, light olive brown (2.5Y 5/4) moist; moderate coarse prismatic structure parting to moderate coarse and medium subangular blocky; hard, friable, moderately sticky and moderately plastic; common very fine and fine irregular pores; common distinct dark yellowish brown (10YR 3/4) clay films lining pores and on faces of peds; 35 percent gravel and 15 percent cobbles; moderately acid (pH 6.0). (Combined thickness of Bt horizon is 30 to 48 inches )
TYPE LOCATION: Wenatchee National Forest, Yakima County, Washington; about 8 miles west of the Nile community, Washington; about 2,600 feet east and 100 feet north of the southwest corner of section 16, T. 15 N., R. 14 E.; Latitude 46 degrees, 57 minutes, 30 seconds N., Longitude 121 degrees, 06 minutes, 46 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 44 to 46 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. The particle-size control section averages 35 to 60 percent clay and 5 to 25 percent rock fragments. Reaction is moderately acid or slightly acid throughout.
The A horizon is ashy sandy loam or ashy loam. It has volcanic glass of 30 to 40 percent, acid oxalate extractable aluminum plus one-half iron of 0.2 to 0.3. percent and moist bulk density of 1.10 to 1.30 g/cc.
The 2Bw horizon has value of 5 or 6 dry and 3 or 4 moist. Texture is ashy loam or gravelly ashy clay loam. It has volcanic glass of 10 to 20 percent and acid oxalate extractable aluminum plus one-half iron of 0.2 to 0.3 percent.
The 3Bt horizon has a hue of 10YR or 2.5Y, value of 4 to 7 dry, 4 or 5 moist and chroma 2 to 4 dry or moist. It is clay, clay loam, silty clay, gravelly clay or gravelly clay loam and averages 35 to 60 percent clay. The 3Bt4 horizon, when present, may range to more than 35 percent rock fragments. Base saturation (NH4OAC) is 75 to 95 percent.
In some pedons, a BC horizon is present.
COMPETING SERIES: There are no competing series. The Kewach series has a similar classification with isotic mineralogy rather than mixed. It also has Btk and Bk horizons with disseminated calcium carbonate and slightly or moderately aklaline soil reaction.
GEOGRAPHIC SETTING: Bearrun soils are on mountains. Landscapes are typically hummocky reflecting past land flows of various magnitudes. They are formed in basalt colluvium with a thin mantle of volcanic ash. Elevation is 2,150 to 4,900 feet. Slopes range from 3 to 55 percent. These soils are in a climate with warm, dry summers and cool, moist winters. The mean annual precipitation is 25 to 55 inches. The average January temperature is 26 degrees F. and the average July temperature is 65 degrees F. The mean annual temperature is 43 to 45 degrees F. The frost-free season is 40 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bograp, McDanielake and Singh soils. Bograp soils are on mountains and are fine-loamy. McDanielake soils are on mountains and are loamy-skeletal. Singh soils are on mountain benches, plateaus and side slopes and are ashy over loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: These soils are used mainly for timber production, recreation, wildlife habitat and livestock grazing. Native vegetation is Douglas fir, ponderosa pine, grand fir, elk sedge, pinegrass and shinyleaf spirea.
DISTRIBUTION AND EXTENT: Yakima County, Washington. MLRA 6. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wenatchee National Forest, Yakima County, Washington, 2003.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon - from 1 to 7 inches (A horizon)
Argillic horizon - the zone from 23 to 62 inches
Abrupt textural boundary at 23 inches (between 2Bw2 and 3Bt1 horizons)
PSCS - the zone from 23 to 43 inches (3Bt1 and part of the 3Bt2 horizon) with mixed mineralogy based on lab data.
Vitrandic feature - the zone from 1 to 23 inches based on lab data.
Depths to diagnostic horizons and features are measured from the top of the first mineral layer.
This series is classified as mixed, active based on lab data for the official type location. NaF pH is greater than 8.4 however 15-bar/clay ration is less than 0.6. The dominant concept used in correlation of similar ash influenced soils within this vegetative zone is isotic mineralogy. Laboratory data is available for similar soils supporting both the isotic and mixed mineralogy.
ADDITIONAL DATA: Laboratory data for this pedon is available. NSSL pedon number 92P-23, sample number S91WA-077-008.