LOCATION WAPAL WAEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, isotic, frigid Vitrandic Haploxerepts
TYPICAL PEDON: Wapal ashy sandy loam - forested. (Colors are for dry soil unless otherwise stated)
0i--0 to 1.5 inches; undecomposed needles, twigs, bark, and grass. (0 to 2 inches thick)
A--1.5 to 4 inches; brown (10YR 5/3) ashy sandy loam, dark brown (10YR 3/3) moist; weak very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; common roots; common fine and very fine pores; 5 percent gravel; neutral (pH 6.6); clear smooth boundary. (3 to 7 inches thick)
Bw1--4 to 11 inches; yellowish brown (10YR 5/4) ashy coarse sandy loam, dark yellowish brown (10YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common roots; common fine and very fine pores; 5 percent gravel; slightly acid (pH 6.4); gradual smooth boundary. (3 to 10 inches thick)
Bw2--11 to 20 inches; light yellowish brown (10YR 6/4) coarse sandy loam, dark yellowish brown (10YR4/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common roots; common fine and very fine pores; 5 percent gravel; slightly acid (pH 6.2); abrupt wavy boundary. (0 to 9 inches thick)
C--20 to 61 inches; multicolored very gravelly coarse sand; single grain; loose; few roots; 40 percent gravel, 15 percent cobbles and stones; slightly acid (pH 6.4).
TYPE LOCATION: Ferry County, Washington; 1,320 feet east and 1,580 feet north of southwest corner section 20, T.36N., R.32E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 44 to 46 degrees F. These soils are usually moist but are dry in all parts between depths of 12 and 35 inches for 60 to 75 consecutive days following the summer solstice. The solum is 10 to 20 inches thick. The upper 7 to 14 inches 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 0.4 to 1.0 percent, and 15-bar water retention of 5 to 10 percent for air dried samples. The particle-size control section averages 35 to 70 percent rock fragments. Reaction is moderately acid to neutral above the substratum and slightly acid to neutral in the substratum.
The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3 dry or moist. Texture is ashy sandy loam, cobbly ashy sandy loam, stony ashy coarse sandy loam or gravelly ashy sandy loam. Some pedons have a thin discontinuous deposit of unweathered volcanic ash above the A horizon.
The Bw1 horizon has chroma of 3 or 4 dry or moist. Texture is ashy sandy loam or ashy coarse sandy loam. It is commonly gravelly and ranges to nongravelly, cobbly, very cobbly or very gravelly. It is 5 to 40 percent gravel and 0 to 35 percent cobbles.
The Bw2 horizon has chroma of 3 or 4 dry or moist. Texture is sandy loam or coarse sandy loam. It commonly is gravelly or very gravelly, and less commonly nongravelly, cobbly, or very cobbly. It is 5 to 40 percent gravel and 0 to 35 percent cobbles.
The C horizon is usually multicolored but may have hue of 10YR, value of 6 or 7 dry, 4 or 5 moist, and chroma of 3 dry or moist. Textures range from very gravelly loamy sand to extremely cobbly coarse sand. It is 30 to 70 percent gravel and 5 to 35 percent cobbles.
COMPETING SERIES: This is the Pebcreek series. Pebcreek soils have a densic contact at 30 to 45 inches.
GEOGRAPHIC SETTING: Wapal soils are on outwash terraces, long narrow eskers, kame terraces, and terrace escarpments. Slopes are 0 to 65 percent. These soils formed in glacial outwash derived primarily from granitic rocks with a minor component of volcanic ash and loess in the upper part. Elevation is 1,400 to 5,600 feet. The climate is characterized by warm, dry summers, and cool, moist winters. The average annual precipitation is 16 to 25 inches. The average January temperature is about 23 degrees F, the average July temperature is about 64 degrees F, and the average annual temperature is 40 to 46 degrees F. The frost-free period is 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Goddard, Kiehl, Merkel, Nevine, Sacheen, and Torboy soils. Goddard, Kiehl, and Nevine soils have a volcanic ash mantle. Merkel soils are loamy-skeletal and are on mountains. Sacheen and Torboy soils are sandy. Goddard, Kiehl, Sacheen and Torboy soils are on similar landscapes as the Wapal soils. Nevine soils are on foothills and mountains.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow to rapid runoff; moderately rapid permeability in the solum and very rapid in the substratum.
USE AND VEGETATION: These soils are used for timber production, livestock grazing, wildlife habitat, hay and pasture, and watershed are the principal uses. Native vegetation is Douglas-fir, ponderosa pine, and western larch, with an understory of pinegrass, common snowberry, Saskatoon serviceberry, kinnikinnick, and Oregon-grape.
DISTRIBUTION AND EXTENT: Northeastern Washington; MLRA 43A. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Ferry County (North Ferry Area), 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from 0 to 7 inches (Oi, A, and part of the Bw horizon)
Cambic horizon - the zone from 4 to 20 (Bw1 and Bw2 horizons)
Vitrandic feature - the zone from 1.5 to 11 inches
Particle-size control section - the zone from 11 to 42 inches (Bw2 and part of the C horizon)
Classification has been revised from sandy-skeletal, mixed, frigid Typic Xerochrepts to Vitrandic Xerochrepts and as of 7/01, a revision to sandy-skeletal, isotic, frigid Vitrandic Haploxerepts.
ADDITIONAL DATA: Partial laboratory data are available on these soils NSSL #85P4789-4790.