LOCATION YALELAKE WATentative Series
TAXONOMIC CLASS: Ashy over medial, glassy over amorphic, mesic Humic Udivitrands
TYPICAL PEDON: Yalelake sandy loam - forested, on a 10 percent southeast-facing slope at an elevation of 1,360 feet. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
Oi--2 to 0.5 inch; needles, leaves and twigs.
Oa--0.5 inch to 0; decomposed organic material.
A--0 to 4 inches; very dark brown (10YR 2/2) sandy loam (volcanic ash), dark grayish brown (10YR 4/2) dry; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine and medium roots; many very fine irregular pores; slightly acid (ph 6.2); clear wavy boundary. (2 to 5 inches thick)
AB--4 to 11 inches; dark brown (10YR 3/3) sandy loam (volcanic ash), brown (10YR 5/3) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, fine and few coarse roots; many fine irregular pores; 5 percent pebbles; slightly acid (pH 6.4), clear wavy boundary. (5 to 10 inches thick)
Bw1--11 to 20 inches; dark grayish brown (10YR 4/2) gravelly loamy sand (volcanic ash), very pale brown (10YR 7/3) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic;many very fine and common fine and medium roots; many fine irregular pores; 30 percent pebbles; neutral (pH 6.6); clear wavy boundary.
2Bw2--20 to 39 inches; dark yellowish brown (10YR 4/4) gravelly sandy loam, light yellowish brown (10YR 6/4) dry; weak fine subangular blocky structure; soft, friable, nonsticky and nonplastic; weakly smeary; common very fine and fine and few medium roots; many fine and medium irregular pores; 15 percent pebbles; 5 percent cobbles; neutral (pH 6.6); abrupt wavy boundary. (Combined thickness of the Bw horizon is 20 to 32 inches)
3C1--39 to 44 inches; brownish yellow (10YR 6/8) sand, yellow (10YR 7/6) dry; single grain; loose, nonsticky and nonplastic; weakly smeary; few fine roots; many medium irregular pores; 10 percent pebbles; 40 percent weathered pumice; neutral (pH 6.8) abrupt wavy boundary. (0 to 5 inches thick)
4C2--44 to 60 inches; dark yellowish brown (10YR 4/4) gravelly loam, light yellowish brown (10YR 6/4) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; few fine and medium roots; common fine irregular pores; 20 percent pebbles; neutral (pH 6.8).
TYPE LOCATION: Skamania County, Washington; south of US Forest Service Road N90, About 2,600 feet south and 250 feet east of the northwest corner of section 22, T. 7 N., R. 5 E.
RANGE IN CHARACTERISTICS: Average annual soil temperature is 49 to 53 degrees F. These soils are dry in the moisture control section for less than 45 consecutive days. Depth of the solum ranges from 35 to 45 inches. The ashy mantle is 17 to 25 inches thick and contains more than 60 percent volcanic ash and pumice. Coarse fragments in the control section range from 0 to 30 percent. The umbric epipedon ranges from 10 to 13 inches thick.
The A and AB horizons have value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 dry and moist. Reaction is strongly acid to slightly acid.
The Bw horizon has value of 3 or 4 moist, 5 through 7 dry and chroma of 2 through through 6 moist and dry. It is gravelly loamy sand, loamy sand, gravelly sandy loam or sandy loam. Reaction is moderately acid to neutral. It has 10 to 12 percent (estimated) 15-bar moisture (dry).
The 2Bw horizon has value of 4 or 5 moist, 6 or 7 dry and chroma of 4 through 8 dry and moist. It is sandy loam, loam or gravelly sandy loam. Reaction is moderately acid to neutral. It has greater than 15 percent (estimated) 15-bar moisture (dry).
The C horizon has value of 4 through 6 moist, 6 or 7 dry and chroma of 4 through 8 dry and moist. It is sandy loam or loam with thin strata of loamy sand, sand or weathered pumice. Pebbles range from 10 to 25 percent and soft weathered pumice fragments range from 15 to 40 percent. Reaction is moderately acid to neutral. Some pedons have an extremely gravelly sand or weathered pumice substratum below 40 inches.
COMPETING SERIES: There are no competing series. The Bull Run series in a similar family. Bull Run soils are medial.
GEOGRAPHIC SETTING: Yalelake soils are on terraces and terrace escarpments. Slopes are 2 to 90 percent. Elevations range from 300 to 1,800 feet. Yalelake soils formed in volcanic ash and pumice over older pyroclastic deposits. The climate is marine with cool, wet winters and warm, moist summers. Average annual precipitation is 115 to 125 inches. Average January temperature is about 35 degrees F.; average July temperature is about 62 degrees F. Average annual temperature is 47 to 51 degrees F. The frost-free season is 100 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cinnamon, Forsyth, Pinchot, and Swift soils. Cinnamon, Forsyth and Swift soils are frigid. Forsyth soils have a sandy-skeletal subhorizon at 30 inches. Pinchot soils have an ashy over sandy or sandy-skeletal control section. Swift soils are ashy over loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderate permeability.
USE AND VEGETATION: Used mainly for timber production, recreation, wildlife habitat and watershed. Native vegetation is mainly Douglas-fir, western hemlock, bigleaf maple, western redcedar, and red alder. Understory vegetation is mainly vine maple, salal, western brackenfern, western swordfern, Oregongrape, Oregon oxalis, and Pacific dogwood.
DISTRIBUTION AND EXTENT: Northern Skamania, northeast Clark and southeast Cowlitz Counties, Washington. The series is of small extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: As Yale by the Weyerhaeuser Company Soil Survey, St. Helens Tree Farm, Washington, 1969--SCS January 1980.
REMARKS: Diagnostic horizons and features recognized in this pedon are an umbric epipedon from the mineral surface to 11 inches, a cambic horizon from 20 to 39 inches, and a lithologic change from ashy to medial soil material at 20 inches. Field test of NaF pH is 10.0 in the A1 horizon and greater than 11.0 throughout the rest of the profile. The particle-size control section has an estimated moist bulk density of less than 0.90 g/cc, volcanic glass content of 30 to 60 percent, acid-oxalate extractable aluminum plus one-half iron of more than 1 percent. Vitrands feature - 15-bar moisture (dry) throughout 83 percent of upper 60 cm of less than 12 percent. More investigation is needed to confirm the medial classification of the "B" tephra set (2Bw).
Classificaiton changed 6/98 based on revisions to mineralogy classes in Soil Taxonomy.