LOCATION SHOESTRING WA

Established Series
Rev. TA/EH/RJE
01/2011

SHOESTRING SERIES

The Shoestring series consists of very deep, well drained soils that formed in layers of aerially deposited volcanic ash and pumice over pyroclastic flows and lahars. They are on terraces and terrace escarpments at elevations of 2,700 to 4,500 feet. Slopes are 0 to 90 percent. The mean annual precipitation is about 130 inches. Mean annual temperature is about 41 degrees F.

TAXONOMIC CLASS: Medial over sandy or sandy-skeletal, amorphic over mixed Andic Haplocryods

TYPICAL PEDON: Shoestring ashy fine sandy loam - forested on a 5 percent south-facing slope at 2,700 feet. (Colors are for moist soil unless other wise noted. All textures are apparent field textures.)

Oi--0 to1 inch; slightly decomposed plant material.

Oa--1 to 3 inches; highly decomposed plant material.

E--3 to 6 inches; very dark gray (10YR 3/1) ashy fine sandy loam (volcanic ash), gray (10YR 5/1) dry; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, and medium and few coarse roots; many very fine irregular pores; strongly acid (pH 5.2); abrupt smooth boundary. (2 to 4 inches thick)

Bhs--6 to 8 inches; black (10YR 2/1) ashy fine sandy loam (volcanic ash), dark brown (10YR 3/3) dry; weak fine granular structure; soft, very friable, nonsticky, nonplastic and weakly smeary; many very fine, fine, and medium and few coarse roots; many very fine and fine irregular pores; 10 percent gravel; moderately acid (pH 5.6); abrupt smooth boundary. (1 to 3 inches thick)

2Bs1--8 to 11 inches; dark gray (10YR 4/1) very gravelly sand (volcanic ash and cinders), light gray (10YR 7/1) dry; stains of yellowish brown (10YR 5/6); single grain; loose; many very fine, fine and common medium roots, many coarse irregular pores; 45 percent gravel and 35 percent pumice paragravel; moderately acid (pH 6.0); abrupt smooth boundary. (2 to 4 inches thick)

3Bs2--11 to 21 inches; dark brown (7.5YR 3/4) ashy sandy loam, brownish yellow (10YR 6/6) dry; weak fine subangular blocky structure; soft, friable, nonsticky and nonplastic, weakly smeary; common fine and medium and few coarse roots; many fine irregular and common fine tubular pores; moderately acid (pH 6.0) clear wavy boundary. (8 to 12 inches thick)

3Bw--21 to 27 inches; very dark brown (10YR 2/2) paragravelly loamy sand, brown (10YR 4/3) dry; massive; slightly hard, firm, nonsticky and nonplastic; few fine roots; common fine and medium irregular pores; 30 percent paragravel; slightly acid (pH 6.4); clear smooth boundary. (4 to 10 inches thick)

4C1--27 to 35 inches; dark grayish brown (10YR 4/2) very cobbly sand, brown (10YR 5/3) dry; single grain; loose; few fine roots; many medium, and coarse irregular pores; 25 percent gravel and 15 percent cobbles; slightly acid (pH 6.2); clear smooth boundary. (0 to 15 inches)

4C2--35 to 63 inches; dark gray (10YR 4/1) very gravelly sand, gray (10YR 6/1) dry; single grain; loose; few fine roots; many medium and coarse irregular pores; 30 percent gravel, 10 percent cobbles, and 5 percent stones; slightly acid (pH 6.2).

TYPE LOCATION: Skamania County, Washington; about 1,200 feet south and 1,700 feet west of the northeast corner sec. 36, T. 8 N., R. 5 E.

RANGE IN CHARACTERISTICS: Mean annual soil temperature is 35 to 42 degrees F. Depth to 4C horizon is 20 to 35 inches. The soil is 30 to 60 percent by weight vitric material in the upper part of the control section. Rock fragments in the upper part of the control section ranges from 0 to 10 percent, and 35 to 60 percent in the lower part. Soil reaction in the B and C horizons is moderately acid or slightly acid.

The E horizon has value of 2 through 4 moist, 4 through 6 dry, and chroma of 1 or 2 moist and dry.

The Bhs horizon has value of 2 or 3 moist, 3 or 4 dry, and chroma of 1 or 2 moist and dry.

The 2Bs horizon has 30 to 45 percent pebbles and 30 to 45 percent pumice fragments. Iron stains on pumice fragments have hue of 10YR or 7.5YR, value of 5 or 6.

The 3Bs horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 5 or 6 dry, and chroma of 3 through 6 moist and dry. It is sandy loam or loamy sand and has intermittent lenses of loam.

The 3Bw horizon has value of 2 to 4 moist, 4 or 5 dry, and chroma of 1 to 3 moist and dry. It is loamy sand or sandy loam and contains 15 to 35 percent soft scoria fragments that can be crushed between fingers.

The 4C horizon has value of 4 to 6 moist, 5 to 8 dry, chroma of 1 to 3 moist and dry. It is very gravelly sand or very cobbly sand. Rock fragments average from 35 to 60 percent including 25 to 40 percent pebbles, 5 to 20 percent cobbles, and 0 to 5 percent stones.

COMPETING SERIES: These are the Chulitna, Kashwitna, Nancy, Soldatna, and Tuxekan series. Chulitna, Kashwitna, and Nancy soils are silt loam in the upper part of the control section and have a bi-sequum. Soldatna and Tuxekan soils are silt loam in the upper part of the control section.

GEOGRAPHIC SETTING: The Shoestring soils are on terraces, terrace escarpments and toe slopes of Mount St. Helens at elevations of 2,700 to 4,500 feet. Slopes are 0 to 90 percent. Shoestring soils formed in layers of aerially deposited volcanic ash and pumice over pyroclastic flows and lahars. Beginning from the surface of the mineral soils the stratigraphy of pyroclastic material represented in a typical profile includes: (1) fresh ash from the 176-year-old "Layer T", (2) pumice from the 400-year-old "Layer W", (3) ash, pumice and scoria from the 2,500-year-old "B set", (4) pyroclastic flows or lahars. The climate is characterized by cool, moist summers, and cold, wet winters. Mean annual precipitation is 120 to 140 inches including snow cover from November to June. The average January temperature is about 25 degrees F., the average July temperature is about 53 degrees F., and the average annual temperature is 38 to 42 degrees F. The frost- free season in 70 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Forsyth, Lonestar, Pelee, Polepatch, and St. Helens soils. Forsyth soils are sandy-skeletal and frigid. Lonestar soils are ashy over medial. Pelee soils are cindery. Polepatch soils are sandy skeletal and lack a spodic horizon. St. Helens soils are ashy and frigid.

DRAINAGE AND PERMEABILITY: Well drained, slow to rapid runoff; moderate permeability above the 4C and rapid below.

USE AND VEGETATION: Used mainly for timber production, recreation, wildlife habitat, and watershed. Overstory vegetation includes Pacific silver fir, western hemlock, and Douglas-fir. Understory vegetation includes salal, red huckleberry, false-Solomons-seal, trillum and bunchberry dogwood.

DISTRIBUTION AND EXTENT: Northern Skamania and Eastern Cowlitz Counties, Washington. The seres is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Skamania County, Washington, 1980.

REMARKS: Field test of NaF pH is less than 9.2 for the E horizon, greater than 11.5 for the Bhs, 2Bs, 3Bs, 2Bw, and 4C1, and 10.0 for 4C2.

Diagnostic horizons and features recognized in this pedon:

Albic horizon - zone from mineral surface to 3 inches (E horizon)

Spodic horizon - zone from 3 to 5 inches (Bhs horizon) and 8 to 18 inches (3Bs2 horizon). The 5 to 8 inch zone (2Bs1 horizon) fails to meet the color requirement for a spodic horizon.

Andic soil properties - zone from 0 to 18 inches.

Particle-size control sectin - the zone from 10 to 40 inches with 10 to 18 inches qualifying as medial, and 18 to 40 inches qualifying as sandy or sandy-skeletal.

Classification changed 6/98 reflecting revision in mineralogy classes in Soil Taxonomy.

National Cooperative Soil Survey
U.S.A.