LOCATION CONSTITUTION WA

Established Series
Rev. MPR/EED/SBC
06/2011

CONSTITUTION SERIES

The Constitution series consists of moderately deep, well drained soils formed in colluvium from glacial drift, metasedimentary bedrock, and volcanic ash. Constitution soils are on hillslopes and mountain slopes. Slope ranges from 5 to 30 percent. Average annual precipitation is about 1,015 millimeters and the average annual air temperature is about 8 degrees C.

TAXONOMIC CLASS: Coarse-loamy, isotic, mesic Andic Dystroxerepts

TYPICAL PEDON: Constitution sandy loam, forested, on a northeast-facing sideslope of 20 percent at 140 meters elevation. (Colors are for dry soil unless otherwise noted. When described on September 25, 2003 the soil was dry throughout.)

Oi--0 to 3 cm; slightly decomposed plant material; clear wavy boundary. (3 to 5 cm thick)

A--3 to 15 cm; dark yellowish brown (10YR 3/4) sandy loam, very dark brown (10YR 2/2) moist; strong medium granular structure; soft, very friable, nonsticky and nonplastic; many fine and medium roots, and common coarse and very coarse roots; many very fine and fine irregular pores; 10 percent gravel; NaF pH 9.3; strongly acid (pH 5.4); clear smooth boundary. (5 to 15 cm thick)

Bw1--15 to 41 cm; strong brown (7.5YR 4/6) gravelly sandy loam, dark brown (7.5YR 3/4) moist; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and medium roots; common very fine irregular and few fine tubular pores; 30 percent gravel; NaF pH 10.8; strongly acid (pH 5.4); gradual wavy boundary. (15 to 64 cm thick)

Bw2--41 to 66 cm; light olive brown (2.5Y 5/6) gravelly coarse sandy loam, olive brown (2.5Y 4/4) dry; weak coarse subangular blocky structure; soft, very friable, nonsticky and nonplastic; few coarse roots; few very fine irregular pores; 30 percent gravel; NaF pH 10.8; moderately acid (pH 5.6); abrupt wavy boundary. (18 to 46 cm thick)

R--66 cm; metasedimentary bedrock

TYPE LOCATION: Orcas Island, San Juan County, Washington; 308 meters north and 388 meters west of the southeast corner of sec. 32, T. 37 N., R. 1 W. Willamette Meridian. USGS Mount Constitution SW quarter quadrangle; lat. 48 degrees 38 minutes 53 seconds N. and long. 122 degrees 50 minutes 28 seconds W.

RANGE IN CHARACTERISTICS: Depths to diagnostic horizons and features start from the mineral soil surface.

Average annual soil temperature - 9 to 10 degrees C.
Soil moisture control section - dry 45 to 60 days following summer solstice
Depth to lithic contact - 50 to 100 cm
Reaction - strongly acid to moderately acid
Particle size control section:
Clay content - 5 to 15 percent
Rock fragments - 0 to 35 percent

A horizon
Value - 2 or 3 moist
Chroma - 1 to 3 moist, 3 or 4 dry
Ammonium oxalate extractable aluminum plus one half iron - 1.5 to 2.5 percent
Bulk Density - 0.8 to 1.0 g/cm3
Phosphorous retention - 50 to 80 percent
Volcanic glass - 0 to 4 percent
Rock fragments - 0 to 15 percent gravel

Bw1 horizon
Hue - 10YR to 7.5YR
Value - 3 or 4 moist, 5 to 6 dry
Chroma - 3 to 6 moist or dry
Texture - L, SL, or FSL
Rock fragments - 0 to 35 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones, 0 to 35 percent total
Ammonium oxalate extractable aluminum plus one half iron - 1.5 to 2.5 percent
Bulk Density - 0.8 to 1.0 g/cm3
Phosphorous retention - 50 to 80 percent
Volcanic glass - 0 to 4 percent

Bw2 horizon
Hue - 2.5Y to 10YR
Value - 3 or 4 moist, 4 to 6 dry
Chroma - 3 to 6 moist or dry
Texture - SL, or COSL
Rock fragments - 0 to 35 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones, 0 to 35 percent total

COMPETING SERIES: These are the Kapowsin, Menzel, Sadie, and Skipjack (T) series. Kapowsin soils formed in dense glacial till, have redoximorphic features within 100 cm, and are 50 to 100 cm deep to a pan cemented with aluminum, iron, and organic matter. Menzel soils formed in alluvium and are greater than 100 cm to a restrictive layer. Sadie soils have a densic contact at 65 to 100 cm and have redoximorphic features within 100 cm. Skipjack soils are greater than 150 cm to a lithic contact.

GEOGRAPHIC SETTING: Constitution soils occur on hillslopes and mountain slopes. Slope ranges from 5 to 30 percent and elevations range from 0 to 732 meters. These soils formed in colluvium from glacial drift, bedrock of metasedimentary lithology, and volcanic ash. The climate is characterized by warm, dry summers and mild, moist winters with intermittent snow cover. The annual precipitation ranges from 890 to 1,140 millimeters. The average annual air temperature ranges from 8 to 9 degrees C. The frost-free season is 160 to 220 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kahboo, Pickett, and Skipjack series. Kahboo soils have a lithic contact between 25 and 50 cm and occur on summits, hillslopes, and mountain slopes. Pickett soils have greater than 35 percent rock fragments in the particle-size control section and occur on adjacent hillsides and mountainsides. Skipjack soils are greater than 150 cm to a lithic contact and occur on adjacent hillsides and mountainsides.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; Saturated hydraulic conductivity is high.

USE AND VEGETATION: Used for timber production, recreation, wildlife habitat, homesites, and watershed. Potential natural vegetation consists of western hemlock, Douglas-fir, western redcedar, Cascade Oregongrape, prickly currant, false Solomons-seal, swordfern, and bracken fern.

DISTRIBUTION AND EXTENT: Northwest Washington; MLRA 2, Northern Part. The series is of small extent.

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

SERIES ESTABLISHED: San Juan County, Washington - 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Andic subgroup properties - 3 to 41 cm (A and Bw1 horizons)
Cambic horizon - 15 to 66 cm (Bw horizons)
Lithic contact - 66 cm (top of the R horizon)
Particle-size control section - 28 to 66 cm

Bulk density of A and Bw1 horizons is assumed to be less than 1 g/cc

ADDITIONAL DATA: Reference sample - National Soil Survey Laboratory pedon number 04N0754.

National Cooperative Soil Survey
U.S.A.