LOCATION KAHBOO WAEstablished Series
TAXONOMIC CLASS: Loamy, isotic, mesic Lithic Dystroxerepts
TYPICAL PEDON: Kahboo gravelly fine sandy loam, forested, on a northwest-facing sideslope of 12 percent at 512 meters elevation. (Colors are for moist soils unless otherwise stated. When described on October 20, 2004 the soil was moist throughout.)
Oi--0 to 3 cm, slightly decomposed plant material; gradual wavy boundary. (3 to 5 cm thick)
Oe--3 to 5 cm, moderately decomposed plant material; abrupt smooth boundary (0 to 3 cm thick)
A--5 to 23 cm, dark yellowish brown (10YR 3/4) gravelly fine sandy loam, dark yellowish brown (10YR 4/4) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots, and few medium and coarse roots; common very fine and fine irregular pores, and common fine tubular pores; 20 percent gravel and 10 percent cobbles; NaF pH 9.3; strongly acid (pH 5.4); gradual wavy boundary. (8 to 23 cm thick)
Bw--23 to 36 cm, strong brown (7.5YR 4/6) gravelly fine sandy loam, brown (7.5YR 4/4) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots, and common medium roots; many very fine and fine irregular pores, and few fine tubular pores; 20 percent gravel and 10 percent cobbles; NaF pH 10.8; moderately acid (pH 5.6); abrupt wavy boundary. (10 to 28 cm thick)
R--36 cm, metasedimentary bedrock
TYPE LOCATION: Orcas Island, San Juan County, Washington - 152 meters feet north and 492 meters west of the southeast corner of section 27, T. 37 N., R. 1 W. Willamette Meridian. USGS Mount Constitution SE quarter quadrangle; lat. 48 degrees 42 minutes 30 seconds N. and long. 122 degrees 53 minutes 41 seconds W.
RANGE IN CHARACTERISTICS: Depths to diagnostic horizons and features start from the mineral soil surface.
Average annual soil temperature - 8 to 9 degrees C.
Soil moisture control section - dry 45 to 60 days following summer solstice
Depth to lithic contact - 25 to 50 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
Clay content - 5 to 15 percent
Hue - 10YR to 7.5YR
Value - 3 or 4 moist, 5 to 6 dry
Chroma - 3 to 6 moist, 3 to 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, 0 to 5 percent cobbles, 0 to 15 percent total
Bw horizon
Texture - FSL, SL, L
Clay content - 5 to 15 percent
Rock fragments - 0 to 35 percent gravel
Hue - 10YR to 7.5YR
Value - 3 or 4 moist, 5 to 6 dry
Chroma - 3 to 6 moist, 3 to 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 35 percent gravel, 0 to 10 percent cobbles, 0 to 35 percent total
COMPETING SERIES: This is the Cady series. Cady soils formed in colluvium from glacial drift and metasedimentary bedrock, have an average annual soil temperature ranging from 10 to 11 degrees C., and are dry in the soil moisture control section for 60 to 90 days Soils in similar families include the Dicecreek, Jahjo and Maymen series. Dicecreek soils average 25 to 35 percent clay in the particle-size control section and have mixed mineralogy. Jahjo soils have mixed mineralogy, more than 5 percent volcanic glass, and are dry in the moisture control section for more than 100 days (early June to late September). Maymen soils have mixed mineralogy and are dry in the moisture control section for more than 120 days (mid-May or June through September or early October).
GEOGRAPHIC SETTING: Kahboo soils are on slopes and summits of hills and mountains. Slope ranges from 5 to 100 percent and elevations range from 0 to 732 meters. The 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 average 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 include the Constitution, Pickett, and Skipjack soils. Constitution soils occur on adjacent hillslopes and mountain slopes and are 50 to 100 cm to a lithic contact. Pickett soils are also on slopes of mountains and hills, are 50 to 100 cm to a lithic contact, and have greater than 35 percent coarse fragments in the particle-size control section. Skipjack soils are in concave areas on sideslopes and are greater than 150 cm to a lithic contact.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; Saturated hydraulic conductivity is high.
USE AND VEGETATION: Used for 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 A2, Northern Part. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: San Juan County, Washington, 2006. The name is taken from Kahboo Hill on Orcas Island.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon
Andic subgroup properties - 5 to 36 cm (A and Bw horizons)
Cambic horizon - 5 to 36 cm (Bw horizons)
Lithic contact - 36 cm (top of the R horizon)
Particle-size control section - 5 to 36 cm (A and Bw horizons)
Bulk density of the A and Bw horizons is assumed to be less than 1 g/cm3