LOCATION KLAWATTI WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, amorphic Andic Haplocryods
TYPICAL PEDON: Klawatti very gravelly loam - on a 40 percent west-facing convex slope under a forest canopy of Pacific silver fir and mountain hemlock at 2,700 feet elevation. (Colors are for moist soils unless otherwise noted. All textures are apparent field textures.)
0i--7 to 5 inches; undecomposed needles, twigs, and bark.
Oa--5 inches to 0; decomposed organic mat; many very fine, fine, medium, and coarse roots; 20 percent pebbles.
E--0 to 0.5 inch; dark gray (5YR 4/1) gravelly loam, light gray (5YR 7/1) dry; massive; slightly hard, friable, nonsticky and nonplastic; many very fine, fine, and common medium roots; many very fine irregular pores; 25 percent pebbles; NaF pH 10.0; extremely acid (pH 4.2); abrupt smooth boundary. (0.5 to 2 inches thick)
Bs1--0.5 to 2 inches; dark reddish brown (5YR 3/3) very gravelly loam, reddish brown (5YR 5/3) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic, weakly smeary; many fine and common medium roots; many very fine irregular pores; 30 percent pebbles and 10 percent cobbles; NaF pH 11.0; strongly acid (pH 5.4); clear wavy boundary. (1.5 to 4 inches thick)
Bs2--2 to 10 inches; dark yellowish brown (10YR 4/4) extremely gravelly loam, light yellowish brown (10YR 6/4) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic, weakly smeary; many fine and medium roots; many very fine irregular pores; 45 percent pebbles and 20 percent cobbles; NaF pH 11.0; slightly acid (pH 6.2); clear wavy boundary. (6 to 17 inches thick)
Bs3--10 to 25 inches; dark yellowish brown (10YR 3/4) extremely gravelly loam, light yellowish brown (10YR 6/4) dry; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic, and weakly smeary; common fine, many medium and coarse roots; many very fine, irregular pores; 40 percent pebbles, 20 percent cobbles, and 5 percent stones; NaF pH 11.0; slightly acid (pH 6.2); abrupt wavy boundary. (8 to 18 inches thick)
2R--25 inches; dunite.
TYPE LOCATION: Whatcom County, Washington; about 10 miles southeast of Van Zandt; 2,300 feet south and 400 feet west of the northeast corner of sec. 34, T. 38 N., R. 6 E.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 40 to 43 degrees F. Depth to a lithic contact with dunite or serpentine is 20 to 40 inches. The particle-size control section is 40 to 70 percent dunite or serpentine fragments by weighted average.
The E horizon has hue of 5YR or 7.5YR, value of 3 to 5 moist, 4 to 7 dry, and chroma of 1 or 2 moist and dry. Reaction is extremely acid through strongly acid.
The Bs1 horizon has hue of 2.5YR, 5YR, or 7.5YR, value of 3 or 4 moist, 5 or 6 dry, and chroma of 3 through 6 moist and dry. It is loam or silt loam with 20 to 45 percent dunite or serpentine pebbles. Reaction is strongly acid through slightly acid.
The Bs2 and Bs3 horizons have hue of 7.5YR or 10YR, value of 3 or 4 moist, 5 or 6 dry, and chroma of 3 through 6 moist and dry. It is loam or silt loam and has 30 to 50 percent dunite or serpentine pebbles and 5 to 20 percent dunite or serpentine cobbles. Reaction is strongly acid through slightly acid.
COMPETING SERIES: These are the Jackman and Twinsi soils. Jackman soils are deep. Twinsi soils are 20 to 40 inches deep to a paralithic contact with dense glacial till.
GEOGRAPHIC SETTING: Klawatti soils are on mountain shoulder slopes and ridgetops at elevations of 2,200 to 4,300 feet. Slopes are 10 to 80 percent. The soils formed in volcanic ash, colluvium, and slope alluvium from dunite or serpentine. Klawatti soils are in a marine climate with cool, moist summers and cold, wet winters. Snow cover lasts from November through May. Average annual precipitation is 85 to 105 inches. Mean January temperature is about 29 degrees F.; mean July temperature is about 57 degrees F. The mean annual temperature is about 40 degrees F. The frost-free season is about 85 to 105 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Jackman and Twinsi soils and the Edfro soils. Edfro soils have dense glacial till at 14 to 20 inches.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Used for timber production, watershed, wildlife habitat, and recreation. Native vegetation is Pacific silver fir, mountain hemlock, western hemlock, and Alaska-cedar, with an undergrowth of blue-leaved huckleberry, red huckleberry, princes pine, and western brackenfern.
DISTRIBUTION AND EXTENT: Twin Sisters Mountain area of Skagit and Whatcom Counties in northwestern Washington. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skagit County, Washington, l981.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy. This draft reflects a change in classification from loamy-skeletal, serpentinitic Typic Cryorthods to medial-skeletal Andic Haplocryods. Partial laboratory data are available on this soil--Sample Numbers 807271-7273. Diagnostic horizons and features recognized in this pedon are: Spodic horizon from 0.5 to 25 inches, a lithic contact at 25 inches, and 65 percent dunite in the particle-size control section.