LOCATION DUCKABUSH WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, ferrihydritic, frigid Typic Hapludands
TYPICAL PEDON: Duckabush extremely gravelly medial loam- forestland, on a 68 percent west-facing slope at an elevation of 2,050 feet in a western hemlock/salal-common beargrass plant association. (When described on June 25, 1990 the soil was moist throughout. Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
Oi--0 to 1 inch; slightly decomposed needles, leaves, twigs, and cones; abrupt wavy boundary. (1 to 4 inches thick)
A--1 to 8 inches; dark brown (7.5YR 3/4) extremely gravelly medial loam, strong brown (7.5YR 5/6) dry; weak very fine subangular blocky and weak very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; common very fine, fine, medium, and coarse roots; common very fine and fine tubular and irregular pores; 55 percent gravel, 10 percent cobbles; very strongly acid (pH 4.8); clear smooth boundary. (4 to 10 inches thick)
Bw1--8 to 19 inches; dark brown (7.5YR 4/4) extremely gravelly medial loam, strong brown (7.5YR 5/6) dry; weak very fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; common very fine, fine, medium, and coarse roots; common very fine and fine tubular and irregular pores; 50 percent gravel, 15 percent cobbles; strongly acid (pH 5.1); clear wavy boundary.
Bw2--19 to 32 inches; dark yellowish brown (10YR 3/6) extremely gravelly medial sandy loam, brownish yellow (10YR 6/6) dry; weak very fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; common very fine and fine and few medium and coarse roots; common very fine and fine irregular pores; 45 percent gravel, 20 percent cobbles; strongly acid (pH 5.1); clear wavy boundary.
Bw3--32 to 41 inches; dark yellowish brown (10YR 4/6) extremely gravelly medial sandy loam, yellow (10YR 7/6) dry; weak very fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; common very fine and fine irregular pores; 50 percent gravel, 15 percent cobbles; strongly acid (pH 5.2); clear wavy boundary. (Combined thickness of the Bw horizon is 30 to 40 inches.)
BC--41 to 62 inches; dark yellowish brown (10YR 4/6) extremely gravelly sandy loam, yellow (10YR 7/6) dry; weak very fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; few very fine irregular pores; 55 percent gravel, 10 percent cobbles; strongly acid (pH 5.4).
TYPE LOCATION: Mason County, Washington; about 5 miles northwest of Dennie Ahl Hill about 1,190 feet west and 1,585 feet south of the northeast corner of section 29, T. 23 N., R. 5 W. (Latitude 47 degrees, 27 minutes, 26 seconds N, Longitude 123 degrees, 20 minutes, 22 seconds W)
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 45 to 47 degrees F. These soils are usually moist, and are dry in the soil moisture control section 0 to 30 consecutive days after the summer solstice; udic moisture regime. Depth to bedrock is 40 to over 60 inches. The particle size control section has andic soil properties with an estimated moist bulk density of 0.60 to 0.90 g/cc, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 2 to 3 percent, phosphate retention is 85 to 100 percent, and 15-bar water retention of 15 to 30 percent for air dried samples, and 60 to 90 percent rock fragments by volume. It has 1 to 2 cmol/kg of aluminum. Acid oxalate extractable iron is 1.5 to 3.0 percent.
The A horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist and 5 through 7 dry, and chroma of 3 or 4 moist and 4 or 6 dry. It has 5 to 15 percent organic matter.
The Bw horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist and 5 through 7 dry, and chroma of 5 or 6 moist and 6 or 8 dry. It is extremely gravelly medial sandy loam, extremely gravelly medial loam, or extremely cobbly medial sandy loam. It has 1 to 7 percent organic matter The reaction is moderately or strongly acid.
The BC horizon has an estimated moist bulk density of 0.90 to 1.20 g/cc. It has less than 1 to 2 percent organic matter.
COMPETING SERIES: These are the Fricaba, Gunderson, Lotloh, Maidenpeak, Ruggedridge and Halfoss series. Fricaba, Ruggedridge and Halfoss soils are moderately deep to bedrock. Gunderson soils have densic material at 40 to 60 inches. Maidenpeak soils are dry for 30 to 45 consecutive days. Lotloh soils are over sedimentary bedrock and have 40 to 60 percent sand in the particle-size control section.
GEOGRAPHIC SETTING: Duckabush soils are on mountain slopes. Slopes are 60 to 90 percent. The soils formed in colluvium from marine basalt and associated volcanic rocks. Elevations are 1,900 to 2,900 feet. Average annual precipitation is 70 to 150 inches. Average annual temperature is 43 to 45 degrees F. Frost-free season is 140 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Fricaba soils and the Hammahamma, Hoodcanal, McGravey, Sawpeak, Waketickeh, and Walkinshaw soils. Hammahamma and Hoodcanal soils are on glaciated mountain slopes and glacial valleys and are moderately deep to a cemented layer. McGravey soils are on mountain slopes and have over 2 cmol/kg of aluminum. Sawpeak soils are on mountain slopes and glacial valleys and are moderately deep to bedrock. Waketickeh and Walkinshaw soils are on mountain slopes and are very shallow and shallow to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; moderately rapid permeability
USE AND VEGETATION: Timber production, wildlife habitat, recreation, and watershed. Native vegetation is Douglas-fir, western hemlock, Pacific rhododendron, red huckleberry, salal, Oregon-grape, and western swordfern.
DISTRIBUTION AND EXTENT: Mason and Jefferson Counties, Washington; MLRA 1. Series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Mason County, Washington, 2000; Olympic National Forest.
REMARKS: Diagnostic horizons and features recognized in this pedon are an ochric epipedon, a cambic horizon from 8 to 41 inches and andic soil properties from the mineral soil surface to 41 inches. The particle-size control section is from 1 to 41 inches (A, Bw1, Bw2, and Bw3 horizons). The BC horizon lacks andic soil properties.
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.
ADDITIONAL DATA: NSSL 91P0685.