LOCATION HEDGEUM WAEstablished Series
TAXONOMIC CLASS: Medial, ferrihydritic, frigid Typic Hapludands
TYPICAL PEDON: Hedgeum medial fine sandy loam-forestland, on a 20 percent northeasterly aspect at an elevation of 1,630 feet in a Western hemlock/salal-swordfern plant association. (When described on July 22, 1996, the soil was moist throughout. Colors are for moist soil unless otherwise stated.)
Oi--0 to 1 inch; slightly decomposed needles, leaves, and twigs; abrupt smooth boundary. (1 to 3 inches thick)
A--1 to 8 inches; dark yellowish brown (10YR 3/4) medial fine sandy loam, light yellowish brown (10YR 6/4) dry; weak very fine and fine granular and weak very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many very fine, fine, medium, and coarse roots; many very fine and fine tubular and irregular pores; strongly acid (pH 5.4); clear wavy boundary. (5 to 8 inches thick)
Bw1--8 to 23 inches; dark yellowish brown (10YR 3/4) medial fine sandy loam, light yellowish brown (10YR 6/4) dry; weak very fine, fine, and medium 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; 5 percent gravel; moderately acid (pH 5.6); clear wavy boundary.
Bw2--23 to 37 inches; dark brown (7.5YR 3/4) medial very fine sandy loam, brownish yellow (10YR 6/6) dry; weak very fine, fine, and medium subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; common very fine, fine, and medium and few coarse roots; common very fine and fine tubular and irregular pores; 5 percent gravel; moderately acid (pH 5.8); clear wavy boundary.
Bw3--37 to 44 inches; dark yellowish brown (10YR 3/6) medial very fine sandy loam brownish yellow (10YR 6/6) dry; weak very fine, fine, and medium subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; few very fine, fine, medium, and coarse roots; few very fine and fine tubular and irregular pores; moderately acid (pH 5.8); abrupt wavy boundary. (Combined thickness of the Bw horizon is 25 to 35 inches.)
BC--44 to 61 inches; yellowish brown (10YR 5/6) very fine sandy loam, very pale brown (10YR 7/4) dry; weak very fine, fine, and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; few very fine and fine tubular and irregular pores; moderately acid (pH 6.0); clear wavy boundary.
TYPE LOCATION: Clallam County, Washington, about 3.25 miles southwest of Fairholm along Lake Crescent, about 950 feet north and 1,320 feet east of the southwest corner of Section 2, T. 29 N., R. 10 W. (Latitude 48 degrees, 01 minutes, 56 seconds N., Longitude 123 degrees, 57 minutes, 40 seconds W.)
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 43 to 45 degrees F. These soils are usually moist, and are dry 0 to 30 consecutive days in the soil moisture control section; udic moisture regime. Depth to bedrock is greater than 60 inches. The particle-size control section has andic soil properties with a cumulative thickness of 30 to 45 inches and 0 to 15 percent rock fragments by volume. The andic soil material has 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 of 85 to 100 percent, and 15-bar water retention of 20 to 30 percent for air dried samples. It has 1 to 2 cmol/kg of aluminum. Acid oxalate extractable iron is 1.5 to 3.0 percent.
The A horizon has value of 5 or 6 dry and chroma of 4 or 6 moist and dry. Reaction is strongly or moderately acid. It has 5 to 15 percent organic matter.
The Bw horizon has hue of 10YR or 7.5YR moist and dry, value of 3 through 5 moist and 5 through 7 dry, and chroma of 4 or 6 moist and dry. It is medial fine sandy loam, medial very fine sandy loam, or medial silt loam. Reaction is moderately or strongly acid. It has 1 to 7 percent organic matter.
The BC horizon has 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 Jonas and Lates series. Jonas soils are dry for 30 to 45 consecutive days. Lates soils are moderately deep to basalt.
GEOGRAPHIC SETTING: Hedgeum soils are on mountain slopes. Slopes are 20 to 50 percent. The soils formed in residuum and colluvium from sedimentary and metasedimentary rocks. Elevations are 1,300 to 1,850 feet. Average annual precipitation is 90 to 100 inches. Average annual temperature is 41 to 45 degrees F. The frost-free season is 140 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ishmael, Gunderson, Lotloh, and Ruggedridge soils. Ruggedridge soils are moderately deep and medial-skeletal. Ishmael and Lotloh soils are medial-skeletal. Gunderson soils are deep to dense till and are medial-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Timber production, wildlife habitat, recreation, and watershed. Native vegetation is western hemlock, Douglas-fir, threeleaf foamflower, western swordfern, salal, deer fern, red huckleberry, violet, and Alaska huckleberry.
DISTRIBUTION AND EXTENT: Clallam County, Washington; MLRA 1. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Clallam County, Washington, 2000; Olympic National Forest.
REMARKS: Diagnostic horizons and features recognized in this pedon are the following:
Ochric epipedon
Cambic horizon - 8 to 44 inches
Andic soil properties - 1 to 44 inches
PSCS - 1 to 41 inches
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.