LOCATION LARSENCREEK WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, ferrihydritic, isofrigid Pachic Fulvudands
TYPICAL PEDON: Larsencreek very gravelly medial silt loam - forestland, on an 81 percent east-northeasterly aspect at an elevation of 1,350 feet in a Pacific silver fir/swordfern-oxalis plant association. (When described on June 17, 1998, 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 cone fragments; abrupt smooth boundary. (0.5 to 1.5 inches thick)
Oe--1 to 6 inches; moderately decomposed organic materials; abrupt smooth boundary. (0 to 6 inches thick)
Oa--6 to 12 inches; highly decomposed organic materials; abrupt smooth boundary. (0 to 6 inches thick)
A1--12 to 20 inches; very dark brown (10YR 2/2) very gravelly medial silt loam, dark brown (10YR 3/3) dry; weak very fine and fine granular and weak very fine and 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; 55 percent gravel; very strongly acid (pH 4.6); clear smooth boundary.
A2--20 to 29 inches; very dark brown (10YR 2/2) very gravelly medial silt loam, dark brown (10YR 3/3) dry; weak very fine and fine granular and weak very fine and 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; 50 percent gravel; very strongly acid (pH 4.8); clear wavy boundary. (Combined thickness of the A horizon is 10 to 20 inches.)
Bw1--29 to 39 inches; dark brown (7.5YR 3/4) very gravelly medial silt loam, yellowish brown (10YR 5/6) dry; weak very fine, fine, 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; 40 percent gravel; very strongly acid (pH 4.8); clear wavy boundary.
Bw2--39 to 46 inches; strong brown (7.5YR 4/6) extremely gravelly medial silt loam, yellowish brown (10YR 5/6) 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 and fine and few medium and coarse roots; common very fine tubular and irregular pores; 65 percent gravel; strongly acid (pH 5.2); clear wavy boundary.
Bw3--46 to 64 inches; strong brown (7.5YR 4/6) extremely gravelly medial silt 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 and fine and few medium and coarse roots; common very fine and fine tubular and irregular pores; 75 percent gravel; strongly acid (pH 5.4); abrupt wavy boundary. (Combined thickness of the Bw horizon is 30 to 50 inches.)
R--64 inches; marine basalt.
TYPE LOCATION: Grays Harbor County, Washington, about 2 miles northeast of Humptulips Ridge, about 1,955 feet east and 1,795 feet south of the northwest corner of Section 29, T. 22 N., R. 9 W. (Latitude 47 degrees, 22 minutes, 08 seconds N., Longitude 123 degrees, 43 minutes, 49 seconds W.)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 43 to 47 degrees F. The mean summer soil temperature is 47 to 50 degrees F. and the mean winter soil temperature is 40 to 45 degrees F. The difference between the mean summer and mean winter soil temperature is 5 to 9 degrees F. These soils are usually moist and have a surplus of available water on a monthly basis throughout the year; perudic moisture regime. Depth to bedrock is 40 to greater than 60 inches. The umbric epipedon is 10 to 30 inches thick. The solum has andic soil properties throughout, and 35 to 85 percent rock fragments by volume. The andic soil material has an estimated moist bulk density of 0.30 to 0.70 g/cc, acid-oxalate extractable aluminum plus one half of the acid-oxalate extractable iron of 2 to 6 percent, phosphate retention of 85 to 100 percent, and 15-bar water retention of 30 to 50 percent for air dried samples. Acid oxalate iron is 1.5 to 3.5 percent. The particle-size control section has 5 to 18 percent field estimated clay and 20 to 40 percent sand.
The combined thickness of the O horizon is 1 to 14 inches thick.
The A horizon has hue of 10YR or 7.5YR moist and dry, value of 2 or 3 moist and 3 or 4 dry, and chroma of 1 through 3 moist and 2 or 3 dry. It has 20 to 40 percent organic matter. It has 5 to 20 cmol/kg of aluminum.
The Bw horizon has hue of 10YR or 7.5YR moist and dry, value of 3 or 4 moist and 3, 5, or 6 dry, and chroma of 3, 4, or 6 moist and dry. It is very gravelly medial silt loam, extremely gravelly medial silt loam, or extremely gravelly medial loam. Reaction is very strongly acid or strongly acid. It has 9 to 25 percent organic matter. It has 1 to 5 cmol/kg of aluminum.
COMPETING SERIES: These are the Elklake, Fawceter, Flatbottom, McKinnon, Urboden and Zenobia series. Elklake, Killam, Flatbottom and Zenobia soils are moderately deep. McKinnon soils are dry 0 to 30 consecutive days;udic soil moisture regime. Urboden soils have an umbric epipedon 20 to 40 inches thick. Fawceter soils are dry for 0 to 30 consecutive days; udic moisture regime.
GEOGRAPHIC SETTING: Larsencreek soils are on mountain slopes and dissected mountain slopes. Slopes are 60 to 90 percent. The soils formed in colluvium from marine basalt. Elevations are 800 to 2900 feet. Average annual precipitation is 140 to 180 inches. Fog drip contributes to the effective precipitation totals. Average annual temperature is 41 to 43 degrees F. The frost-free season is 120 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Eatoncreek, Elklake, Flatbottom, Lizardlake, and McKinnon soils. Eatoncreek and Lizardlake soils are on dissected mountain slopes and mountain headwalls and are shallow. Elklake and Flatbottom soils are on mountain slopes, dissected mountain slopes, and mountain headwalls and are moderately deep. McKinnon soils are on mountain slopes and dissected mountain slopes and have a udic soil moisture regime.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Timber production, wildlife habitat, recreation, and watershed. Native vegetation is western hemlock, Pacific silver fir, western redcedar, vine maple, western swordfern, Oregon oxalis, Alaska huckleberry, red huckleberry, salmonberry, threeleaf foamflower, mosses, and deer fern.
DISTRIBUTION AND EXTENT: Grays Harbor County, Washington; MLRA 1. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Grays Harbor County, Washington, 200; Olympic National Forest.
REMARKS: Diagnostic horizons and features recognized in this pedon are the following:
Folistic epipedon - 0 to 12 inches
Umbric epipedon - 12 to 29 inches
Cambic horizon - 29 to 64 inches
Andic soil properties - 12 to 64 inches
Lithic contact - 64 inches
PSCS - 12 to 52 inches
This soil has a perudic moisture regime.
All depths to diagnostic horizons and features are measured from the top of the first mineral horizon.
ADDITIONAL DATA: Pedon NSSL S98WA-027-006; melanic index was run on the A1 and A2 horizons by NSSL 6/2003. Melanic index values are 2.307 and 22.43 respectively.