LOCATION CALAWAH WAEstablished Series
TAXONOMIC CLASS: Medial, ferrihydritic, isomesic Typic Fulvudands
TYPICAL PEDON: Calawah medial silt loam - forested. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
Oi--0 to 2 inches; slightly decomposed needles, leaves, and twigs.
A1--2 to 6 inches; very dark grayish brown (10YR 3/2) medial silt loam, brown (10YR 4/3) dry; weak very fine and fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic and weakly smeary; many very fine, fine and medium roots; many very fine and fine irregular pores; very strongly acid (pH 5.0); clear smooth boundary. (4 to 7 inches thick)
A2--6 to 12inches; dark brown (10YR 3/3) medial loam, brown (10YR 4/3) dry; weak very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic and weakly smeary; many very fine and fine, and common medium roots; many very fine irregular, and many very fine and fine tubular pores; very strongly acid (pH 5.0); clear smooth boundary. (6 to 10 inches thick)
AB--12 to 20 inches; dark brown (10YR 3/3) medial silty clay loam, yellowish brown (10YR 5/4) dry; moderate very fine and fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic and weakly smeary; many very fine and fine, and common medium roots; many very fine irregular, and many very fine and fine tubular pores; strongly acid (pH 5.2); clear smooth boundary. (0 to 8 inches thick)
Bw1--20 to 32 inches; dark yellowish brown (10YR 4/4) medial silty clay loam, light yellowish brown (10YR 6/4) dry; moderate very fine and fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic and weakly smeary; common very fine and fine, and few medium roots; many very fine irregular, and many very fine and fine tubular pores; strongly acid (pH 5.4); clear smooth boundary. (8 to 14 inches thick)
Bw2--32 to 48 inches; yellowish brown (10YR 5/6) medial silty clay loam, very pale brown (10YR 7/4) dry; moderate very fine and fine angular blocky structure; slightly hard, friable, moderately sticky and moderately plastic and weakly smeary; few very fine and fine and medium roots; many very fine irregular, and many very fine tubular pores; strongly acid (pH 5.4); gradual smooth boundary. (16 to 36 inches thick)
2Bw3--48 to 62 inches; yellowish brown (10YR 5/6) gravelly silty clay loam, very pale brown (10YR 7/4) dry; moderate very fine and fine angular blocky structure; slightly hard, friable, moderately sticky and moderately plastic and weakly smeary; few very fine and fine roots; many very fine irregular and tubular pores; 15 percent gravel and 5 percent cobbles; strongly acid (pH 5.4).
TYPE LOCATION: Clallam County, Washington; approximately 75 feet north of new logging road; 2,500 feet north and 2,000 feet west of the SE corner of sec. 36, T. 28 N., R. 13 W.
RANGE IN CHARACTERISTICS: The umbric epipedon is 10 to 20 inches thick. Depth to the 2Bw horizon is 40 to over 60 inches. The particle-size control section has 20 to 35 percent field estimated clay and 0 to 5 percent coarse fragments. The mean annual soil temperature is 47 to 51 degrees F. The difference between mean summer and mean winter soil temperature is 5 to 9 degrees F. The soil moisture regime is udic. The upper 40 inches has andic soil properties with moist bulk density of 0.75 to 0.90 g/cc, acid oxalate aluminum plus one-half the iron is 2 to 4 percent, phosphate retention of 85 to 100. Acid oxalate iron is 1.5 to 3.0 percent and 15 bar water of 15 to 35 percent on air dry samples. The soil is strongly acid or very strongly acid.
The A and AB horizon has hue of 10YR or 7.5YR, value of 2 or 3 moist, 3 through 5 dry, and chroma of 2 or 3 moist and 2 through 4 dry. It has granular or subangular blocky structure. It has 7 to 15 percent organic matter. It has 5 to 15 cmol/kg of aluminum.
The Bw horizon has hue of 7.5YR, 10YR or 2.5Y, value of 3 through 6 moist, 5 through 8 dry, and chroma of 3 through 6 moist and 3 or 4 dry. It is medial silt loam or medial silty clay loam. It has 2 to 8 cmol/kg of aluminum. It has 2 to 7 percent organic matter. It has 0 to 15 percent rounded gravel in the lower part.
The 2Bw horizon is gravelly silt loam or gravelly silty clay loam and is at depths greater than 60 inches in some pedons. Few fine distinct redox concentrations are in the lower part of some pedons. It has a moist bulk density of 0.90 to 1.20 g/cc.
COMPETING SERIES: These are the Ilwaco, Klootchie, Knappton, Lint, Lytell, Mopang, Narel, Neotsa, Neskowin, Newskah, Palix, Queets and Salander series. Ilwaco soils are on uplands over sandstone and contain 0 to 15 percent sandstone paragravels. Klootchie soils are on mountains over basalt and contain a significant amount of rock and pararock fragments. Knappton soils are on mountains over basalt and have gravelly textures throughout the subsoil. Lint soils are similar and future re-correlation needs review. Lytell soils are on mountains over siltstone or sandstone and have a paralithic contact at 40 to 60 inches. Mopang soils have cemented glacial till at depths between 40 to 60 inches. Narel soils are on mountains over sandstone and have a paralithic contact at 40 to 60 inches. Newskah soils have loamy sand or loamy fine sand textures at 40 to 60 inches. Palix soils are on mountains over siltstone and have a paralithic contact at 40 to 60 inches. Neotsu and Neskowin soils are moderately deep to bedrock. Queets soils have an ochric epipedon. Salander soils have a umbric epipedon over 20 inches thick, are on mountains and have angular rock fragments.
GEOGRAPHIC SETTING: Calawah soils are on terraces at elevations of 20 to 1,200 feet. Slopes are 0 to 65 percent. They formed in loess over old alluvium or glacial outwash. The soils are in a mild marine climate and have cool, moist summers and cool, wet winters. Mean annual precipitation is 80 to 130 inches. Average January temperature is about 38 degrees F., average July temperature is about 59 degrees F., and mean annual temperature is about 48 degrees F. Frost-free season is 180 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Ilwaco, Newskah soils and the Hoquiam, Klone, Ozette, Snahopish and Tealwhit soils. Hoquiam soils are mesic. Klone soils are medial-skeletal. Snahopish soils are medial-skeletal. Tealwhit soils are fine textures. Ozette soils have dense till at 40 to 60 inches.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Timber production is the principal use. Native vegetation is predominantly western hemlock with some western redcedar, Pacific silver fir, red alder and Sitka spruce. Understory species include salal, red huckleberry, tall blue huckleberry, evergreen huckleberry, vine maple, blackberry, red elderberry, western swordfern, deer fern, ladyfern, salmon berry and Oregon oxalis.
DISTRIBUTION AND EXTENT: Western Clallam, Jefferson, and Grays Harbor Counties, Washington; MLRA 4A. This series is moderately extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Jefferson County, Washington, 1970.
REMARKS: Diagnostic horizons and other features are:
Umbric epipedon - 2 to 20 inches
Cambic horizon - 20 to 62 inches
Andic soil properties from 2 to 48 inches. The 2Bw horizon has bulk density of over 0.90 g/cc.
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.
The cool phase map units characterized with Pacific silver fir in the plant community need to be correlated to isofrigid soil temperature regime.
ADDITIONAL DATA: National Soil Survey Laboratory; sample numbers: S77WA 9-9-8; type location and S84WA-027-001.