LOCATION WINEMA OREstablished Series
TAXONOMIC CLASS: Medial over clayey, ferrihydritic over isotic, isomesic Typic Fulvudands
TYPICAL PEDON: Winema medial silt loam, pasture on a 25 percent south-facing slope and elevation of 150 feet. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 10 inches; black (10YR 2/1) medial silt loam, very dark gray (10YR 3/1) dry; strong very fine to medium granular structure; soft, friable, slightly sticky and slightly plastic; weakly smeary; many very fine roots; many very fine and fine irregular pores; very strongly acid (pH 5.0); clear wavy boundary.
A--10 to 21 inches; black (10YR 2/1) medial silt loam, very dark gray (10YR 3/1) dry; moderate fine subangular blocky structure parting to strong fine and very fine granular; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many very fine roots; many very fine and fine irregular pores; very strongly acid (pH 4.9); clear wavy boundary. (combined A horizon is 12 to 25 inches thick)
2BA--21 to 28 inches; dark brown (10YR 3/3) silt clay loam, brown (10YR 4/3) dry; strong very fine and fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; many very fine roots; many very fine tubular pores; common thin black (10YR 2/1) organic stains in pores, channels, and on some faces of peds; very strongly acid (pH 4.8); clear wavy boundary. (0 to 10 inches thick)
2Bw--28 to 42 inches; dark yellowish brown (10YR 4/4) silty clay, light yellowish brown (10YR 6/4) dry; strong fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine roots; many very fine tubular pores; few very dark brown (10YR 2/2) distinct organic stains in pores and channels; 5 percent siltstone paragravel; very strongly acid (pH 4.6); gradual smooth boundary. (10 to 20 inches thick)
2C--42 to 60 inches; mottled yellowish brown (10YR 5/4) and grayish brown (2.5Y 5/2) very paragravelly silty clay; massive; hard, firm, moderately sticky and moderately plastic; 45 percent siltstone paragravel; very strongly acid (pH 4.8).
TYPE LOCATION: Tillamook County, Oregon; about 800 feet south and 1,700 feet west of the northeast corner of section 34, T. 1 S., R. 9 W. Willamette Meridian; Tillamook USGS 7.5 minute topographic quadrangle; Latitude 45 degrees 26 minutes and 47 seconds N. and Longitude 123 degrees 46 minutes and 3 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is about 51 to 54 degrees F. The difference between mean summer and mean winter soil temperature varies from 5 to 9 degrees F. under canopy cover. The soils are usually moist and are dry for less than 45 consecutive days in all parts between depths of 4 and 12 inches during the four-month period following the summer solstice. Depth to sedimentary bedrock is dominantly greater than 60 inches but ranges from 40 to about 80 inches. The umbric epipedon is 20 to 30 inches thick. The upper part of the particle-size control section has a P-retention of 95 to 100 percent, ammonium-oxalate extractable aluminum plus one-half iron of 2.0 to 4.0 percent, and moist bulk density of 0.55 to 0.85 g/cubic centimeter Reaction is strongly acid to very strongly acid in the A horizons and is very strongly acid below.
The Ap, A, and AB horizon, when present, has hue of 10YR, value of 2 or 3 moist and 3 dry and chroma of 1 or 2 moist and dry to depth of 12 to 25 inches. Value and chroma are 1 unit greater below these depths in some pedons. It has 10 to 15 percent organic matter and a melanic index greater than 1.7. The Ap and A horizons have an apparent field texture of medial silt loam with 20 to 27 percent clay. The AB horizon, when present, has an apparent field texture of medial silty clay loam with 27 to 30 percent clay.
The 2BA horizon, when present, has hue of 10YR, value of 2 or 3 moist, 3 through 5 dry and chroma of 2 or 3 moist and dry. Texture is silty clay loam with 30 to 35 percent clay and 0 to 10 percent paragravel.
The 2Bw horizon has value of 3 or 4 moist, 4 or 5 dry, and chroma of 3 to 6 moist and dry. Texture is silty clay loam or silty clay with 35 to 50 percent clay and 0 to 30 percent paragravel.
The 2C horizon or 2BC horizon (when present), has hue of 10YR, value of 4 to 6 moist and dry, chroma of 4 to 6 moist, and 4 to 8 dry. Texture is silty clay or silty clay loam with 35 to 50 percent clay and 0 to 60 percent paragravel.
COMPETING SERIES: This is the Labam series. The Lebam soils have an umbric epipedon 10 to 20 inches thick.
GEOGRAPHIC SETTING: The Winema soils are on coastal hills at elevations of 50 to 700 feet. The soils formed in colluvium and residuum weathered from sedimentary rocks. Winters are cool and wet and summers are cool and moist. The mean annual precipitation is 70 to 100 inches. Slopes are 3 to 70 percent. The mean January temperature is about 40 degrees F. and the mean July temperature about 61 degrees F. The mean annual air temperature is 49 to 52 degrees F. The frost-free period is about 145 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Fendall, Munsoncreek, Templeton and Tolovana soils. All of these soils occur on coastal hills. Fendall, Munsoncreek and Templeton soils qualify as an andic subgroup. In addition, Munsoncreek soils have a fine particle-size family class. Fendall soils are 20 to 40 inches deep to bedrock and have a fine particle-size family class. Templeton soils average less than 35 percent clay in the particle-size control section and have a fine-silty particle-size family class. Tolovana soils have a medial over loamy particle-size family class.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: This soil is used for timber production, wildlife habitat, homesites, recreation sites, and pasture. Native vegetation includes western swordfern, salmonberry, salal, red huckleberry, red elderberry, Sitka spruce, western hemlock, and Douglas fir.
DISTRIBUTION AND EXTENT: In the Coastal hills near Pacific Ocean in Oregon; MLRA 4A. The series of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Tillamook County, Oregon, 1942.
REMARKS: Diagnostic features in this pedon include:
Umbric epipedon - from the surface to 28 inches (Ap, A, and 2BA horizons).
Cambic horizon - from 28 to 42 inches (Bw horizon).
Andic feature - a bulk density of less than 0.85 g/cc in the zone from the surface of the soil to a depth of 21 inches (Ap and A horizons).
Particle-size control section - the zone from 0 to 40 inches with 0 to 21 inches qualifying as medial and 21 to 40 inches qualifying as clayey.
Classification revised 04/2000 from medial over clayey, mixed, isomesic Alic Fulvudands to medial over clayey, ferrihydritic over isotic, isomesic Typic Fluvudands. This reclassification is based on changes in the Andisol Order to Soil Taxonomy.
ADDITIONAL DATA: Characterization data for 2 profiles (S56Oreg-29-19(1- 5) and S56Oreg-29(1-5) as reported in the Soil Survey, Tillamook Area, Oregon, 1964.