LOCATION ANUNDE OREstablished Series
TAXONOMIC CLASS: Medial, ferrihydritic, mesic Alic Hapludands
TYPICAL PEDON: Anunde silt loam, wooded. (Colors are for moist soil unless otherwise noted.)
Oi--2 inches to 0; leaves, twigs and moss.
A1--0 to 8 inches; dark brown (7.5YR 3/2) silt loam, brown (7.5YR 5/3) dry; strong very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many very fine and common fine roots; many very fine irregular pores; common 2 to 5 mm concretions; very strongly acid; clear smooth boundary. (7 to 9 inches thick)
A2--8 to 17 inches; brown (7.5YR 4/4) silt loam, yellowish brown (10YR 5/4) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many very fine and common fine roots; many very fine tubular pores; common 2 to 5 mm concretions; strongly acid; clear smooth boundary. (8 to 10 inches thick)
Bw1--17 to 34 inches; dark yellowish brown (10YR 4/4) silt loam, very pale brown (10YR 7/4) dry; moderate medium subangular blocky structure; slightly hard, friable, sticky and slightly plastic; weakly smeary; common very fine and fine roots; few very fine tubular pores; moderately acid; gradual wavy boundary. (14 to 18 inches thick)
Bw2--34 to 47 inches; dark yellowish brown (10YR 4/4) silt loam, very pale brown (10YR 7/4) dry; moderate coarse subangular blocky structure; slightly hard, friable, sticky and slightly plastic; weakly smeary; few very fine and fine roots; few very fine tubular pores; moderately acid; gradual wavy boundary. (12 to 16 inches thick)
Bw3--47 to 60 inches; dark yellowish brown (10YR 4/4) silty clay loam, very pale brown (10YR 7/4) dry; moderate coarse subangular blocky structure; slightly hard, friable, sticky and plastic; weakly smeary; few very fine and fine roots; few very fine tubular pores; moderately acid.
TYPE LOCATION: Columbia County, Oregon; about 1.6 miles WSW of Marshland, 50 feet east of logging road and 2,000 feet NE of the SW corner, section 9, T.7N., R.5W.
RANGE IN CHARACTERISTICS: The soil is usually moist but is dry between 4 and 12 inches for a period of less than 45 consecutive days following the summer solstice. The mean annual soil temperature is 47 to 54 degrees F. The solum and depth to bedrock is more than 60 inches. The particle-size control section has 12 to 27 percent clay (by field estimate). The solum has a moist bulk density of 0.70 to 0.85g/cubic centimeter and is weakly or moderately smeary.
The A horizon has hue of 7.5YR or 10YR, value of 3 or 4 moist and 5 or 6 dry, and chroma of 2 to 4 moist and 3 or 4 dry. It has 0 to 10 percent coarse fragments of which 0 to 5 percent are basalt gravel and 0 to 5 percent are 2 to 5 mm concretions.
The Bw horizon has hue of 7.5YR or 10YR, value of 4 to 6 moist, 6 or 7 dry, and chroma of 3 to 6 moist and 6 to 8 dry. ; The upper part is silt loam and some pedons have about 5 percent fine concretions. The lower part below 40 inches is silt loam or silty clay loam with 0 to 15 percent basalt gravel.
COMPETING SERIES: These are the Hemcross and Tolke soils. Hemcross soils have an umbric epipedon 10 to 20 inches thick. Tolke soils have an apparent clay content of 27 to 35 percent in the Bw horizon above 40 inches.
GEOGRAPHIC SETTING: Anunde soils are on mountains in the Coast Range at elevations of 80 to 1000 feet. Slopes are 0 to 30 percent. The soils formed in colluvium weathered from siltstone but in some areas the underlying bedrock may be basalt. The climate is characterized by warm wet winters and hot moist summers. The mean annual precipitation is 60 to 90 inches. The mean July temperature is 60 to 64 degrees F., the mean January temperature is 35 to 37 degrees F., and the mean annual temperature is 45 to 53 degrees F. The frost-free period is 140 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Braun, Scaponia and the competing Tolke soils. Braun and Scaponia are fine-loamy. In addition, Scaponia soils have an umbric epipedon.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: These soils are used for timber production, recreation and wildlife habitat. Native vegetation is Douglas fir, western hemlock, western redcedar, vine maple, cascade Oregongrape, red and evergreen huckleberry, salal, and western swordfern.
DISTRIBUTION AND EXTENT: Foot slopes of the Coast Range in northwestern Oregon; MLRA 1. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Columbia County, Oregon, l983.
REMARKS: This draft reflects a change in classification from medial, mesic Entic Dystrandepts to medial, mesic Alic Hapludands based on the Andisol Order.
Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon - A2 has moist value and chroma of 4.
Cambic horizon - from 17 to 60 inches (Bw1, Bw2, and Bw3 horizons).
Andic soil properties - from surface to 60 inches.
Particle-size control section - from surface to 40 inches.
Competing series using the Entic Dystrandepts classification also includes the Stabler series from Washington. It has a solum depth of 30 to 40 inches, has 10 to 18 percent clay (apparent field texture) in the Bw horizon, and is dominated by Mt. St. Helens ash.
ADDITIONAL DATA: Lincoln Laboratory Reference Samples 83T7287-7289 (Clatsop County).