LOCATION WOODCHOPPER OREstablished Series
TAXONOMIC CLASS: Fine, isotic, frigid Pachic Ultic Argixerolls
TYPICAL PEDON: Woodchopper gravelly loam, in forest on an 8 percent slope. (Colors are for moist soil unless otherwise noted.)
0i--3 inches to 0; ponderosa pine and white fir needles.
A1--0 to 4 inches; dark reddish brown (5YR 3/2) gravelly loam, reddish brown (5YR 4/3) dry; moderate fine granular structure; slightly hard, very friable, sticky and plastic; many roots; many irregular pores; 2 percent stones, 15 percent gravel; moderately acid (pH 6.0); clear smooth boundary. (3 to 10 inches thick)
A2--4 to 14 inches; dark reddish brown (5YR 3/2) gravelly loam, reddish brown (5YR 4/3) dry; moderate medium granular structure and weak fine subangular blocky; slightly hard, very friable, sticky and plastic; many roots; many irregular pores; 2 percent stones, 15 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (8 to 14 inches thick)
Bt1--14 to 25 inches; dark reddish brown (5YR 3/3) cobbly clay loam; reddish brown (5YR 4/3) dry; moderate fine and medium subangular blocky structure; hard, friable, very sticky and plastic; common roots; common very fine and fine tubular pores; common faint clay films on peds and in pores; 5 percent stones, 10 percent cobbles, 15 percent gravel; neutral (pH 6.6); gradual wavy boundary. (7 to 15 inches thick)
Bt2--25 to 36 inches; dark reddish brown (5YR 3/3) clay, reddish brown (5YR 4/3) dry; moderate fine and medium subangular blocky structure; hard, friable, very sticky and plastic; common roots; common very fine and fine tubular pores; common faint clay films on peds and in pores; 25 percent soft fragments of weathered tuff; neutral (pH 6.6); gradual wavy boundary. (8 to 18 inches thick)
Bt3--36 to 49 inches; dark reddish brown (5YR 3/4) clay, reddish brown (5YR 5/3) dry; moderate fine and medium subangular blocky structure; hard, friable, very sticky and plastic; few roots; common very fine and fine tubular pores; many distinct clay films on peds and in pores; 40 percent soft fragments of weathered tuff; neutral (pH 6.6); clear wavy boundary. (10 to 20 inches thick)
Bt4--49 to 60 inches; reddish brown (5YR 4/3) gravelly clay, reddish brown (5YR 5/3) dry; strong fine and medium subangular blocky structure; few roots; common very fine and fine tubular pores; many distinct clay films on peds and in pores; 2 percent stones, 5 percent cobbles, 40 percent soft fragments of weathered tuff; 15 percent hard gravel; neutral (pH 6.6).
TYPE LOCATION: Lake County, Oregon; NW1/4, SW1/4 of section 26, T. 39 S., R. 21 E.
RANGE IN CHARACTERISTICS: The soils are moist in the winter and spring and are dry for 60 to 100 consecutive days after the summer solstice. The mean annual soil temperature is 45 to 47 degrees F. The mollic epipedon is 20 to 30 inches thick. The base saturation (sum of cations) throughout the upper 30 inches is 50 to 75 percent. Depth to bedrock is 60 inches or more. The particle-size control section averages 5 to 30 percent rock fragments and 35 to 50 percent clay.
The A horizon has a hue of 7.5YR or 5YR, value of 2 or 3 when moist and 4 or 5 when dry, and chroma of 2 or 3 when moist and 3 or 4 when dry.
The Bt horizon has a hue of 7.5YR, 5YR, or 2.5YR, value of 3 or 4 moist, 4 to 6 dry, and chroma of 3 or 4 moist and dry. It is clay loam and clay. Rock fragments range from 0 to 35 percent of which 0 to 15 percent are cobbles and stones and 0 to 20 percent are gravel.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Woodchopper soils are on rolling plateaus and tablelands at elevations of 5,500 to 7,200 feet. Slopes are 0 to 40 percent. The soils formed in residuum and colluvium primarily from andesite, basalt and tuff. The climate is characterized by cool moist winters and warm dry summers. The mean annual precipitation is 28 to 32 inches. The mean annual temperature is 43 to 45 degrees. The frost-free period is 30 to 50 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Mound, Polander, Rogger, Twelvemile, Sherval and Winterim soils. The Mound soil is clayey-skeletal in the particle-size control section. The Polander soil is ashy in the particle-size control section and lacks a mollic epipedon. Rogger soils are loamy-skeletal in the particle-size control section and have a mollic epipedon 10 to 16 inches thick. Sherval soils are loamy-skeletal in the particle-size control section and are moderately well drained. Winterim soils are clayey-skeletal in the particle-size control section and have montmorillonitic mineralogy.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately slow permeability.
USE AND VEGETATION: The soils are used for timber production, wildlife habitat, watershed, grazing by livestock and recreation. Vegetation is primarily ponderosa pine, white fir, common snowberry, heartleaf arnica, and wheeler bluegrass.
DISTRIBUTION AND EXTENT: South central Oregon, MLRA 21. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lake County, Oregon, Southern Part; 1991.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon (pachic) - 0 to 25 inches (A1, A2, Bt1 horizons)
Argillic horizon - 14 to 60 inches (Bt1, Bt2, Bt3, Bt4 horizons)
Ultic feature - Base saturation is less than 75 percent within 30 inches of the surface.
ADDITIONAL DATA: Laboratory data for 3 horizons (A1, A2, Bt1) S87OR-037-002. Forest Service vegetative site CW-S3-13.