LOCATION TAMARACK MTEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Vitrandic Eutrudepts
TYPICAL PEDON: Tamarack ashy loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 2 inches; undecomposed and slightly decomposed forest litter. (1 to 3 inches thick)
E--2 to 5 inches; light gray (10YR 7/2) ashy loam, grayish brown (10YR 5/2) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium and coarse roots; volcanic ash component; moderately acid (ph 6.0); clear wavy boundary. (1 to 4 inches thick)
Bw--5 to 14 inches; very pale brown (10YR 7/4) ashy fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine and few medium and coarse roots; slightly acid (ph 6.2); clear wavy boundary. (7 to 10 inches thick)
2E and Bt1--14 to 32 inches; E part (85 percent) is very pale brown (10YR 7/3) loamy sand, brown (10YR 5/3) moist, Bt part (15 percent) is brown (10YR 5/3) sandy loam, brown (10YR 4/3) moist, broken discontinuous lamellae 1/8- to 1/4-inch thick; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium and few coarse roots; moderately acid (ph 6.0); gradual wavy boundary. (10 to 20 inches thick)
2E and Bt2--32 to 46 inches; E part (80 percent) is very pale brown (10YR 7/3) loamy coarse sand, brown (10YR 5/3) moist, Bt part (20 percent) is brown (10YR 5/3) sandy loam, brown (10YR 4/3) moist, broken discontinuous lamellae 1/4- to 1/2-inch thick; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium and coarse roots; moderately acid (ph 6.0); clear wavy boundary. (10 to 20 inches thick)
2C--46 to 60 inches; pale brown (10YR 6/3) loamy coarse sand, brown (10YR 5/3) moist; single grain; loose, nonsticky and nonplastic; slightly acid (ph 6.2).
TYPE LOCATION: Lincoln County, Montana; 1,300 feet east and 700 feet north of the SW corner of sec 11, T. 26 N., R. 27 W.
RANGE IN CHARACTERISTICS:
Soil temperature - 44 to 47 degrees F.
Moisture control section - between 8 and 24 inches.
E horizon
Hue: 10YR or 7.5YR
Value: 6 or 7 dry; 4 or 5 moist
Texture: ashy loam or ashy fine sandy loam
Clay content: 8 to 20 percent
Bulk density: 1.0 to 1.3 g/cm3
Acid Oxalate (Al + 1/2 Fe): .2 to 1.0 percent
Volcanic glass: 20 to 45 percent
Reaction: pH 5.6 to 7.3
Bw horizon
Hue: 10YR or 7.5YR
Value: 6 or 7 dry; 4 or 5 moist
Clay content: 8 to 20 percent
Bulk density: 1.0 to 1.3 g/cm3
Acid Oxalate (Al + 1/2 Fe): .4 to 1.0 percent
Volcanic glass: 20 to 45 percent
Reaction: pH 5.6 to 7.3
2E and Bt horizons
Hue: 10YR or 7.5YR
Value: E part 6 or 7, Bt part 5 or 6 dry; E part 4 or 5, Bt part 4 or 5 moist
Clay content: E part 2 to 8 percent, Bt part 5 to 10 percent
Reaction: pH 5.6 to 7.3
2C horizon
Hue: 10YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Clay content: 2 to 8 percent
Reaction: pH 5.6 to 7.3
COMPETING SERIES:
Caseycreek (ID) - is moderately well drained.
Presnal (ID) - does not have horizons containing lamellae.
GEOGRAPHIC SETTING:
Landform- stream terraces, outwash terraces, kame terraces, outwash plains and escarpments in valleys.
Elevation - 2,200 to 4,200 feet.
Slope - 0 to 60 percent.
Parent material - vocanic ash over alluvium or outwash.
Climate - long, cold winters; moist springs; warm summers.
Mean annual precipitation - 23 to 34 inches, much of which falls as snow and spring rains.
Mean annual air temperature - 38 to 45 degrees F.
Frost-free period - 70 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Well drained, moderately rapid or rapid permeability.
USE AND VEGETATION: Tamarack soils are used mainly as woodland, understory grazing, and wildlife habitat. Potential native vegetation is ponderosa pine, Douglas fir, western larch, lodgepole pine, grand fir, and Engelmann spruce. Understory vegetation is mainly pinegrass, huckleberry, sedges, and forbs.
DISTRIBUTION AND EXTENT: Tamarack soils are of small extent in the valleys of northwestern Montana. MLRA 44A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lincoln County, Montana, 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ash influenced layer - 2 to 14 inches (E, Bw horizons);
Ochric epipedon - 0 to 7 inches (Oi, E, Bw horizons);
Cambic horizon - 5 to 14 inches (Bw horizon); and
Particle-size control section - 10 to 40 inches (Bw, 2E and Bt1, 2E and Bt2 horizons).
Tamarack soils have a frigid temperature regime and a udic moisture regime that borders on ustic.
ADDITIONAL DATA: Laboratory data S92MT-053-001; Soil interpretation record MT1357.