LOCATION DOUGCITY CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Ultic Palexeralfs
TYPICAL PEDON: Dougcity gravelly loam--on a northeast facing slope of 32 percent (in a burned area) under buckbrush, western brackenfern, Pacific madrone, deerbrush, and grass at an elevation of 2,625 feet. (Colors are dry soil unless otherwise stated. When described on October 8, 1982, the upper 4 inches were moist from recent rains; the soil was dry below that depth.)
Oi--1 to 0 inches; leaves, needles, and twigs.
A--0 to 4 inches; yellowish brown (10YR 5/4) gravelly loam, dark yellowish brown (10YR 4/4) moist; moderate fine and very fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common fine and medium, many very fine roots; common very fine tubular pores; 10 percent pebbles on the surface; 20 percent pebbles in the horizon; slightly acid (pH 6.5); clear wavy boundary. (3 to 6 inches thick).
AB--4 to 13 inches; light brown (7.5YR 6/4) gravelly loam, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common medium, fine, and very fine roots; common fine and very fine tubular pores; 25 percent pebbles; slightly acid (pH 6.5); gradual wavy boundary. (8 to 10 inches thick).
Bt1--13 to 28 inches; reddish yellow (5YR 6/6) very gravelly loam, yellowish red (5YR 4/6) moist; strong medium and fine subangular blocky structure; hard, friable, sticky and plastic; few coarse, common medium, fine, and very fine roots; common fine and very fine tubular pores; few thin clay films lining pores and bridging mineral grains; 40 percent pebbles; slightly acid (pH 6.5); gradual wavy boundary. (13 to 17 inches thick).
Bt2--28 to 39 inches; reddish yellow (5YR 6/6) very gravelly loam, yellowish red (5YR 4/6) moist; strong medium and fine subangular blocky structure; very hard, firm, very sticky and plastic; few coarse, common medium, fine and very fine roots; few fine, common very fine tubular pores; many thin clay films lining pores and on ped faces; 50 percent pebbles; slightly acid (pH 6.5); gradual wavy boundary. (10 to 12 inches thick).
Bt3--39 to 57 inches; yellowish red (5YR 5/6) very gravelly clay loam, red (2.5YR 5/6) moist; moderate fine subangular blocky structure; very hard, firm, very sticky and very plastic; few fine, common very fine roots; few fine, common very fine tubular pores; many thin clay films lining pores and on ped faces; 55 percent pebbles; slightly acid (pH 6.5); gradual wavy boundary. (16 to 20 inches thick).
Bt4--57 to 80 inches; yellowish red (5YR 5/6) very gravelly clay loam, red (2.5YR 4/6) moist; moderate fine subangular blocky structure; very hard, firm, very sticky and very plastic; few fine common very fine roots; few fine common very fine tubular pores; many thin clay films lining pores and on ped faces; 55 percent pebbles; slightly acid (pH 6.5).
TYPE LOCATION: Trinity County, California; about 3 miles south of Douglas City, California; take Highway 3 west from Douglas City 5.2 miles, turn south onto dirt road, go 1.2 miles, take right fork, go 0.7 mile, pedon described in uphill roadcut; 1,650 feet east, and 1,100 feet north of the southwest corner of section 24, T.32 N., R.10W. Hoosimbim Mtn. Quadrangle. 40 degrees North latitude, 36 minutes, 4 seconds, 122 degrees West longitude, 57 minutes, 51 seconds.
RANGE IN CHARACTERISTICS: The particle-size control section averages 25 to 35 percent clay, and 35 to 50 percent rock fragments (mostly pebbles). It contains 15 to 40 percent mica minerals in the very fine sand fraction. The mean annual soil temperature is 47 to 59 degrees F. The soil moisture control section between the depths of 15 and 35 inches is dry in all parts from about July 20 to October 20 (80 to 100 days). The soil temperature at a depth of 20 inches exceeds 41 degrees F from about March 20 to December 10 (260 days), and exceeds 47 degrees F from about April 20 to November 10. The particle-size control section has a ratio of extractable iron plus gibbsite to clay of 0.2 to 0.3 and contains less than 40 percent of any other mineral.
The A horizon is 10YR 5/4, 6/4, 7/4, 7.5YR 6/4, 6/6, or 5YR 4/4. Moist color is 10YR 4/4, 5/6, 7.5YR 4/4, 4/6, or 5YR 3/4. The A horizon is slightly acid or neutral.
The Bt horizon is 5YR 6/6, 4/4, 7/6, 4/4, 4/6, 5/6, 5/8, 6/6, 6/8, 7.5YR 6/6 or 7/6. Moist color is 5YR 4/6, 5/8, 4/4, 2.5YR 5/6, 4/6, 4/4, 5/8, or 7.5YR 4/6. Chroma is 4 more than in the lower part. It is very gravelly loam, very gravelly clay loam, gravelly loam, gravelly clay loam, or extremely gravelly clay loam. The Bt is moderately acid to neutral. Base saturation ranges from 50 to 75 percent by sum of cations.
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: Dougcity soils are on mountains. Elevation is 1,750 to 4,500 feet. Slopes are 15 to 75 percent. These soils formed in colluvium weathered from mica schist. The climate is characterized by warm, dry summers and cool, moist winters. Mean annual precipitation is 30 to 60 inches. Snowfall ranges from 6 to 36 inches. Mean January temperature is about 35 degrees F. Mean July temperature is about 68 degrees F. Mean annual temperature is 45 to 57 degrees F. The frost-free period is 90 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brownscreek, Springgulch, Sheetiron, and Barpeak soils. The Brownscreek and Sheetiron soils are 20 to 40 inches deep to a lithic contact. The Springgulch soils have less than 35 percent rock fragments throughout. The Barpeak soils lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; rapid or very rapid runoff; moderately slow permeability.
USE AND VEGETATION: This soil is used for timber production, water supply and wildlife habitat. Natural vegetation is Douglas-fir, sugar pine, ponderosa pine, California black oak, California hazel, canyon live oak, poisonoak, and grasses.
DISTRIBUTION AND EXTENT: Klamath Mountains of northern California. The series is not extensive. MLRA 5.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Trinity County, California, Weaverville Area, 1990. Series name coined from Douglas City.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--zone from the surface to a depth of 13 inches (A, AB horizons).
Argillic horizon--zone from a depth of 13 to 80 inches (Bt1, Bt2, Bt3, Bt4 horizons).
Particle-size control section--zone from a depth of 13 to 33 inches (Bt1, Bt2 horizons).
ADDITIONAL DATA: NSSL pedon S83CA-105-015 (type location) originally sampled as Bottlerock.
Field estimates for percent clay are higher than NSSL data, for both measured clay, and amount adjusted to 15 bar water content. Field estimates are used, with the assumption that weathered mica fragments crushed in in sample preparation influenced measured clay and 15 bar water content.