LOCATION KISTIRN CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Typic Haploxerults
TYPICAL PEDON: Kistirn very gravelly loam--on a north facing slope of 60 percent under Douglas-fir, tanoak, and madrone at 1,180 feet elevation. (Colors are for dry soil unless otherwise stated. When described on September 13, 1977, the soil was dry throughout.)
O--3 to 0 inches; fresh and decomposing leaf and needle litter.
A--0 to 3 inches; yellowish brown (10YR 5/4) very gravelly loam, dark reddish brown (5YR 3/3) moist; weak fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine, fine, medium, and coarse roots; many very fine interstitial pores; 40 percent pebbles; moderately acid (pH 5.7); gradual smooth boundary. (3 to 10 inches thick)
AB--3 to 8 inches; light yellowish brown (10YR 6/4) very gravelly loam, dark yellowish brown (10YR 4/4) moist; weak fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine, fine medium, and coarse roots; many very fine interstitial pores; 40 percent pebbles; moderately acid (pH 5.7); gradual smooth boundary. (4 to 10 inches thick)
Bt1--8 to 24 inches; light yellowish brown (10YR 6/4) very cobbly clay loam, dark brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine, many medium, common coarse roots; many very fine interstitial pores; common thin clay films on peds and in pores; 30 percent pebbles, 20 percent cobbles; strongly acid (pH 5.4); gradual smooth boundary. (6 to 26 inches thick)
Bt2--24 to 53 inches; strong brown (7.5YR 5/6) very gravelly clay loam, dark brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine and fine, common medium and coarse roots; many very fine interstitial pores; many thin clay films on peds and in pores; 35 percent pebbles, 5 percent cobbles; strongly acid (pH 5.4), abrupt wavy boundary. (6 to 30 inches thick)
C--53 to 79 inches; very pale brown (10YR 7/3) extremely gravelly silty clay yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; very hard, firm, sticky and plastic; common medium and coarse roots; common very fine interstitial pores; many thin clay films on peds and in pores; 55 percent pebbles, 10 percent cobbles; strongly acid (pH 5.3).
TYPE LOCATION: Humboldt County, California; roadcut on Salyer-Mad River Road, about 2.4 miles from Friday Ridge Road turnoff: SW 1/4, SW 1/4 sec. 22, T. 6 N., R. 5 E., H.B.M.
RANGE IN CHARACTERISTICS: Depth to metasedimentary rock is 40 to more than 80 inches. The mean annual soil temperature is estimated to be 50 degrees to 59 degrees F. The soil between the depths of 8 and 24 inches is usually dry in all parts from mid-June to mid-October and moist in all parts from November to April. The base saturation (by Hack Kit) is 14 to 28 percent in the lower part of the argillic horizon.
The A horizon is 5YR 5/4; 7.5YR 6/4, 7/4; 10YR 4/2, 5/2, 5/4, 6/3, 6/4. Moist colors are 5YR 3/3; 7.5YR 3/2, 4/4, 5/6; 10YR 3/3. It is loam or silt loam with 15 to 27 percent clay, and 15 to 60 percent gravel. It is slightly or moderately acid.
The Bt horizon is 5YR 5/6; 7.5YR 5/6, 6/6, 6/8, 7/6, 7/8; 10YR 6/4, 7/1, 7/2, 7/3, 7/4, 7/6. Moist colors are 5YR 4/6, 5/6; 7.5YR 4/4, 5/6, 5/8; 10YR 4/4, 5/4, 5/6, 6/8. It is clay loam or silty clay loam, with 27 to 35 percent clay, 30 to 60 percent gravel, and 5 to 20 percent cobbles. The Bt1 horizon has an average of 30 to 35 percent clay. It is slightly through strongly acid.
The C horizon is 10YR 7/2, 7/3. Moist colors are 10YR 5/4, 6/4. It is clay loam, clay or silty clay with 30 to 50 percent clay, and 50 to 60 percent gravel and 10 to 30 percent cobbles. It is moderately or strongly acid. Some pedons lack C horizons.
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: Kistirn soils are on mountain sideslopes. Slopes are 30 to 75 percent. The soils formed in material weathered from metasedimentary rock. Elevations are 1,000 to 4,500 feet. The climate is subhumid with warm dry summers and cool wet winters. Mean annual precipitation varies from 60 to 70 inches. Mean January temperature is 43 degrees F; mean July temperature is 60 degrees F; and mean annual temperature is 50 degrees F. Frost-free season is estimated to be about 140 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: See Remarks.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for timber production, wildlife habitat, and watershed. Native vegetation is Douglas-fir, tanoak and madrone, with some bigleaf maple and ceanothus.
DISTRIBUTION AND EXTENT: Northwestern California. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Plumas National Forest Area, California, 1983.
REMARKS: Series established to use series family name.
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET