LOCATION TANNIN CA
Established Series
REV: JWH/JTB/ET
01/2013
TANNIN SERIES
The Tannin series consists of very deep, well drained soils formed in colluvium and residuum derived from sandstone and mudstone. Tannin soils are on mountains. Slope ranges from 9 to 75 percent. Mean annual precipitation is about 2160 mm and the mean annual temperature is about 13 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Typic Dystroxerepts
TYPICAL PEDON: Tannin gravelly loam on a northeast-facing 74 percent slope under tanoak, Douglas-fir, and pacific madrone at an elevation of 340 meters. (Colors are for dry soil unless otherwise noted) When described on April 22, 2002, the soil was moist throughout.
Oi--0 to 2 centimeters; 50 percent very dark brown (7.5YR 2.5/2) and 50 percent pinkish gray (7.5YR 6/2) slightly decomposed plant material; black (7.5YR 2.5/1) rubbed; about 80 percent fiber, 50 percent rubbed; 25 percent gravel; moderately acid (pH 5.9); abrupt smooth boundary. (0 to 8 centimeters thick)
A--2 to 14 centimeters; light yellowish brown (10YR 6/4) gravelly loam, dark brown (10YR 3/3) moist; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots throughout; 34 percent gravel; slightly acid (pH 6.1); abrupt smooth boundary. (3 to 25 centimeters thick)
Bt1--14 to 37 centimeters; light yellowish brown (10YR 6/4) gravelly loam, brown (7.5YR 4/3) moist; weak very fine subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots throughout; few very fine tubular pores; common distinct clay films on all faces of peds and in pores; 23 percent gravel; moderately acid (pH 5.9); clear smooth boundary. (10 to 50 centimeters thick)
Bt2--37 to 68 centimeters; light yellowish brown (10YR 6/4) gravelly loam, brown (7.5YR 4/4) moist; moderate very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium, and few coarse roots throughout; few very fine tubular pores; common distinct clay films on all faces of peds and in pores; 30 percent gravel; moderately acid (pH 6.0); clear wavy boundary. (20 to 60 centimeters thick)
Bt3--68 to 108 centimeters; light yellowish brown (10YR 6/4) gravelly loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure parting to weak fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine, and few medium and coarse roots throughout; few very fine tubular pores; common faint clay films on all faces of peds and in pores; 33 percent gravel; moderately acid (pH 6.0); gradual smooth boundary. (20 to 100 centimeters thick)
Bt4--108 to 172 centimeters; yellow (10YR 8/6) gravelly loam, yellowish brown (10YR 5/4) moist; weak very fine subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; few very fine, fine, and coarse roots throughout; few very fine tubular pores; common faint clay films on all faces of peds and in pores; 31 percent gravel and 1 percent cobbles; moderately acid (pH 5.7); gradual smooth boundary. (0 to 100 centimeters thick)
Bt5--172 to 200 centimeters; yellow (10YR 8/6) gravelly loam, yellowish brown (10YR 5/4) moist; weak very fine subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; few very fine, fine, and medium roots throughout; few very fine tubular pores; common faint clay films on faces of peds and in pores; 28 percent gravel 1 percent cobbles, and 5 percent paragravel; moderately acid (pH 5.9). (0 to 100 centimeters thick)
TYPE LOCATION: Humboldt County, California; about 3 kilometers east of the town of Harris, CA; USGS Jewett Rock Quadrangle, CA; 40 degrees 5 minutes 16 seconds north latitude and 123 degrees 37 minutes 37 seconds west longitude; UTM zone 10 0446552mE, 4437702mN; NAD 83.
RANGE IN CHARACTERISTICS:
Soil Temperature: The mean annual soil temperature at 50 centimeters is 10 to 15 degrees C. (50 to 59 degrees F.) and the difference between mean summer and mean winter soil temperatures is 6 degrees or more. This soil has a mesic soil temperature regime.
Soil Moisture: The soil moisture control section, in normal years, is dry in all parts for 45 or more consecutive days in the 4 months following the summer solstice and moist in all parts for 45 or more consecutive days in the 4 months following the winter solstice. This soil has a xeric soil moisture regime.
Base Saturation: Less than 60 percent by ammonium acetate in all horizons between 25 and 75 centimeters.
Surface Fragments: 0 to 34 percent gravel and 0 to 5 percent cobbles
Particle-size control section (weighted average):
Clay content: 20 to 30 percent
Rock fragments: 0 to 34 percent strongly cemented sandstone and mudstone
Pararock fragments: 0 to 34 percent moderately cemented sandstone and mudstone
Reaction: strongly or moderately acid
A horizon:
Hue: 7.5YR or 10YR
Value: 4 to 6 dry, 2 to 4 moist)\
Chroma: 2 to 4 dry and moist
Clay content: 16 to 27 percent
Rock fragments: 0 to 35 percent strongly cemented mudstone and sandstone gravel
Pararock fragments: 0 to 15 percent moderately cemented mudstone and sandstone paragravel
Reaction: strongly to slightly acid
Upper Bt or Bw horizons:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 2 to 4 dry or moist
Texture of fine earth: loam, sandy clay loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 35 percent strongly cemented mudstone and sandstone gravel, 0 to 5 percent cobbles
Pararock fragments: 0 to 50 percent moderately cemented mudstone and sandstone paragravel
Reaction: strongly to slightly acid
Lower Bt or Bw horizons:
Hue: 7.5YR, 10YR, or 2.5Y
Value: 5 to 8 dry, 4 or 5 moist
Chroma: 2 to 6 dry or moist
Texture: sandy clay loam, clay loam, or loam
Clay content: 18 to 30 percent
Rock fragments: 0 to 50 percent strongly cemented mudstone and sandstone gravel, 0 to 5 percent cobbles
Pararock fragments: 0 to 50 percent moderately cemented mudstone and sandstone paragravel
Reaction: strongly to slightly acid
COMPETING SERIES: These are the
Colestine,
Eagreek,
Holkat,
Hugo,
Hurlbut, and
Littlesand soils. Colestine soils are moderately deep to fractured metamorphic rock. Eagreek soils are derived from volcanic material. Holkat soils are moderately deep to soft metasedimentary rock. Hugo soils have soft bedrock between 100 and 150 centimeters. Hurlbut soils are moderately deep to soft metamorphosed sedimentary bedrock. Littlesand soils are moderately deep to soft fine-grained sandstone bedrock.
GEOGRAPHIC SETTING: Tannin soils are on linear to slightly concave or convex positions on summits, shoulders, and backslopes on mountain slopes. Slopes are 9 to 75 percent. Elevations are 60 to 1000 meters. These soils formed in residuum and colluvium derived from sandstone and mudstone. The climate is subhumid with warm, dry summers and cool, wet winters. Mean annual precipitation is 1250 to 3050 millimeters. The mean annual temperature is 12 to 14 degrees C. Frost free season is about 240 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Burgsblock,
Coolyork, and
Rockyglen soils. Burgsblock and Rockyglen soils contain more than 35 percent rock fragments in the particle size control section. Coolyork soils have mollic epipedons and contain more than 35 percent clay in the particle size control section. Burgsblock soils occur on linear to convex positions. Rockyglen soils occur on slightly to strongly convex positions. Coolyork soils occur on linear to concave positions on backslopes
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium to very high runoff; moderately low to moderately high saturated hydraulic conductivity.
USE AND VEGETATION: This soil is used mainly for timber production, wildlife habitat, and watershed. Natural vegetation is tanoak, Douglas-fir, California black oak, Oregon white oak, pacific madrone, California huckleberry, and poison oak.
DISTRIBUTION AND EXTENT: Siskiyou-Trinity Area. MLRA 5. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Humboldt County, South Part, California, 2010. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon: The zone from 0 to 14 centimeters. (Oi and A horizons)
2. Cambic horizon: The zone from 14 to 200 centimeters. (Bt1, Bt2, Bt3, Bt4, and Bt5 horizons)
3. Particle size control section: The zone from 27 to 102 centimeters. (Bt1, Bt2, and Bt3 horizons)
ADDITIONAL DATA: NSSL Pedon No. 05N0130, Humboldt County, CA, October, 2004. Some rock fragments reported by the lab were parafragments
Keys to Soil Taxonomy, 10th edition.
National Cooperative Soil Survey
U.S.A.