LOCATION WOODIN                  CA

Established Series
Rev. NHS-DJE- JJJ-JWH
01/2013

WOODIN SERIES


The Woodin series consists of moderately deep, well drained soils formed in residuum weathered from sandstone. Woodin soils are on hills and mountains and have slopes of 9 to 75 percent. The mean annual precipitation is about 1400 mm (55 inches) and the mean annual temperature is about 13 degrees C (55 degrees F)

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Typic Dystroxerepts

TYPICAL PEDON: Woodin extremely gravelly sandy loam - on a west facing convex slope of 75 percent under Douglas-fir, tanoak, and sugar pine at 1,450 feet elevation. (Colors are for dry soil unless otherwise stated. When described July 3, 1978, the soil was dry throughout.)

A1--0 to 5 centimeters (0 to 2 inches); very dark brown (10YR 2/2) extremely gravelly sandy loam, black (10YR 2/1) moist; moderate very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; common fine and very fine roots; many very fine and fine interstitial pores; 85 percent gravel (2 to 75 mm); strongly acid (pH 5.4); abrupt smooth boundary. (3 to 5 centimeters thick)

A2--5 to 15 centimeters (2 to 6 inches); very dark brown (10YR 2/2) extremely gravelly sandy loam, black (10YR 2/1) moist; strong very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, and medium roots; many very fine and fine interstitial pores; 61 percent angular gravel (2 to 75 mm); strongly acid (pH 5.4); clear smooth boundary. (3 to 10 centimeters thick)

Bw1--15 to 33 centimeters (6 to 13 inches); very pale brown (10YR 7/4) extremely gravelly loam, dark yellowish brown (10YR 4/4) moist; strong very fine and fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine and common medium, and coarse roots; many very fine, fine, and medium interstitial pores; few silt coatings on peds; 60 percent gravel (2 to 75 mm), 5 percent cobbles; very strongly acid (pH 4.9); clear wavy boundary. (18 to 38 centimeters thick)

Bw2--33 to 56 centimeters (13 to 22 inches); very pale brown (10YR 7/3) extremely gravelly loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine, and fine, and common medium and coarse roots; many fine and medium interstitial pores; few faint silt coatings on peds; 60 percent gravel (30 to 75 mm), 10 percent cobbles (75 to 250 mm), and 2 percent stones; strongly acid (pH 5.3); abrupt irregular boundary. (23 to 50 centimeters thick)

R--56 centimeters (22 inches); very hard fractured sandstone; fractures are less than 1 mm wide and are 6 to 30 cm apart; few very fine roots follow fractures; few thin silt coatings and manganese stains on rock faces.

TYPE LOCATION: Mendocino County, California; about 20 miles west on Fish Rock Road from the junction of Highway 128 and Fish Rock Road; about 20 feet west and 2,650 feet south of the northeast corner of section 35, T.12 N.; R.15 W., Ornbaun Valley Southwest Quadrangle, MDB&M.

RANGE IN CHARACTERISTICS: Depth to a lithic contact and thickness of the solum is 50 to 100 centimeters. The mean annual soil temperature is 12 to 15 degrees C and the difference between mean summer and mean winter soil temperature is 6 degrees C or more. The soils have a mesic temperature regime. The soil between depths of 25 and 78 centimeters or lithic contact, whichever is shallower, is dry in all parts from July 1 to October 1, and is moist in all parts from November 1 to May 15 in most years. The soils have a xeric soil moisture regime. The particle-size control section averages from 18 to 25 percent clay and averages from 45 to 70 percent rock fragments.

The A horizon is 10YR 2/2, 3/2, 4/3, 5/2, 5/3, 5/4, 6/3, 6/4; 7.5YR 5/4 or 6/4. Moist color is 10YR 2/1, 2/2, 3/2, 3/3, 3/4, 4/2, 4/3; 7.5YR 5/4 or 6/4. It is gravelly sandy loam, very gravelly loam or extremely gravelly sandy loam. Clay content ranges from 15 to 25 percent. Gravel content ranges from 20 to 85 percent. Cobble content ranges from 0 to 10 percent. Reaction is very strongly acid through neutral. Base saturation (ammonium acetate) ranges from 50 to 80 percent.

The Bw horizon is 10YR 5/4, 5/6, 6/3, 6/4, 7/3, 7/4; 7.5YR 5/4, 5/6, 6/4 or 7/4. Moist color is 10YR 3/3, 3/4, 4/3, 4/4; 7.5YR 3/4, 4/4 or 5/6. It is very gravelly loam, sandy loam or sandy clay loam; extremely gravelly loam or sandy loam; or very cobbly loam or sandy loam. Clay content ranges from 15 to 25 percent. There is a slight increase in clay over the A horizon, but not enough to qualify for an argillic horizon. Gravel content ranges from 15 to 70 percent, cobble content ranges from 5 to 50 percent, and stone content ranges from 0 to 5 percent. Total rock fragment content ranges from 35 to 75 percent. Reaction is very strongly acid through neutral. Base saturation (ammonium acetate) ranges from 20 to 55 percent.

COMPETING SERIES: These are the Atring, Barpeak, Beekman, Farber, Forgay, Geppert, Hartless, Hiltish, Kanid, Rockyglen, Straight, and Vena soils. Atring and Geppert soils have a paralithic contact between 50 and 100 centimeters. Hilltish soils are moderately deep to conglomerate. Straight soils are moderately deep to soft igneous bedrock. Kanid soils have soft bedrock between 100 and 150 centimeters. Barpeak, Farber, Forgay, Kanid, Rockyglen, and Terbies soils are very deep. Hartless soils are deep and very deep. Vena soils are moderately deep to hard igneous bedrock. Beekman soils have mean annual soil temperature of 8 to 12 degrees C. Straight and Vena soils have a mean annual soil temperature of 8 to 11 degrees C.

GEOGRAPHIC SETTING: Woodin soils occur on hills and mountains. Slopes are 9 to 75 percent. Elevations are 152 to 1295 meters. The soils are formed in residuum weathered from sandstone. The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation ranges from 890 to 1780 mm. Occasional snow occurs above 915 meters. Mean January temperature is about 9 degrees C and mean July temperature is about 20 degrees C. The mean annual temperature is about 13 degrees C. The frost-free season is 150 to 270 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Casabonne, Holohan, Hopland, Maymen, Ornbaun, Pardaloe, Wohly, Yellowhound, and Yorktree soils. Casabonne, Holohan, Ornbaun, Pardaloe, Yellowhound and Yorktree soils are greater than 100 centimeters deep. Hopland and Wohly soils have argillic horizons. Maymen soils are less than 50 centimeters deep.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, surface runoff under bare soil conditions is medium to high; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: This soil is used for limited timber production, wildlife and watershed. Vegetation consists of Douglas-fir, tanoak, California nutmeg, sugar pine, madrone, and Canyon live oak.

DISTRIBUTION AND EXTENT: Siskiyou-Trinity Area, MLRA 5. The series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Mendocino County, California, Eastern Part, 1985.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - 0 to 15 centimeters (A1, A2 horizons)

Cambic horizon - the zone from 15 to 56 centimeters (Bw1, Bw2 horizons)

Lithic contact - the boundary at 56 centimeters (R layer)

ADDITIONAL DATA:

Soil classified using Keys to Soil Taxonomy, 10th edition.


National Cooperative Soil Survey
U.S.A.