LOCATION GUDGREY CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Humic Haploxerepts
TYPICAL PEDON: Gudgrey gravelly sandy clay loam on a northwest facing convex slope of 33 percent under Douglas-fir and ponderosa pine forest at an elevation of 4080 feet. (Colors are for dry soil unless otherwise stated. When described, August 6, 1979, the soil was slightly moist below 40 in- ches.)
0--1.5 inches to 0; undecomposed and partially decomposed conifer needles, bark and twigs.
A1--0 to 12 inches; gray (10YR 5/1) gravelly sandy clay loam, very dark gray (10YR 3/1) moist; moderate very fine and fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; common very fine, fine and medium tubular pores; 20 percent 2 to 15mm pebbles; strongly acid (pH 5.5); gradual wavy boundary.
A2--12 to 28 inches; gray (10YR 5/1) gravelly sandy clay loam, very dark gray (10YR 3/1) moist; moderate very fine, fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common fine, medium, and coarse roots; many very fine and common fine and medium tubular pores; 20 percent 2 to 10mm pebbles; medium acid (pH 5.8); clear wavy boundary. (Combined thickness of the A horizon is 23 to 35 inches.)
Bt1--28 to 39 inches; light brownish gray (10YR 6/2) gravelly clay loam, dark gray (10YR 4/1) moist; moderate fine and medium subangular blocky structure; hard, friable, sticky and plastic; common fine, medium and coarse roots; common very fine and fine tubular pores; common thin clay films on peds, as bridges and in pores; 34 percent 2 to 75mm pebbles; medium acid (pH 5.8); clear wavy boundary. (10 to 12 inches thick)
Bt2--39 to 58 inches; variegated light gray (10YR 7/1) and yellowish brown (10YR 5/6) gravelly clay loam, grayish brown (2.5Y 5/2) and dark yellowish brown (10YR 4/6) moist; weak medium prismatic structure parting to moderate fine and medium angular blocky; hard, friable, sticky and plastic; few very fine, fine and medium roots; few very fine tubular pores; many pressure faces present; few moderately thick clay films in pores; 30 percent 2 to 75mm pebbles; medium acid (pH 5.8); abrupt wavy boundary (18 to 20 inches thick).
B3--58 to 70 inches; gray (10YR 5/1) gravelly sandy clay loam, very dark gray (10YR 3/1) moist; weak medium prismatic structure parting to moderate medium and coarse angular blocky; hard, firm, sticky and plastic; few very fine, fine and medium roots; few very fine tubular pores; many pressure faces present; 20 percent 2 to 50mm pebbles; slightly acid (pH 6.3).
TYPE LOCATION: Mendocino County, California; along the south side of the logging road in road cut on Bluenose Ridge 10 miles northeast of Covelo, California; 2000 feet west and 1700 feet north of the southeast corner of Round Valley Indian Reservation Tract 16; 1600 feet north and 650 feet east of the northwest corner of section 4, T.23 N., R.12 W. MDBM, Bluenose Ridge Quadrangle.
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to bedrock are greater than 60 inches. The soil, between a depth of 7 to 23 inches is dry in all parts from June to October and is moist in all parts from November to May. The mean annual soil temperature is 47 to 54 degrees F. Difference between mean summer/winter soil temperatures is about 30 degrees F. Organic matter at a depth of 20 inches is greater than 1 percent and decreases regularly with depth. The base saturation (ammonium acetate ranges from 40 to 75 percent but is less than 50 in some part of the profile. Rock fragments average 15 to 35 percent throughout.
The A horizon is 10YR 4/2, 4/3, 5/1, 5/2 or 5/3. Moist colors are 10YR 2/2, 3/1, 3/2, or 3/3. It is gravelly sandy clay loam or gravelly loam with 20 to 30 percent clay. Reaction is strongly or medium acid.
The B horizon is 10YR 4/3, 5/1, 5/4, 5/6, 6/2, 6/3, 7/1 or 7/3. Moist colors are 10YR 3/1, 3/2, 3/3, 3/4, 4/1, 4/2, 4/3, 4/6, 5/2, 5/4; or 2.5Y 5/2. It is gravelly clay loam, gravelly sandy clay loam, or cobbly clay loam with 20 to 35 percent clay, and more than 25 percent sand. Reaction is medium or slightly acid.
COMPETING SERIES: This is the Doty series in the same family, and the Aptos, Elmore, Nisene and Roseburg (T) series in other families. Aptos soils are 20 to 40 inches deep. Doty soils are only dry for 60 to 90 days and they have less than 15 percent fragments and less than 20 percent sand in the B horizon. Elmore soils are only dry for 45 to 70 days, and they have less than 15 percent rock fragments throughout. Nisene soils have a mean annual soil temperature of 56 degrees to 59 degrees F and have mean base saturation (ammonium acetate) more than 50 percent throughout. Roseburg soils are only dry for 60 to 80 days, and depth to gravel is over 60 inches, above 60 inches there is less than 15 percent gravel.
GEOGRAPHIC SETTING: The Gudgrey soils are on mountains and have slopes of 8 to 75 percent. They formed in material weathered from sandstone, schist or shale at elevations of 2500 to 5000 feet. The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation varies from 40 to 60 inches. Some falls as snow in December, January, February or March. Mean January temperature is 40 degrees F; mean July temperature is 70 degrees F; mean annual temperature varies from 47 to 54 degrees F. Frost-free season ranges from 125 to 175 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bluenose (T) and Nuens soils. Bluenose and Neuns soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderate premeability.
USE AND VEGETATION: Used for timber production, watershed and wildlife habitat. Vegetation is Douglas-fir, ponderosa pine, black oak and Pacific madrone.
DISTRIBUTION AND EXTENT: Northern California in the Coast Range. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Mendocino County, Eastern Part, California, 1985. Soil name is coined.
REMARKS:
Taxonomic Class: Fine-loamy, mixed, mesic Pachic Xerumbrepts
Major Diagnostic Horizons:
1. Mollic epipedon - 0 to 28 inches, (A1, A2); range from 23 to 35 inches thick.
1.1 O.C. (NSSL) ranges from 3.1 to 2.6 percent to a depth of 28 inches, and less than 0.6 percent below that depth.
1.2 O.C. decreases regularly.
1.3 Clay content ranges from 28 to 30 percent (NSSL).
1.4 The base saturation ranges from 43 to 60 percent (ammonium acetate, NSSL).
2. Cambic Horizon - 28 to 70 inches (Bt1, Bt2, Bt3); ranges from 38 to 43 inches thick.
2.1 No significant increase in clay over the A was observed in the field.
2.2 Clay content is 30 to 33 percent in the particle-size control section. (NSSL) not sufficient increase for argillic horizon.
2.3 Base saturation ranges from 65 to 86 percent. (ammonium acetate, NSSL).
Other Diagnostic Horizons or Soil Characteristics:
1. Soil Temperature and Moisture
1.1 Soil temperature is mesic based on data from Covelo and Hullville weather stations.
1.2 Soil moisture regime is xeric based on weather station data and field observation.
ADDITIONAL DATA: NSSL:S79CA-045-111.