LOCATION GSCHWEND CA

Established Series
Rev. CAR/NHS/DJE/JWH/KP
10/2016

GSCHWEND SERIES

The Gschwend series consists of very deep, well drained soils formed in alluvium derived from mixed sources. Gschwend soils are on stream terraces and have slopes of 0 to 9 percent. The mean annual precipitation is about 1520 centimeters (60 inches) and the mean annual temperature is 12 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, isomesic Typic Humustepts

TYPICAL PEDON: Gschwend loam - on a gently sloping stream terrace of 3 percent, under Douglas-fir, tanoak and California huckleberry, at 275 meters elevation. (Colors are for dry soil unless otherwise stated. When described on June 13, 1980 the soil was moist throughout.)

Oi--0 to 3 centimeters (0 to 1 inch); partially decomposed Douglas-fir and tanoak leaves and twigs.

A1--3 to 8 centimeters (1 to 3 inches); dark grayish brown (10YR 4/2) loam, black (10YR 2/1) moist; strong fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and few fine and medium roots; few very fine tubular and common very fine and fine interstitial pores; 10 percent, rounded sandstone gravel; moderately acid (pH 6.0); clear wavy boundary. (3 to 8 centimeters thick)

A2--8 to 33 centimeters (3 to 13 inches); brown (10YR 4/3) loam, very dark brown (10YR 2/2) moist; moderate medium and coarse subangular blocky structure; soft, friable, slightly sticky and slightly plastic; few fine and very fine roots; common very fine interstitial and few fine tubular pores; 10 percent, rounded sandstone gravel; moderately acid (pH 5.7); clear wavy boundary. (8 to 25 centimeters thick)

Bw--33 to 50 centimeters (13 to 20 inches); yellowish brown (10YR 5/4) stratified sandy loam, dark brown (10YR 3/3) moist; weak medium and coarse subangular blocky structure; soft, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine interstitial and few fine tubular pores; 10 percent rounded sandstone gravel; strongly acid (pH 5.5); gradual wavy boundary. (8 to 25 centimeters thick)

Bt--50 to 91 centimeters (20 to 36 inches); light yellowish brown (10YR 6/4) stratified loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; few fine and medium roots; common very fine interstitial and few fine tubular pores; few thin clay films bridging sand grains and lining pores; 10 percent rounded sandstone gravel; strongly acid (pH 5.2); clear wavy boundary. (25 to 50 centimeters thick)

C--91 to 158 centimeters (36 to 62 inches); very pale brown (10YR 7/4) extremely gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; few fine and medium roots; many very fine, fine and medium interstitial pores; 60 percent rounded gravel and 10 percent rounded sandstone cobbles; strongly acid (pH 5.2).

TYPE LOCATION: Mendocino County, California Standish Hickey State Park, Rouck Creek campground, campsite number one, 20 feet north of access road; about 3,200 feet south and nd about 1,900 feet west of the northeast corner of Section 3, T.23N., R.17W., USGS Leggett Quadrangle, Ca; WGS84 Decimal degrees 39.87496 latitude and -123.72336 longitude, UTM Zone 10 438028mE, 4414422mN; NAD 83.

RANGE IN CHARACTERISTICS:

Soil depth is greater than 150 centimeters (60 inches). Thickness of the solum ranges from 43 to 102 centimeters (17 to 40 inches).

The mean annual soil temperature ranges from 11 to 13 degrees C. The difference between mean summer and mean winter soil temperature ranges from 3 to less than 6 degrees C. The soils have an isomesic temperature regime. The soil between the depths of 18 and 56 centimeters is moist in all parts from November 1 to June 15 and is dry in some or all parts from July 15 to October 1 in most years. The soils have an ustic soil moisture regime.

The particle-size control section ranges from 10 to 27 percent clay but averages 18 to 23 percent clay. Coarse fragment content in the particle-size control section averages 5 to 34 percent.

Base saturation (ammonium acetate) ranges from 10 to 50 percent throughout.

The A horizon is 10YR 4/2, 4/3, 5/3 or 5/4. Moist color is 10YR 2/1, 2/2, 3/2, 3/3, 4/3 or 5/3. It is loam or sandy loam. Clay content ranges from 10 to 20 percent. Gravel content ranges from 0 to 10 percent. Organic matter content ranges from 1 to 4 percent. Reaction is neutral through strongly acid.

The B horizon is 10YR 5/4, 6/3, 6/4, 7/3, 7/4 or 7.5YR 5/4. Moist color is 10YR 3/3, 4/3, 4/4, 4/6, 5/3, 5/4, 5/6; 7.5YR 3/4 or 4/4. It is stratified sandy loam, loam, sandy clay loam or clay loam. Clay content ranges from 10 to 30 percent. Gravel content ranges from 0 to 15 percent. Reaction is neutral through very strongly acid.

The C horizon is 10YR 5/4, 6/4, 6/6, 7/3 or 7/4. Moist color is 10YR 4/3, 4/4, 5/4, 5/6, 6/4 or 7.5YR 4/4. It is loamy sand, sandy loam, loam, or sandy clay loam, and may be gravelly, very gravelly or extremely gravelly and is stratified. Clay content ranges from 5 to 27 percent. Gravel content ranges from 0 to 89 percent. Cobble content ranges from 0 to 15 percent and stone content ranges from 0 to 89 percent. Reaction is neutral through very strongly acid.

COMPETING SERIES: This is the Northbear series. Northbear soils formed in colluvium from sandstone and mudstone and have an umbric epipedon that is 50 to 100 centimeters thick.

GEOGRAPHIC SETTING: Gschwend soils occur on stream terraces. They are 6 to 60 meters above present river levels and do not flood. Slopes are 0 to 9 percent. Elevations are 76 to 518 meters. They formed in alluvium derived from mixed sources. The climate is humid with cool foggy summers and cool moist winters. A moderate coastal fog influence limits the diurnal and annual range of temperature. Mean annual precipitation ranges from 1000 to 2030 millimeters. Mean January temperature is about 6 degrees C.; mean July temperature is about 18 degrees C. and the mean annual temperature is about 12 degrees C. The frost-free period is 220 to 320 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Frenchman, Kibesillah, Ornbaun, Yellowhound, and Zeni soils. Frenchman soils are located on the same position and contain more than 35 percent coarse fragments in the control section. The Kibesillah, Ornbaun, Yellowhound, and Zeni soils are on surrounding uplands. Kibesillah and Yellowhoundsoils are loamy-skeletal. Ornbaun soils are 100 to 150 centimeters deep to paralithic contact. Zeni soils are 50 to 100 centimeters deep to a paralithic contact.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; low or medium runoff under bare soil conditions; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: This soil is used for timber production, recreation, wildlife habitat, and watershed. Vegetation consists of Douglas-fir, coast redwood, tanoak, and California huckleberry.

DISTRIBUTION AND EXTENT: Coastal Redwood Belt, MLRA 4B. The series is not extensive.

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

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

REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Umbric epipedon: the zone from 3 to 33 centimeters (A1 and A2 horizons)
2. Cambic horizon: the zone from 33 to 91 centimeters (Bw and Bt horizons)
3. Particle size control section: The zone from 28 to 103 centimeters (A2, Bw, Bt, and C) averages 18 percent clay and 15 percent fine sand or coarser, by weight, including 10 percent gravel, by volume.

ADDITIONAL DATA: NASIS User Pedon ID: 07CA601846

Soil classified using Keys to Soil Taxonomy, 12th edition. Previously classified as Fine-loamy, mixed, superactive, isomesic Humic Dystrudepts.

National Cooperative Soil Survey
U.S.A.