LOCATION HECKER CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Mollic Haploxeralfs
TYPICAL PEDON: Hecker gravelly sandy loam, brush and conifer cover. (Colors are for dry soil unless otherwise noted).
A1--0 to 4 inches; brown (7.5YR 5/2) gravelly sandy loam, dark brown (7.5YR 3/2) moist; moderate very coarse angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common medium, fine and very fine tubular and common very fine and fine interstitial pores; 25 percent pebbles, 2 percent cobbles and 1 percent stones; neutral (pH 6.6); abrupt wavy boundary. (3 to 9 inches thick).
A2--4 to 9 inches; pinkish gray (7.5YR 6/2) and brown (10YR 5/3) rubbed, gravelly loam, dark brown (7.5YR 3/2, 4/4) moist; weak medium and coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium and coarse roots; common medium and fine tubular, common fine and very fine interstitial pores; 25 percent pebbles, 2 percent cobbles and 1 percent stones; moderately acid (pH 6.0); clear wavy boundary. (4 to 10 inches thick).
Bt1--9 to 16 inches; variegated pale brown (10YR 6/3) and light yellowish brown (10YR 6/4) very gravelly sandy loam, brown (7.5YR 4/4) and strong brown (7.5YR 5/6) moist; weak medium subangular blocky structure; hard, friable, sticky and plastic; many coarse and medium, common fine interstitial pores; 35 percent pebbles, 2 percent cobblestones and 1 percent stones by volume; few thin clay films lining pores, common thin clay films as bridges between mineral grains; moderately acid (pH 6.0); gradual wavy boundary. (4 to 10 inches thick).
Bt2--16 to 23 inches; light brown (7.5YR 6/4) and pink (7.5YR 7/4) gravelly sandy loam, strong brown (7.5YR 5/6) moist; weak medium and coarse subangular blocky structure; very hard, friable, sticky and plastic; many coarse and medium, common fine and very fine roots; many very fine interstitial, many very fine and fine tubular pores; common thin clay films as bridges between mineral grains and lining pores; 30 percent pebbles, 2 percent cobbles, and 1 percent stones; moderately acid (pH 6.0); gradual wavy boundary. (6 to 10 inches thick).
Bt3--23 to 31 inches; light brown (7.5YR 6/4) and pink (7.5YR 7/4) very gravelly loam, strong brown (7.5YR 5/6) moist; weak medium and coarse subangular blocky structure; very hard, friable, sticky and plastic; many coarse and medium, common fine and very fine roots; many very fine interstitial, many very fine and fine tubular pores; 70 percent pebbles, 2 percent cobbles and stones; common thin clay films as bridges between mineral grains and lining pores; moderately acid (pH 6.0); gradual wavy boundary. (6 to 10 inches thick).
Bt4--31 to 41 inches; light brown (7.5YR 6/4) and pink (7.5YR 7/4) very gravelly clay loam, brown (7.5YR 4/4), strong brown (7.5YR 5/6) rubbed, moist; moderate medium subangular blocky structure, crushes to fine granules before powdering; hard, friable, sticky and plastic; few fine and very fine, common medium roots; few and common very fine tubular and few very fine interstitial pores; 70 percent pebbles, 5 percent cobbles and 5 percent stones; many thin clay films as bridges between mineral grains and lining pores; medium acid (pH 6.0); gradual wavy boundary. (7 to 11 inches thick).
Cr--41 to 58 inches; shattered shale.
TYPE LOCATION: Santa Cruz, California; about 1.8 miles east southeast from the intersection of Mt. Bache Road and Highland Way about 200 feet below Highland Way on an east turn in the SE1/4 NE1/4 of section 5 (projected).
RANGE IN CHARACTERISTICS: Depth to a paralithic contact is 40 to 60 inches. The soil between depths of 10 to 40 inches becomes moist in some part in October or early November and remains moist until June or July. The mean annual soil temperature is about 57 degrees F. This soil contains up to 80 percent stones, cobbles and pebbles by volume. It is neutral to medium acid throughout. Base saturation is 75 to 95 percent throughout the solum.
The A horizon is (7.5YR 6/2, 6/4, 5/4, 5/2; 10YR 6/2, 6/3, 6/4, 5/2, 5/3, or 5/4). It is gravelly sandy loam and gravelly loam and has 20 to 40 percent by volume pebbles and up to 10 percent cobbles and stones combined.
The upper part of the Bt horizon is 10YR 5/3, 6/3, 6/4; 7.5YR 7/4, 6/2, 6/4, 5/4, 5/2; 5YR 6/3, 6/4, 5/4, 5/3). It is very gravelly or gravelly sandy loam, loam or clay loam and has 30 to 50 percent by volume pebbles and up to 10 percent cobbles and stones combined.
The lower part of the Bt is (10YR 6/3, 6/4,; 7.5YR 7/4, 6/4; 5YR 6/3, 6/4, 5/3, 5/4). It is gravelly, very gravelly, cobbly, very cobbly or stony loam, sandy clay loam or clay loam, averaging about 40 to 80 percent, by volume, rock fragments.
COMPETING SERIES: These are the Melder, Vanvor (T) and Voorhies series. Melder soils have mean annual soil temperatures of 47 to 49 degrees. Vanvor (T), and Voorhies series have bedrock within 40 inches.
GEOGRAPHIC SETTING: Hecker soils are on uplands and have slopes of 30 to 75 percent. They formed from shale and sandstones on or near active fault zones. Elevations are 1,000 to 3,000 feet. The climate is Mediterranean having warm, dry summers and cool, moist winters. The mean annual precipitation is 35 to 60 inches. The average January temperature is 44 degrees F; the average July temperature is 64 degrees F; and the mean annual temperature is 54 to 57 degrees F. The frost-free season is about 210 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ben Lomond, Catelli, Felton, Lompico, Maymen and Sur soils. Ben Lomond soils have thick, dark colored surface layers with more than 1 percent organic matter, and have between 50 and 75 percent base saturation in some part within depth of 30 inches. Catelli, Felton and Lompico soils have dark colored A horizons with more than 1 percent organic matter and between 50 to 75 percent base saturation in some part within depth of 30 inches. Maymen soils are less than 20 inches deep to hard rock. Sur soils have dark colored A horizons with more than 1 percent organic matter and lack B2t horizons.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderate permeability.
USE AND VEGETATION: Used mainly for limited timber and firewood production, wildlife, recreation and watershed. Vegetation is mainly knobcone pine, manzanita, chamise, other brush types, and scattered oaks and madrone, except in canyons where it is redwood, tanoak, and madrone.
DISTRIBUTION AND EXTENT: Santa Cruz Mountains in the central California Coastal area. The soils are of small extent in MLRA 15.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Santa Cruz County, California, 1976.
REMARKS: Diagnostic horizon and features recognized in this pedon include:
Ochric epipedon - the zone from the soil surface to about 9 inches (A1 and A2 horizon).
Cambic horizon - the zone from about 9 to 23 inches (Bt1 and Bt2 horizon).
Argillic horizon - the zone from about 23 to 41 inches (Bt3 and Bt4 horizon).
Paralithic contact - the boundary at 41 inches (Cr).
Particle size control section - the zone from 23 to 41 inches (Bt3 and Bt4 horizons).
ADDITIONAL DATA: NSSL pedon S73CA-087-004 (type location)