LOCATION CHAWANAKEE CAEstablished Series
TAXONOMIC CLASS: Loamy, mixed, active, mesic, shallow Typic Dystroxerepts
TYPICAL PEDON: Chawanakee coarse sandy loam - on a south facing slope of 50 percent under ponderosa pine, sugar pine, and Jeffrey pine, at 5,650 feet elevation. (Colors are for dry soil unless otherwise stated. When described on May 12, 1981, the soil was moist throughout).
0--0 to 0.5 inches; discontinous layer of partially decomposed pine needles and twigs.
A--0.5 to 4 inches; grayish brown (10YR 5/2) coarse sandy loam, dark brown (10YR 3/3) moist; weak medium granular structure; slightly hard, friable, nonsticky and nonplastic; few fine and medium roots; many fine interstitial, common fine and medium tubular pores; 10 percent pebbles; slightly acid (pH 6.2); gradual smooth boundary. (2 to 6 inches thick)
Bw--4 to 19 inches; very pale brown (10YR 7/3) coarse sandy loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine, many medium, common coarse roots; common fine and medium tubular pores; 10 percent pebbles; moderately acid (pH 5.8); clear wavy boundary. (8 to 18 inches thick)
Cr--19 inches; very pale brown (10YR 8/4) highly weathered granodiorite.
TYPE LOCATION: Madera County, California; Sierra National Forest; about 1.2 miles (airline) northwest of Minarets Work Center; about 50 yards uphill of Forest Road 4S81, approximately 1.3 miles north of the junction with Forest Road 6S01; in SE 1/4, NW 1/4, sec. 10, T. 6 S., R. 24 E., MDBM.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact is 10 to 20 inches. The mean annual soil temperature just above the contact is 47 to 59 degrees F. The soil between 8 inches and the paralithic contact is usually dry from mid-June to mid-October and usually moist in some or all parts the rest of the year. The soil is sandy loam, gravelly sandy loam, coarse sandy loam, gravelly or cobbly coarse sandy loam, gravelly loamy coarse sand or loamy sand and averages 5 to 35 percent pebbles and cobbles. It is strongly to slightly acid throughout. Base saturation is 60 to 70 percent in the A horizon and 50 to 60 percent below.
The A horizon has dry color of 10YR 7/1,6/3, 6/2, 6/1, 5/3, 5/2, 5/1, 4/3, 4/1, 2.5Y 8/1,6/2, 5/2 or 4/2; and moist color of 10YR 5/2,4/3, 4/2,4/1 3/3, 3/2, 2.5Y 8/1,4/2 or 3/2. Some or all of the A horizon has less than one percent organic matter except the upper 2 or 3 inches in some pedons. The lower part of the A horizon commonly has value of 4 moist or 6 dry.
The Bw horizon has dry color of 10YR 8/3, 8/2,7/4, 7/3, 7/2, 6/4, 6/3, 6/2, 5/4, 5/3, 5/2, 2.5Y 7/4, 7/2, 6/4, 6/2, 5/4, or 5/2; and moist color of 10YR 6/4, 6/3, 6/2, 5/4, 5/3, 5/2, 4/4, 4/3, 4/2, 3/4, 2.5Y 6/4, 6/2 or 5/4. There is about 1 or 2 percent more clay than the A horizon in some pedons.
COMPETING SERIES: These are the Catla and Nonpareil (T) series in the same family and the Chaix, Cieneba, and Tollhouse series. Catla soils are deep. Nonpareil soils have a loam or clay loam control section that averages 22 to 35 percent clay and are very strongly acid. Chaix soils lack a paralithic contact above a depth of 20 inches. Cieneba soils have a thermic soil temperature. Tollhouse soils have a mollic epipedon.
GEOGRAPHIC SETTING: Chawanakee soils are on mountainsides and ridges. Slopes are 2 to 110 percent. The soils formed in material weathered from quartz diorite and granodiorite low in mafic minerals. Elevations are 1,200 to 6,500 feet. The climate is humid with warm dry summers and cool moist winters. Mean annual precipitation is 25 to 60 inches. Seasonal snowfall is 20 to over 100 inches. Mean January temperature is 32 to 41 degrees F; mean July temperature is 63 to 75 degrees F; mean annual temperature is 48 to 56 degrees F. Frost-free season is about 120 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Chaix and Tollhouse soils and Holland soil. Holland soils are deep and have an argillic horizon.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; medium to very high runoff; moderately rapid permeability but the weathered rock retards downward percolation of water.
USE AND VEGETATION: Used mainly for timber production, wildlife, recreation and watershed. Provides limited browse. Native vegetation is a dense woody cover of shrubs and semi-open cover of mixed conifers; principal shrubs are bear clover, Mariposa manzanita and wedgeleaf ceanothus; principal trees are ponderosa pine, incense cedar, black oak and canyon live oak.
DISTRIBUTION AND EXTENT: Lower parts of the middle mountain areas of the Sierra Nevada Mountains and northern California. The soils are extensive.
MLRA OFFICE RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Sierra National Forest Area, Fresno County, California, 1972.
REMARKS: This is a new type location. The original pedon was sampled and analyzed by the National Soil Survey Laboratory. Pedon number is S77CA-019-002. It was determined that it would qualify as a mollisol, after the upper 7 inches are mixed.
Edit log 10/2006 Proposed edits for use in Butte County. Expand: MAST from 50 to 47; add the following textures gravelly sandy loam, gravelly loamy coarse sand, or loamy sand, add to A horizon dry colors 10YR 7/1; 2.5Y 8/1 moist colors 10YR 5/2, 4/1; 2.5Y 8/1. Add to Bw horizon dry colors 10YR 8/2, 8/3. Moist colors 10YR 4/2. Expand Slope from 5 to 75 to 2 to 110 percent.