LOCATION BUNDORA CAEstablished Series
TAXONOMIC CLASS: Medial over loamy-skeletal, mixed, superactive, frigid Alfic Humic Haploxerands
TYPICAL PEDON: Bundora sandy loam on a south facing 4 percent slope under a cover of white fir, Jeffrey pine, snowbrush, sugar pine and incense cedar at an elevation of 4650 feet. (Colors are for dry soil unless otherwise stated. When described September 2, 1986 the soil was dry throughout).
Oi--1 to 0 inches; partially and undecomposed needles, leaves and twigs.
A1--0 to 3 inches; dark brown (7.5YR 3/2) sandy loam, dark reddish brown (5YR 3/2) moist; weak fine and medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; 5 percent gravel; neutral (pH 7.0); clear smooth boundary. (2 to 5 inches thick)
A2--3 to 6 inches; dark brown (7.5YR 3/3) sandy loam, dark reddish brown (5YR 3/3) moist; weak fine and medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots; many very fine and fine interstitial pores; 5 percent gravel; neutral (pH 6.8); clear smooth boundary. (3 to 8 inches thick)
Bw1--6 to 14 inches; dark brown (7.5YR 3/3) sandy loam, dark reddish brown (5YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, medium and coarse roots; many very fine and fine interstitial pores; 5 percent gravel; neutral (pH 6.8); clear smooth boundary. (0 to 10 inches thick)
Bw2--14 to 29 inches; brown (7.5YR 4/3) sandy loam, dark reddish brown (5YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few very fine and common fine and medium roots; common very fine, fine and medium interstitial and tubular pores; 10 percent gravel; neutral (pH 6.8); clear wavy boundary. (10 to 16 inches thick)
2Btb1--29 to 38 inches; brown (7.5YR 4/4) very gravelly loam, dark brown (7.5YR 3/2) moist; moderate medium and coarse subangular blocky structure; very hard, very firm, sticky and plastic; few very fine and fine and common medium roots; common very fine and fine tubular pores; common moderately thick clay films on peds and in pores; 40 percent gravel; moderately acid (pH 5.9); gradual wavy boundary (8 to 15 inches thick).
2Btb2--38 to 50 inches; brown (7.5YR 4/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse subangular blocky structure; very hard, very firm, sticky and plastic; few very fine and fine and common medium roots; common very fine and fine tubular pores; few thin clay films on peds and common moderately thick clay films in pores; 40 percent gravel; moderately acid (pH 5.7); gradual wavy boundary. (8 to 14 inches thick)
2Btb3--50 to 63 inches; grayish brown (10YR 5/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common very fine, fine, medium and coarse roots; few very fine and fine tubular and common very fine and fine interstitial pores; common thin clay films on peds and in pores; 40 percent gravel; strongly acid (pH 5.4).
TYPE LOCATION: Siskiyou County, California; about 3 miles east and 4.8 miles south of Hambone, 3,000 feet south and 2,300 feet west of the northeast corner of sec. 28, T. 40 N., R. 2 E., Hambone SW (Hambone) quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: The umbric epipedon is 10 to 29 inches thick. The volcanic ash layer ranges from 22 to 35 inches thick and has 0 to 15 percent gravel. The mean annual soil temperature is 42 to 46 degrees F. The soil temperature exceeds 41 degrees F. from mid May to mid November (about 180 to 200 days) and exceeds 47 degrees F. from early July to early October. The soil moisture control section is dry in all parts from mid August to mid October about 70 to 90 days and is moist in some or all parts the rest of the year. Base saturation by sum of cations ranges from 24 to 35 percent in the upper 29 inches and 35 to 49 percent between 29 and 63 inches.
The A horizon color is 10YR 4/2, 4/3; 7.5YR 3/2, or 3/3. Moist color is 10YR 2/1, 2/2; 7.5YR 3/2, 3/4; 5YR 2/2, 3/2, or 3/3. Organic matter ranges from 4 to 8 percent. Clay content ranges from 5 to 7 percent. Rock fragments range from 5 to 15 percent with 0 to 5 percent cobbles. Base saturation by ammonium acetate ranges from 20 to 35 percent.
The Bw horizon color is 7.5YR 3/3, or 4/3. Moist color is 10YR 3/3; 7.5YR 3/4, 4/4; 5YR 3/3, or 3/4. Organic matter ranges from 1 to 2 percent. Clay content averages 10 percent. Rock fragments range from 0 to 15 percent with 0 to 5 percent stones and boulders. Base saturation by ammonium acetate, ranges from 25 to 35 percent.
The 2Bt horizon color is 10YR 5/2; 7.5YR 4/2, or 4/4. Moist color is 10YR 3/2, 3/3, 4/3; 7.5YR 3/2, 3/4, 4/4; 5YR 3/3, or 3/4. Organic matter averages less than 1 percent. Texture is very gravelly loam or very gravelly sandy clay loam. Clay content ranges from 15 to 25 percent. Rock fragments, mostly gravel or cobbles, range from 20 to 45 percent. Base saturation by ammonium acetate ranges from 35 to 50 percent.
Andic property data (see remarks for explanation):
Depth P-ret B.D. pH NaF Glass Alo Feo 15 barH20
0-3 95 0.65 NC NC 2.5 25.2 3-6 94 0.85 NC 5.5 2.71 18.6 6-14 91 0.94
NC 5.6 2.0 17.9 14-29 91 NC NC 2.2 1.86 17.3 29-38
22.8 38-50 27.3 50-63 28.8
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING: Bundora soils are on hills and lava plateaus. Slopes are 2 to 50 percent. These soils formed in volcanic ash and tuff breccia. Elevation is 4,000 to 6,800 feet. The climate is subhumid with warm dry summers and cold moist winters. Mean annual precipitation is 35 to 50 inches. Snowfall is 48 to 60 inches. The mean annual temperature is 39 to 44 degrees F. The mean January temperature is about 27 degrees F. The mean July temperature is about 55 degrees F. Frost free season is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Revit, Mounthat and Obie (T) soils. Revit and Mounthat soils are less than 40 inches deep to bedrock. Mounthat and Obie soils have skeletal control sections.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: This soil is used for woodland, watershed and wildlife habitat. The vegetation is white fir, ponderosa pine, Jeffrey pine, sugar pine, incense cedar, bush chinkapin, snowbrush and greenleaf manzanita.
DISTRIBUTION AND EXTENT: Siskiyou County, California. The soils are not extensive. MLRA is 22.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Siskiyou County, Intermountain Soil Survey Area, California 1994. Source of name is Bundora spring, Big Bend NW (Pondosa) Quadrangle, 7.5 minute series.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - the zone from the soil surface to 29 inches (A1, A2, Bw1, Bw2)
Cambic horizon - the zone from 6 to 29 inches (Bw1, Bw2)
Buried Bt horizon - the zone from 29 to 63 inches (2Btb1, 2Btb2, 2Btb3)
Andic properties data definition:
P-ret: phosphate retention of the less than 2mm fraction.
B.D.: bulk density of the less than 2mm fraction on an oven dry basis.
pH NaF: pH of soil mixed with saturated sodium floride solution.
Glass: percent volcanic glass.
Alo: acid-oxalate-extractable aluminum of the less than 2mm fraction.
Feo: acid-oxalate-extractable iron of the less than 2mm fraction.
15 bar H20: dried 1500 kPa water retention as a percent.
Data elements with a * are estimated.
NC: not calculated.
ND: not done.
*Proposed Alfic Haploxerands
ADDITIONAL DATA: This pedon was characterized by the U.C. Davis Laboratory in 1986. Lab Number 1671. unpublished.