LOCATION HOWLER CATentative Series
TAXONOMIC CLASS: Loamy-skeletal over fragmental, mixed, active, mesic Typic Dystroxerepts
TYPICAL PEDON: Howler loam - under a stand of Douglas-fir, tanoak, Pacific madrone and salal. When described on May 8, 2002 the soil was dry throughout. (Colors are for dry soil unless otherwise stated).
Oi--0 to 3 centimeters (0 to 1 inches); very dark grayish brown (2.5Y 3/2), slightly decomposed plant material, black (2.5Y 2.5/1), moist; about 100 percent fiber, 80 percent rubbed; loose, nonsticky and nonplastic; many very fine roots; many very fine tubular pores; strongly acid (pH 5.4); abrupt smooth boundary. (0 to 10 centimeters thick)
A--3 to 9 centimeters (1 to 4 inches); pinkish gray (7.5YR 6/2), loam, dark brown (7.5YR 3/3), moist; moderate very fine subangular blocky structure; loose, very friable, nonsticky and nonplastic; many very fine, fine, and common medium roots; many very fine, fine, medium, and common coarse tubular pores; 10 percent gravel; strongly acid (pH 5.4); clear wavy boundary. (3 to 15 centimeters thick)
AB--9 to 18 centimeters (4 to 7 inches); light brown (7.5YR 6/3), gravelly loam, brown (7.5YR 4/4), moist; strong fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine, common medium, an few coarse roots; many very fine, fine, common medium, and few coarse tubular pores; 25 percent gravel; moderately acid (pH 5.6); clear wavy boundary. (0 to 10 centimeters thick)
Bw1--18 to 40 centimeters (7 to 16 inches); light brown (7.5YR 6/3), gravelly clay loam, brown (7.5YR 5/4), moist; moderate medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; many fine, medium, common very fine, and few coarse roots; many very fine, and fine, common medium, and few coarse tubular pores; 30 percent gravel; moderately acid (pH 5.6); clear wavy boundary.
Bw2--40 to 64 centimeters (16 to 25 inches); reddish yellow (7.5YR 6/6), very gravelly clay loam, strong brown (7.5YR 5/6), moist; moderate medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; many fine, and medium, common very fine, and coarse roots; many very fine, fine, common medium, and few coarse tubular pores; 40 percent gravel; moderately acid (pH 5.6); clear wavy boundary.
Bw3--64 to 99 centimeters (25 to 39 inches); reddish yellow (7.5YR 6/6), extremely gravelly clay loam, reddish yellow (7.5YR 6/6), moist; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many medium, common fine, coarse, and few very fine roots; common very fine, fine, medium, and few coarse tubular pores; 65 percent gravel; moderately acid (pH 5.6); clear wavy boundary. (combined thickness of Bw horizons is 45 to 90 centimeters)
2C--99 to 180 centimeters (39 to 71 inches); gravel; highly fractured very strongly cemented metavolcanic bedrock, fractures 5 to 10 centimeters apart; common medium, and coarse roots in fractures; 85 percent gravel, 10 percent cobbles.
TYPE LOCATION: Humboldt County, California; Hoopa Tribal Nation; about three kilometers southwest of the town of Hoopa, near Telescope Peak; the northeast quarter of section 10, township 7 north and range 4 east; USGS Hoopa topographic quadrangle; 41 degrees, 0 minutes, 14.00 seconds north latitude, and 123 degrees, 41 minutes, 59.10 seconds west longitude; UTM 441153 meters E, 4539426 meters N, zone 10, NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is dry from July 1st to October 15th and moist in all parts from November 15 to June 1st.The soil has a xeric moisture regime.
Soil temperature: The mean annual soil temperature is 9 to 13 degrees C (49 to 57 degrees F). The difference between the mean summer and mean winter temperature is greater than 6 degrees C. The soil has a mesic soil temperature regime.
Depth to bedrock with fractures less than 10 centimeters apart: 50 to 100 centimeters
Surface Fragments: 0 to 5 percent gravel
Soil reaction: strongly acid to moderately acid throughout the soil profile.
Particle Size Control Section (weighted average):
Clay: 25 to 32 percent.
Rock fragments: 35 to 55 percent with 0 to 10 percent cobbles in the upper part and 90 to 100 percent with 0 to 10 percent cobbles in the lower part
A Horizon
Hue: 10YR or 7.5YR
Value: 3 through 6 dry and moist.
Chroma: 2 through 5 dry, 3 through 6 moist.
Texture of fine earth fraction: loam
Clay content: 20 to 25 percent
Rock fragments: 5 to 35 percent gravel and 0 to 5 percent cobbles
Bw Horizons
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 3 through 6 moist.
Chroma: 3 through 6, dry or moist.
Texture of fine earth fraction: loam, or clay loam.
Clay content: 20 to 32 percent.
Rock fragments: 30 to 65 percent gravel and 0 to 15 percent cobbles
2C Horizon
Rock fragments: 90 to 100 percent gravel and 0 to 15 percent cobbles
COMPETING SERIES: There are no competing series at this time.
GEOGRAPHIC SETTING: These soils occur on mountains with slopes of 50 to 110 percent at elevations of 109 to 1468 meters (358 to 4816 feet). These soils formed in colluvium and residuum from metavolcanic rocks. The climate is subhumid with warm dry summers and cool moist winters. The mean annual precipitation is 1250 to 2032 millimeters (49 to 80 inches). Mean annual air temperature is about 12 degrees C (54 degrees F). Mean summer temperature is 20 degrees C (68 degrees F) and the mean winter temperature is 7 degrees C (44 degrees F), and mean annual temperature ranges from 9 to 13 degrees C (49 to 57 degrees F). The growing season is about 75 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hospiter(T), Tellopeak, and Hewent(T) soils. Hospiter soils have an argillic horizon and are fine-loamy with less than 35 percent rock fragments in the particle size control section. Tellopeak soils are shallow to bedrock. Hewent soils are moderately deep and have an argillic horizon. Hospiter soils are located on more stable mountain slopes. Tellopeak and Hewent soils are on convex or strongly convex portions of the mountain slopes.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high runoff; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Used for timber production, watershed, and wildlife habitat. Native vegetation is Douglas-fir, tanoak, Pacific madrone with an understory of salal, Oregon grape, poison oak, and bracken fern.
DISTRIBUTION AND EXTENT: Siskiyou-Trinity Area, MLRA 5. These soils are of small extent.
MLRA OFFICE RESPONSIBLE: Davis, California
SERIES PROPOSED: Humboldt and Del Norte Area, Humboldt County, California, 2001.
REMARKS: Diagnostic horizons and features include:
1. Ochric epipedon - The zone from 0 to 18 centimeters (Oi, A & AB, horizons)
2. Cambic horizon - The zone from 18 to 99 centimeters (Bw1, Bw2 & Bw3 horizons)
3. Particle-size control section - the zone from 28 to 103 centimeters, averages 31 percent clay, by weight, and 40 percent rock fragments in the upper part and 95 percent in the lower part, by volume.
Soil classified using the 10th Edition of the Keys to Soil Taxonomy.