LOCATION OHANA WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, amorphic Typic Haplocryands
TYPICAL PEDON: Ohana very paragravelly medial sandy loam - under a coniferous forest 6 years old on a 14 percent convex north facing slope an elevation of 3,600 feet. (The soil was moist when described. Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
Oi--0 to 1/2 inch; slightly decomposed organic litter including charcoal from clearcut burn and roots; abrupt smooth boundary. (0.5 to 2 inches thick)
Oe--1/2 to 5 inches; moderately decomposed organic material, dark grayish brown (10YR 4/2) dry; moderately acid (pH 5.8); abrupt wavy boundary. (3 to 6 inches thick)
E--5 to 5 1/2 inches; dark grayish brown (10YR 4/2) very paragravelly medial sandy loam, light brownish gray (10YR 6/2) dry; weak fine subangular blocky structure; soft, very friable, slightly sticky, nonplastic and weakly smeary; 40 percent pumice fragments (0.5 to 2 inches in diameter); moderately acid (pH 6.0); abrupt broken boundary. (0 to 2 inches thick)
Bs1--5 1/2 to 11 inches; dark brown (7.5YR 3/4) very paragravelly medial sandy loam, light brown (7.5YR 6/4) dry; weak fine subangular blocky structure parting to weak fine granular; slightly hard, friable, slightly sticky, slightly plastic and weakly smeary; common very fine, fine, medium, and few coarse roots; common fine pores; 50 percent pumice fragments (0.5 to 4 inches in diameter); moderately acid (pH 6.0); clear wavy boundary. (5 to 8 inches thick)
2Bs2--11 to 16 inches; dark reddish brown (5YR 3/4) cobbly medial sandy loam, light reddish brown (5YR 6/4) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic and weakly smeary; common fine roots; common fine pores; 10 percent unweathered pebbles and 10 percent subangular cobbles (3 to 4 inches in diameter); 5 percent pumice fragments; moderately acid (pH6.0); clear wavy boundary. (5 to 7 inches thick)
2Bw--16 to 25 inches; dark brown (7.5YR 4/4) very cobbly medial loam, light brown (7.5YR 6/4) dry; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky, slightly plastic and weakly smeary; common fine roots; common fine pores; 15 percent unweathered pebbles and 25 percent subangular cobbles (3 to 8 inches in diameter); slightly acid (pH 6.2); clear wavy boundary. (7 to 11 inches thick)
3BC--25 to 35 inches; dark yellowish brown (10YR 4/4) glacial till that breaks to very cobbly medial sandy loam, light yellowish brown (10YR 6/4) dry; massive; very hard, firm, slightly sticky, slightly plastic and weakly smeary; few fine roots; few pores; 25 percent rounded pebbles and 30 percent rounded cobbles; moderately acid (pH 5.6); clear irregular boundary. (8 to 14 inches thick)
3Cd--35 inches; dark brown (10YR 4/3) dense glacial till that crushes to extremely cobbly sandy loam, light yellowish brown (10YR 6/4) dry; massive; extremely hard, extremely firm; 75 percent rounded hard pebbles and cobbles, and a few hard stones; moderately acid (pH 6.0).
TYPE LOCATION: Lewis County, Washington; 850 feet south and 1,600 feet west of the northeast corner, sec. 30, T. 11 N., R. 5 E., W.M.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 40 to 42 degrees F. Depth to densic material and thickness of andic soil material is 30 to 40 inches. Reaction ranges from slightly acid or moderately acid throughout. The combined thickness of the E, Bs and 2Bs horizons is 10 to 16 inches thick. The combined thickness of the E and Bs horizons is 5 to 10 inches thick.
The Bs1 horizon has hue of 5YR through 10YR, value of 3 or 4 moist and 5 to 7 dry, and chroma of 4 to 6 moist and dry. It is 35 to 50 percent pebble-size pumice fragments and 0 to 10 percent unweathered pebbles.
The 2Bs2 horizon has hue of 5YR or 7.5YR, value of 3 or 4 moist, 5 to 7 dry, and chroma of 4 to 6 moist and dry. It has 0 to 10 percent pebble-size pumice fragments, 10 to 15 percent unweathered pebbles and 5 to 30 percent unweathered cobbles.
The 2Bw horizon has hue of 7.5YR or 10YR, value of 6 or 7 dry, and chroma of 3 or 4 moist and dry. It is medial loam or medial sandy loam and has 10 to 20 percent unweathered pebbles and 25 to 30 percent unweathered cobbles.
The 3BC horizon has value of 5 or 6 dry and chroma of 3 or 4 moist and dry. It has 10 to 25 percent unweathered pebbles and 25 to 35 percent unweathered cobbles.
COMPETING SERIES: These are the Esmeralda, Fears, Gilpar, Hatchet, Howson, Kachess, Lemah, Polallie, Ronsel, Thetis, Vabus, and Waptus series. Esmeralda, Fears, Gilpar, Kachess, Lemah, Ronsel, and Thetis soils are more than 40 inches deep. Hatchet, Howson, and Polallie soils are 20 to 40 inches deep to a lithic contact. Vabus soils have a spodic horizon 4 to 7 inches thick. Waptus soils have a spodic horizon 1 to 3 inches thick.
GEOGRAPHIC SETTING: Ohana soils are on convex glaciated mountain slopes and broad ridgetops at elevations of 2,800 to 3,700 feet. Slopes are 3 to 65 percent. These soils formed in mantle of volcanic ash and pebble-size rounded and subangular pumice over colluvium from glacial till and weathered tuff breccia over dense glacial till. The climate is characterized by cool dry summers and cool wet winters. Average annual
precipitation is 70 to 80 inches including considerable snow. Mean annual temperature is 38 to 40 degrees F. The growing season (28 F.) is 70 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Hatchet soils and the
Bellicum,
Bromo,
Cattcreek,
Cotteral,
Dobbs,
Domell,
Hoffstadt, and
Zynbar soils. Bellicum soils are cindery over medial-skeletal and have a frigid temperature regime. Bromo soils have a frigid temperature regime. Cattcreek soils are cindery over medial-skeletal. Cotteral soils are cindery over medial. Dobbs soils have a cambic
horizon and have a frigid temperature regime. Domell soils are medial and have a frigid temperature regime. Hoffstadt soils have a frigid temperature regime. Zynbar soils are medial and have a frigid temperature regime.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Used for timber production, watershed and wildlife habitat. Vegetation is Douglas-fir, western hemlock, Pacific silver fir, western redcedar, and noble fir with an understory of Oregon-grape, red huckleberry, common beargrass, western brackenfern, and western rattlesnake plantain.
DISTRIBUTION AND EXTENT: Mountain slopes of Central Cascades in southeastern Lewis, northern Skamania, and northern Cowlitz Counties, Washington; MLRA 3. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lewis County, Washington, 1979.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Albic horizon from 5 to 5 1/2 inches
Cambic horizon from 5 1/2 to 25 inches.
The Bs horizon meets the color requirement for spodic but the pH is
above 5.9 in water.
Andic soil properties from 5 to 35 inches. Assume 5 to 11 inches has 15 bar dry of less than 15 percent and 15 bar moist of less than 30 percent. Assume 11 to 35 inches has 15 bar dry of more than 15 percent and 15 bar moist of less than 30 percent. (Vitric from 5 to 11 and non-vitric from 11 to 35 inches). The zone from 5 to 16 inches is considered medial and 16 to 35 inches is considered medial-skeletal. The thickest part is
medial-skeletal.