LOCATION ONEONTA OREstablished Series
TAXONOMIC CLASS: Medial, amorphic Typic Haplocryands
TYPICAL PEDON: Oneonta gravelly loam-forested, on a southwest-facing slope of 14 percent at an elevation of 4240 feet. (Colors are for moist soil unless otherwise stated.)
Oi---2 inches to 0; partially decomposed leaves and twigs.
A1---0 to 5 inches; very dark brown (10YR 2/2) gravelly loam, dark brown (10YR 3/3) dry; strong very fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and medium and common fine and coarse roots; many very fine irregular pores; 10 percent gravel and 5 percent cobbles; strongly acid (pH 5.4); clear wavy boundary. (3 to 12 inches thick)
A2---5 to 11 inches; very dark brown (10YR 2/2) loam, brown (10YR 4/3) dry; strong fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine, medium and coarse roots; many very fine irregular pores; 3 percent gravel and 2 percent cobbles; strongly acid (pH 5.4); clear wavy boundary. (5 to 12 inches thick)
AB---11 to 18 inches; dark brown (7.5YR 3/2) loam, brown (10YR 4/3) dry; moderate very fine and fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine, medium and coarse roots; common very fine tubular pores; 3 percent gravel; strongly acid (pH 5.4); clear wavy boundary. (0 to 12 inches thick)
Bw1--18 to 34 inches; dark brown (7.5YR 3/3) loam, yellowish brown (10YR 5/4) dry; moderate very fine and fine subangular blocky structure; slightly hard, friable, slightly hard and slightly plastic; few very fine, fine and medium roots; common very fine tubular pores; 3 percent gravel; very strongly acid (pH 4.8); clear wavy boundary. (10 to 20 inches thick)
Bw2--34 to 60 inches; dark yellowish brown (10YR 4/4) loam, light yellowish brown (10YR 6/4) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; 35 percent soft gravel; very strongly acid (pH 4.6).
TYPE LOCATION: Douglas County, Oregon, 2 miles west of Huckleberry Mountain on the Calapooya Divide, 2000 feet north and 100 feet west of the southeast corner of section 35, T. 23 S., R. 2 W. W.M. (43 degrees, 31 minutes, 41 seconds N, Longitude 122 degrees, 53 minutes, 30 seconds W)
RANGE IN CHARACTERISTICS: Solum thickness and depth to bedrock is 60 inches or more. The mean annual soil temperature is 40 to 47 degrees F, and the mean summer soil temperature is less than 47 degrees F with an O horizon. The soil is usually moist but is dry within all parts of the moisture control section for less than 45 consecutive days following the summer solstice. The umbric epipedon is 20 to 50 inches thick. Hue is 10YR or 7.5YR. The particle-size control section has a phosphate retention of 90 to 100 percent and acid oxalate extractable aluminum plus one-half iron of 2.0 to 4.0 percent. The 15-bar water retention on air-dried sample is 15 to 30 percent.
The A horizon has value of 2 or 3 moist, 3 to 5 dry, and chroma of 2 or 3 moist and dry. It is gravelly loam in the upper part and loam or gravelly loam in the lower part. It has 5 to 30 percent gravel and 0 to 5 percent cobbles. It has a moist bulk density of 0.75 to 0.90 grams per cubic centimeter. It is strongly acid to very strongly acid. It has 5 to 10 percent organic matter and decreased to below 7 percent below a depth of 12 inches.
The Bw horizon has value of 3 or 4 moist, 5 to 7 dry, and chroma of 3 or 4 moist and dry. It is loam, gravelly loam, clay loam, or gravelly clay loam and has 5 to 25 percent gravel and 0 to 10 percent cobbles. There are up to 50 percent soft rock fragments in the lower part of this horizon. It has a moist bulk density of 0.80 to 0.90 grams per cubic centimeter. It is strongly acid to very strongly acid.
COMPETING SERIES: These are the Cruiser, Keel, and Soosap series. The Keel and Soosap soils are 20 to 40 inches deep to bedrock. Cruiser soils have an ochric epipedon.
GEOGRAPHIC SETTING: The Oneonta soils are on hill slopes and plateaus. They formed in residuum and colluvium derived from basalt, andesite, and welded tuffs. Slopes are 3 to 60 percent. Elevations are 3800 to 4800 feet. The climate is characterized by cold, wet winters and cool, moist summers. The mean annual temperature is 40 to 45 degrees F, and the mean annual precipitation is 60 to 80 inches. The frost free period is 50 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hummington, Illahee, Keel, Lempira, Mellowmoon, and Scaredman soils. Illahee, Lempira, Mellowmoon, and Scaredman soils are frigid. In addition, Illahee and Scaredman soils are loamy-skeletal and are on convex or more steeply sloping positions. Mellowmoon soils have an umbric epipedon less than 20 inches thick. Hummington soils are moderately deep and loamy-skeletal and are on convex or more steeply sloping positions.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: The Oneonta soils are used for recreation, wildlife, and timber production. Natural overstory vegetation is Douglas fir, Pacific silver fir, western hemlock. The understory vegetation is dominated by Pacific rhododendron, golden chinkapin, cascade Oregongrape, common beargrass, whiteveined shinleaf, vine maple, American twinflower, western swordfern, big huckleberry, and feather Solomons-seal.
DISTRIBUTION AND EXTENT: Cascade mountains of southwestern Oregon; MLRA 3. The series is inextensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Multnohah County, Oregon, (Bull Run - Sandy Area), 1976.
REMARKS; Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - from the soil surface to 34 inches. (A1, A2, AB, and Bw1 horizons)
Cambic horizon - from 18 to 60 inches. (Bw1 and Bw2 horizons)
Andic soil properties - throughout the soil; based on data from the associated Keel and Lempira series. Haplocryand based on not meeting organic carbon/thickness requirement for melanic/fulvic; below 12 inches organic carbon drops to below 4 percent
Particle-size control section - from 0 to 40 inches. (A1, A2, A3, Bw1, and part of the Bw2 horizon)
This draft reflects a change in the series type location from Multnomah to Douglas County. A previous draft changed the classification from medial Andic Cryumbrepts to Typic Haplocryands
ADDITIONAL DATA: Characterization data on one pedon (FS62Ore-045-16-1-7) by OSU