LOCATION BOBSGARDEN OR

Established Series
Rev. MHF/CDJ/RWL
06/2011

BOBSGARDEN SERIES

The Bobsgarden series consists of very deep, well drained soils formed in colluvium and residuum from metasedimentary or metavolcanic rock types. Bobsgarden soils are on broad ridgetops and south-facing side slopes of mountains. Slopes are 0 to 90 percent. The mean annual precipitation is about 145 inches and the mean annual temperature is about 43 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Humic Dystrudepts

TYPICAL PEDON: Bobsgarden gravelly loam - woodland, on a 37 percent west-facing slope at 2,920 feet elevation. (When described on November 8, 1989 the soil was moist throughout. Colors are for moist soil unless otherwise noted.)

Oi--0 to 3 inches; slightly decomposed needles, leaves, twigs, and woody materials.

A--3 to 11 inches; dark brown (10YR 3/3) gravelly loam, brown (10YR 4/3) dry; moderate very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium, and common very fine and coarse roots; many very fine tubular pores; 30 percent gravel; strongly acid (pH 5.3); clear smooth boundary. (7 to 9 inches thick)

Bw1--11 to 20 inches; dark yellowish brown (10YR 4/4) very gravelly clay loam; yellowish brown (10YR 5/4) dry; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; common very fine, fine, medium and coarse roots; many very fine and fine tubular pores; 35 percent gravel and 5 percent cobbles; strongly acid (pH 5.4); clear smooth boundary.

Bw2--20 to 28 inches; dark yellowish brown (10YR 4/6) very gravelly clay loam, light yellowish brown (10YR 6/4) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; few very fine, fine, medium and coarse roots; many fine tubular pores; 40 percent gravel and 5 percent cobbles; strongly acid (pH 5.4); gradual smooth boundary. (Combined thickness of the Bw horizon ranges from 16 to 32 inches)

C1--28 to 49 inches; yellowish brown (10YR 5/6) very gravelly clay loam, light yellowish brown (10YR 6/4) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; few medium and coarse roots; many fine tubular pores; 50 percent gravel and 5 percent cobbles; strongly acid (pH 5.4); gradual smooth boundary. (12 to 24 inches thick)

C2--49 to 71 inches; yellowish brown (10YR 5/6) very gravelly clay loam, light yellowish brown (10YR 6/4) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; few medium and coarse roots; many fine tubular pores; 35 percent gravel and 10 percent cobbles; strongly acid (pH 5.4).

TYPE LOCATION: Curry County, Oregon; about 330 feet south and 2,310 feet east of the northwest corner of section 13, T. 37 S., R. 13 W. (Latitude 42 degrees, 22 minutes, 48 seconds N.; Longitude 124 degrees, 11 minutes, 42 seconds W.)

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 41 to 46 degrees F. The soils are usually moist but are dry in all parts of the moisture control section for less than 45 consecutive days between depths of 4 and 12 inches in the four months following the summer solstice. The particle-size control section averages 27 to 35 percent clay and 35 to 65 percent rock fragments. Depth to bedrock is greater than 60 inches. Solum thickness is 25 to 40 inches. The solum has hue of 10YR or 7.5YR.

The A horizon has value of 2 or 3 moist, 3 or 4 dry and chroma of 2 or 3 moist and dry. It is gravelly loam with 18 to 25 percent clay. It has 15 to 30 percent gravel and 0 to 5 percent cobbles.

The Bw horizon has value of 4 or 5 moist, 5 or 6 dry and chroma of 4 to 6 moist and dry. It is very gravelly clay loam or extremely gravelly clay loam with 27 to 35 percent clay. It has 35 to 50 percent gravel and 5 to 15 percent cobbles.

The C horizon has hue of 10YR or 2.5Y, value of 5 or 6 moist, 6 or 7 dry and chroma of 4 to 6 moist and dry. It is very gravelly clay loam, extremely gravelly clay loam, or extremely gravelly loam with 20 to 35 percent clay. It has 35 to 60 percent gravel and 0 to 20 percent cobbles.

COMPETING SERIES: These are the Bigdutch and Tincup series. Bigdutch soils are 20 to 40 inches deep to a lithic contact. Tincup soils are 20 to 40 inches deep to a lithic contact and have 5 to 20 percent clay in the particle size control section.

GEOGRAPHIC SETTING: The Bobsgarden soils are on metastable broad ridgetops and active south-facing side slopes of mountains. Slopes are 0 to 90 percent. The soils formed in colluvium and residuum derived from metasedimentary or metavolcanic rock types of the Dothan Formation. Elevations are 2,500 to 3,800 feet. The climate is characterized by cool wet winters and warm moist summers. The mean annual precipitation is 130 to 160 inches. The mean annual temperature is 40 to 45 degrees F. The frost-free period is 60 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Euchrand, Pyrady, Rilea, Stackyards, Yorel, and Zalea soils. Euchrand soils occur on side slopes of mountains and are less than 20 inches deep to bedrock. Pyrady soils are on ridgetops and side slopes of mountains, have argillic horizons, and are moderately well drained. Rilea and Yorel soils are on ridgetops and side slopes of mountains and are 20 to 40 inches deep to bedrock. Stackyards soils occur on side slopes of mountains and are 40 to 60 inches deep to bedrock. Zalea soils are on ridgetops and side slopes of mountains, are 20 to 40 inches deep to bedrock, and are fine-loamy.

DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.

USE AND VEGETATION: The soils are used for timber production, watershed, recreation and wildlife habitat. The native vegetation is Douglas-fir, western hemlock, golden chinkapin, tanoak, Pacific madrone, canyon live oak, salal, cascade Oregongrape, Pacific rhododendron, western swordfern, Sadler oak, common beargrass, baldhip rose, western princes pine, western rattlesnake plantain, and western brackenfern.

DISTRIBUTION AND EXTENT: Mountainous areas of southwestern Oregon; MLRA 1. The series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Coos County, Oregon, 1993.

REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon
Humic subgroup - colors requirements are meet from 3 to 11 inches
Cambic horizon - from a depth of 11 to 28 inches (Bw1, Bw2 horizons).
Particle-size control section - from 13 to 43 inches (part of Bw1, the Bw2, and most of C1 horizons).

ADDITIONAL DATA: Partial data available from pedon 90P 310, sample 90P1905 from Curry County, Oregon sampled by NSSL at Lincoln, Nebraska - 3/90.

National Cooperative Soil Survey
U.S.A.