LOCATION JAYAR OREstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Dystroxerepts
TYPICAL PEDON: Jayar very gravelly loam, on a forested northwest facing slope of 50 percent. (Colors are for moist soil unless otherwise noted.)
Oi--1 inch to 0; loose litter of needles, leaves, bark and lichen.
A--0 to 3 inches; dark yellowish brown (10YR 3/4) very gravelly loam, yellowish brown (10YR 5/4) dry; strong very fine granular structure; slightly hard, friable, nonsticky and nonplastic; many fine and medium and coarse roots; many interstitial pores; 5 percent cobbles and 55 percent gravel; moderately acid (pH 6.0); clear smooth boundary. (2 to 5 inches thick)
Bw1--3 to 14 inches; dark brown (7.5YR 4/4) very gravelly loam, light yellowish brown (10YR 6/4) dry; moderate fine subangular blocky and moderate very fine granular structure; slightly hard, friable, nonsticky and nonplastic; many fine, medium and coarse roots; many very fine tubular and irregular pores; 5 percent cobbles and 50 percent gravel; slightly acid (pH 6.2); gradual wavy boundary.
Bw2--14 to 31 inches; dark brown (7.5YR 4/4) extremely gravelly loam, light yellowish brown (10YR 6/4) dry; moderate fine subangular blocky and moderate very fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and medium roots; many very fine tubular pores; 25 percent cobbles and 55 percent gravel; slightly acid (pH 6.4); gradual irregular boundary. (Combined thickness of the Bw horizon is 23 to 35 inches)
R--31 inches; fractured metamorphic volcanic bedrock.
TYPE LOCATION: Josephine County, Oregon, approximately 380 feet west and 1,450 north of the southeast corner of sec. 23, T. 33 S., R. 5 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 42 to 47 degrees F. The soils are usually moist but are dry during the summer for 45 to 60 consecutive days in all parts of the moisture control section and are moist throughout during the winter and spring. Depth to bedrock is 20 to 40 inches. Rock fragments range from 35 to 80 percent in the particle-size control section. It is moderately acid or slightly acid.
The A horizon has hue of 10YR or 7.5YR, value of 2 to 4 moist, 5 or 6 dry and chroma of 2 to 4 moist and dry. Rock fragments range from 35 to 60 percent gravel, 0 to 15 percent cobbles, and 0 to 5 percent stones.
The Bw horizon has hue of 7.5YR or 10YR, value of 3 to 5 moist, 5 to 7 dry and chroma of 3 to 6 moist and dry. It is loam or clay loam and averages 18 to 30 percent clay, 30 to 70 percent gravel, 0 to 25 percent cobbles, and 0 to 5 percent stones.
COMPETING SERIES: These are the Althouse, Ardtoo, Beargulch, Hangtown, Minaloosa, Notned, Smokey, Treble and Umpa series. Althouse, Ardtoo, Beargulch, Hangtown, Minaloosa, Notned and Treble soils are greater than 40 inches deep. Smokey soils have a paralithic contact at 20 to 40 inches. Umpa soils are dry for 75 to 85 consecutive days, have greater than 15 percent mica and have less than 18 percent clay in the particle-size control section
GEOGRAPHIC SETTING: Jayar soils are on mountain side slopes at elevations of 3,000 to 5,500 feet. Slopes are 12 to 90 percent. The soils formed in colluvium weathered from sedimentary or metamorphic volcanic rocks. The climate is characterized by cool, moist to wet winters and hot, dry summers. The mean annual precipitation is typically 40 to 70 inches but in areas of high winter rainfall, may range to 120 inches. The mean annual temperature is 40 to 45 degrees F. The frost-free period is 50 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beekman, Bigelow, Colestine, Crannler, Goodwin, Josephine, Skymor, Speaker and Woodseye series and the competing Althouse series. Beekman, Colestine, Josephine and Speaker soils are on associated south facing slopes and have mesic soil temperature. Bigelow and Crannler soils have an umbric epipedon, are at higher elevations, and have cryic soil temperature. Goodwin and Woodseye soils have an umbric epipedon. Also, Goodwin soils are deeper than 40 inches to bedrock. Skymor soils are 12 to 20 inches deep to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Jayar soils are used mainly for timber production, water supply, and wildlife habitat. Vegetation is white fir, Douglas fir, creambush oceanspray, common snowberry, Pacific serviceberry, cascade Oregongrape, western princes pine, and deerfoot vanillaleaf. In high rainfall areas of Curry County, Oregon natural vegetation includes sugar pine, tanoak, golden chinkapin, and Saddler oak.
DISTRIBUTION AND EXTENT: Mountainous areas of southwestern Oregon; MLRA 5. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Josephine County, Oregon, 1979.
REMARKS: The classification was updated in July 2001 using the Eighth Edition to Soil Taxonomy. This series was formerly classified as loamy-skeletal, mixed, frigid Dystric Xerochrepts. Competing series were not checked at that time.
Diagnostic horizons and features include:
Ochric epipedon
Cambic horizon - the zone from 3 to 31 inches (Bw1 and Bw2 horizons)
Particle-size control section - the zone from 10 to 31 inches
Dystric feature - base saturation (NH4OAc) is assumed to be less than 60 percent in all horizons between 10 and 30 inches based on lab data from similar Althouse series.