LOCATION VENA OREstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Typic Dystroxerepts
TYPICAL PEDON: Vena gravelly loam, forested. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inch; loose litter of twigs, needles and tree limbs, and partially decomposed twigs, tree limbs, needles, leaves and bark.
A--1 to 6 inches; very dark grayish brown (10YR 3/2) gravelly loam, gray (10YR 6/1) dry; weak fine granular structure; soft, very friable, nonsticky, nonplastic; many very fine to medium roots; many very fine irregular pores; 20 percent gravel and 5 percent cobbles; moderately acid (pH 5.6); clear smooth boundary. (3 to 9 inches thick)
BC--6 to 10 inches; dark grayish brown (10YR 4/2) very gravelly loam, light gray (10YR 7/1) dry; weak fine and medium granular structure; soft, very friable, nonsticky, nonplastic; many very fine to coarse roots; many very fine irregular pores; 35 percent gravel and 15 percent cobbles; moderately acid (pH 6.0); clear smooth boundary. (3 to 10 inches thick)
Bw--10 to 22 inches; grayish brown (10YR 5/2) very gravelly loam, light gray (10YR 7/1) dry; weak fine subangular blocky structure; soft, very friable, nonsticky, nonplastic; many very fine to medium roots; many very fine irregular pores; 40 percent gravel and 15 percent cobbles; strongly acid (pH 5.5); abrupt wavy boundary. (10 to 30 inches thick)
R--22 inches; fractured rhyolitic tuff bedrock with soil materials along fractures.
TYPE LOCATION: Douglas County, Oregon; NE1/4 NW1/4 section 30, T. 28 S., R. 2 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 52 degrees F. The soils are usually moist and are dry in the control section for 60 to 90 consecutive days during the summer. Depth to bedrock is 20 to 40 inches. The particle-size control section is loam or fine sandy loam with less than 18 percent clay, 30 to 55 percent gravel and 5 to 30 percent cobbles.
The A horizon has value of 2 to 4 moist, 4 or 6 dry, and chroma of 1 to 4 moist and dry. It has 15 to 50 percent gravel and 0 to 20 percent cobbles.
The AC or Bw horizon has value of 4 or 5 moist, 6 to 8 dry, and chroma of 1 to 4 moist and dry. It has 35 to 60 percent gravel and 5 to 30 percent cobbles. It is very gravelly loam or fine sandy loam, very cobbly loam, or extremely gravelly loam.
The C horizon has value of 5 or 6 moist, 6 to 8 dry, and chroma of 1 to 4 moist and dry. It has 25 to 50 percent gravel and 5 to 30 percent cobbles.
COMPETING SERIES: These are the Atring, Baldhill, Beausite, Beekman, Chamate, Clallam, Farber, Inskip, Kanid, Kindig, Longdoe, Mayacama, Neuns, Straight, Terbies and Woodin series. Atring, Clallam and Straight soils are 20 to 40 inches to a paralithic contact. Baldhill, Chamate, Farber, Kanid and Terbies soils are over 40 inches deep. Beausite soils have sandy loam Bs horizons with chroma of 4 and are underlain by an indurated iron-silica cemented conglomerate. Inskip soils have chroma of 4 in the A and C horizons and have a mean annual soil temperature of about 54 degrees F. Longdoe, Mayacama, Neuns and Woodin soils are dry for more than 90 consecutive days in the moisture control section. The Mayacama and Woodin soils have a mean annual soil temperature of 54 to 59 degrees F. Beekman soils have 18 to 30 percent clay in the particle-size control section.
GEOGRAPHIC SETTING: The Vena soils are on uplands at elevations of 800 to 4,000 feet. Slopes are 20 to 100 percent. The soils formed in colluvium weathered from acid igneous rock, dominantly rhyolite. The climate is subhumid with cool wet winters and warm dry summers. The mean annual precipitation is 40 to 60 inches; the mean annual temperature is about 45 to 50 degrees F., the mean July temperature is about 64 degrees F., and the mean January temperature is 25 to 32 degrees F. The frost-free period is 100 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Acker, Chamate and Gustin soils. Acker soils dominantly have less steep slopes and are deep soils with moderately fine textured argillic horizons. Gustin soils are drained and fine textured. Chemate soil are over 40 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Well-drained; moderate permeability.
USE AND VEGETATION: Used for timber production, water supply and wildlife. Present vegetation is mainly Douglas fir, Pacific madrone, and sugar pine with an understory of golden chinquapin, Pacific rhododendron, salal, creambush oceanspray, red huckleberry, serviceberry, cascade Oregongrape, whipplevine, and western fescue.
DISTRIBUTION AND EXTENT: The west side of Central-southern Cascade Mountains, Oregon. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Douglas County, Oregon, 1974.
REMARKS: Depths to diagnostic horizons and features are measured from the top of the first mineral horizon. Diagnostic horizons and features included in this pedon:
Ochric epipedon
Cambic horizon - from 6 to 22 inches
Classification updated 1/00 from Dystric Xerochrepts to Typic Dystroxerepts based on amendment to Soil Taxonomy.
ADDITIONAL DATA: Partial characterization data by Oregon State University reported in the Soil Survey of the South Umpqua Area, Oregon, 1973.