LOCATION FORMADER OREstablished Series
TAXONOMIC CLASS: Medial over loamy, ferrihydritic over isotic, mesic Alic Hapludands
TYPICAL PEDON: Formader medial loam, woodland. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inch; duff layer of decomposing leaves, roots, twigs, and needles.
A1--1 to 8 inches; very dark brown (7.5YR 2.5/2) medial loam, brown (7.5YR 4/2) dry; strong very fine granular structure; soft, very friable, nonsticky and slightly plastic; weakly smeary; many very fine roots; many very fine irregular pores; 5 percent paragravel; strongly acid (pH 5.2); clear smooth boundary.
A2--8 to 19 inches; dark brown (7.5YR 3/2) medial loam, brown (7.5YR 4/4) dry; weak medium and fine subangular blocky structure parting to strong very fine granular; soft, friable, slightly sticky and slightly plastic; weakly smeary; common fine and very fine roots; many very fine irregular pores; 5 percent paragravel; very strongly acid (pH 5.0); clear smooth boundary. (combined A horizon is 10 to 20 inches thick)
Bw1--19 to 30 inches; brown (7.5YR 4/4) silty clay loam, brown (7.5YR 5/4) dry; moderate medium, fine, and very fine subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine roots; many fine and very fine tubular pores; 5 percent gravel and 15 percent paragravel; very strongly acid (pH 4.6); clear wavy boundary.
Bw2--30 to 34 inches; brown (7.5YR 4/4) gravelly silty clay loam, brown (7.5YR 5/4) dry; moderate medium, fine, and very fine subangular blocky structure; slightly hard, friable, sticky and plastic; few very fine roots; many fine and very fine tubular pores; 20 percent gravel and 25 percent paragravel; very strongly acid (pH 4.5); clear wavy boundary. (combined Bw horizon is 9 to 20 inches thick)
Cr--34 inches; weathered basic igneous rock.
TYPE LOCATION: Lane County, Oregon; 1/2 mile west of rock quarry on south side of Saddle Mountain; NW1/4 SE1/4 of section 14, T.16S., R.11W. W.M.; Cummins Peak, OR 7.5 minute USGS quadrangle; NAD 1927.
RANGE IN CHARACTERISTICS: The soil is usually moist but is dry for a short period of less than 45 consecutive days between depths of 4 to 12 inches in the four month period following the summer solstice in most years. The mean annual soil temperature is 47 to 55 degrees F. The depth to bedrock is 20 to 40 inches. The pscs has 18 to 30 percent clay (field estimate) with 15 to 30 percent rock fragments and 5 to 30 percent pararock fragments. The umbric epipedon is 10 to 20 inches thick. Reaction is strongly acid or very strongly acid.
The A horizon has hue of 10YR to 5YR moist, 10YR or 7.5YR dry, value of 2 or 3 moist and 2 to 4 dry and chroma of 2 or 3 moist, 2 to 4 dry. Texture of the fine-earth fraction is medial loam,or medial silt loam with 15 to 20 percent clay (field estimate), 0 to 20 percent gravel and 0 to 30 percent paragravel. It has a moist bulk density of 0.75 to 0.90 g/cubic centimeter, greater than 85 percent phosphate retention, 2.0 to 4.0 percent acid-oxalate extractable aluminum plus one-half iron, 2.0 to 15 cmol/kg of KCL-extractable aluminum, and 15 to 30 percent 15-bar moisture (air dried).
The Bw horizon has hue of 7.5YR or 5YR moist, 10YR or 7.5YR dry, value of 3 or 4 moist, 4 or 5 dry and chroma of 2 to 4 moist and dry. Texture of the fine-earth fraction is loam, clay loam, or silty clay loam with 18 to 35 percent clay. It has 5 to 30 percent gravel, 0 to 10 percent cobbles, and 5 to 30 percent pararock fragments. Moist bulk density is 0.90 to 1.20 g/cubic centimeter.
COMPETING SERIES: This is the
Slickrock series. Slickrock soils are 40 to over 60 inches deep to sedimentary bedrock.
GEOGRAPHIC SETTING: Formader soils occur on summits, shoulder slopes, and back slopes of mountains. Slopes are 3 to 80 percent. These soils have formed in loamy colluvium and residuum derived from basalt or coarse-grained intrusive rock. Elevations are typically 200 to 1,800 feet but range to 2,400 feet in
Lane County, Oregon. The climate is characterized by warm wet winters and hot moist summers. The mean annual precipitation is 60 to 120 inches. The mean annual temperature is 45 to 53 degrees F. The mean January temperature is about 40 degrees F. and the mean July temperature is about 61 degrees F. The frost-free period is 110 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bohannon, Blachly, Harslow, Hembre, Hemcross, Klickitat, Klistan, and Kilchis soils. All these soils occur on mountains. Bohannon soils are fine-loamy and have a surface layer less than 14 inches thick which meets Andic subgroup criteria. Blachly soils are fine textured and more than 60 inches deep to bedrock. Harslow soils have greater than 35 percent rock fragments in the particle-size control section. Hembre soils are fine-loamy and more than 40 inches deep to basalt. Klickitat soils are loamy-skeletal and are more than 40 inches deep to basalt. Kilchis soils are loamy-skeletal and are less than 20 inches deep to basalt. Klistan soils have greater than 35 percent rock fragments in the particle-size control section and are 40 to 60 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Formader soils are used for timber production, recreation, wildlife habitat and watersheds. Native vegetation is Douglas fir, western hemlock, vine maple, salal, huckleberry, brackenfern, Oregongrape, rose and other shrubs, forbs and grasses.
DISTRIBUTION AND EXTENT: Central portion of the Coast Range Mountains in Oregon: MLRA 1. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lane County Area, Oregon, 1981. The source of the name is taken from Formader Ridge in western Lane County, Oregon.
REMARKS: Diagnostic features in this pedon include:
Umbric epipedon - from the surface to 19 inches (A1 and A2 horizons).
Cambic horizon - from 19 to 34 inches (Bw1 and Bw2 horizons).
Andic soil properties - from the surface of the soil to a depth of 19 inches (A1 and A2 horizons).
Particle-size control section - from 1 to 34 inches with the zone from 1 to 19 inches meeting andic soil properties and medial family and the zone from 19 to 34 inches meeting a contrasting loamy family. Below a depth of approximately 19 inches, andic soil properties are absent primarily due to reduced organic matter and higher bulk density.
Depth to diagnostic horizons and features is measured from the top of the first mineral horizon.
Classification revised 9/03 from Medial over loamy, mixed, mesic Typic Dystrandepts to Medial over loamy, ferrihydritic over isotic, mesic Alic Hapludands. This reclassification is based on the addition of the Andisol Order to Soil Taxonomy.
Further investigation may be needed where the series in recognized above 1,800 feet. This elevation has historically been considered the transition to the frigid soil temperature regime within the central to northern Coast Range Mountains.