LOCATION LONGBOW OR
Tentative Series
DRJ/KMS
01/2017
LONGBOW SERIES
Landscape--western Cascade Mountains
Landform--glacially influenced structural benches, cirque floors
Slope--0 to 60 percent
Parent material--colluvium derived from igneous rock mixed with till and volcanic ash throughout
Mean annual precipitation--about 2600 mm
Mean annual air temperature--about 6 degrees C
Depth class-very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Medial, amorphic Typic Haplocryands
TYPICAL PEDON: Longbow gravelly medial loam on a 13-percent, forested slope at an elevation of 1140 m
Oi--0 to 2 cm; slightly decomposed plant material; abrupt wavy boundary
A--2 to 35 cm; gravelly medial loam, brown (7.5YR 4/2) dry, dark brown (7.5YR 3/2) moist; moderate fine granular structure; very friable, loose, slightly sticky and nonplastic; many very fine, common medium and coarse, and few fine roots; many very fine and fine irregular pores and common medium and coarse tubular pores; 20 percent basalt gravel and 5 percent basalt cobbles; strongly acid (pH 5.3); clear wavy boundary
AB--35 to 59 cm; gravelly medial silt loam, yellowish brown (10YR 5/4) dry, brown (10YR 4/3) moist; moderate very fine and fine subangular blocky structure; very friable, loose, slightly sticky and slightly plastic; many very fine, common medium, and few fine and coarse roots; many very fine dendritic tubular and irregular pores and common fine, medium, and coarse tubular pores; 20 percent basalt gravel and 5 percent basalt cobbles; strongly acid (pH 5.5); clear wavy boundary
Bw1--59 to 82 cm; gravelly medial silt loam, light yellowish brown (10YR 6/4) dry, brown (10YR 4/3) moist; moderate fine subangular blocky structure; friable, slightly hard, slightly sticky and slightly plastic; common very fine and few fine and medium roots; common very fine and fine dendritic tubular pores and common very fine and fine and few medium tubular pores; 20 percent basalt gravel and 10 percent basalt cobbles; moderately acid (pH 5.7); gradual wavy boundary
Bw2--82 to 150 cm; cobbly medial silt loam, light yellowish brown (10YR 6/4) dry, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; friable, slightly hard, slightly sticky and slightly plastic; few very fine and fine roots; common very fine and fine dendritic tubular pores and common very fine and fine and few medium tubular pores; 15 percent basalt gravel and 15 percent basalt cobbles; moderately acid (pH 5.8)
TYPE LOCATION: Linn County, Oregon, about 36 km east of Sweet Home and 7.5 km northeast of the junction of Upper Soda Fork Road and OR Highway 20; about 255 m south and 335 m east of the northwest corner of section 9, T. 13 S., R. 5 E.; latitude 44.4582500, longitude -122.2226944, datum WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Dry days--less than 45 consecutive days following summer solstice
Mean annual soil temperature--4 to 6 degrees C
Thickness of umbric epipedon--25 to 50 cm (below mineral soil surface)
Thickness of cambic horizon--50 to 150 cm (below mineral soil surface)
Reaction--5.0 to 6.0
Thickness of andic soil properties--greater than 150 cm (below mineral soil surface)
Estimated properties of layers with andic soil properties
*1/3-bar bulk density--0.6 to 0.9 g/cm3
*Phosphate retention--greater than 85 percent
*Ammonium oxalate extractable Al + Fe--2 to 4 percent
*15-bar water retention--30 to 70 percent (undried samples), greater than 15 percent (dried samples)
*0.02- to 2.0-mm fraction--greater than 30 percent
*Volcanic glass content in 0.02- to 2.0-mm fraction--5 to 30 percent
Particle-size control section
*Clay content--18 to 27 percent
*Total rock fragment content--15 to 35 percent
*Total pararock fragment content--0 to 5 percent
Oi horizon
*Thickness--1 to 10 cm
A horizon
*Hue--7.5YR, 10YR
*Value--2 to 3 moist, 3 to 5 dry
*Chroma--2 or 3 moist or dry
*Clay content--15 to 20 percent
*Sand content--30 to 45 percent
*Total fragment content--15 to 35 percent
*Gravel content--15 to 35 percent
*Cobble content--0 to 10 percent
*Stone content--0 to 5 percent
*Thickness--20 to 36 cm
AB horizon, and BA horizon (where present)
*Hue--10YR, 7.5YR
*Value--3 or 4 moist, 4 to 6 dry
*Chroma--3 or 4 moist or dry
*Fine-earth texture--medial silt loam, medial loam
*Clay content--18 to 27 percent
*Sand content--20 to 40 percent
*Total fragment content--10 to 35 percent
*Gravel content--10 to 30 percent
*Cobble content--0 to 10 percent
*Stone content--0 to 5 percent
*Thickness--0 to 30 cm
Bw1 horizon
*Hue--2.5Y, 10YR, 7.5YR
*Value--3 or 4 moist, 5 or 6 dry
*Chroma--3 or 4 moist, 3 to 6 dry
*Fine-earth texture--medial silt loam, medial loam
*Clay content--18 to 27 percent
*Sand content--20 to 35 percent
*Total fragment content--10 to 35 percent
*Gravel content--10 to 30 percent
*Cobble content--0 to 15 percent
*Stone content--0 to 10 percent
Bw2 horizon
*Hue--2.5Y, 10YR, 7.5YR
*Value--3 to 5 moist, 5 to 7 dry
*Chroma--3 or 4 moist, 3 to 6 dry
*Fine-earth texture--medial silt loam, medial loam
*Clay content--18 to 27 percent
*Sand content--20 to 35 percent
*Total fragment content--15 to 50 percent
*Gravel content--15 to 35 percent
*Cobble content--0 to 20 percent
*Stone content--0 to 10 percent
*Combined thickness of Bw horizon--50 to 150 cm
COMPETING SERIES:
Cruiser--ochric epipedon
Keel--50 to 100 cm deep to lithic contact
Molawa--ochric epipedon
Oneonta--umbric epipedon greater than 50 cm thick
Soosap--50 to 100 cm deep to paralithic contact
GEOGRAPHIC SETTING:
Elevation--1100 to 1800 m
Climate--cool, dry summers; cold, wet winters
Mean annual precipitation--2300 to 2900 mm
Mean annual air temperature--5.0 to 7.5 degrees C
Frost-free period--60 to 105 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Icecap--50 to 100 cm deep to lithic contact; greater than 35 percent rock fragments; in convex positions
Kinzel--greater than 35 percent rock fragments; in linear and slightly convex positions
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation in normal years--none within profile
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--moderately high
USE AND VEGETATION:
Use--watershed, recreation, wildlife habitat, timber production
Potential natural vegetation--Douglas-fir, western hemlock, Pacific silver fir, noble fir, Pacific rhododendron, Cascade Oregon grape, Alaska blueberry, bunchberry dogwood, starry false lily of the valley, prince's pine, twinflower
DISTRIBUTION AND EXTENT: Central western Cascade Mountains, Oregon; MLRA 3; small extent
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Willamette National Forest, Linn County, Oregon; name from a group camp area in Linn County
REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Particle-size control section--zone from 2 to 102 cm
*Umbric epipedon--zone from 2 to 35 cm
*Cambic horizon--zone from 35 to 150 cm
*Andic soil properties--zone from 2 to 150 cm
*Volcanic glass--zone from 2 to 150 cm
06/2016--Assumed to meet criteria 2 (no ash required) for andic soil properties, in the 12th edition of Keys to Soil Taxonomy. It is also assumed that enough ash is present for the soils to meet criteria 3. Additional lab data is needed to confirm the degree of ash influence.
ADDITIONAL DATA: Type location user site ID--2013OR043024
National Cooperative Soil Survey
U.S.A.