LOCATION BTREE OR
Established Series
Rev. AEK/RJO
11/2018
BTREE SERIES
Landscape--mountains
Landform--north-facing, concave backslopes of canyons; mountain slopes; mass failures and landslides on mountain slopes
Slope--0 to 90 percent
Parent material--thick mantle of volcanic ash over colluvium and residuum derived from acidic tuff
Mean annual precipitation--about 630 mm
Mean annual air temperature--about 6 degrees C
Depth class--very deep or deep to paralithic bedrock
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--frigid
Soil moisture subclass--typic
TAXONOMIC CLASS: Ashy over clayey-skeletal, amorphic over smectitic, frigid Alfic Udivitrands
TYPICAL PEDON: Btree ashy silt loam in an area of woodland, on a 24-percent, convex, southwest-facing slope at an elevation of 1414 m
Oi--0 to 3 cm; slightly decomposed needles, twigs, and grass
A--3 to 8 cm; ashy silt loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure parting to weak medium granular; soft, very friable, nonsticky and slightly plastic; many very fine and fine and common medium roots; many very fine irregular pores; strongly acid (pH 5.4); clear smooth boundary
Bw--8 to 41 cm; ashy silt loam, pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; weak medium subangular blocky structure parting to weak fine subangular blocky; soft, very friable, nonsticky and slightly plastic; many very fine, fine, and medium roots; many very fine irregular pores; strongly acid (pH 5.2); clear wavy boundary
2EBb--41 to 48 cm; very gravelly loam, light gray (10YR 7/2) dry, brown (10YR 5/3) moist; moderate fine subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; common very fine, fine, and medium roots; many fine tubular pores; 30 percent gravel and 15 percent cobbles; moderately acid (pH 5.8); abrupt wavy boundary
2Btb1--48 to 89 cm; very gravelly clay, light yellowish brown (10YR 6/4) dry, yellowish brown (10YR 5/4) moist; strong coarse subangular blocky structure parting to medium subangular blocky; very hard, very firm, sticky and very plastic; few very fine and fine roots; few fine tubular pores; many distinct clay films on faces of peds; 35 percent gravel, 5 percent cobbles, and 10 percent stones; moderately acid (pH 5.8); gradual wavy boundary
2Btb2--89 to 112 cm; very gravelly clay loam, very pale brown (10YR 7/4) dry, light yellowish brown (10YR 6/4) moist; strong coarse subangular blocky structure; hard, firm, sticky and very plastic; common distinct clay films on faces of peds; 40 percent gravel and 5 percent cobbles; moderately acid (pH 5.8); gradual wavy boundary
2Cr--112 cm; weathered tuff
TYPE LOCATION: Union County, Oregon; 536 m east and 191 m north of the southwest corner of section 8, T. 5 S, R. 36 E.; latitude 45.1396144, longitude -118.3347895, datum WGS 84 (coordinates estimated from PLSS details)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--6 to 7 degrees C
Mean summer soil temperature--10 to 12 degrees C
Soil moisture--usually moist, but dry 20 to 35 consecutive days
Depth to paralithic contact--100 to 150 cm
Depth to abrupt textural change--31 to 64 cm
Thickness of ash-influenced layers--36 to 51 cm
Estimated properties of layers influenced by volcanic ash
*Ammonium oxalate extractable Al + 1/2 Fe--2 to 3 percent
*0.02- to 2.0-mm fraction--45 to 55 percent
*Glass content in 0.02- to 2.0-mm fraction--10 to 25 percent
*1/3-bar bulk density--0.80 to 1.10 g/cm3
*Phosphate retention--60 to 85 percent
*15-bar water retention--5 to 15 percent (dried samples)
*Organic matter content--0.5 to 4.0 percent
Particle-size control section
*Clay content--5 to 10 percent in upper part, 35 to 50 percent in lower part
*Total rock fragment content--0 to 10 percent in upper part, 35 to 65 percent in lower part
A horizon
Hue--10YR
Value--3 or 4 moist, 5 or 6 dry
Chroma--2 to 4 moist or dry
Fine-earth texture--silt loam
Clay content--5 to 15 percent
Sand content--15 to 35 percent
Organic matter content--1 to 8 percent
Total rock fragment content--0 to 5 percent
Gravel content--0 to 5 percent
Reaction--5.1 to 6.5
Base saturation--40 to 70 percent
Thickness--5 to 33 cm
Bw horizon
Hue--10YR
Value--3 or 4 moist, 6 or 7 dry
Chroma--2 to 4 moist or dry
Fine-earth texture--ashy silt loam, ashy very fine sandy loam, ashy loam
Clay content--5 to 15 percent
Sand content--15 to 60 percent
Organic matter content--1 to 3 percent
Total rock fragment content--0 to 15 percent
Gravel content--0 to 15 percent
Reaction--5.1 to 6.5
Base saturation--40 to 70 percent
Thickness--10 to 36 cm
2EBb or 2Eb horizon
Hue--10YR, 7.5YR
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 or 3 moist or dry
Fine-earth texture--loam
Clay content--10 to 20 percent
Sand content--35 to 50 percent
Organic matter content--1 to 2 percent
Total rock fragment content--20 to 55 percent
Gravel content--10 to 40 percent
Cobble content--0 to 15 percent
Stone content--0 to 5 percent
Boulder content--0 to 5 percent
Reaction--5.6 to 6.5
Base saturation--60 to 75 percent
Thickness of 2EBb horizon--8 to 18 cm
2Btb1 horizon
Hue--7.5YR, 10YR, 2.5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--3 or 4 moist or dry
Fine-earth texture--clay, clay loam
Clay content--35 to 50 percent
Sand content--20 to 40 percent
Organic matter content--1 to 2 percent
Total rock fragment content--35 to 65 percent
Gravel content--15 to 60 percent
Cobble content--0 to 25 percent
Stone content--0 to 10 percent
Boulder content--0 to 10 percent
Reaction--5.6 to 7.3
Base saturation--60 to 75 percent
2Btb2 horizon
Hue--7.5YR, 10YR, 2.5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--3 or 4 moist or dry
Fine-earth texture--clay, clay loam
Clay content--35 to 50 percent
Sand content--20 to 40 percent
Organic matter content--1 to 2 percent
Total rock fragment content--35 to 70 percent
Gravel content--15 to 60 percent
Cobble content--5 to 20 percent
Stone content--0 to 10 percent
Boulder content--0 to 10 percent
Reaction--5.6 to 7.3
Base saturation--60 to 85 percent
Combined thickness of 2Btb horizon--15 to 89 cm
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--1100 to 1860 m
Climate--cool, wet winters; warm, moist summers
Mean annual precipitation--420 to 890 mm
Mean annual air temperature--4 to 7 degrees C
Frost-free period--30 to 100 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Bler--mollic surface; on side slopes of mountains
Flycreek--moderately deep; on toeslopes of mountains
Flyvalley--lithic; on shoulders of mountains
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Saturation during normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--moderately high or high over moderately low and moderately high
USE AND VEGETATION:
Use--timber production, watershed, recreation, wildlife habitat
Potential native vegetation--grand fir, Engelmann spruce, Douglas-fir, western larch, ponderosa pine, lodgepole pine, subalpine fir, Douglas maple, northern twinflower, big huckleberry, grouse huckleberry, heartleaf arnica, singleleaf pinyon, pinegrass, elk sedge, baldhip rose, western meadow-rue, prince's pine, Columbia brome, darkwoods violet, northwestern sedge, pathfinder, starry false Solomon's seal, white hawkweed, sidebells wintergreen, western rattlesnake plantain, longtube twinflower
DISTRIBUTION AND EXTENT: Northeastern Oregon; MLRA 10; small extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wallowa County, Oregon; 1998
REMARKS:
Diagnostic horizons and other features recognized in this pedon
*Ochric epipedon
*Argillic horizon--zone from 44 to 112 cm
*Cambic horizon--zone from 8 to 41 cm
*Volcanic glass--zone from 3 to 41 cm
*Andic soil properties--zone from 3 to 41 cm
*Depth to lithologic discontinuity--48 cm
*Particle-size control section--zone from 3 to 103 cm
National Cooperative Soil Survey
U.S.A.