LOCATION BROWDER                 OR

Tentative Series
JGM/KMS
01/2017

BROWDER SERIES

Landscape--western Cascade Mountains
Landform--mountain slopes, structural benches, earthflows with some on complex landslides
Slope--0 to 90 percent
Parent material--colluvium and earthflow deposits derived from igneous rock with volcanic ash mixed in upper part
Depth class--very deep
Drainage class--well drained
Mean annual precipitation--2100 mm
Mean annual air temperature--about 7 degrees C
Soil moisture regime--udic
Soil temperature regime--frigid
Soil moisture subclass--typic

TAXONOMIC CLASS: Fine-loamy, isotic, frigid Andic Humudepts

TYPICAL PEDON: Browder gravelly medial silt loam on a forested, 4-percent slope at an elevation of 780 m (The soil was moist throughout when described on July 17, 2014.)

Oe--0 to 6 cm; moderately decomposed plant material; clear smooth boundary

A--6 to 13 cm; gravelly medial silt loam, brown (10YR 5/3) dry, very dark grayish brown (10YR 3/2) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine to very coarse roots; many fine irregular and tubular pores; 20 percent tuff gravel; strongly acid (pH 5.4); gradual smooth boundary

BA--13 to 38 cm; gravelly medial silt loam, brown (7.5YR 5/4) dry, dark brown (7.5YR 3/3) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine to very coarse roots; many fine irregular and tubular pores; 20 percent tuff gravel; strongly acid (pH 5.2); clear smooth boundary

2Bw1--38 to 60 cm; silt loam, brown (7.5YR 5/4) dry, dark brown (7.5YR 3/4) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and common medium to very coarse roots; many fine irregular pores and common fine tubular pores; 10 percent tuff gravel; strongly acid (pH 5.2); gradual wavy boundary

2Bw2--60 to 88 cm; silt loam, brown (7.5YR 5/4) dry, dark brown (7.5YR 3/4) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine to very coarse roots; many fine irregular pores and common fine tubular pores; 10 percent tuff gravel; very strongly acid (pH 5.1); gradual wavy boundary

2Bw3--88 to 150 cm; silt loam, brown (7.5YR 5/4) dry, dark brown (7.5YR 3/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine to very coarse roots; many fine irregular pores and common fine tubular pores; 10 percent tuff gravel; very strongly acid (pH 5.1)

TYPE LOCATION: Linn County, Oregon, 2 km northwest of Mount Bruno; 750 m south and 790 m east of the northwest corner of section 30, T. 10 S., R. 7 E.; latitude 44.6772222, longitude -121.9992500, 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--5 to 8 degrees C
Thickness of umbric epipedon--25 to 50 cm (below mineral soil surface)
Reaction--5.1 to 6.0 throughout all mineral horizons
Thickness of andic soil properties--18 to 34 cm (below mineral soil surface)

Estimated properties of layers with andic soil properties
*1/3-bulk density--0.70 to 0.90 g/cm3
*Phosphate retention--greater than 85 percent
*Ammonium oxalate extractable Al + Fe--2.0 to 4.0 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 in 0.02- to 2.0-mm fraction--5 to 30 percent

Particle-size control section
*Clay content--18 to 35 percent
*Total fragment content--0 to 35 percent
*Total parafragment content--0 to 10 percent in lower part

O horizon
*Thickness--0 to 10 cm

A and BA horizons
*Hue--10YR, 7.5YR
*Value--2 or 3 moist, 3 to 5 dry
*Chroma--2 or 3 moist or dry
*Fine-earth texture--medial silt loam, medial loam
*Clay content--18 to 27 percent
*Sand content--15 to 40 percent
*Total fragment content--0 to 35 percent
*Gravel content--0 to 30 percent
*Cobble content--0 to 10 percent
*Combined thickness--18 to 34 cm

2Bw1 horizon
*Hue--10YR, 7.5YR
*Value--3 or 4 moist, 4 or 5 dry
*Chroma--2 or 3 moist or dry
*Fine-earth texture--silt loam, loam
*Clay content--18 to 27 percent
*Sand content--15 to 40 percent
*Total fragment content--0 to 35 percent
*Gravel content--0 to 30 percent
*Cobble content--0 to 10 percent
*Thickness--0 to 25 cm

2Bw2 and 2Bw3 horizons
*Hue--10YR, 7.5YR
*Value--4 or 5 moist, 5 or 6 dry
*Chroma--3 to 6 moist or dry
*Fine-earth texture--silt loam, loam, clay loam
*Clay content--18 to 35 percent
*Sand content--15 to 40 percent
*Total fragment content--0 to 35 percent
*Gravel content--0 to 30 percent
*Cobble content--0 to 10 percent
*Paragravel content--0 to 10 percent

COMPETING SERIES:
Oldblue--50 to 100 cm to paralithic contact; no volcanic ash in epipedon
Wilhoit, Xeno--100 to 150 cm to paralithic contact

GEOGRAPHIC SETTINGS:
Elevation--700 to 1200 m
Climate--warm, dry summers; cool, wet winters
Mean annual precipitation--1900 to 2300 mm
Mean annual air temperature--6 to 9 degrees C
Frost-free period--90 to 135 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Cadenza--greater than 35 percent rock fragments throughout; on mountain slopes
Coffin--andic soil properties throughout; on complex earthflows
Menagerie--andic soil properties throughout; in similar landform 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 or high

USE AND VEGETATION:
Use--timber production, wildlife habitat, recreation
Potential natural vegetation--Douglas-fir, western hemlock, Pacific rhododendron, dwarf Oregon grape, salal, western swordfern, vanilla leaf, twinflower, bunchberry dogwood; commonly supports a western hemlock/dwarf Oregon grape-salal-Northwest Oregon Cascades (CHS160) plant association

DISTRIBUTION AND EXTENT: 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; 2016; name from Browder Ridge

REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 31 to 106 cm
*Umbric epipedon--zone from 6 to 38 cm
*Cambic horizon--zone from 38 to 150 cm
*Andic soil properties--zone from 6 to 38 cm
*Volcanic glass--zone from 6 to 38 cm
*Depth to lithologic discontinuity--38 cm

8/2016--Layers with andic soil properties are assumed to meet criteria 2 (no ash required) in the 12th edition of Keys to Soil Taxonomy. It is also assumed that enough ash is present for those layers to meet criteria 3. Additional lab data is needed to confirm the degree of ash influence.

ADDITIONAL DATA: Type location user site ID--2014OR043531

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National Cooperative Soil Survey
U.S.A.