LOCATION ASCHOFF                 OR+WA

Established Series
Rev. AON/JGM/KMS
01/2017

ASCHOFF SERIES

Landscape--western Cascade Mountains
Landform--mountain slopes, complex landslides, alluvial fans, drainageways of mountain slopes
Slope--5 to 90 percent
Parent material--colluvium and slide deposits derived from igneous rock mixed with volcanic ash in upper part
Mean annual precipitation--2200 mm
Mean annual air temperature--10 degrees C
Depth class-- very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--mesic
Soil moisture subclass--typic

TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Andic Humudepts

TYPICAL PEDON: Aschoff cobbly medial loam, forested

Oi--0 to 8 cm; slightly decomposed litter of needles, twigs, and cones

Oe--8 to 10 cm; moderately decomposed plant material, black (10YR 2/1) moist; abrupt smooth boundary

A--10 to 25 cm; cobbly medial loam, brown (7.5YR 4/2) dry, dark brown (7.5YR 3/2) moist; moderate fine and very fine subangular blocky structure; very dark brown (10YR 2/2) ped surfaces; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine and fine irregular and tubular pores; 15 percent cobbles and 15 percent gravel; moderately acid (pH 5.7); clear wavy boundary

AB--25 to 41 cm; cobbly medial loam, brown (7.5YR 4/3) dry, dark brown (7.5YR 3/3) moist; moderate fine and very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; many very fine and fine irregular and tubular pores; 15 percent cobbles and 15 percent gravel; moderately acid (pH 5.8); clear wavy boundary

2Bw--41 to 69 cm; very cobbly loam, brown (7.5YR 4/4) dry, dark brown (7.5YR 3/4) moist; moderate fine and very fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common roots; many very fine and fine irregular and tubular pores; 25 percent cobbles, 15 percent gravel, and 10 percent stones; moderately acid (pH 5.9); gradual wavy boundary

2BC--69 to 97 cm; very cobbly loam, brown (7.5YR 4/4) dry, dark brown (7.5YR 3/4) moist; weak very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common roots; many very fine and fine irregular and tubular pores; 25 percent cobbles, 20 percent gravel, and 10 percent stones; moderately acid (pH 6.0); gradual wavy boundary

2C--97 to 160 cm; very cobbly loam, brown (7.5YR 5/4) dry, brown (7.5YR 4/4) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; common roots; many very fine and fine irregular and tubular pores; 30 percent cobbles, 5 percent stones, and 20 percent gravel; slightly acid (pH 6.2)

TYPE LOCATION: Multnomah County, Oregon; along Palmer Mill Road; in the SE1/4SW1/4SE1/4 of section 22, T. 1 N., R. 5 E.; latitude 45.5491540, longitude -122.1719534, datum WGS 84 (coordinates estimated from PLSS details)

RANGE IN CHARACTERISTICS:
Dry days--less than 45 consecutive days following summer solstice
Mean annual soil temperature--8 to 13 degrees C
Thickness of umbric epipedon--25 to 50 cm (below mineral soil surface)
Reaction--5.0 to 6.5
Thickness of andic soil properties--18 to 34 cm (below mineral soil surface)

Estimated properties of layers with andic soil properties
*1/3-bar bulk density--0.70 to 0.90 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--10 to 27 percent
*Total fragment content--35 to 70 percent

O horizon
*Thickness--3 to 10 cm

A and AB horizons
*Hue--10YR, 7.5YR
*Value--2 or 3 moist, 4 or 5 dry
*Chroma--1 to 3 moist or dry
*Fine-earth texture--medial loam, medial silt loam
*Clay content--7 to 27 percent
*Sand content--25 to 50 percent
*Total fragment content--20 to 50 percent
*Gravel content--0 to 40 percent
*Cobble content--0 to 30 percent
*Stone content--0 to 10 percent
*Reaction--5.1 to 6.0
*Combined thickness--18 to 36 cm

2Bw horizon
*Hue--10YR, 7.5YR
*Value--3 or 4 moist, 4 to 6 dry
*Chroma--3 or 4 moist or dry
*Fine-earth texture--loam, silt loam
*Clay content--10 to 27 percent
*Sand content--30 to 50 percent
*Total fragment content--35 to 70 percent
*Gravel content--15 to 40 percent
*Cobble content--15 to 45 percent
*Stone content--0 to 10 percent
*Reaction--5.1 to 6.5
*Thickness--15 to 45 cm

2BC and 2C horizons
*Hue--10YR, 7.5YR
*Value--3 or 5 moist, 5 to 7 dry
*Chroma--3 or 4 moist or dry
*Fine-earth texture--loam, silt loam
*Clay content--10 to 27 percent
*Sand content--30 to 50 percent
*Total fragment content--50 to 80 percent
*Gravel content--20 to 50 percent
*Cobble content--20 to 55 percent
*Stone content--0 to 15 percent
*Reaction--5.1 to 6.5
*Thickness of 2BC horizon--15 to 45 cm

COMPETING SERIES:
Damewood--50 to 100 cm deep to lithic bedrock
Hoodview--umbric epipedon greater than 50 cm thick
Norby--no cobbles; sand or loamy sand textures within particle-size control section

GEOGRAPHIC SETTING:
Elevation--30 to 850 m
Climate--warm, wet winters; hot, moist summers
Mean annual precipitation--1500 to 2900 mm
Frost-free days--100 to 200 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Bull Run--not skeletal; dominantly pyroclastic material
Headly--not skeletal in particle-size control section; ochric epipedon
Sahalie--ochric epipedon; firm, hard C horizon
Hoodview--umbric epipedon greater than 50 cm thick

DRAINAGE AND PERMEABILITY:
Drainage class--well drained
Saturation in normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--moderately high

USE AND VEGETATION:
Use--timber production, watershed, recreation, wildlife habitat
Potential natural vegetation--Douglas-fir, western hemlock, western red alder, Oregon oxalis, salal, swordfern, vine maple

DISTRIBUTION AND EXTENT: Cascade Mountains in northwestern Oregon and southwestern Washington; MLRA 3; moderate extent

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Multnomah County, Oregon; 1975

REMARKS:
Diagnostic horizons and features recognized in this pedon
*Umbric epipedon--zone from 10 to 41 cm
*Cambic horizon--zone from 41 to 97 cm
*Andic soil properties--zone from 10 to 41 cm
*Volcanic glass--zone from 10 to 41 cm
*Depth to lithologic discontinuity--41 cm
*Particle-size control section--zone from 35 to 110 cm

7/2016--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. The type location was moved to the taxonomic unit description (TUD) in the Multnomah County, Oregon, manuscript. It could not be determined why the TUD type location was different than that of the OSD. The Multnomah County TUD had the same pedon profile description as the OSD; thus, it appeared to be a better location. The type location in the unedited OSD read "Multnomah County, Oregon, along Cougar Creek Road; in the NW1/4NW1/4 of section 17, T. 1 S., R. 6 E." The GIS roads layer for Multnomah County did not have a Cougar Creek Road.

6/1998--Classification changed from loamy-skeletal, mixed, mesic Andic Haplumbrepts to loamy-skeletal, isotic, mesic Andic Dystrudepts. Additional data on andic soil properties is needed to confirm the classification of the andic subgroup or Andisols order. The frigid counterpart of this series is the Zygore series; it should also be investigated.

It is not known when the classification was changed from Dystrudepts to Humudepts.

ADDITIONAL DATA:
Partial characterization data-profiles FS63Oreg-045-32(1-6), FS63Oreg-045-31(1-6), and FS62Oreg-045-11(1-6) by Oregon State University (unpublished)

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National Cooperative Soil Survey
U.S.A.