LOCATION TIDBITS OR
Tentative Series
JGM/KMS
01/2017
TIDBITS SERIES
Landscape--western Cascade Mountains
Landform--earthflows with some on complex landslides
Slope--0 to 30 percent
Parent material--slide deposits derived from soft tuff mixed with till and volcanic ash
Mean annual precipitation--about 1700 mm
Mean annual air temperature--about 9 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--mesic
Soil moisture subclass--typic
TAXONOMIC CLASS: Medial, amorphic, mesic Typic Hapludands
TYPICAL PEDON: Tidbits medial loam on a southeast-facing, 8-percent slope of a forested complex landslide at an elevation of 454 m (The soil was dry throughout when described on September 9, 2014.)
Oe--0 to 3 cm; moderately decomposed plant material; abrupt wavy boundary
A--3 to 11 cm; medial loam, dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine to medium and common coarse and very coarse roots; many fine tubular and irregular pores; 10 percent igneous gravel; moderately acid (pH 5.6); abrupt wavy boundary
BA--11 to 49 cm; medial loam, brown (10YR 5/3) dry, dark brown (7.5YR 3/3) moist; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine to medium and common coarse and very coarse roots; many fine tubular and irregular pores; 10 percent igneous gravel; moderately acid (pH 5.6); abrupt wavy boundary
Bw--49 to 150 cm; cobbly medial silt loam, light yellowish brown (10YR 6/4) dry, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine to coarse roots; many fine tubular and irregular pores; 15 percent igneous gravel and 15 percent igneous cobbles; moderately acid (pH 5.8)
TYPE LOCATION: Linn County, Oregon, 1070 m northeast of Upper Soda, along Upper Soda Road (Forest Service Road 2041); 260 m south and 555 m west of the northeast corner of section 25, T. 13 S., R. 4 E.; latitude 44.4125527, longitude -122.2706246, datum WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Dry days--30 to 45 consecutive days following summer solstice
Mean annual soil temperature--7 to 9 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--greater than 150 cm (below mineral soil surface)
Estimated properties of layers with andic soil properties
*1/3-bar bulk density--0.7 to 0.9 g/cm3
*Phosphate retention--greater than 85 percent
*Ammonium oxalate extractable Al + 1/2 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 fragment content--0 to 35 percent
O horizon
*Thickness--0 to 6 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 loam, medial silt loam
*Clay content--18 to 27 percent
*Sand content--25 to 45 percent
*Total fragment content--0 to 25 percent
*Gravel content--0 to 25 percent
*Cobble content--0 to 5 percent
*Thickness--25 to 50 cm
Bw horizon
*Hue--10YR, 7.5YR
*Value--3 to 5 moist, 4 to 6 dry
*Chroma--3 to 6 moist or dry
*Fine-earth texture--medial loam, medial silt loam
*Clay content--18 to 27 percent
*Sand content--20 to 45 percent
*Total fragment content--0 to 35 percent
*Gravel content--0 to 30 percent
*Cobble content--0 to 20 percent
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--200 to 700 m
Climate--warm, wet winters; hot, dry summers
Mean annual precipitation--1500 to 1900 mm
Mean annual air temperature--8 to 10 degrees C
Frost-free period--120 to 150 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Aschoff--greater than 35 percent rock fragments; andic soil properties only in upper 34 cm; on steeper side slopes
Husky--poorly drained; in sags of complex landslides
Kinney--andic soil properties only in upper 34 cm; on mountain slopes and landslides with no glacially worked material
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation in normal years--below a depth of 200 cm
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, salal, dwarf Oregon grape, vine maple, red huckleberry, Oregon oxalis, western swordfern, Pacific trillium
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 Tidbits Mountain
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 3 to 103 cm
*Umbric epipedon--zone from 3 to 49 cm
*Cambic horizon--zone from 49 to 150 cm
*Andic soil properties--zone from 3 to 150 cm
*Volcanic glass--zone from 3 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. Samples should also be collected to determine if the soils meet the criteria for the Alic Hapludand or Eutric Hapludand subgroup.
ADDITIONAL DATA: Type location user site ID--2014OR043053
National Cooperative Soil Survey
U.S.A.