LOCATION DORENA OR
Tentative Series
DCR/MPR
12/2024
DORENA SERIES
Landscape--central western Cascade mountains
Landform--complex landslides, plateaus
Slope--0 to 30 percent
Parent material--residuum weathered from volcanic rocks
Mean annual precipitation--about 1700 mm
Mean annual air temperature--about 8.5 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--mesic
Soil moisture subclass--typic
TAXONOMIC CLASS: Fine, isotic, mesic Andic Haplohumults
TYPICAL PEDON: Dorena gravelly silt loam, on a complex landslide with a slope of 10 percent and an elevation of 598 m
Oi--0 to 6 cm; slightly decomposed plant material; abrupt smooth boundary
A1--6 to 16 cm; gravelly silt loam, brown (7.5YR 5/3) dry, dark reddish brown (5YR 3/2) moist; weak fine granular structure; soft, loose , slightly sticky, slightly plastic; many very fine and medium and common fine roots; many very fine interstitial pores; 30 percent gravel and 10 percent paragravel; strongly acid (pH 5.2); abrupt wavy boundary
A2--16 to 30 cm; silt loam, brown (7.5YR 4/4) dry, dark reddish brown (5YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; many very fine and medium and common fine and coarse roots; common very fine dendritic tubular pores; 8 percent gravel and 5 percent paragravel; strongly acid (pH 5.2); clear wavy boundary
AB--30 to 43 cm; silty clay loam, reddish brown (5YR 4/4) dry, dark reddish brown (5YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky, moderately plastic; few fine and common very fine, medium, and coarse roots; common very fine dendritic tubular pores; 1 percent paragravel; strongly acid (pH 5.2); clear wavy boundary
Bt1--43 to 85 cm; silty clay, yellowish red (5YR 4/6) dry, dark reddish brown (5YR 3/4) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky, moderately plastic; common very fine and medium and few coarse roots; common very fine dendritic tubular pores; 20 percent dark reddish brown (5YR 3/4), moist, clay films on all faces of peds; strongly acid (pH 5.2); clear smooth boundary
Bt2--85 to 110 cm; silty clay, yellowish red (5YR 4/6) dry, reddish brown (5YR 4/4) moist; 5 percent medium light yellowish brown (10YR 6/4) mottles; moderate coarse subangular blocky structure; hard, friable, moderately sticky, moderately plastic; common very fine and few medium roots; common very fine dendritic tubular pores; 20 percent reddish brown (5YR 4/4), moist, clay films on all faces of peds; very strongly acid (pH 5.0); gradual smooth boundary
Bt3--110 to 150 cm; silty clay loam, yellowish red (5YR 4/6) dry, dark reddish brown (2.5YR 3/4) moist; 20 percent coarse white (5YR 8/1) mottles; weak very coarse subangular blocky structure; very hard, friable, moderately sticky, moderately plastic; few very fine roots; few very fine dendritic tubular pores; 10 percent dark reddish brown (2.5YR 3/4), moist, clay films on all faces of peds; very strongly acid (pH 4.8); gradual smooth boundary
TYPE LOCATION: Lane County, Oregon, about 12 km east of Lowell in Willamette National Forest; 500 m north and 170 m east of the southwest corner of section 18, T. 19 S., R. 2 E., Willamette Meridian; latitude 43.91459, longitude -122.62490, datum WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--8 to 11 degrees C
Thickness of umbric epipedon--25 to 50 cm
Depth to bedrock--greater than 150 cm
Reaction--pH 4.5 to 5.5
Properties of layers meeting andic subgroup criteria
*1/3-bar bulk density--0.7 to 1.0 g/cm3
*Ammonium oxalate Al plus 1/2 Fe--1 to 2 percent
*Phosphate retention--50 to 100 percent
*Volcanic glass in the coarse silt fraction--0 to 5 percent
*Thickness--18 to 50 cm
Particle-size control section (weighted average)
*Clay content--35 to 50 percent
*Total fragment content--0 to 15 percent
Oi horizon
*Thickness--0 to 6 cm
A horizons
*Hue--5YR, 7.5YR, 10YR
*Value--2 to 3 moist, 4 or 5 dry
*Chroma--1 to 3 moist, 2 to 4 dry
*Fine-earth texture--silt loam, loam
*Clay content--18 to 27 percent
*Total fragment content--5 to 50 percent
*Gravel content--5 to 35 percent
*Paragravel content--0 to 15 percent
*Organic carbon content--2 to 7 percent
*Combined thickness--18 to 36 cm
AB horizon
*Hue--7.5YR, 5YR
*Value--3 or 4 moist, 4 or 5 dry
*Chroma--3 or 4 moist or dry
*Fine-earth texture--silty clay loam, clay loam
*Clay content--27 to 35 percent
*Total fragment content--0 to 15 percent
*Gravel content--0 to 5 percent
*Cobble content--0 to 5 percent
*Paragravel content--0 to 10 percent
*Organic carbon content--1.5 to 3 percent
*Thickness--10 to 20 cm
Bt1 and Bt2 horizons
*Hue--7.5YR, 10YR, 2.5YR
*Value--3 or 4 moist and dry
*Chroma--4 to 6 moist or dry
*Fine-earth texture--silty clay, clay, silty clay loam
*Clay content--35 to 50 percent
*Total fragment content--0 to 15 percent
*Gravel content--0 to 5 percent
*Cobble content--0 to 5 percent
*Paragravel content--0 to 15 percent
*Organic carbon content--0.2 to 1.5 percent
*Combined thickness--50 to 100 cm
Bt3 horizon
*Hue--7.5YR, 10YR, 2.5YR
*Value--3 or 4 moist and dry
*Chroma--4 to 6 moist or dry
*Fine-earth texture--silty clay loam, clay loam
*Clay content--27 to 40 percent
*Total fragment content--0 to 35 percent
*Gravel content--0 to 5 percent
*Cobble content--0 to 5 percent
*Paragravel content--0 to 35 percent
*Organic carbon content--0.1 to 0.5 percent
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--240 to 790 m
Climate--mild, wet winters; warm, dry summers
Mean annual precipitation--1500 to 1900 mm
Mean annual air temperature--7 to 10 degrees C
Frost-free period--120 to 180 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Dutchoven--greater than 150 cm to bedrock; umbric epipedon; located on mountain slopes
Mooseridge--aquic conditions within 50 to 100 cm; located on complex landslides
Kinney--18 to 35 percent clay in the particle-size control section; located on complex landslides and mountain slopes
Jory--xeric soil moisture regime; located on foothills and plateaus
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--moderately low
USE AND VEGETATION:
Use--timber production, recreation, wildlife habitat
Potential natural vegetation--Douglas-fir, western hemlock, bigleaf maple, Cascade barberry, salal, and western swordfern; commonly supports a western hemlock/dwarf Oregon grape-salal (CHS160) plant association (see Field Guide to the Forested Plant Associations of the Westside Central Cascades of Northwest Oregon)
DISTRIBUTION AND EXTENT: Central western Cascade Mountains, Oregon; MLRA 3; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Willamette National Forest, Lane County, Oregon; 2022; Dorena is a placename in Lane County
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 43 to 93 cm
*Umbric epipedon--zone from 6 to 43 cm
*Argillic horizon--zone from 43 to 150 cm
*Andic subgroup feature--zone from 6 to 30 cm
5/2023--laboratory data for geographically associated soils support andic subgroup criteria in the 13th edition of Keys to Soil Taxonomy.
ADDITIONAL DATA: Characterization data from pedon 19N0445 from Linn County, Oregon, is available from the NRCS-NSSC-Kellogg Soil Survey Laboratory, Lincoln, NE, 5/2018 . Typical pedon ID--2019OR039767
National Cooperative Soil Survey
U.S.A.