LOCATION TAMARA OREstablished Series
TAXONOMIC CLASS: Ashy over loamy, amorphic over isotic, frigid Alfic Udivitrands
TYPICAL PEDON: Tamara ashy silt loam, woodland, on a 20 percent east-facing slope at an elevation of 4,660 feet. (Colors are for moist soil unless otherwise noted.)
Oe--0 to 1 inch; decomposed leaves, needles, and twigs.
A--1 to 6 inches; brown (10YR 5/3) ashy silt loam, yellowish brown (10YR 5/4) dry; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many fine and few medium roots; common fine irregular pores; moderately acid (pH 6.0); clear wavy boundary. (3 to 9 inches thick).
Bw1--6 to 13 inches; brown (10YR 5/3) ashy silt loam, light yellowish brown (10YR 6/4) dry; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many fine and few medium and coarse roots; few fine and medium tubular pores; moderately acid (pH 6.0); gradual smooth boundary.
Bw2--13 to 22 inches; yellowish brown (10YR 5/4) ashy silt loam, very pale brown (10YR 7/4) dry; weak fine and medium angular blocky structure; soft, very friable, nonsticky and nonplastic; common fine and few medium and coarse roots; few fine tubular pores; moderately acid (pH 6.0); abrupt irregular boundary. (Combined thickness of the Bw horizon is 14 to 35 inches.)
2EBb--22 to 30 inches; brown (7.5YR 4/4) loam, light brown (7.5YR 6/4) dry; weak to moderately fine and medium subangular blocky structure; soft, friable, nonsticky and nonplastic; common fine and few medium roots; common fine tubular pores; 5 percent gravel; moderately acid (pH 6.0); gradual smooth boundary. (0 to 11 inches thick.)
2Btb1--30 to 45 inches; reddish brown (5YR 4/4) gravelly loam, reddish brown (5YR 5/4) dry; weak coarse subangular blocky structure parting to weak fine subangular blocky; hard, firm, slightly sticky and slightly plastic; few faint clay films on ped faces; few fine and medium roots; few very fine tubular pores; 15 percent gravel; slightly acid (pH 6.5); gradual smooth boundary. (9 to 15 inches thick.)
2Btb2--45 to 62 inches; reddish brown (5YR 4/4) clay loam, reddish brown (5YR 5/4) dry; moderate fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few faint clay films on ped faces; few fine roots; few very fine tubular pores; 10 percent gravel; neutral (pH 7.0.)
TYPE LOCATION: Union County, Oregon, Section 36, T. 3 S., R. 33 E. (45 degrees, 15 minutes, 15 seconds N. Latitude; 118 degrees, 40 minutes, 22 seconds W. Longitude).
RANGE IN CHARACTERISTICS:
Soil moisture - usually moist but are dry for 30 to 45 consecutive days
Mean annual soil temperature - 42 to 46 degrees F
Upper part of the particle-size control section - 5 to 10 percent clay (apparent field texture) and 0 to 10 percent rock fragments
Lower part of the particle-size control section - 20 to 35 percent clay and 5 to 30 percent rock fragments
Depth to bedrock - greater than 60 inches
Volcanic ash mantle - 20 to 35 inches thick
Particles of 0.02 to 2.0 mm - 45 to 55 percen
Organic matter - 1 to 5 percent
Acid-oxalate A1 plus 1/2 Fe - 2 to 3 percent
Phosphate retention - 40 to 75 percent
Glass content - 10 to 25 percent
15-bar water retention on air-dried sample - 5 to 15 percent
A horizon
Hue - 10YR or 7.5YR
Value - 4 or 5 moist, 5 or 6 dry
Chroma - 3 or 4 moist and dry
Texture - ashy SIL or ashy VFSL
Rock fragments - 0 to 10 percent total with 0 to 10 percent gravel
Clay - 5 to 15 percent
Reaction - 5.6 to 6.5
Bw horizon
Hue - 10YR or 7.5YR
Value - 4 to 6 moist, 6 to 8 dry
Chroma - 3 to 6 moist and dry
Texture - ashy SIL or ashy VFSL
Rock fragments - 0 to 10 percent total with 0 to 10 percent gravel
Clay - 5 to 15 percent
Reaction - 5.6 to 6.5
2EBb horizon
Hue - 7.5YR
Value - 3 or 4 moist, 5 or 6 dry
Chroma - 2 to 4 moist and dry
Texture - L
Rock fragments - 5 to 15 percent total with 5 to 10 percent gravel and 0 to 5 percent cobbles
Clay - 15 to 20 percent
Reaction - 5.6 to 6.5
2Btb1 horizon
Hue 5YR or 7.5YR
Value 3 or 4 moist, 5 or 6 dry
Chroma - 3 or 4 moist and dry
Texture - GR-L, CL, L, GR-CL, SICL
Rock fragments - 5 to 30 percent total with 5 to 20 percent gravel and 0 to 10 percent cobbles
Clay - 20 to 35 percent
Reaction - 5.6 to 6.5
2Btb2 horizon
Similar color as 2Btb1
Texture - CL, GR-CL, SICL, GR-SICL, L
Rock fragments - 5 to 30 percent total with 5 to 25 percent gravel and 0 to 5 percent cobbles
Clay - 25 to 35 percent
Reaction 6.1 to 7.3
COMPETING SERIES: These are Dowper, Jacot, Mackatie, Secunda (T), Tomodo, and Turpentine (T) series.
Dowper soils - ash mantle 14 to 18 inches thick; 5 to 50 percent soft gravel in the 2Bt horizon
Jacot soils - 40 to 60 percent glass in the ash mantle; solum thickness of 36 to 52 inches; and a lower particle-size control section dominated by gneiss and granitic type rock fragments
Mackatie soils - 40 to 60 inches to a paralithic contact; ash mantle 14 to 20 inches thick with 30 to 50 percent glass
Secunda soils - lower pscs with 6 to 21 percent clay, 0 to 5 percent mica, and greater than 15 percent coarse and very coarse sand and greater than 40 percent very fine and fine sand
Tomodo soils - fragic properties at a depth of 20 to 51 inches; have 2E/B and 2B/E horizons
Turpentine soils - lower pscs has 12 to 18 percent clay; 40 to 70 inches to paralithic contact (sandstone)
GEOGRAPHIC SETTING: Tamara soils occur on dissected basalt plateaus, canyons, and back slopes of mountains. Elevations are 2,800 to 5,800 feet. Slopes are 0 to 60 percent. The soil is formed in a mantle of volcanic ash overlying material derived from a mixture of loess and colluvium and residuum from basalt. The climate is characterized by cold, wet winters and cool, moist summers. The mean annual precipitation is 20 to 40 inches but can range to 16 inches on north-facing slopes. The mean annual air temperature is 41 to 45 degrees F. The frost-free period is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Geisercreek and Syrupcreek soils. Geisercreek soils have clayey materials below the ash and are on similar landscape positions. Syrupcreek soils are ashy over loamy-skeletal, moderately deep and are associated with a more convex position and steeper slopes and the canopy is more open.
DRAINAGE AND PERMEABILITY: Well drained; permeability is moderately slow in the lower layers
USE AND VEGETATION: These soils are used for watershed, wildlife habitat, timber production, livestock grazing and recreation. The native vegetation is grand fir, Engleman spruce, Douglas fir, western larch, ponderosa pine, lodgepole pine, twinflower, big huckleberry, baldhip rose, prince's pine, queen's cup beadlily, roundleaf violet, rattlesnake plantain, western meadowrue, white-vein pyrola, sidebells pyrola, pathfinder, western hawkweed, pinegrass and northwestern sedge.
DISTRIBUTION AND EXTENT: Blue Mountains of northeastern Oregon; MLRA 43c. The soils are of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wallowa County, Oregon 1998.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Cambic horizon - from 6 to 22 inches (Bw1 and Bw2 horizon)
Argillic horizon - from 30 to 62 inches (2Btb1 and 2Btb2 horizons)
Ash mantle - from 1 to 22 inches
The dominant USFS plant association is ABGR/LIBO2; others may include ABGR/CLUN and ABGR/VAME