LOCATION TREEN WAEstablished Series
TAXONOMIC CLASS: Medial, amorphic Lithic Haplocryands
TYPICAL PEDON: Treen medial loam, on a valley wall landform with a smooth south facing slope of 50 percent with herbaceous vegetation. (Colors are for moist soil unless otherwise noted)
0i--0 to 5 cm; matted herbaceous plant material; fibrous.
A1--5 to 18 cm; very dark grayish brown(10YR 3/2)medial loam, brown(10YR 5/3) dry; weak fine and medium granular structure; soft, very friable, slightly sticky, slightly plastic, and moderately smeary; many very fine and fine roots; common very fine irregular pores; 10 percent gravel; 25 percent by volume organic fibers; moderately acid (pH 5.6); NaF pH 10.5; abrupt smooth boundary.
A2--18 to 40 cm; dark brown (7.5YR 3/2)medial sandy loam, brown (7.5YR 4/2) dry; moderate fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic, and weakly smeary; common very fine, fine, medium, and coarse roots; common fine irregular pores; 10 percent gravel; strongly acid (pH 5.4); NaF pH 12.0; clear smooth boundary.
Bw--40 to 51 cm; brown (7.5YR 5/4) gravelly medial sandy loam, light yellowish brown (10YR 6/4) dry; weak medium granular structure; slightly hard, very friable, slightly sticky, slightly plastic, and weakly smeary; few fine and medium roots; common fine irregular pores; 25 percent gravel; moderately acid (pH 5.8); NaF pH 11.5; abrupt smooth boundary.
R--51 cm; schist bedrock
TYPE LOCATION: Snoqualmie Pass, King County, Washington; near Captain Point; 800 feet north and 2,500 feet east of the southeast corner, sec. 6, T. 26 N., R. 13 E. Willamette Meridian.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 1 to 8 degrees C, Cryic temperature regime.
Moisture control section: dry for less than 30 consecutive days following the summer solstice. Udic soil moisture regime.
Depth to a lithic contact: 25 to 50 centimeters from the mineral surface.
Particle-size control section:
Moist bulk density - 0.65 to 1.25 g/cc
Volcanic glass content - 30 to 65 percent
Ammonium oxalate extractable aluminum plus one-half iron - more than 2.0 percent.
15-bar water retention - 12 to 30 percent for air dried samples.
A horizons:
Hue - 10YR or 7.5YR
Value - 2 or 3 moist, 4 or 5 dry
Chroma - 1 to 3 moist or dry
Fine earth textures - medial SL, medial FSL, medial L
Rock Fragments - 0 to 30 percent total
0 to 15 percent gravel
0 to 10 percent cobbles
0 to 5 percent stones
Clay content - 2 to 10 percent
Thickness - 20 to 40 centimeters
Reaction - slightly acid to strongly acid
Bw horizon:
Hue - 10YR, 7.5YR, or 2.5Y
Value - 3 to 6 moist, 4 to 7 dry
Chroma - 2 to 6 moist or dry
Fine earth textures - medial SL, medial FSL, medial L
Rock Fragments - 0 to 40 percent total
0 to 25 percent gravel
0 to 15 percent cobbles
0 to 5 percent stones
Clay content - 2 to 10 percent
Thickness - 5 to 30 centimeters
Reaction - slightly acid to strongly acid
COMPETING SERIES: There are no competing series in this family. The Buckman, Bungalow, Constance, Graves, Weatherwax, and Yellowstone series are in a similar family. All these soils are medial-skeletal and have ferrihydritic mineralogy.
GEOGRAPHIC SETTING: Treen soils are on valley walls, ridges, and cirque basins at elevations of 1,000 to 1,900 meters. The areas where these soils occur are sometimes referred to as mountain meadows. Slopes range from 0 to 90 percent. These soils formed in volcanic ash mixed with residuum and colluvium. The mean annual air temperature is 0 to 7 degrees C. Mean annual precipitation ranges from 1500 to 3500 millimeters. Frost-free season is 30 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Altapeak, Chinkmin, Haywire, Index, Klapatche, Playco, Nagrom, Maggib(T), Nimue, Reggad, Serene, Spukwush, and Triumph (T) soils. All these soils are greater than 20 inches deep to a paralithic or lithic contact. All these soils except Reggad and Triumph are Spodosols. Reggad soils are organic soils over fragmental material. Triumph soils lack andic soil properties.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, high saturated hydraulic conductivity.
USE AND VEGETATION: Used for watershed, recreation, woodland, and wildlife habitat. Native vegetation is primarily herbaceous plants with small islands of subalpine coniferous trees. The herbaceous vegetation consists of lupine, pink and white mountain heather, tiger lily, Cascade huckleberry, false-hellebore and the coniferous trees are subalpine fir, mountain hemlock, and Alaska yellow cedar.
DISTRIBUTION AND EXTENT: High mountainous areas of the Cascade Range in Washington. MLRA 3. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Snoqualmie Pass Area, King County, Washington, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon: 5 to 40 centimeters (A1 and A2 horizons)
Cambic horizon: 40 to 51 centimeters (Bw horizon)
Andic soil properties: 5 to 51 centimeters (A1, A2, and Bw horizons)
Lithic contact: 51 centimeters
Particle-size control section: 5 to 51 centimeters
This description was updated in 2/2009 to incorporate the data from the North Cascades National Park Service Complex survey. It was converted to metric units and reformatted in semi-tabular format.
ADDITIONAL DATA: Laboratory data is available for this series. National Soil Survey Laboratory Pedon number 08N0313 (User Pedon ID S08WA007001).