LOCATION AMBRANT MT
Established Series
Rev. NRS/JAL/KLS
03/2022
AMBRANT SERIES
The Ambrant series consists of very deep, somewhat excessively drained soils that formed in colluvium or alluvium derived from igneous rocks. These soils are on alluvial fans, stream terraces, and mountains. Slopes are 0 to 80 percent. Mean annual precipitation is about 510 mm, and mean annual air temperature is about 6 degrees C.
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Lamellic Haplustepts
TYPICAL PEDON: Ambrant gravelly sandy loam, forested (colors are for dry soil unless otherwise noted).
Oi--0 to 5 cm; undecomposed and slightly decomposed forest litter.
E1--5 to 15 cm; light brownish gray (10YR 6/2) gravelly sandy loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine pores; 25 percent pebbles; neutral (pH 7.2); clear wavy boundary. (8 to 25 cm thick)
E2--15 to 56 cm; light brownish gray (2.5Y 6/2) gravelly coarse sandy loam, grayish brown (2.5Y 5/2) moist; strong fine granular structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine pores; 25 percent pebbles; neutral (pH 7.2); gradual wavy boundary. (0 to 41 cm thick)
E and Bt--56 to 104 cm; E part (75 percent) is light brownish gray (2.5Y 6/2) gravelly coarse sandy loam, dark grayish brown (2.5Y 4/2) moist; Bt part (25 percent) is dark grayish brown (2.5Y 4/2) gravelly sandy loam lamellae very dark grayish brown (2.5Y 3/2) moist; lamellae are 3 to 10 mm thick; texture mixed is gravelly coarse sandy loam; weak fine and medium blocky structure parting to moderate fine and medium granular; soft, very friable, nonsticky, and nonplastic; few very fine and fine roots; common very fine and fine pores; 30 percent pebbles; neutral (pH 7.2); gradual wavy boundary. (38 to 76 cm thick)
2C--104 to 157 cm; light brownish gray (2.5Y 6/2) very gravelly coarse sand, grayish brown (2.5Y 5/2) moist; single grain; slightly hard, very friable, nonsticky and nonplastic; 55 percent pebbles; neutral (pH 7.2).
TYPE LOCATION: Missoula County, Montana; about 310 meters east and 90 meters south of the NW corner of sec. 9, T. 12 N., R. 16 W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--4 to 8 degrees C
Moisture control section--between 20 and 60 cm
Depth to 2C horizon--70 to 117 cm
E1 horizon
Value--5 through 7 dry; 3 or 4 moist
Chroma--2 or 3
Texture--sandy loam or loam
Clay content--5 to 15 percent
Rock fragment content--0 to 35 percent: 0 to 25 percent cobbles, stones, or boulders; 5 to 35 percent angular pebbles
Reaction--pH 5.6 to 7.3
E2 horizon
Hue: 10YR or 2.5Y
Value--5 through 7 dry, 4 or 5 moist
Chroma-1 through 3
Texture--coarse sandy loam or loamy coarse sand
Clay content--5 to 15 percent
Rock fragments content--0 to 35 percent: 0 to 10 percent cobbles, stones, or boulders; 5 to 35 percent angular pebbles
Reaction--pH 5.6 to 7.3
E and Bt horizon
Hue--E part: 10YR or 2.5Y, Bt part: 10YR or 2.5Y
Value--E part: 5 through 7, B part: 4 or 5 dry; E part: 4 through 6, B part: 3 or 4 moist
Chroma--2 through 4
Clay content, mixed--5 to 18 percent, lamellae has less than 3 percent clay increase
Texture--sandy loam or coarse sandy loam
Rock fragments--0 to 35 percent: 0 to 10 percent cobbles; 10 to 35 percent angular pebbles
Reaction--pH 5.6 to 7.3
2C horizon
Hue--10YR or 2.5Y
Value--5 through 7 dry, 4 or 5 moist
Chroma--1 through 4
Texture--coarse sandy loam, coarse sand, loamy coarse sand, sand, or loamy sand
Clay content--0 to 5 percent
Rock fragment content--15 to 60 percent: 10 to 25 percent cobbles and stones, 10 to 45 percent angular pebbles
Reaction--pH 5.6 to 7.3
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landform--mountains; alluvial fans; stream terraces
Elevation-- 1,100 to 2,380 meters
Slope--0 to 80 percent
Parent material--colluvium or alluvium derived from igneous rocks
Climate--long, cold winters; moist springs; warm summers
Mean annual precipitation--430 to 630 mm, much of which falls as snow or as spring rain.
Mean annual air temperature--3 to 7 degrees C
Frost-free period--70 to 110 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; moderately rapid permeability in the coarse-loamy material and rapid permeability in the sandy or sandy-skeletal material.
USE AND VEGETATION: Ambrant soils are used as woodland, wildlife habitat, and watersheds. The native vegetation is lodgepole pine, ponderosa pine, and Douglas fir with an understory of pinegrass, common snowberry, elk sedge, and white spiraea.
DISTRIBUTION AND EXTENT: Ambrant soils are moderately extensive in western Montana. MLRAs 43A, 43B
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Missoula County, Montana, 1985
REMARKS: Soil interpretation records: MT0216, MT1199, MT0706.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon (the upper part of the albic horizon) --5 to 15 cm (E1 horizon)
Albic horizon--15 to 56 cm (E2 horizon)
Cambic horizon--56 to 104 cm (E and Bt horizon)
Particle-size control section--25 to 100 cm (part of E2 horizon and part of E and Bt horizons).
Ambrant soils have an ustic moisture regime and a frigid temperature regime.
Converted to metric and O horizons were updated to start at zero. 2/2022
National Cooperative Soil Survey
U.S.A.