LOCATION APIKUNI MT
Tentative Series
Rev. EMR-JMS-RJS
04/2017
APIKUNI SERIES
The Apikuni series consists of very deep, well drained soils that formed in till derived from metamorphic and sedimentary rock. These soils are on moraines. Slopes range from 4 to 35 percent. Mean annual precipitation is about 1,100 millimeters, and the mean annual air temperature is about 3.0 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Typic Haplocryepts
TYPICAL PEDON: Apikuni silt loam in aspens on a 7 percent slope at an elevation of 1,503 meters. (Colors are for dry soil unless otherwise noted.)
A--0 to 15 cm; brown (7.5YR4/2) silt loam, very dark gray (7.5YR 3/1) moist; moderate coarse granular structure; friable, slightly hard, very sticky and moderately plastic; many very fine and fine roots throughout; many very fine and fine irregular pores; 1 percent gravel; neutral (pH 6.8); gradual smooth boundary.
Bw1--15 to 42 cm; gray (10YR 5/1) clay loam, dark gray (10YR 4/1) moist; moderate fine subangular blocky structure; firm, hard, very sticky and very plastic; many fine and medium roots throughout; common very fine and fine irregular pores; 5 percent gravel; neutral (pH 6.7); gradual smooth boundary.
Bw2--42 to 82 cm; grayish brown (10YR 5/2) gravelly clay loam, dark gray (10YR 4/1) moist; moderate fine subangular blocky structure; firm, hard, very sticky and very plastic; many very fine and fine roots throughout; common very fine and fine irregular pores; 15 percent gravel and 5 percent cobbles; neutral (pH 6.9); gradual wavy boundary.
BC--82 to 95 cm; brown (10YR 5/3) gravelly clay loam, grayish brown (10YR 5/2) moist; massive; firm, hard, very sticky and very plastic; common very fine roots throughout; common very fine and few fine irregular pores; 25 percent gravel, 5 percent cobbles; neutral (pH 7.1); gradual wavy boundary.
C--95 to 150 cm; light yellowish brown (2.5Y 6/3) gravelly loam, light olive brown (2.5Y 5/3) moist; massive; friable, moderately hard, moderately sticky and moderately plastic; common very fine roots throughout; few very fine and fine irregular pores; 30 percent gravel; neutral (pH 7.2).
TYPE LOCATION: Glacier County, Montana; located about 75 meters south and 280 meters west of the northeast corner of sec. 35, T. 15N, R. 4W; Lake Sherburne topographic quadrangle; UTM Zone 12, 311468e, 5411375n. NAD 83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 2.0 to 6.0 degrees C.
Depth to cambic horizon: 10 to 30 cm
Particle-size control section: averages 18 to 34 percent clay
O horizons (where present)
Thickness: 0 to 6 cm
A horizon
Hue: 7.5YR, 10YR or 2.5Y dry or moist
Value: 2 to 4 dry or moist
Chroma: 1 or 2 dry or moist
Texture: silt loam or loam
Clay content: 18 to 27 percent
Rock fragments: 0 to 15 percent gravel
Reaction: pH 6.3 to 7.2
Thickness: 8 to 24 cm
Bw1, Bw2 horizons
Hue: 10YR or 2.5Y dry or moist
Value: 4 or 5 dry or moist
Chroma: 1 to 4 dry or moist
Texture: clay loam or loam
Clay content: 18 to 34 percent
Rock fragments: 5 to 25 percent--5 to 25 percent gravel; 0 to 10 percent cobbles
Reaction: pH 6.3 to 7.4
Thickness (Bw1, Bw2 combined): 30 to 80 cm
BC horizon
Hue: 10YR or 2.5Y dry or moist
Value: 4 to 5 dry or moist
Chroma: 2 to 4 dry or moist
Texture: loam, clay loam or sandy clay loam
Clay content: 18 to 34 percent
Rock fragments: 15 to 35 percent--10 to 35 percent gravel; 0 to 10 percent cobbles
Reaction: pH 6.4 to 7.6
Thickness: 10 to 35 cm
C horizon (where present)
Hue: 10YR or 2.5Y dry or moist
Value: 4 to 6 dry or moist
Chroma: 3 or 4 dry or moist
Texture: loam or sandy clay loam
Clay content: 18 to 25 percent
Rock fragments: 25 to 60 percent--25 to 60 percent gravel, 0 to 20 percent cobbles, 0 to 5 percent stones
Reaction: pH 6.4 to 7.6
COMPETING SERIES:
Chelina (AK): have a lithologic discontinuity
Chetaslina (AK):do not have a cambic horizon
Nimerick (CO): are moderately deep to a lithic contact
Ripple (CO): have a lithologic discontinuity
GEOGRAPHIC SETTING:
Landform: moraines
Elevation: 1,400 to 1,900 meters
Slope: 4 to 35 percent
Parent material: till derived from metamorphic and sedimentary rock
Climate: long, cold winters; moist springs; short warm summers with May and June receiving the most precipitation
Mean annual precipitation: 800 to 1,500 mm
Mean annual air temperature: 1.0 to 5.5 degrees C.
Frost-free period: 30 to 65 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: Well drained and moderate permeability (5 to 15 um/sec).
USE AND VEGETATION: These soils are typically forested and are used mainly for recreation and wildlife. The vegetation is typified by an open to moderately closed overstory of Douglas-fir with a diverse and multilayered understory of shrubs, grasses and forbs including white spirea, common snowberry, pinegrass and heartleaf arnica.
DISTRIBUTION AND EXTENT: Apikuni soils are of limited extent in northern Montana. MLRA 43A and 43B.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana.
SERIES PROPOSED: Glacier County 2016, Montana, 2016. The series name is derived from a mountain in Glacier National Park.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 15 cm (A horizon)
Cambic horizon: 15 to 82 cm (Bw1, Bw2 horizons)
Particle-size control section: 25 to 100 cm (part of Bw1, Bw2, BC, part of C horizons)
Apikuni soils have a cryic temperature regime and an udic moisture regime.
Taxonomic version: Keys to Soil Taxonomy, Twelfth Edition, 2014.
National Cooperative Soil Survey
U.S.A.