LOCATION KUPREANOF AK
Established Series
Rev. JPM
12/2022
KUPREANOF SERIES
The Kupreanof series consists of very deep, well drained soils that formed in colluvium and glacial till. Kupreanof soils occur on moraines and mountain sideslopes. Slopes range from 2 to 100 percent. Mean annual temperature is about 42 degrees F., and the average annual precipitation is about 90 inches.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Typic Humicryods
TYPICAL PEDON: Kupreanof silt loam - on a NE facing slope of 10 percent at 900 feet elevation under forest vegetation. (All colors are for moist soil unless otherwise indicated).
Oe--2 inches to 0; moderately decomposed twigs, leaves and moss; clear wavy boundary. (1 to 5 inches thick).
E--0 to 3 inches; dark gray (10YR 4/1) silt loam; weak fine granular structure; friable; nonsticky and nonplastic; many fine, medium, and coarse roots; 5 percent gravel; extremely acid (pH 3.9); abrupt smooth boundary. (1 to 5 inches thick).
Bhs1--3 to 8 inches; dark reddish brown (5YR 3/3) gravelly sandy loam; weak fine granular structure; friable; nonsticky and nonplastic; many fine, medium and coarse roots; 20 percent gravel; extremely acid (pH 4.4); gradual irregular boundary. (1 to 10 inches thick).
Bhs2--8 to 13 inches; dark reddish brown (5YR 3/3) very gravelly coarse sandy loam; weak fine granular structure; friable; nonsticky and nonplastic; many very fine, fine, medium and coarse roots; 30 percent gravel, 5 percent cobbles; very strongly acid (pH 4.6); gradual wavy boundary. (4 to 15 inches thick).
Bs--13 to 22 inches; dark brown (7.5YR 3/4) very gravelly coarse sandy loam; weak fine granular structure; friable; nonsticky and nonplastic; common fine, medium, and coarse roots; 30 percent gravel, 10 percent cobbles; few pockets of very dark grayish brown (2.5Y 3/2) and dark yellowish brown (10YR 3/4) sandy loam; very strongly acid (pH 5.0); gradual wavy boundary. (0 to 15 inches thick).
C--22 to 60 inches; dark brown (7.5YR 3/2) very cobbly sandy loam; single grain; loose, nonsticky and nonplastic; few fine and medium roots; 25 percent gravel, 20 percent cobble; strongly acid (pH 5.3).
TYPE LOCATION: Haines Area, Alaska. SE1/4, NW1/4, Section 23, T.28S., R.53E. Copper River Meridian.
RANGE IN CHARACTERISTICS: MAST ranges from 38 to 42 degrees F. The solum ranges from 9 to 45 inches thick. There is more than 6 percent organic carbon in the upper 4 inches of the spodic horizon. Coarse fragment content in the control section ranges from 35 to 75 percent with 25 to 50 percent gravel and 5 to 40 percent cobble. Tree throw and soil creep has resulted in mixing and churning of horizons in many profiles. Reaction throughout the profile ranges from ultra acid to slightly acid.
An A horizon is present in some pedons.
The E horizon has hue of 5YR, 7.5YR, 10YR, 2.5Y or 5Y, value moist from 3 to 7, and chroma moist from 1 to 3. Texture is loam, silt loam, fine sandy loam, or sandy loam. Coarse fragments range from 0 to 30 percent, with 0 to 30 percent gravel and 0 to 20 percent cobble.
The Bhs and Bs horizons have hue of 2.5YR, 5YR, 7.5YR, or 10YR, value moist from 2 to 5, and chroma moist from 0 to 6. Texture is loam, silt loam, coarse sandy loam, or sandy loam.
The C horizon is loam, coarse sandy loam or sandy loam. Hue ranges from 7.5YR to 2.5Y, value from 2 to 6, and chroma from 1 to 6.
COMPETING SERIES: These are the
Deming (WA),
Passage (AK),
Hinker (WA),
Karta (AK),
Mitkof (AK),
Saar (WA),
Shuksan (WA), and
Thader (OR) series. Deming, Saar and Shuksan soils have volcanic ash within the control section. Passage, Hinker and Thader soils have a lithic contact within 40 inches of the surface. Karta soils have paralithic compact till within 40 inches of the surface. Mitkof soils are mottled in the control section.
GEOGRAPHIC SETTING: The Kupreanof soils occur on moraines and mountain sideslopes. They formed from moderately coarse textured glacial till and colluvium. The climate is humid maritime with the average annual precipitation ranging from 21 to 150 inches. The slope gradient commonly is 10 to 50, but the range is 2 to 100 percent. Mean annual temperature ranges from 40 to 48 degrees F. Elevations range from 0 to 3000 feet. The frost free season is 90 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS:
DRAINAGE AND PERMEABILITY: Well drained; moderate to moderately rapid permeability; slow to rapid runoff. In some pedons, the lower part of the solum may be saturated.
USE AND VEGETATION: The Kupreanof soils are used for timber production, wildlife habitat, and recreation. The native vegetation is dominantly Sitka spruce, western hemlock, and western red cedar with an understory of devil's club, Sitka alder, rustyleaf menziesia, and mosses.
DISTRIBUTION AND EXTENT: Southeastern Alaska. The series is of major extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Haines Area, Alaska. 1985.
REMARKS: Diagnostic horizons and features recognized in this soil are: an albic horizon from 0 to 3 inches; a spodic horizon from 3 to 22 inches with more than 6 percent organic carbon in the upper 4 inches; a weighted average of greater than 35 percent coarse fragments in the control section. The particle size of the control section has a significant relation to the physical and chemical properties of the soil.
ADDITIONAL DATA: Laboratory data is available on this soil: NSSL Numbers 823229-3235.
National Cooperative Soil Survey
U.S.A.