LOCATION JAKOLOF AK
Established Series
Rev. DVP-JDW
05/2022
JAKOLOF SERIES
The Jakolof series consists of very deep, moderately well drained soils that formed in a silty mantle of volcanic ash over alluvial deposits. Jakolof soils are on stream terraces and alluvium fans. Slopes range from 0 to 8 percent. Mean annual temperature is about 38 degrees F. and the mean annual precipitation is about 70 inches.
TAXONOMIC CLASS: Sandy-skeletal, mixed Typic Humicryods
TYPICAL PEDON: Jakolof silt loam, on a 1 percent slope under grass and forbs at 80 feet elevation. (Colors are for moist soil unless otherwise stated. When described, the soil was moist throughout).
Oe--2 to 0 inches; mucky peat; many very fine, fine, medium, and coarse roots; abrupt smooth boundary. (1 to 6 inches thick)
E--0 to 2 inches; dark grayish brown (10YR 4/2) silt loam; moderate fine granular structure; very friable, nonsticky, nonplastic, weakly smeary; many very fine, fine, medium, and coarse roots; strongly acid (pH 4.5); abrupt smooth boundary.
Bhs--2 to 4 inches; dark reddish brown (5YR 3/2) silt loam; weak fine granular structure; very friable, nonsticky, nonplastic, moderately smeary; many very fine, fine, medium, and coarse roots; very strongly acid (pH 5.0); abrupt wavy boundary.
Bs--4 to 6 inches; dark brown (7.5YR 4/4) silt loam; weak fine granular structure; very friable, nonsticky, nonplastic, moderately smeary; many very fine, fine, medium, and coarse roots; very strongly acid (pH 5.0); abrupt wavy boundary.
Eb--6 to 7 inches; dark brown (10YR 4/3) silt loam; weak fine granular structure; very friable, nonsticky, nonplastic, weakly smeary; common very fine, fine, medium, and coarse roots; very strongly acid (pH 5.0); clear wavy boundary. (combined thickness of E horizons is 4 to 8 inches)
2Bhsb--7 to 15 inches; dark reddish brown (5YR 2/2) very gravelly sand; single grain; loose, nonsticky, nonplastic; common very fine and fine roots; 30 percent gravel and 10 percent cobble; very strongly acid (pH 5.0); clear wavy boundary. (combined thickness of B horizons is 5 to 19 inches)
2C--15 to 60 inches; variegated very gravelly sand; single grain; loose, nonsticky, nonplastic; 35 percent gravel and 10 percent cobble; very strongly acid (pH 5.0).
TYPE LOCATION: Kenai Peninsula Area, Alaska; Port Dick drainage; 1850 feet south and 1050 feet west of the NE corner of section 13, T. 10S., R. 13W., Seward Meridian; USGS Seldovia B-4 quadrangle; lat. 59 degrees 18 minutes 54 seconds N. and long. 151 degrees 23 minutes 05 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 37 to 40 degrees F. Thickness of the ashy mantle ranges from 3 to 10 inches. Thickness of the solum ranges from 11 to 25 inches. Depth to bedrock is greater than 60 inches. The pH of the mineral horizons ranges from 4.5 to 6.0.
The E horizon has hue of 2.5Y or 10YR, value of 4 to 6, and chroma of 2 or 3. It is silt loam or very fine sandy loam. It is weakly smeary throughout.
The Eb horizon has hue of 2.5Y or 10YR, value of 4 to 6, and chroma of 2 to 4. It is silt loam or very fine sandy loam. It is weakly smeary throughout.
The Bs horizon has hue of 7.5YR or 5YR, value of 3 or 4, and chroma of 2 to 4. It is silt loam, very fine sandy loam, or gravelly very fine sandy loam with 0 to 30 percent gravel. It is moderately smeary throughout.
The Bhs horizon has hue of 2.5YR or 5YR, value of 2 or 3, and chroma of 0 to 2. Texture of the fines is silt loam or very fine sandy loam. Rock fragments range from 0 to 30 percent and include 0 to 25 percent gravel and 0 to 5 percent cobble. It is moderately smeary throughout. Organic carbon content is assumed to be 12 to 16 percent.
The 2Bhsb horizon has hue of 2.5YR or 5YR, value of 2 or 3, and chroma of 0 to 2. It is very gravelly sand or very gravelly loamy sand. Rock fragments range from 35 to 60 percent and include 25 to 45 percent gravel and 10 to 15 percent cobble. Organic carbon content is assumed to be 12 to 16 percent.
The 2C horizon has variegated colors. It is very gravelly or extremely gravelly sand. Rock fragments range from 40 to 65 percent and include 30 to 45 percent gravel and 10 to 20 percent cobble.
COMPETING SERIES: The
Blashke series is in the same family. Blashke soils do not have ash is the silty surface mantel. Soils in the same great group include the
Kasitsna(T) and
Seldovia(T) series. Kasitsna soils have a particle size control section that is composed of medial over loamy skeletal material. Seldovia soils have a particle size control section that is composed entirely of medial material.
GEOGRAPHIC SETTING: Jakolof soils are formed in an ash mantle less than 10 inches thick over alluvium. Jakolof soils are on stream terraces and alluvial fans. Slopes range from 0 to 8 percent. Elevations are 10 to 1000 feet.
The climate is maritime with mild winters and cool summers. Mean annual precipitation ranges from 65 to 75 inches and the mean annual snowfall is 70 to 120 inches. Mean January temperature is 25 degrees F., mean July temperature is 54 degrees F., and the mean annual temperature ranges from 36 to 39 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the
Chenega,
Kasitsna,
Koyuktolik,
Seldovia, and
Tutka soils. Chenega soils do not have spodic horizons, are sandy-skeletal, and are on floodplains. Kasitsna soils are on glacial moraines and mountainslopes. Koyuktolik soils are formed in organic matter accumulated in depressions. Seldovia soils occur on mountainslopes. Tutka soils have bedrock within 20 inches and are on glacially abraded ridges and mountainslopes.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is slow. Permeability is moderate in the ash mantle and rapid in the substratum.
USE AND VEGETATION: These soils are used for timber production, subsistence, recreation, and wildlife habitat. Jakolof soils have native vegetation of Sitka spruce with an understory of salmonberry, fern, and moss. Grasses, fireweed, lupine, and other forbs grow in small scattered meadows that occur on Jakolof soils.
DISTRIBUTION AND EXTENT: Kenai Peninsula, Alaska. The series is of small extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Lower Kenai Peninsula Area, Alaska. 1998.
REMARKS: Diagnostic horizons and features recognized in this profile include:
Albic horizon 0 to 2 (E) and 6 to 7 inches (Eb). Spodic horizons 2 to 6, and 7 to 15 inches (Bhs, Bs, and 2Bhsb). Assumed 6 percent or more organic carbon in the Bhsb horizon 7 to 15 inches. Assumed cryic temperature regime.
National Cooperative Soil Survey
U.S.A.