LOCATION KOYUKTOLIK              AK

Established Series
Rev. DVP-JDW
05/2022

KOYUKTOLIK SERIES

The Koyuktolik series consists of very deep, very poorly drained soils that formed in accumulations of partially decomposed mosses, sedges, and woody material. Koyuktolik soils are on slopes affected by seepage and in depressions between glacial moraines. Slopes range from 0 to 25 percent. Mean annual temperature is about 38 degrees F. and the mean annual precipitation is about 70 inches.

TAXONOMIC CLASS: Euic Typic Cryohemists

TYPICAL PEDON: Koyuktolik peat, on 1 percent slope under sphagnum moss, sedge, and dwarf shrubs, at 20 feet elevation. (Colors are for moist soil unless otherwise stated. When described, the soil was moist throughout).

Oi--0 to 3 inches; dark brown (7.5YR 3/2, broken face, rubbed and pressed) peat; 95 percent fiber, 85 percent rubbed; dominantly moss fibers; many very fine, fine, medium, and coarse roots; 5 percent mineral content; very strongly acid (pH 5.2); clear smooth boundary. (2 to 21 inches thick)

Oe1--3 to 8 inches; dark brown (7.5YR 3/2, broken face, rubbed) dark brown (7.5YR 4/4 pressed) mucky peat; 50 percent fiber, 25 percent rubbed; weak thick platy structure; admixture of sedge and moss fibers; many very fine and fine roots; 5 percent mineral content; very strongly acid (pH 5.2); clear smooth boundary.

Oe2--8 to 55 inches; dark brown (7.5YR 3/3, broken face, rubbed and pressed) mucky peat; 75 percent fiber, 35 percent rubbed; weak thick platy structure; admixture of sedge and moss fibers; few very fine and fine roots; 10 percent mineral content; thin discontinuous strata of volcanic ash; very strongly acid (pH 5.2); abrupt smooth boundary.

C--55 to 60 inches; dark grayish brown (2.5Y 4/2) very gravelly sandy loam; massive; friable, nonsticky, nonplastic; 35 percent gravel, 10 percent cobble.

TYPE LOCATION: Kenai Peninsula Area, Alaska; about 150 feet southwest of Port Graham airstrip, 1000 feet north and 50 feet west of the SE corner of section 32, T. 9S., R. 15W., Seward Meridian; USGS Seldovia B-5 quadrangle; lat. 59 degrees 21 minutes 05 seconds N. and long. 151 degrees 49 minutes 55 seconds W.

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 38 to 40 degrees F. The subsurface tier is composed dominantly of hemic material but includes thin layers of fibric and sapric material. Thickness of the organic material ranges from 51 inches to more than several feet.

The Oi horizon is comprised dominantly of sphagnum moss fibers and woody debris that are relatively undecomposed. Thickness of the Oi horizon ranges from 2 to 21 inches. Thin discontinuous strata of volcanic ash are common.

The Oe horizon is comprised dominantly of moss and sedge fibers that are in an intermediate stage of decomposition. The pH ranges from 4.2 to 5.7. Thin discontinuous strata of volcanic ash are common.

The C horizon has hue of 2.5Y or 5Y, value of 2 to 5, and chroma of 2 to 4. It is gravelly loam, very gravelly loam, or very gravelly sandy loam. Rock fragments range from 20 to 45 percent with 15 to 35 percent gravel and 5 to 15 percent cobble.

COMPETING SERIES: The Moose Lake(MN) and Rifle(MI) are in the same family.

GEOGRAPHIC SETTING: Koyuktolik soils are formed in partially decomposed mosses, sedges, and woody material, that are always saturated, over compact glacial till. Koyuktolik soils are on slopes affected by seepage and in depressions between glacial moraines. Slopes range from 0 to 25 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 37 to 39 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Kasitsna and Nuka soils. Kasitsna soils are well drained mineral soils that occur on glacial moraines in complex with Nuka soils. Nuka soils occur in swallower depressions than Koyuktolik soils.

DRAINAGE AND PERMEABILITY: Very poorly drained. Runoff is very slow to ponded. Permeability is rapid in the organic material and slow in the glacial till.

USE AND VEGETATION: These soils are used for subsistence, recreation, and wildlife habitat. Koyuktolik soils have native vegetation of stunted Sitka spruce, labrador tea, bog blueberry, willow, sedge, and sphagnum moss.

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:

Dominantly hemic soil material in the subsurface tier 12 to 35 inches (Oe2).
Thickness of organic material greater than 51 inches (130 cm). Control section pH is greater than 4.5.
Assumed cryic temperature regime; freeze below a depth of 2 inches (5cm) from the surface.

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National Cooperative Soil Survey
U.S.A.