LOCATION PARTOFSHIKOF            AK

Established Series
Rev.CSC/JMD/JPM
02/2022

PARTOFSHIKOF SERIES

The Partofshikof series consists of very deep, somewhat poorly drained and moderately well drained soils formed in volcanic ash on mountain and hill sideslopes and on ash mantled till plains. Slopes range from 5 to 75 percent. Mean annual precipitation is in excess of 60 inches and the mean annual temperature is about 46 degrees F.

TAXONOMIC CLASS: Medial, amorphic Andic Humicryods

TYPICAL PEDON: Partofshikof silt loam - on a southwest facing concave slope of 40 percent at 800 feet elevation under conifer forest vegetation. (All colors are for moist soil, all textures are apparent field textures)

Oi--12 to 3 inches; forest litter and living mosses; many very fine and fine, and common medium and coarse roots; clear smooth boundary. (1 to 9 inches thick)

Oa--3 to 0 inches; muck; decomposed forest litter; many very fine and fine, common medium, and few coarse roots; extremely acid (pH 4.0); abrupt smooth boundary. (0 to 7 inches thick)

E--0 to 1 inch; grayish brown (2.5Y 5/2) silt loam; weak very fine subangular blocky structure; slightly sticky and slightly plastic; common very fine and fine roots; very strongly acid (pH 5.0); abrupt smooth boundary. (1 to 3 inches thick)

Bhs--1 to 5 inches; very dusky red (2.5YR 2.5/2) and dark reddish brown (5YR 3/2) silt loam; weak fine subangular blocky structure; slightly sticky and slightly plastic; strongly smeary; common very fine and fine roots; strongly acid (pH 5.5); clear wavy boundary. (4 to 8 inches thick)

Bs--5 to 32 inches; dark brown (7.5YR 3/4) silt loam; weak fine subangular blocky structure; slightly sticky and slightly plastic; strongly smeary; common medium distinct very dark grayish brown (10YR 3/2) mottles; few fine roots; strongly acid (pH 5.5); clear smooth boundary. (6 to 28 inches thick)

2C--32 to 41 inches; olive gray (5Y 4/2) loamy sand; massive; nonsticky and nonplastic; many medium distinct dark yellowish brown (10YR 4/4) and brown (7.5YR 4/4) mottles; slightly acid (pH 6.5); abrupt wavy boundary. (9 to 14 inches thick)

3C--41 to 60 inches; yellowish red (5YR 4/6) and strong brown (7.5YR 5/6) silt loam; massive; slightly sticky and slightly plastic; strongly smeary; slightly acid (pH 6.5).

TYPE LOCATION: Kalinin Bay, Chatham Area, Alaska. NE 1/4, SW 1/4, Sec. 5, T.54S., R.61E., Copper River Meridian.

RANGE IN CHARACTERISTICS: MAST ranges from 38 to 42 degrees F. The thickness of the solum ranges from 14 to 39 inches. Phosphorous retention exceeds 85 percent. Moist bulk density is less than 0.90 grams/cc. 15 bar water content moist ranges from 30 to 100 percent (on field moist samples) in the solum. The coarse fragment content in the control section ranges from 0 to 15 percent gravel size pumice. Reaction increases with depth, ranging from extremely acid to neutral.

The combined thickness of the O horizons range from 3 to 12 inches, but is normally less than 8 inches.

The E horizon has hue from 5YR to 5Y, value of 4 or 5, and chroma from 1 to 3. Texture is commonly silt loam but ranges to loamy sand. A Bh horizon, up to 10 inches thick, is present in some pedons.

The Bhs horizon has hue of 2.5YR or 5YR, value of 2.5 or 3, and chroma from 1 to 4. Texture is commonly silt loam but ranges to loam. Thin stratas of very fine sandy loam and fine sandy loam occur in some pedons. Prominent or distinct mottles are often present in the lower part of the horizon.

The Bs horizon has hue of 5YR or 7.5YR, value from 3 to 5, and chroma from 4 to 8. Coarse fragment content ranges from 0 to 15 percent gravel size pumice. Prominent or distinct mottles commonly are present.

The 2C and 3C horizons are composed of several strata of ash deposits. Color is variegated, texture ranges from loamy sand to silt loam, and coarse fragment content ranges from 0 to 20 percent gravel size pumice.

COMPETING SERIES: There are no competing series in the same family.

GEOGRAPHIC SETTING: The Partofshikof soils are on ash mantled mountainslopes, hillslopes, and till plains. The climate is humid maritime with a mean annual precipitation range of 60 to 220 inches. The mean annual temperature is about 46 degrees F. and the mean summer temperature is about 57 degrees F. Elevation ranges from 0 to 3000 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sitka, Sukoi, and Verstovia soils on similar landforms. Sitka and Verstovia soils are well drained with Verstovia soils less than 20 inches to bedrock. Sukoi soils are poorly drained.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained and moderately well drained. Moderate permeability. Runoff is very slow.

USE AND VEGETATION: The Partofshikof soils are used for timber production, watershed protection, wildlife habitat and recreation. The overstory is dominantly western hemlock. The understory is dominantly blueberry with some rusty menziesia.

DISTRIBUTION AND EXTENT: Southeast Alaska. The series is of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA

SERIES ESTABLISHED: Chatham Area, Tongass National Forest, Alaska, 1992.

REMARKS: Diagnostic horizons and features recognized in this soil include: an albic horizon from 0 to 1 inch; spodic horizons from 1 to 32 inches; andic soil properties throughout the soil; cryic temperature regime; assumed moist 15 bar water content between 30 and 100 percent.

No lab data is available for this pedon. Andic soil properties are assumed based on field morphology and lab data for the associated Sukoi series (NSSL S87AK-220-010).

This series could classify as a Typic Cryaquod under the 1991 revised Spodosol criteria. This soil, however, does not exhibit the saturated conditions typical of an Aquod which is reflected in the forest productivity. Redoximorphic features are present lower in the spodic horizon and the soil exhibits the characteristics of somewhat poor drainage. It is assumed the soil is not saturated to the surface nor does the capillary fringe extend to the surface during the year.

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National Cooperative Soil Survey
U.S.A.