LOCATION ESTER                   AK

Established Series
Rev. DKS/DM/JPM
02/2022

ESTER SERIES

The Ester series consists of very poorly drained soils formed in a thin mantle of micaceous colluviated loess overlying weathered schist bedrock. Ester soils are on dominantly north-facing mountain and hill sideslopes. Slopes range from 7 to 100 percent. Mean annual temperature is about 26 degrees F., and the average annual precipitation is about 12 inches.

TAXONOMIC CLASS:

TYPICAL PEDON: Ester peat under forest vegetation. (All colors are for moist soil)

Oi--0 to 6 inches; peat consisting of raw sphagnum moss; clear smooth boundary.

Oe--6 to 12 inches; yellowish brown (10YR 5/4) partially decomposed sphagnum moss; many twigs, leaves, and roots; extremely acid; abrupt smooth boundary.

A--12 to 14 inches; very dark grayish brown (10YR 3/2) silt loam; weak thin platy structure; very friable, nonsticky and nonplastic; black (10YR 2/1) irregular streaks; common roots; very strongly acid; clear wavy boundary. (1 to 8 inches thick)

Bgf--14 to 24 inches; dark gray (5Y 4/1) silt loam; weak thin platy structure; many very dark grayish brown (2.5Y 3/2) streaks; frozen with clear ice lenses; 5 percent angular gravel; strongly acid; clear wavy boundary. (0 to 15 inches thick)

2Cf--24 to 28 inches; very dark grayish brown (2.5Y 3/2) extremely gravelly silt loam; 70 percent gravel size weathered schist fragments; frozen; strongly acid; gradual wavy boundary. (4 to 10 inches thick)

2Crf--28 inches; weathered schist bedrock.

TYPE LOCATION: Salcha-Big Delta Area, Alaska; in the SE 1/4 of the SE 1/4 of Section 15, T.5S., R.6E., Fairbanks Meridian.

RANGE IN CHARACTERISTICS: Thickness of the loess mantle over weathered bedrock ranges from 12 to 20 inches. The organic mat ranges in thickness from 8 to 16 inches. Depth to permafrost ranges from 2 to 14 inches below the mineral surface. Texture of the control section is silt loam or silt with more than 15 percent fine sand or coarser and less than 18 percent clay. There is a substantial mica content, but less than 40 percent. Weighted average coarse fragment content ranges from 10 to 35 percent and is dominantly gravel size schist fragments. Reaction throughout the profile ranges from extremely acid to slightly acid.

The A horizon has hue of 7.5YR or 10YR; value moist of 2 or 3; and chroma moist of 1 or 2.

The B horizon has hue of 2.5Y or 5Y; value moist of 3 or 4; and chroma moist from 1 to 4. This horizon may be very thin or absent in some profiles.

The 2Cf horizon has hue of 10YR, 2.5Y or 5Y; value moist of 2, 3 or 4; and chroma moist from 1 to 4. There is greater than 40 percent weathered angular schist fragments.

The 2Crf horizon is perennially frozen weathered schist overlying consolidated schist at depth.

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

GEOGRAPHIC SETTING: Ester soils formed in a thick organic mat overlying a micaceous loess mantle underlain by weathered schist bedrock. They occur on steep, dominantly north facing mountain sideslopes. Slopes range from 7 to 100 percent. The climate is subarctic continental with long, cold winters and short, warm summers. Mean annual temperature ranges from 24 to 28 degrees F., and mean annual precipitation ranges from 10 to 14 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Gilmore, Saulich, and Steese soils. Gilmore and Steese soils are on slopes other than north facing, lack permafrost, and are well drained. Saulich soils are on footslopes and are deeper than 20 inches over weathered bedrock.

DRAINAGE AND PERMEABILITY: Very poorly drained. Runoff is moderate to rapid. Permeability is moderately rapid in the organic mat and moderate in the mineral soil above the permafrost. The profile is saturated and free water is present above the permafrost. Loss of the organic mat may results in lowering of the permafrost level with subsequent release of meltwater.

USE AND VEGETATION: Native vegetation is dominantly black spruce, alder, and willows. Paper birch occurs in areas that have a history of fire. The soil is used primarily for wildlife habitat.

DISTRIBUTION AND EXTENT: East-central Interior Alaska. The series is of moderate extent.

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

SERIES ESTABLISHED: Fairbanks Area, Alaska, 1961.

REMARKS: Diagnostic horizons and features recognized in this profile include: a histic epipedon from 12 to 0 inches; permafrost at 12 inches below the mineral surface; saturated conditions above the permafrost; weighted average of loamy particle size and pH less than 5.5 (1:1,H20) throughout the control section.

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National Cooperative Soil Survey
U.S.A.