LOCATION NIBLACK                 AK

Established Series
Rev. EJK-JPM
05/2022

NIBLACK SERIES


The Niblack series consists of very poorly drained organic soils formed in highly decomposed organic material overlying bedrock. Niblack soils are on plateaus and on benches on mountainslopes and hillslopes. Slopes range from 0 to 45 percent. Elevation ranges from sea level to 2,000 feet.

TAXONOMIC CLASS: Dysic Lithic Cryosaprists

TYPICAL PEDON: Niblack peat - on a southeast facing slope of 5 percent in an open muskeg. (All colors are for moist soil.)

Oi--0 to 2 inches; dark reddish brown (5YR 3/3) and dark brown (7.5YR 3/4) peat; 95 percent fiber, 90 percent rubbed; primarily sphagnum fibers; many very fine and few fine roots; extremely acid (pH 4.3 Truog); abrupt wavy boundary. (1 to 4 inches thick)

Oe--2 to 5 inches; black (5YR 2.5/1) and very dusky red (2.5YR 2.5/2) mucky peat; 85 percent fiber, 40 percent rubbed; mixed sphagnum and sedge fibers; many very fine and fine common medium roots; extremely acid (pH 4.0 Truog); abrupt wavy boundary. (2 to 6 inches thick)

Oa1--5 to 8 inches; dark reddish brown (5YR 2.5/2) muck; 60 percent fiber, 5 percent rubbed; mixed sphagnum and sedge fiber; common medium roots; extremely acid (pH 4.0 Truog); abrupt wavy boundary. (0 to 10 inches thick)

Oa2--8 to 11 inches; dark reddish brown (5YR 2.5/2) muck; 30 percent fiber, 5 percent rubbed; mixed sphagnum and sedge fibers; extremely acid (pH 4.2 Truog); gradual wavy boundary. (0 to 10 inches thick)

Oa3--11 to 35 inches; dark reddish brown (5YR 2.5/2) muck; 20 percent fiber, 2 percent rubbed; mixed sphagnum and sedge fibers; 2 percent wood fragments; extremely acid (pH 4.3 Truog); abrupt wavy boundary. (0 to 25 inches thick)

R--35 inches; granitic bedrock.

PEDON LOCATION: South Zarembo Island, in Section 36, T.64S., R.80E., Copper River Meridian.

RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 38 to 42 degrees F. Combined thickness of the organic horizons ranges from 21 to 36 inches. Depth to bedrock ranges from 21 to 42 inches. pH is less than 4.5 throughout the profile. The profile does not freeze below a depth of 2 inches due to a maritime climate.

The Oa horizons have hue ranging from 2.5YR to 7.5YR, value of 2 or 3 and chroma from 1 to 4.

Some pedons have a C horizon, ranging up to 6 inches thick, overlying the bedrock. Texture of the C horizon is sandy loam, loam or gravelly loam.

COMPETING SERIES: This is the Kaikli series in the same subgroup. Kaikli soils have pH greater than 4.5 in some horizons.

GEOGRAPHIC SETTING: The Niblack soils are on benches of mountain sideslopes and on broad ridgetops. Slope gradients range from 0 to 45 percent. The mean annual temperature ranges from 43 to 47 degrees F. Mean annual precipitation ranges from 60 to over 200 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kushneahin and St. Nicholas soils. Kushneahin soils are on lowlands or less sloping positions and are developed in very deep organic materials. St. Nicholas soils are poorly drained mineral soils on similar landscape positions.

DRAINAGE AND PERMEABILITY: Very poorly drained. Permeability is rapid. Runoff is slow.

USE AND VEGETATION: The Niblack soils are used for wildlife habitat, recreation and watershed protection. The vegetation is dominantly sphagnum moss, hydrophytic forbs and a few sedges, with some stunted lodgepole pine, western hemlock and Alaska yellow cedar.

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

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

SERIES ESTABLISHED: Stikine Area, Alaska, 1993.

REMARKS: Diagnostic horizons and features recognized in this profile include: sapric material from 5 to 35 inches; assumed cryic temperature regime; a lithic contact at 35 inches; pH less than 4.5 (0.01M CaCl2) in all horizons.


National Cooperative Soil Survey
U.S.A.