LOCATION TYONEK AK
Established Series
KMO - JPM
02/2022
TYONEK SERIES
The Tyonek series consist of very deep, very poorly drained soils formed in organic materials interlayered with strata of ash-influenced loess and alluvium. Tyonek soils are in depressional areas along the toeslopes of moraines. Slopes range from 0 to 2 percent. The mean annual temperature is about 32 degrees F., and the average annual precipitation is about 28 inches.
TAXONOMIC CLASS: Euic Fluvaquentic Cryosaprists
TYPICAL PEDON: Tyonek peat - on a 2 percent slope under forest vegetation. (All colors are for moist soil.)
Oe--0 to 4 inches; very dark grayish brown (10YR 3/2) peat; 75 percent fibers unrubbed, 50 percent rubbed; 15 percent twigs and woody particles; many fine and medium roots, common coarse roots; extremely acid; clear wavy boundary. (0 to 5 inches thick)
Oe--4 to 10 inches; very dark grayish brown (10YR 3/2) mucky peat; 50 percent fibers unrubbed, 20 percent rubbed; 5 percent twigs and woody particles; many fine, common medium and coarse roots; very strongly acid; abrupt smooth boundary. (0 to 16 inches thick)
C--10 to 11 inches; brown (10YR 5/3) loamy sand; single grained; loose; common fine roots; very strongly acid; abrupt smooth boundary. (1 to 4 inches thick)
Oa1--11 to 26 inches; dark grayish brown (10YR 4/2) muck; 30 percent fibers unrubbed, 10 percent rubbed; 15 percent woody fragments; extremely acid; abrupt smooth boundary. (1 to 15 inches thick)
C1--26 to 32 inches; light brownish gray (10YR 6/2) silt loam; massive; friable; few fine roots; very strongly acid; abrupt smooth boundary. (0 to 6 inches thick)
Oa2--32 to 60 inches; dark grayish brown (10YR 4/2) muck; 10 percent fibers unrubbed, 5 percent rubbed; 5 percent woody fragments; strongly acid.
TYPE LOCATION: Yentna Area, Alaska, NW 1/4, SE 1/4, Sec. 29, T.10N., R.14W., Seward Meridian.
RANGE IN CHARACTERISTICS: Strata of mineral material, including volcanic ash, occur throughout the profile. Combined thickness of the mineral strata is less than 12 inches. The subsurface tier is dominantly highly decomposed forest litter, sedges, and grasses with less than 15 percent fibers after rubbing. Content of woody fragments throughout the profile ranges from 5 to 25 percent. Buried logs and branches occur in some pedons. Reaction throughout the profile ranges from extremely acid to medium acid. The pH (0.01M CaC12) of the organic materials is 4.5 or greater within some parts of the control section.
The organic materials have hue of 7.5YR to 10YR, value moist from 2 to 4, and chroma moist from 1 to 3.
The mineral strata have value moist from 3 to 5, and chroma moist from 2 to 4. Textures range from silt loam to sand.
COMPETING SERIES: These are the
Bowstring and
Chichantna series in the same family and the
Doroshin and
Nikolai series. Bowstring
soils do not have strata of volcanic ash.
Chichantna soils are formed in decomposing moss and sedge peat.
Doroshin and
Nikolai soils have a mineral layer thicker than 12 inches within the control section.
GEOGRAPHIC SETTING: Tyonek soils are in depressional areas along the toeslopes of moraines. They are commonly adjacent to muskegs. Slopes range from 0 to 2 percent. The soils formed in decomposing forest and grass litter. These organic materials are interlayered with ash-influenced loess and alluvium. The mean annual temperature ranges from 30 to 34 degrees F. The average annual precipitation ranges from 20 to 30 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Chichantna and
Doroshin soils, and the
Kichatna ,
Spenard,
Starichkof, and
Strandline soils. Kichatna soils are poorly drained mineral soils on adjacent steep slopes. Spenard and Strandline are mineral soils on adjacent forested moraines. Starichkof soils consist of dominantly hemic material and occur in muskegs.
DRAINAGE AND PERMEABILITY: Very poorly drained. Slow runoff. Water table at or near surface. Permeability is rapid.
USE AND VEGETATION: The native vegetation consists of alder, paper birch, and white spruce with an understory of shrubs, moss, and grass. Used as wildlife habitat.
DISTRIBUTION AND EXTENT: South-central Alaska. The series is of minor extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Yentna Area, Alaska, 1986.
REMARKS: Diagnostic features recognized in this pedon include: sapric material dominant from 11 to 60 inches; strata of mineral material from 10 to 11 inches and 26 to 32 inches; and pH (0.01M CaCl2) of 4.5 or greater.
National Cooperative Soil Survey
U.S.A.