LOCATION UGRUK                   AK

Established Series
SAS/TJR
02/2022

UGRUK SERIES

Landscape--plains
Landform--depressions
Microrelief--microlow
Slope--0 to 1 percent
Parent material--organic material over loess
Mean annual precipitation--about 500 mm
Mean annual air temperature--about -3 degrees C
Depth class--very deep (very shallow to permafrost)
Drainage class--very poorly drained
Soil moisture regime--peraquic
Soil temperature regime--gelic
Soil moisture subclass--typic

TAXONOMIC CLASS: Loamy, mixed, euic, subgelic Terric Sapristels

TYPICAL PEDON: Ugruk peat on a convex, linear concave microlow in a depression, on a slope of 1 percent at an elevation of 39 m (The soil was moist to 20 cm and wet to 150 cm when described on June 20, 2016.)

Oi--0 to 9 cm; peat, reddish yellow (7.5YR 6/6) dry, strong brown (7.5YR 4/6) moist; many very fine and fine and common medium roots throughout; strongly acid (pH 5.2); clear wavy boundary

Oa1--9 to 32 cm; muck, brown (7.5YR 5/4) dry, dark brown (7.5YR 3/4) moist; many very fine roots and common fine and medium roots throughout; strongly acid (pH 5.3); abrupt irregular boundary

Oa2--32 to 54 cm; muck, brown (7.5YR 5/3) and brown (7.5YR 5/2) dry, dark brown (7.5YR 3/3) and dark brown (7.5YR 3/2) moist; many very fine and common fine roots; strongly acid (pH 5.5); diffuse irregular boundary

C/Agjj--54 to 65 cm; silt loam, light brownish gray (2.5Y 6/2) and brown (7.5YR 5/2) dry, 80 percent dark grayish brown (2.5Y 4/2) and 20 percent dark brown (7.5YR 3/2) moist; few fine irregular pores; massive; moderately acid (pH 5.6); abrupt irregular boundary

Cf--65 to 150 cm; silt loam, light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; massive; moderately acid (pH 5.7)

TYPE LOCATION: Nome Census Area County, Alaska, latitude 63.8615560, degrees, longitude - 160.4121140degrees, datum WGS84 (Coordinates determined with a GPS unit)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature-- -2 to -1 degrees C
Soil moisture control section--saturated at the soil surface during much of the growing season (peraquic moisture regime)
Thickness of combined organic layers--greater than 40 cm
Depth to permafrost contact--45 to 75
Depth to cryoturbation--40 to 70 cm
Reduced matrix--54 to 65

Particle Size Control Section:
*Clay--5 to 18 percent

Oi horizon
Value--3 or 4 moist, 5 or 6 dry
Chroma--3 to 6
Reaction--5.0 to 5.5
Organic carbon content--35 to 55 percent
Rubbed fiber content--40 to 100 percent
Sodium pyrophosphate color value and chroma where rubbed fiber content is 40 to 75 percent--7/1, 7/2, 8/1, 8/2, 8/3
Thickness--5 to 40 cm

Oa1 and Oa2 horizons
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 to 4
Reaction--4.7 to 5.8
Organic carbon content--35 to 55 percent
Rubbed fiber content--0 to 17 percent
Combined thickness--15 to 70 cm

C/Agjj horizon
Hue--2.5Y or 7.5YR
Value--2 to 4 moist, 4 to 6 dry
Fine-earth texture--silt, silt loam
Clay--8 to 18 percent
Sand--5 to 40 percent
Organic carbon--1 to 3 percent
Reaction--5.5 to 6.0
Thickness--5 to 35 cm

Cf horizon
Fine-earth texture--permanently frozen silt, permanently frozen silt loam
Clay--8 to 18 percent
Sand--5 to 40 percent
Organic carbon--0 to 0.5 percent
Reaction--5.5 to 6.1

COMPETING SERIES: None

GEOGRAPHIC SETTING:
*Elevation--25 to 400 m
*Climate--warm, moist summers; cold, dry winters
*Mean annual precipitation--400 to 600 mm
*Mean annual air temperature-- -5 to -1 degrees C
*Frost-free period--55 to 90 days

GEOGRAPHICALLY ASSOCIATED SOILS:
* Sikinik--coarse fragments present, poorly drained, plains and toeslopes of hills
* Akpik--total thickness of organic layers less than 40 cm, poorly drained, coarse fragments present, plains
* Ukpik--total thickness of organic layers less than 40 cm, somewhat poorly drained, swales on plains

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
*Drainage class--very poorly drained
*Ponding--long, frequent
*Saturation during normal years--saturated at the soil surface for much of the growing season
*Saturated hydraulic conductivity (Ksat)--moderately high or high in the upper part of the profile, very low in the permafrost layer

USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential native vegetation--tussock cottongrass, water sedge, reindeer lichen, dwarf birch

DISTRIBUTION AND EXTENT: Nulato Hills-Southern Seward Peninsula Highlands, Alaska; MLRA 240; moderate extent

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

SERIES ESTABLISHED: Nulato Hills BLM area, Nome Census Area, Alaska; 2021

REMARKS:
Diagnostic horizons and features recognized in this pedon
*Particle-size control section--zone from 54 to 90 cm
*Thickness of organic soil material--54 cm
*Sapric soil materials--9 to 54 cm
*Depth to permafrost--65 cm
*Reduced matrix--zone from 54 to 65 cm
*Cryoturbation--zone from 54 to 65 cm
*Depth to aquic conditions--0 cm (a positive reaction to alpha-alpha dipyridyl is assumed at and below this depth for much of the growing season)

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National Cooperative Soil Survey
U.S.A.