LOCATION SCAUP                   AK

Established Series
JDP/NR/TJR
02/2022

SCAUP SERIES

Landscape--alluvial plains
Landform--stream terraces
Slope--0 to 3 percent
Parent material--organic material over alluvium
Mean annual precipitation--about 255 mm
Mean annual air temperature--about -6 degrees C
Depth class--very deep
Drainage class--poorly drained
Soil moisture regime--aquic
Soil temperature regime--cryic
Soil moisture subclass--typic

TAXONOMIC CLASS: Coarse-silty over sandy or sandy-skeletal, mixed, superactive, nonacid Histic Cryaquepts

TYPICAL PEDON: Scaup peat on a woodland terrace with a slope of 0 percent and an elevation of 190 m (The soil was wet throughout when described on July 13, 2013.)

Oi--0 to 10 cm; peat; neutral (pH 7.2); abrupt smooth boundary

Oe--10 to 20 cm; mucky peat; neutral (pH 7.1); abrupt smooth boundary

C1--20 to 60 cm; silt loam; brown (10YR 5/3) dry, dark brown (10YR 3/3) moist; massive; slightly hard, friable; moderately sticky and moderately plastic; common fine and very fine roots; few fine and medium pores; 5 percent dark yellowish brown (10YR 4/4) moist, masses of oxidized iron in matrix; noneffervescent; neutral (pH 6.7); abrupt smooth boundary

2C2--60 to 150 cm; fine sand; pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; massive; slightly hard, friable; moderately sticky and moderately plastic; few fine pores; 65 percent gravel; noneffervescent; neutral (pH 6.6); clear smooth boundary

TYPE LOCATION: Yukon-Koyukuk Census Area, Alaska; latitude 67.0478500 degrees, longitude -145.4639900 degrees, datum WGS84 (coordinates determined with a GPS)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--0.5 to 2.5 degrees C
Depth to permafrost--25 to 50 cm
Depth to redoximorphic features--10 to 25 cm
Depth to lithologic discontinuity--35 to 75 cm (shallow and moderately deep)
Rock fragment content--0 to 35 percent gravels (by weighted average) above the lithologic discontinuity, and 35 to 85 percent gravels (by weighted average) below the lithologic discontinuity

Oi and Oe horizons
Combined thickness--5 to 15 cm
Reaction--5.0 to 8.0

Oa horizons (where present)
Thickness--5 to 15 cm
Reaction--5.0 to 8.0

A & AC horizons (where present)
Hue--10YR, 2.5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 or 2 moist
Fine-earth texture--silt loam, very fine sandy loam
Clay content--0 to 18 percent
Reaction--7.0 to 8.0
Effervescence--none to slight
Combined thickness--5 to 15 cm

C1 horizon
Hue--10YR, 2.5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 to 3 moist
Fine-earth texture--silt loam, very fine sandy loam
Clay content--0 to 18 percent
Reaction--6.5 to 8.0
Effervescence--none to slight
Thickness--10 to 45 cm

2C2 horizon
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 to 3 moist
Fine-earth texture--fine sand to coarse sand
Rock fragment content--20 to 85 percent total
Clay content--0 to 10 percent
Reaction--6.5 to 8.5
Effervescence--none to strong
Thickness--75 to 115 cm

COMPETING SERIES:
None

GEOGRAPHIC SETTING:
Elevation--100 to 300 m
Climate--short, warm summers and long, very cold winters
Mean annual precipitation--210 to 310 mm
Mean annual air temperature-- -12 to 0 degrees C
Frost-free period--45 to 97 days

GEOGRAPHICALLY ASSOCIATED SOILS:
Tlozhavun (gravelly taxadjuncts)--no aquic conditions within 150 cm; higher positions on similar landforms
Yanert--aquic conditions within 25 cm; swales on similar landforms
Canvasback--aquic conditions within 100 cm (moderately well drained); higher positions on similar landforms
Kocacho--aquic conditions within 50 cm; sandy or sandy-skeletal throughout entire profile

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--poorly drained
Saturation in normal years--water table top depth between a depth of 10 to 25 cm in June, saturated below a depth of 50 cm in July, and saturated below a depth of 75 cm throughout the rest of the year
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high in the surface horizons and very high in the substratum

USE AND VEGETATION:
Use--wildlife habitat, subsistence, recreation
Potential natural vegetation--black spruce, white spruce, quaking aspen, grayleaf willow, entireleaf mountain-avens, red fruit bearberry, lingonberry, bog Labrador tea, dwarf scouringrush, greygreen reindeer lichen, star reindeer lichen, stairstep moss, Tomentypnum moss, Aulacomnium moss

DISTRIBUTION AND EXTENT: Yukon Flats Lowlands, Alaska; MLRA 232; small extent

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

SERIES ESTABLISHED: Yukon Flats National Wildlife Refuge, Yukon-Koyukuk Census Area, Alaska; 2020

REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 45 to 120 cm
*Histic epipedon--Oi and Oe horizons
*Redoximorphic iron concentrations--C1 horizon
*Redoximorphic iron depletions with chroma of 2 or less--C1 horizon
*Aquic conditions--C1 horizon
*Lithologic discontinuity--2C2 horizon
*Strongly contrasting particle size
At least one horizon between 20 to 50 cm depth must have less than 8 percent clay, or have an n value of 0.7 or less.

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National Cooperative Soil Survey
U.S.A.