LOCATION CANVASBACK              AK

Established Series
JDP/NDP/TJR
02/2022

CANVASBACK SERIES

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

TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive Aquic Haplocryepts

TYPICAL PEDON: Canvasback silt loam on a forested fan remnant with a slope of 2 percent and an elevation of 126 m (The soil was moist throughout when described on August 25, 2014.)

Oi--0 to 3 cm; slightly decomposed plant material; very dark grayish brown (10YR 3/2) moist; common very fine to medium roots; moderately acid (pH 5.6); abrupt wavy boundary

E/Bw--3 to 29 cm; silt loam; 85 percent light gray (10YR 7/2) dry, grayish brown (10YR 5/2) moist, and 15 percent light brown (7.5YR 6/4) dry, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine to very coarse roots; few fine and medium pores; 10 percent strong brown (7.5YR 5/6) moist, mottles in matrix; 3 percent gravels; noneffervescent; slightly acid (pH 6.2); clear wavy boundary

BC--29 to 53 cm; gravelly silt loam; 80 percent pale yellow (2.5Y 7/3) dry, light olive brown (2.5Y 5/3) moist, and 20 percent light brownish gray (10YR 6/2) dry, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine to very coarse roots; few fine and medium pores; 15 percent yellowish brown (10YR 5/6) moist, mottles in matrix; 16 percent gravel; noneffervescent; neutral (pH 6.7); clear smooth boundary

C1--53 to 76 cm; gravelly fine sandy loam; pale yellow (2.5Y 7/4) dry, light olive brown (2.5Y 5/4) moist; massive; soft, very friable, nonsticky and nonplastic; common fine and medium roots, few fine and medium pores; 15 percent olive brown (2.5Y 4/4) moist, masses of oxidized iron in matrix and 25 percent dark gray (10YR 4/1) moist, iron depletions in matrix; 25 percent gravel; strongly effervescent; slightly alkaline (pH 7.5); gradual wavy boundary

2C2--76 to 150 cm; very gravelly loamy fine sand; light yellowish brown (2.5Y 6/3) dry, olive brown (2.5Y 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; common fine roots; few fine and medium pores; 15 percent olive brown (2.5Y 4/4) moist, masses of oxidized iron in matrix; 38 percent gravel; slightly effervescent; slightly alkaline (pH 7.5)

TYPE LOCATION: Yukon-Koyukuk Census Area, Alaska; latitude 66.4500343 degrees, longitude -147.436000 degrees, datum WGS84 (coordinates determined with a GPS)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--0.5 to 2.5 degrees C
Depth to lithologic discontinuity--50 to 100 cm
Depth to redoximorphic iron depletions--50 to 75 cm below the mineral soil surface
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
Base saturation--greater than 50 percent in all layers within 50 cm of the mineral soil surface

Oi horizon
Thickness--3 to 18 cm
Reaction--5 to 7.0

Oe horizon (where present)
Thickness--3 to 18 cm
Reaction--5 to 7.0

A horizon (where present)
Hue--2.5Y, 10YR, 7.5YR
Value--2 to 4 moist, 4 to 6 dry
Chroma--1 and 2 moist
Fine-earth texture--silt loam, silt
Clay content--0 to 18 percent
Reaction--6.0 to 8.0
Rock fragment content--0 to 5 percent gravel
Effervescence--none
Thickness--3 to 15 cm

E/Bw horizon
Hue--10YR, 7.5YR
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 to 4 moist
Fine-earth texture--silt loam, very fine sandy loam, fine sandy loam
Clay content--0 to 18 percent
Reaction--6.0 to 8.0
Effervescence--none
Rock fragment content--0 to 5 percent gravel
Thickness--15 to 30 cm

BC horizon (where present)
Hue--2.5Y, 10YR
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 to 3 moist
Fine-earth texture--silt loam, very fine sandy loam, fine sandy loam
Clay content--0 to 18 percent clay
Reaction--6.0 to 8.0
Effervescence--none to strong
Rock fragment content--0 to 20 percent gravel
Thickness--20 to 60 cm

C, C1, and C2 horizons
Hue--2.5Y, 10YR
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 to 4 moist
Fine-earth texture--silt loam, very fine sandy loam, fine sandy loam
Clay content--0 to 10 percent clay
Reaction--6.0 to 8.5
Effervescence--none to strong
Rock fragment content--15 to 85 percent gravel
Combined thickness--20 to 70 cm

2C2 and 2C3 horizons
Value--3 to 5 moist, 5 to 7 dry
Chroma--1 to 4 moist
Fine-earth texture--sand, coarse sand, loamy sand, loamy fine sand
Clay content--0 to 10 percent clay
Reaction--6.0 to 8.5
Effervescence--none to strong
Rock fragment content--35 to 85 percent gravel
Combined thickness--50 to 100 cm

COMPETING SERIES:
Faa--these soils have a substratum of eolian sands with fewer than 35 percent gravels (by weighted average)

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; similar landforms
Venetie--dry longer than 90 days during the growing season; sandy-skeletal throughout entire profile; similar landforms
Kocacho--aquic conditions within 50 cm; sandy-skeletal throughout entire profile; depressions on similar landforms
Choonjik (gravelly phases)-- no aquic conditions within 150 cm; diagnostic calcic horizon in profile; similar landforms
Yasuda--aquic conditions within 25 cm; horizons with high exchangeable sodium percentages; in depressions on similar landforms

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--moderately well drained
Saturation in normal years--water table top depth between a depth of 50 to 75 cm in June, and between a depth of 50 to 100 cm in July and August; saturated below a depth of 100 cm throughout the rest of the year
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high in the upper profile and very high in the skeletal substratum

USE AND VEGETATION:
Use--wildlife habitat, subsistence
Potential natural vegetation--White spruce, black spruce, quaking aspen, red fruit bearberry, grayleaf willow, prickly rose, lingonberry, twinflower, russet buffaloberry, shrubby cinquefoil, littletree willow, reedgrass, false toadflax, dwarf scouringrush, field horsetail, stairstep moss, Tomentypnum moss, felt lichen, greygreen reindeer lichen

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--28 to 103 cm
*Ochric epipedon
*Cambic horizon--Bw horizon
*Redoximorphic iron concentrations--Bw, BC, C1, and 2C2 horizons
*Redoximorphic iron depletions with chroma of 2 or less--C1 horizon
*Aquic conditions--C1 horizon
*Strongly contrasting particle size
*Lithologic discontinuity--top of 2C horizon

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National Cooperative Soil Survey
U.S.A.