LOCATION CHOONJIK AK
Established Series
JDP/NR/TJR
02/2022
CHOONJIK 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--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Coarse-silty, mixed, superactive Typic Calcicryepts
TYPICAL PEDON: Choonjik very fine sandy loam on a forested terrace with a slope of 2 percent and an elevation of 145 m (The soil was moist throughout when described on July 29, 2014.)
Oi--0 to 6 cm; slightly decomposed plant material; common fine roots, and many very fine roots; very strongly acid (pH 4.9); abrupt wavy boundary
Oe--6 to 8 cm; moderately decomposed plant material; common very fine to coarse roots; very strongly acid (pH 4.6); abrupt wavy boundary
Oa--8 to 10 cm; highly decomposed plant material; common very fine to coarse roots; very strongly acid (pH 4.6); abrupt wavy boundary
Bw--10 to 35 cm; very fine sandy loam; 50 percent light yellowish brown (2.5Y 6/3) dry, olive brown (2.5Y 4/3) moist and 50 percent pale brown (10YR 6/3) dry, brown (10YR 4/3) moist; moderate medium subangular blocky structure parts to weak medium platy structure; soft, very friable, nonsticky and nonplastic; common very fine to coarse roots; few fine and medium pores; slightly effervescent; slightly alkaline (pH 7.8); clear wavy boundary
Bkn--35 to 64 cm; very fine sandy loam; light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; moderate medium subangular blocky structure parts to weak medium platy structure; soft, very friable, nonsticky and nonplastic; common very fine roots; few fine and medium pores; strongly effervescent; strongly alkaline (pH 8.8); clear smooth boundary
BC--64 to 150 cm; very fine sandy loam; light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; weak fine subangular blocky structure and weak medium subangular blocky structure parts to weak thin platy structure; soft, very friable, nonsticky and nonplastic; few fine pores; slightly effervescent; strongly alkaline (pH 8.6)
TYPE LOCATION: Yukon-Koyukuk Census Area, Alaska; latitude 66.3778050 degrees north, longitude 145.2657890 degrees west, datum WGS 84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--0.5 to 2.5 degrees C
Depth to permafrost--110 to 150 cm
Oi, Oe, and Oa horizons
Combined thickness--3 to 15 cm
Reaction--4.5 to 7.0
A horizon (where present)
Hue--10YR
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 to 4 moist
Fine-earth texture--silt loam, very fine sandy loam, loam
Clay content--0 to 18 percent
Reaction--7.5 to 8.5
Effervescence--slight to strong
Thickness--3 to 10 cm
Bw horizon (where present)
Hue--7.5YR, 10YR, 2.5Y
Value--3 or 4 moist, 5 or 6 dry
Chroma--3 or 4 moist
Fine-earth texture--silt loam, very fine sandy loam
Clay content--0 to 18 percent
Reaction--7.5 to 8.5
Effervescence--slight to strong
Thickness--5 to 25 cm
Bkn horizon
Hue--10YR, 2.5Y
Value--4 to 6 moist, 6 to 8 dry
Chroma--2 or 3 moist
Fine-earth texture--silt loam, very fine sandy loam
Clay content--0 to 18 percent
Reaction--7.5 to 9.5
Effervescence--strong to violent
Other features--15 percent or more (by weight, fine-earth fraction) calcium carbonate
Thickness--20 to 60 cm
BC and C horizons
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--7.5 to 9.5
Effervescence--slight to strong
Thickness--40 to 105 cm
Cf horizon (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--7.5 to 9.0
Effervescence--slight to strong
Thickness--10 to 40 cm
COMPETING SERIES:
None
GEOGRAPHIC SETTING:
Elevation--100 to 300 m
Climate--warm, moist, short summers; very cold, dry, long 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--no aquic conditions within 150 cm; no calcic horizons or sodic properties; similar landforms
Tajittro--aquic conditions within 100 cm; permafrost within 1 m; no calcic horizons or sodic properties; similar landforms
Yasuda--aquic conditions within 25 cm; adjacent terrace depressions; sodic properties
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturation in normal years--none
Flooding--none
Ponding--none
Saturated hydraulic conductivity (Ksat)--high throughout
USE AND VEGETATION:
Use--wildlife habitat, subsistence, recreation
Potential natural vegetation--White spruce, quaking aspen, russet buffaloberry, prickly rose, grayleaf willow, twinflower, lingonberry, purple reedgrass, false toadflax, tall bluebells, Jakutsk snowparsley, sidebells wintergreen, eastern pasqueflower, splendid feather moss, Ptilidium liverwort, greygreen reindeer lichen, felt lichen, cup lichen
DISTRIBUTION AND EXTENT: Yukon Flats Lowlands, Alaska; MLRA 232; moderate 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 35 to 110 cm
*Ochric epipedon
*Free carbonates--Bw, Bkn, and C horizons
*Cambic horizon--Bw horizon
Soils in this series do not meet the criteria for a mollic epipedon due to thickness.
Where secondary carbonates are not visible, pedogenic accumulation of carbonates is inferred from increase in effervescence and pH compared to surrounding horizons. See pedon IDs S2014AK290001 and S2014AK290002 in the NCSS database for supporting calcium carbonate data.
Sodic properties may be present in some horizons with an exchangeable sodium percentage of more than 15 percent, but these horizons do not meet diagnostic criteria for a natric horizon. See pedon IDs S2014AK290001 and S2014AK290002 in the NCSS database for supporting chemical data.
National Cooperative Soil Survey
U.S.A.