LOCATION PITKA AK
Established Series
JDP/BB/TJR
02/2022
PITKA SERIES
Landscape--alluvial plains
Landform--depressions on 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--poorly drained
Soil moisture regime--aquic
Soil temperature regime--gelic
Soil moisture subclass--typic
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, nonacid, subgelic Typic Aquorthels
TYPICAL PEDON: Pitka silt loam on a scrubland terrace depression with a slope of 1 percent and an elevation of 133 m (The soil was moist throughout when described on August 12, 2011.)
Oi--0 to 10 cm; slightly decomposed plant material; common fine and medium roots, and many very fine roots; slightly acid (pH 6.5)
Oa--10 to 14 cm; highly decomposed plant material; common fine and medium roots, and many very fine roots; strongly acid (pH 5.4); abrupt wavy boundary
A--14 to 19 cm; silt loam; dark grayish brown (10YR 4/2) dry, very dark brown (10YR 2/2) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; common fine and very fine roots; common fine and medium pores; noneffervescent; slightly acid (pH 6.2); clear wavy boundary
C--19 to 74 cm; silt loam; 50 percent light yellowish brown (2.5Y 6/3) dry, olive brown (2.5Y 4/3) moist and 50 percent light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; weak thin platy structure; soft, very friable, nonsticky and nonplastic; few fine pores; 10 percent iron depletions in matrix and 40 percent dark yellowish brown (10YR 4/6) moist, masses of oxidized iron in matrix; noneffervescent; slightly acid (pH 6.5); clear wavy boundary
Cf--74 to 100 cm; permanently frozen silt loam; light brownish gray (2.5Y 6/2) dry, dark grayish brown (2.5Y 4/2) moist; massive; nonsticky and nonplastic; noneffervescent; slightly acid (pH 6.1); clear wavy boundary
TYPE LOCATION: Yukon-Koyukuk Census Area, Alaska; latitude 66.7113889 degrees, longitude -145.7150000 degrees, datum WGS84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature-- -4 to 1 degrees C
Depth to permafrost--60 to 100 cm
Depth to redoximorphic features--25 to 50 cm
Oi horizons
Thickness--5 to 15 cm
Reaction--5.0 to 8.0
Oe horizons (where present)
Thickness--5 to 15 cm
Reaction--5.0 to 8.0
Oa horizons
Thickness--5 to 15 cm
Reaction--5.0 to 8.0
A horizon
Hue--10YR, 2.5Y
Value--2 or 3 moist, 4 or 5 dry
Chroma--1 or 2 moist
Fine-earth texture--silt loam, loam
Clay content--0 to 18 percent
Reaction--6.0 to 8.5
Effervescence--none to strong
Thickness--5 to 15 cm
Bw horizons (where present)
Hue--2.5Y to 7.5YR
Value--4 or 5 moist, 6 or 7 dry
Chroma--2 to 4 moist
Fine-earth texture--silt loam, loam, very fine sandy loam
Clay content--0 to 18 percent
Reaction--6.0 to 8.5
Effervescence--none to strong
Thickness--5 to 20 cm
C and Cf horizons
Hue--10YR, 2.5Y
Value--3 or 4 moist, 5 or 6 dry
Chroma--1 to 3 moist
Fine-earth texture--silt loam, very fine sandy loam
Clay content--0 to 18 percent
Reaction--6.0 to 8.5
Effervescence--none to strong
Combined thickness--100 to 125 cm
COMPETING SERIES:
Twin--rare flooding; higher positions on similar landforms, forested
Chetlechak--occasional flooding; similar positions on adjacent floodplains
Dotlake--interdunes with sandy substrata; higher mean annual precipitation
GEOGRAPHIC SETTING:
Elevation--90 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:
Yasuda--aquic conditions within 25 cm with frequent ponding; lower positions on similar landforms; sodic properties
Tlozhavun--no aquic conditions within 150 cm; higher positions on similar landforms
Tajittro--aquic conditions within 100 cm; higher positions on similar landforms
Choonjik--no aquic conditions within 150 cm; calcareous; higher positions on similar landforms
Gwichin--aquic conditions within 100 cm with rare flooding; higher positions on similar landforms
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, and between a depth of 25 to 75 cm in July and August
Flooding--none
Ponding--occasional, brief
Saturated hydraulic conductivity (Ksat)--high throughout
USE AND VEGETATION:
Use--wildlife habitat, subsistence, recreation
Potential natural vegetation--white spruce, tealeaf willow, false mountain willow, littletree willow, grayleaf willow, water sedge, bluejoint, and arctic raspberry
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 39 to 114 cm
*Ochric epipedon
*Aquic conditions--C horizon
*Redoximorphic iron concentrations--C horizon
*Redoximorphic iron depletions--C horizon
*Permafrost--Cf horizon
Organic horizons are saturated for more than 30 days (cumulative) in normal years, and do not meet the criteria for a folistic epipedon.
National Cooperative Soil Survey
U.S.A.