LOCATION POKERCREEK AK
Established Series
MPS/SAS
02/2022
POKERCREEK SERIES
Landscape--hills, valleys
Landform--hillslopes
Slope--1 to 10 percent
Parent material--mossy organic material over loess over loamy colluvium
Mean annual precipitation--about 490 mm
Mean annual air temperature--about -3 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-loamy, isotic, acid, subgelic Typic Gelaquepts
TYPICAL PEDON: Pokercreek silt loam on a south southeast facing linear, linear toeslope of a hill on a slope of 4 percent at an elevation of 132 m (The soil was moist throughout the soil profile when described on June 20, 2016.)
Oi--0 to 13 cm; slightly decomposed plant material, reddish yellow (7.5YR 6/6) dry, strong brown (7.5YR 4/6) moist; nonsticky, nonplastic; common very fine, fine, and very coarse roots throughout, and many medium and coarse roots throughout; extremely acid (pH 3.6); clear smooth boundary
Oa--13 to 22 cm; highly decomposed plant material, grayish brown (10YR 5/2) dry very dark grayish brown (10YR 3/2) moist; nonsticky, nonplastic; common very fine, fine, and very coarse roots throughout and many medium and coarse roots throughout; extremely acid (pH 4.0); abrupt wavy boundary
C1--22 to 64 cm; silt loam, pale yellow (2.5Y 7/3) dry, light olive brown (2.5Y 5/3) moist; massive; friable, nonsticky, nonplastic; common very fine, fine, and medium roots throughout; few fine tubular pores; 20 percent coarse distinct irregular noncemented dark gray (10YR 4/1) moist, masses of reduced iron with clear boundaries in matrix and 25 percent medium prominent irregular noncemented strong brown (7.5YR 5/6) moist, masses of oxidized iron with clear boundaries in matrix; strongly acid (pH 5.2); gradual smooth boundary
C2--64 to 150 cm; silt loam, pale yellow (2.5Y 7/3) dry, light olive brown (2.5Y 5/3) moist; massive; friable, nonsticky, nonplastic; 35 percent medium distinct irregular noncemented dark gray (2.5Y 4/1), moist, masses of reduced iron with clear boundaries in matrix; 3 percent subrounded gravel, 10 percent subrounded fine gravel; strongly acid (pH 5.3)
TYPE LOCATION: Yukon-Koyukuk Census Area, Alaska, latitude 63.0529800 longitude -160.8009900 degrees, datum WGS84 (coordinates determined with a GPS unit)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature-- -2 to 0 degrees C
Soil moisture control section--saturated at a depth of between 0 and 25 cm during the growing season (aquic soil moisture regime)
Thickness folistic epipedon--20 to 60 cm
Depth to redoximorphic iron concentrations--20 to 85 cm
Depth to redoximorphic iron depletions--20 to 60 cm
Depth to aquic conditions--25 to 60 cm
Particle Size Control Section:
*Clay--8 to 16 percent
*Total rock fragment content--0 to 13 percent gravels
*Sodium fluoride pH--8.4 to 11.6
*Ratio of 1500 kPa water to measured clay--0.6 to 6.0
Oi horizon
Thickness--10 to 30 cm
Oa horizon
Thickness--8 to 40 cm
C1 horizon
Hue--10YR or 2.5Y
Value--4 or 5 moist, 6 or 7 dry
Chroma--2 to 6
Fine-earth texture--silt loam, silt
Clay--5 to 15 percent
Sand--8 to 20 percent
Organic carbon--0.5 to 2 percent
Reaction--4.6 to 5.4
Thickness--35 to 90 cm
C2 horizon
Hue--10YR or 2.5Y
Value--4 or 5 moist, 6 or 7 dry
Chroma--2 to 4
Fine-earth texture--silt loam, silt
Clay--8 to 18 percent
Sand--8 to 30 percent
Organic carbon--.5 to 2 percent
Total rock fragment content--0 to13 percent gravel
Reaction--5.3 to 6.4
Thickness--20 to 90 cm
COMPETING SERIES: None
GEOGRAPHIC SETTING:
*Elevation--50 to 600 m
*Climate--warm, moist summers; cold, dry winters
*Mean annual precipitation--400 to 640 mm
*Mean annual air temperature-- -5 to -1 degrees C
*Frost-free period--55 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS:
*
Cilla--ochric epipedon, depth to aquic conditions below 50 cm, cambic horizon present, gravel content ranges above 15 percent; toeslopes, footslopes, and northfacing backslopes of hills
*
Imak--aquic conditions at the soil surface, cambic horizon present, permafrost present; similar landscape position
*
Jacksoncreek--histic epipedon, reduced matrix, cryoturbation present, texture ranges to very fine sandy loam; stream terraces in valleys
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
*Drainage class--somewhat poorly drained
*Saturation during normal years--saturated at a depth of between 0 and 25 cm for at least two weeks during the growing season
*Saturated hydraulic conductivity (Ksat)--very high in the folistic epipedon, moderately high throughout the rest of the profile
USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential native vegetation--dwarf birch, Bigelow's sedge, black crowberry, marsh Labrador tea, black spruce, Schreber's big red stem moss, blueberry willow, sphagnum, bog blueberry, lingonberry, cloudberry, splendid feather moss, felt lichen, tealeaf willow, Siberian alder, woodland horsetail, bunchberry dogwood,
DISTRIBUTION AND EXTENT: Yukon-Kuskokwim Highlands, Alaska; MLRA 230; moderate extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Nulato Hills BLM area, Yukon-Koyukuk Census Area, Alaska; 2021
REMARKS:
Diagnostic horizons and features recognized in this pedon
*Particle-size control section--zone from 47 to 122 cm
*Folistic epipedon--zone from 0 to 22 cm
*Redoximorphic iron concentrations--zone from 22 to 64 cm
*Redoximorphic iron depletions with a chroma of 2 or less--zone from 22 to 150 cm
*Aquic conditions--zone from 22 to 150 cm
National Cooperative Soil Survey
U.S.A.