LOCATION AHKLUN AK
Established Series
SAS/TJR/MPR
02/2022
AHKLUN SERIES
Landscape--mountains, hills
Landform--mountain slopes, hillslopes
Slope--20 to 90 percent
Parent material--volcanic ash influenced colluvium over residuum
Mean annual precipitation--about 1300 mm
Mean annual air temperature--about 0 degrees C
Depth class--moderately deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic
TAXONOMIC CLASS: Loamy-skeletal, isotic Andic Humicryepts
TYPICAL PEDON: Ahklun very gravelly medial sandy loam on a west facing, linear backslope of the upper third of a mountain, on a slope of 60 percent at an elevation of 433 m (The soil was moist throughout when described on August 17, 2011.)
Oi--0 to 9 cm; slightly decomposed plant material; many very fine and fine and common medium roots; very strongly acid (pH 4.5); clear smooth boundary
A1--9 to 22 cm; very gravelly medial sandy loam, dark gray (10YR 4/1) dry, black (10YR 2/1) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and common medium and coarse roots; 40 percent gravel and 10 percent cobbles; strongly acid (pH 5.3); gradual smooth boundary
2A2--22 to 50 cm; very gravelly sandy loam, grayish brown (10YR 5/2) dry, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; slightly hard, friable, nonsticky and nonplastic; many fine and common very fine and medium roots; 45 percent gravel and 10 percent cobbles; strongly acid (pH 5.4); gradual smooth boundary
2Bw--50 to 85 cm; extremely gravelly sandy loam, yellowish brown (10YR 5/4) dry, dark yellowish brown (10YR 3/4) moist; weak fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many fine and common very fine and medium roots; 55 percent gravel and 10 percent cobbles; moderately acid (pH 5.9); abrupt smooth boundary
2R--85 cm; bedrock
TYPE LOCATION: Dillingham Census Area, Alaska, about 40 km north of the Village of Togiak; latitude 59.4083333 degrees, longitude -160.3636111 degrees, datum WGS84 (coordinates determined with a GPS)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--0 to 3 degrees C
Soil moisture control section--dry less than 45 consecutive days in June through October
Depth to lithic contact--50 to 100 cm (moderately deep)
Lithology of rock fragments--sedimentary, volcanic
Particle-size control section
*Clay content--4 to 12 percent
*Sand content--35 to 70 percent
*Total rock fragment content--35 to 70 percent
*Sodium fluoride pH--8.4 to 11.6
*Ratio of 1500 kPa water to measured clay--0.6 to 6.0
Oi horizon
Thickness--2 to 12 cm
A1 horizon
Hue--7.5YR or 10YR
Value--2 or 3 moist, 4 or 5 dry
Chroma--1 to 3 moist
Fine-earth texture--medial sandy loam, medial loam, medial silt loam
Clay content--4 to 8 percent
Reaction--4.0 to 5.5
Total rock fragment content--0 to 55
Gravel content--0 to 45 percent
Cobble content--0 to 15 percent
Stone content--0 to 15 percent
Thickness--5 to 20 cm
Bulk density--0.4 to 0.9 g/cm3
Al plus 1/2 Fe--1 to 4 percent
Phosphorous retention--85 to 100 percent
Organic carbon content--5 to 15 percent
Volcanic glass content--10 to 50 percent
Base saturation--0 to 20 percent
2A2 horizon
Hue--7.5YR or 10YR
Value--2 or 3 moist, 4 or 5 dry
Chroma--2 or 3 moist
Clay content--5 to 10 percent
Reaction--4.0 to 5.5
Total rock fragment content--35 to 70
Gravel content--10 to 55 percent
Cobble content--5 to 55 percent
Thickness--0 to 40 cm
Bulk density--0.5 to 1.0 g/cm3
Al plus 1/2 Fe--1 to 4 percent
Organic carbon content--5 to 15 percent
Volcanic glass content--0 to 5 percent
Base saturation--0 to 20 percent
2Bw horizon
Hue--10YR or 2.5Y
Value--3 to 5 moist, 5 to 7 dry
Chroma--2 to 4 moist
Clay content--5 to 12 percent
Reaction--5.0 to 6.0
Total rock fragment content--35 to 85
Gravel content--25 to 55 percent
Cobble content--5 to 40 percent
Stone content--0 to 20
Thickness--25 to 50 cm
COMPETING SERIES:
Goodlow-no lithic contact within a depth of 150 cm (very deep)
Muddycreek-- no lithic contact within a depth of 150 cm (very deep)
GEOGRAPHIC SETTING:
Elevation--10 to 920 m
Climate--warm, moist summers; cold, moist winters
Mean annual precipitation--620 to 2100 mm
Mean annual air temperature-- -3.4 to 1.8 degrees C
Frost-free period--70 to 140 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Mitlak--aquic conditions below a depth of 50 cm; andic soil properties; plains, lower mountain slopes
Klak--no lithic contact within a depth of 150 cm (very deep); lower mountain slopes
Buchia--no lithic contact within a depth 150 cm (very deep); no andic soil properties; similar landscape positions
Kashaiak--no andic soil properties; similar landscape positions
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--moderately high or high in the upper part of the profile, high or very high in the lower part
USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential natural vegetation--alder, bluejoint, arctic starflower, spreading woodfern, common ladyfern
DISTRIBUTION AND EXTENT: Ahklun Mountains, Alaska; MLRA 237; large extent
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA
SERIES ESTABLISHED: Togiak National Wildlife Refuge, Dillingham Census Area, Alaska; 2019
REMARKS:
Diagnostic horizons and other features in this pedon
*Particle-size control section--zone from 34 to 85 cm
*Umbric epipedon--A1 and 2A2 horizons
*Andic soil properties-A1 horizon
*Depth to lithic contact--85 cm
*Lab pedon number--12N0018
National Cooperative Soil Survey
U.S.A.