LOCATION BUCHIA                  AK

Established Series
SAS/TJR/MPR
02/2022

BUCHIA SERIES

Landscape--mountains, hills
Landform--mountain slopes, hillslopes
Slope--5 to 85 percent
Parent material--colluvium
Mean annual precipitation--about 1250 mm
Mean annual air temperature--about 0 degrees C
Depth class--very deep
Drainage class--well drained
Soil moisture regime--udic
Soil temperature regime--cryic
Soil moisture subclass--typic

TAXONOMIC CLASS: Loamy-skeletal, isotic Typic Humicryepts

TYPICAL PEDON: Buchia gravelly silt loam on an east-facing, convex, linear mountain backslope, on a slope of 65 percent at an elevation of 432 m (The soil was moist throughout when described on August 17, 2011.)

Oa--0 to 2 cm; highly decomposed plant material; many very fine and common fine and medium roots; 3 percent gravel; strongly acid (pH 5.2); clear wavy boundary

A1--2 to 15 cm; gravelly silt loam, brown (7.5YR 4/2) dry, very dark brown (7.5YR 2.5/2) moist; weak medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine and medium roots; 20 percent gravel and 2 percent cobbles; moderately acid (pH 5.8); clear wavy boundary

A2--15 to 75 cm; very gravelly silt loam, brown (7.5YR 4/2) dry, very dark brown (7.5YR 2.5/2) moist; moderate medium granular structure; slightly hard, friable, slightly sticky and nonplastic; many very fine and common fine roots; 50 percent gravel and 2 percent cobbles; moderately acid (pH 5.8); gradual smooth boundary

A3--75 to 110 cm; very gravelly silt loam, brown (7.5YR 4/2) dry, very dark brown (7.5YR 2.5/2) moist; weak medium granular structure; slightly hard, friable, slightly sticky and nonplastic; common fine roots; 40 percent gravel; strongly acid (pH 5.5); gradual smooth boundary

A4--110 to 150 cm; extremely gravelly sandy loam, brown (7.5YR 4/2) dry, very dark brown (7.5YR 2.5/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; 65 percent gravel; strongly acid (pH 5.4)

TYPE LOCATION: Dillingham Census Area, Alaska, about 40 km north of the village of Togiak; latitude 59.4083333 degrees north, longitude 160.3611111 degrees west, datum WGS 84 (coordinates determined with a GPS)

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--0 to 2 degrees C
Soil moisture control section--dry less than 45 consecutive days in June through October
Lithology of rock fragments--sedimentary, volcanic

Particle-size control section
*Clay content--4 to 15 percent
*Sand content--30 to 70 percent
*Total rock fragment content--35 to 80 percent
*Sodium fluoride pH--8.4 to 11.6
*Ratio of 1500 kPa water to measured clay--0.6 to 6.0

Oa horizon
Thickness--2 to 6 cm

A1 horizon
Hue--7.5YR, 10YR
Value--2 or 3 moist, 4 or 5 dry
Chroma--1 to 3 moist
Fine-earth texture--silt loam, sandy loam
Clay content--4 to 14 percent
Reaction--5.0 to 6.0
Total rock fragment content--15 to 25 percent
Gravel content--15 to 25 percent
Cobble content--0 to 2 percent
Thickness--8 to 27 cm
Bulk density--0.9 to 1.2 g/cm3
Base saturation--0 to 20 percent

A2 and A3 horizons
Hue--7.5YR, 10YR
Value--2 or 3 moist, 4 or 5 dry
Chroma--2 or 3 moist
Fine-earth texture--silt loam, sandy loam, loam
Clay content--5 to 14 percent
Reaction--5.0 to 6.8
Total rock fragment content--35 to 70 percent
Gravel content--25 to 70 percent
Cobble content--0 to 15 percent
Thickness--20 to 60 cm
Base saturation--0 to 20 percent

A4 horizon
Hue--7.5YR, 10YR
Value--2 or 3 moist, 4 or 5 dry
Chroma--2 or 3 moist
Fine-earth texture--silt loam, sandy loam
Clay content--5 or 6 percent
Reaction--5.0 to 6.0
Total rock fragment content--60 to 80 percent
Gravel content--60 to 80 percent
Cobble content--0 to 5 percent
Thickness--42 to 92 cm
Base saturation--0 to 20 percent

COMPETING SERIES:
Bigelow--mean annual soil temperature higher than 4 degrees C
Causewa, Hossick, Mirror, Nagyagat--moderately deep (50 to 100 cm) to lithic bedrock
Crannler--moderately deep (50 to 100 cm) to lithic bedrock; mean annual soil temperature higher than 3 degrees C
Henline--moderately deep (50 to 100 cm) to lithic bedrock, mean annual soil temperature higher than 6 degrees C

GEOGRAPHIC SETTING:
Elevation--10 to 980 m
Climate--warm, moist summers; cold, moist winters
Mean annual precipitation--620 to 2100 mm
Mean annual air temperature-- -3.6 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 and lower mountain slopes
Ahklun--andic soil properties; similar landscape positions
Kashaiak--lithic contact; similar landscape positions
Klak--andic soil properties; lower mountain slopes

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--moderately high or high throughout

USE AND VEGETATION:
Use--wildlife habitat, recreation, subsistence
Potential natural vegetation--dwarf birch, reindeer lichens, Lapland cornel, black crowberry, splendid feathermoss, marsh Labrador tea, knights plume moss, sphagnum mosses, beauverd spirea, bog blueberry, lingonberry

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 27 to 102 cm
*Umbric epipedon--A horizon

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National Cooperative Soil Survey
U.S.A.