Wetland Classification and Mapping of Seward, Alaska

Mike Gracz

Doug Van Patten

Soil Subgroup Descriptions

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TYPIC DYSTROCRYEPTS, by Douglas J Van Patten

 

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Depth class: very deep
Drainage class: well
Parent material: loess over outwash
Landform: alluvial fan
Slopes: 0 to 6 percent
Mean annual precipitation: 68 inches
Mean annual temperature: 40 degrees F.

TAXONOMIC CLASS: Sandy-skeletal, mixed, Typic Dystrocryepts

TYPICAL PEDON: Typic Dystrocryepts silt loam - on a slope of 3 percent under Sitka spruce forest at 295 feet elevation. (All colors are for moist soil unless noted)

Oe--0 to 3 inches; dark reddish brown (5YR 3/2) moderately decomposed plant material; many very fine, fine, and medium roots, few coarse roots; abrupt smooth boundary.

A--3 to 6 inches; light olive brown (2.5Y 5/3) and dark gray (2.5Y 4/1) silt loam; massive; nonsticky, nonplastic; common very fine, fine, and medium roots, and few coarse roots; 10 percent 3mm dark brown (7.5YR 3/3) high chroma relict redoximorphic concentrations; very strongly acid (pH 5.0); abrupt wavy boundary.

Bw--6 to 9 inches; dark olive brown (2.5Y 3/3) and very dark gray (2.5Y 3/1) very gravelly sandy loam; massive; common very fine, fine and medium roots; 15 percent 5mm dark brown (7.5YR 3/3) high chroma relict redoximorphic concentrations; strongly acid (pH 5.5); abrupt wavy boundary.

C1--9 to 13 inches; very dark gray (2.5Y 3/1) and dark grayish brown (2.5Y 4/2) stratified loamy sand and silt loam; massive; friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; abrupt smooth boundary.

C2--13 to 60 inches; brown (10YR 5/3) very gravelly loamy sand; single grain; loose nonsticky, nonplastic; few very fine roots; medium acid (pH 5.8).

LOCATION:  (PEDON  1002)  About 4 1/4 miles NNE of Seward, Alaska; in the NW1/4 of the SW1/4 of the NW1/4, Sec. 18, T. 1 N., R. 1 E., Seward Meridian; UTM north 6673886, and UTM east 369184, zone 6

REMARKS: Diagnostic features and horizons in this profile include:

• Cambic horizon between depths of 3 to 9 inches (A and Bw horizons)

• A and Bw horizons are weakly developed. 

• C1 has a thin discontinuous layer of high Fe+++ that approaches a spodic horizon.