LOCATION CHISTNA                 AK

Established Series
Rev. MHC/JPM/DLM
02/2022

CHISTNA SERIES

The Chistna series consists of very deep, somewhat excessively drained soils formed in sandy glacial outwash and sandy strandline deposits. Chistna soils are on lacustrine terraces glacial outwash plains. Slopes range from 0 to 27 percent. Mean annual temperature is about 26 degrees F., and the average annual precipitation is about 16 inches.

TAXONOMIC CLASS: Sandy, mixed Typic Haplocryepts

TYPICAL PEDON: Chistna silt loam on a 3 percent slope under white spruce forest at 2300 feet elevation. (All colors are for moist soil)

Oi--1 inches to 0; peat; dark reddish brown (5YR 3/3) fibrous roots, moss, and twigs; abrupt wavy boundary.

A--0 to 1 inches; very dark grayish brown (10YR 3/2) silt loam; weak fine subangular blocky structure; very friable, nonsticky and nonplastic; many roots of all sizes; strongly acid (pH 5.4); clear irregular boundary.

Bw--1 to 4 inches; strong brown (7.5YR 4/6) and dark reddish brown (5YR 3/4) fine sandy loam; weak medium subangular blocky structure; very friable, nonsticky and nonplastic; few very fine and fine roots; strongly acid (pH 5.4); clear irregular boundary.

2C/Bw2--4 to 9 inches; light olive brown (2.5Y 5/3) and dark yellowish brown (10YR 4/6) loamy fine sand; weak coarse subangular blocky structure; very friable, nonsticky and nonplastic; moderately acid (pH 5.8); diffuse irregular boundary.

2C2--9 to 18 inches; dark grayish brown (2.5Y 4/2) loamy fine sand; massive; very friable, nonsticky and nonplastic; moderately acid (pH 6.0); gradual wavy boundary.

2C3--18 to 60 inches; dark grayish brown (2.5Y 4/2) loamy fine sand; massive grain; very friable, nonsticky and nonplastic; 15 percent subrounded gravel and occasional cobble; neutral (pH 7.2).

TYPE LOCATION: Gulkana River Area, main stem, Alaska; about 11 miles northwest of Sourdough; the NW1/4 of the NE1/4 of section 6, T.10N., R.2W., Copper River Meridian.

RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 32 to 35 degrees F. Thickness of the organic mat ranges from 1 to 3 inches. Thickness of the loess cap is 1 to 6 inches. Solum thickness ranges from 3 to 14 inches. Texture in the control section includes sand, loamy sand, and loamy fine sand with a weighted average of less than 50 percent very fine sand. The soil is strongly acid or moderately acid in the solum and moderately or slightly acid in the substratum.

The A horizon has moist hue of 7.5YR or 10YR; moist value of 2 or 3; and moist chroma of 1, 2, or 3.

The Bw or 2Bw horizon has moist hue of 5YR, 7.5YR or 10YR; moist value of 3 or 4 and moist chroma of 3 through 6. Texture includes silt loam fine sandy loam or sandy loam. Coarse fragment content ranges from 0 to 5 percent with 0 to 5 percent gravel.

The 2C horizons have moist hue of 10YR, 2.5Y, or 5Y; moist value of 2 through 4; and moist chroma of 0 through 3. Textures include loamy fine sand, fine sand, and sand. Pockets of fine sandy loam and loam are common.
Coarse fragment content ranges from 0 to 10 percent with 0 to 10 percent gravel.

COMPETING SERIES: These are the Beales and Chistochina series. Beales soils lack coarse fragments and pockets of fine sandy loam and loam textures in the substratum. Chistochina soils have slightly acid or neutral surface horizons.

GEOGRAPHIC SETTING: Chistna soils formed in a thin loess mantle over sandy glacial drift on lacustrine terraces and strandlines. Slopes are convex and range from 0 to 25 percent. The climate is subarctic continental with long, cold winters and short, warm winters. Mean annual precipitation ranges from 14 to 18 inches, and the mean annual temperature ranges from 23 to 27 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS:

DRAINAGE AND PERMEABILITY: Somewhat excessively drained. Runoff is slow to medium. Permeability is moderate in the surface horizon, moderately rapid in the subsoil and rapid in the substratum.

USE AND VEGETATION: Most areas of Chistna soils have native vegetation of white spruce forest. The successional stage of the vegetation is closely related to fire history. This soil is used primarily for wildlife habitat.

DISTRIBUTION AND EXTENT: Copper River Basin, Alaska. The series is of minor extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: WASILLA, ALASKA

SERIES ESTABLISHED: Gulkana River Area, Alaska. 1999

REMARKS: Diagnostic features and horizons recognized in this profile include: a cambic horizon from 1 to 4 inches; sandy particle size from 9 to 60 inches; a cryic temperature regime. Formerly classified as Cryochrepts.

---

National Cooperative Soil Survey
U.S.A.