Established Series


The Nikolai series consists of deep, poorly drained soils formed in decomposing peat mixed with silt and ash and overlying gravelly glacial drift in depressional areas. Slopes range from 0 to 3 percent. Mean annual temperature is about 33 degrees F., and the average annual precipitation is about 21 inches.

TAXONOMIC CLASS: Loamy, mixed, dysic Terric Borosaprists

TYPICAL PEDON: Nikolai peat -- undisturbed (All colors are for moist soil)

Oi--0 to 3 inches; mat of largely undecomposed leaves and stems of grasses.

Oe--3 to 6 inches; dark reddish brown (5YR 2/2) and black (N 2/ ) mat of roots and decomposing grass stems and leaves; charcoal; very strongly acid; abrupt smooth boundary. (2 to 5 inches thick)

Oa--6 to 13 inches; dark reddish brown (5YR 2/2) silty peat; peat is finely divided; moderate very fine granular structure; weakly laminated; very friable and slick; abundant roots; very strongly to strongly acid; clear wavy boundary. (5 to 10 inches thick)

Oa--13 to 33 inches +; mixed dark reddish brown (5YR 2/2, 5YR 3/3) and black (N 2/ ) soft fibrous sedge peat; very finely laminated in places; thin layers of silt between laminations; crumble easily to very friable; slick consistency; roots plentiful; very strongly acid; patches of brown (10YR 5/3) silt loam, and very thin layers of white sand grains; 1 1/2 to 3 feet thick; overlies loose sand or sand and gravel.

TYPE LOCATION: Kenai - Kasilof Area, Alaska. SW 1/4, SW 1/4, section 12, T.4 N., R.12 W, Seward Meridian, Alaska. (about 8 miles south of Kenai)

RANGE IN CHARACTERISTICS: Thickness over the gravelly or sandy substratum ranges from 27 to 40 inches. Lenses of volcanic ash may occur anywhere in the profile. The surface horizon ranges in texture from silty peat to mucky silt loam.

COMPETING SERIES: This is the Beseman series in the same family and the Bullwinke and Cathro series in similar families. Beseman soils do not have strata of mineral material and ash in the organic layers. Bullwinkle and Cathro soils have pH greater than 4.5 (0.01M CaCl2) in parts of the control section.

GEOGRAPHIC SETTING: The Nikolai soils occupy nearly level areas, mostly adjoining the sea cliffs. They are formed in peat overlying sandy or gravelly glacial drift. The climate is maritime with cool summers and long moderately cold winters. Average annual temperature is about 33 degrees F., and the average annual precipitation is 18 to 24 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Cohoe, Island, Kalifonsky, Tustumena, and Swanson soils. Cohoe, Island, Swanson, and Tustumena soils are well drained mineral soils of uplands. Kalifonsky soils are somewhat poorly drained soils of muskeg border positions.

DRAINAGE AND PERMEABILITY: Poorly drained with moderate permeability in the organic layers. Runoff is slow. The water table is near the surface much of the time, but commonly drops several feet in late summer.

USE AND VEGETATION: A few areas are used for gardens or forage crops. Mostly the soils are in native vegetation consisting of tall grass, dominantly bluejoint, and associated forbs and shrubs. In places, there is a forest dominated by white spruce and paper birch with varying amounts of willows and balsam poplar.

DISTRIBUTION AND EXTENT: Western Kenai Peninsula, Alaska. The series is inextensive, with a total of about 6000 acres.


SERIES ESTABLISHED: Kenai - Kasilof Area, Alaska. 1960.

REMARKS: The range in characteristics and overall concept of the Nikolai soils are poorly defined. More data is needed to adequately define the series concept or the series should be inactivated (jpm 2/5/87).



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04 May 2007 10:23