Established Series


The Maybeso Series consists of very deep, very poorly drained soils formed from decomposing organic matter which overlies glacial till. These soils occur on broad ridgetops, mountainsides, and valley sideslopes. Slopes range from 5 to 60 percent. The mean annual temperature is about 45 degrees F., and the average annual precipitation is about 100 inches.

TAXONOMIC CLASS: Loamy-skeletal, mixed, euic Terric Cryosaprists

TYPICAL PEDON: Maybeso mucky peat -- under forest vegetation. (All colors are for moist soil).

Oi--0 to 1/2 inch; living mosses and partially decomposed forest litter; abrupt wavy boundary. (1/2 to 1 inch thick)

Oe--1/2 to 4 inches; black (5YR 2.5/1, broken face and pressed) mucky peat; 80 percent fiber content unrubbed, 50 percent rubbed; common fine and medium roots and few coarse roots; extremely acid (pH 4.3); clear wavy boundary. (3 to 6 inches thick)

Oa1--4 to 13 inches; dark reddish brown (5YR 2.5/2, broken face and pressed) muck; 15 percent fiber content unrubbed, trace when rubbed; nonsticky, slightly plastic; few skunk cabbage roots; very strongly acid (pH 4.5); clear wavy boundary. (7 to 15 inches thick)

Oa2--13 to 23 inches; black (5YR 2.5/1, broken face and pressed) muck; 40 percent fiber content unrubbed, 5 percent rubbed; about 10 percent wood fragments by volume; few skunk cabbage roots; very strongly acid (pH 4.5); clear wavy boundary. (7 to 15 inches thick)

C1--23 to 26 inches; very dark brown (10YR 2/2) gravelly sandy loam with pockets of sedge peat; massive; nonsticky, slightly plastic; very strongly acid (pH 5.0); clear wavy boundary. (0 to 5 inches thick)

C2--26 to 60 inches; olive gray (5Y 4/2) very gravelly sandy loam; massive; weakly cemented; 60 percent gravel; very strongly acid (pH 5.0).

TYPE LOCATION: Hollis Area, Alaska. 25 yards south of No. 1000 Road, 13.6 miles from Thorne Bay (SE 1/4, SE 1/4, S15, T 72 S, R 83 E, Copper River Meridian).

RANGE IN CHARACTERISTICS: The subsurface tier is dominantly sapric material. Depth to the mineral substratum ranges from 21 to 40 inches. Weighted average of coarse fragments in the mineral horizons ranges from 40 to 80 percent. Wood fragments range up to 15 percent by volume in all organic horizons.

Hue of the organic horizons ranges from 5YR to 10YR; value moist of 1 to 3.

COMPETING SERIES: This is the Karheen series in which the organic matter rests on fragmental material and the intersticies are filled with organic materials.

GEOGRAPHIC SETTING: Maybeso soils occur on broad ridgetops, hillslopes, gentle to steep benches, backslopes and summits of mountains, and footslopes and toeslopes of valleys. The substratum is glacial till of mixed mineralogy. The climate is humid maritime with a mean annual precipitation of about 100 inches. The mean annual air temperature is about 45 degrees F, and the mean summer air temperature is about 55 degrees F. The mean annual soil temperature is about 42 degrees F, and the mean summer soil temperature is about 47 degrees F. The slope gradient commonly is less than 35 percent, but the range is 5 to 60 percent. Elevation ranges from sea level to 1100 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Hydaburg, Karta, Kina, Kogish, McGilvery, Tolstoi, St. Nicholas, Ulloa, and Wadleigh series. The Karta, Tolstoi, and Ulloa series are well drained mineral soils. Kina and Kogish soils are very deep, less decomposed organic soils occupying depressional areas associated with drumlinoid hills; and the toeslopes, footslopes, and floors of valleys. McGilvery soils are shallow to bedrock and formed from forest litter on hillslopes and valleysides. St. Nicholas and Wadleigh soils are poorly drained mineral soils. Hydaburg soils are shallow to bedrock organic soils that occur in alpine areas.

DRAINAGE AND PERMEABILITY: Very poorly drained. Very slow permeability in the glacial till substratum. Runoff is very slow.

USE AND VEGETATION: Maybeso soils are used for watershed protection, wildlife habitat, recreation, and timber production. The overstory vegetation is dominantly western redcedar, mountain hemlock, and Alaska-cedar, with lesser amounts of western hemlock and Sitka spruce in the Ketchikan area of Southeast Alaska. Western redcedar is replaced by western hemlock as the dominant overstory species North of Petersburg, Alaska. The understory vegetation is dominantly blueberry and red huckleberry, with lesser amounts of skunk cabbage and marsh marigold.


DISTRIBUTION AND EXTENT: Southeast Alaska. The series is extensive. SERIES ESTABLISHED: Hollis Area, Alaska, 1969.

REMARKS: Diagnostic horizons and features recognized in this soil are: organic soil from 0 to 23 inches dominated by sapric material below 12 inches; loamy-skeletal mineral material from 23 to 60 inches; a pH of 4.5 (0.01 M calcium chloride) from 4 to 23 inches. It is assumed that the soil never freezes below 2 inches. The Maybeso series formerly classified as Dysic. The Maybeso Series is proposed as a benchmark soil series.

National Cooperative Soil Survey