LOCATION MESEI PW+FM PB

Established Series
Rev. CWS/JVP/MRK/KP
03/2017

MESEI SERIES

The Mesei series consists of very deep, very poorly drained soils on bottomlands. These soils formed in deposits of organic material overlying alluvial sediment. Slope is 0 to 1 percent. The mean annual rainfall is about 3683 millimeters (145 inches), and the mean annual temperature is about 27 degrees C (81 degrees F).

TAXONOMIC CLASS: Loamy, mixed, euic, isohyperthermic Terric Haplosaprists

TYPICAL PEDON: Mesei muck - in a level area with wetland taro, hydrophytic grasses and sedges. When described (3/6/80), the soil was saturated throughout. The water table was 10 inches above the soil surface. (Colors are for moist soil. Texture for C horizon is apparent field texture.)

Oa1--0 to 13 centimeters (0 to 5 inches); dark brown (7.5YR 3/2) muck; about 30 percent fiber, 2 percent rubbed; massive; nonsticky and slightly plastic; many very fine and fine roots and medium roots; color is 10YR 7/2 in pyrophosphate solution; very strongly acid (pH 4.5 in calcium chloride); clear smooth boundary. (10 to 30 centimeters (4 to 12 inches thick)).

Oa2--13 to 41 centimeters (5 to 16 inches); very dark grayish brown (10YR 3/2) muck; about 24 percent fiber, 4 percent rubbed; massive; nonsticky and slightly plastic; many very fine and fine roots and medium roots color is 10YR 6/3 in pyrophosphate solution; strongly acid (pH 5.3 in calcium chloride); gradual wavy boundary. (20 to 51 centimeters (8 to 20 inches thick)).

Oa3--41 to 86 centimeters (16 to 34 inches); very dark grayish brown (10YR 3/2) muck; about 29 percent fiber, 1 percent rubbed; massive; nonsticky and slightly plastic; many very fine and fine roots color is 10YR 6/3 in pyrophosphate solution; strongly acid (pH 5.4 in calcium chloride); abrupt smooth boundary. (30 to 51 centimeters (12 to 20 inches thick)).

2Cg--86 to 150 centimeters (34 to 59 inches); dark gray (10YR 4/1) silt loam; massive; slightly sticky and slightly plastic; many very fine roots; many very fine and fine tubular pores; about 5 percent by volume plant fibers .04 to .6 inches in diameter; slightly acid (pH 6.2, 1:1 water); abrupt smooth boundary. (51 to 84 centimeters (20 to 33 inches thick)).

3Oeb--150 to 188 centimeters (59 to 74 inches); black (10YR 2/1) mucky peat, about 76 percent fiber, 48 percent rubbed; friable, nonsticky and nonplastic; color is 10YR 8/1 in pyrophosphate solution; strongly acid (pH 5.4 in calcium chloride).

TYPE LOCATION: Babelthuap Island, Palau, Western Caroline Islands, about 1,919 feet along the main road SE. of T intersection of main road and road leading to Nekken. Turn NE and proceed 66 feet along trail. Site is 33 feet NW of trail; lat. 7 degrees 22 minutes 2.5 seconds N. and long. 134 degrees 32 minutes and 28 seconds E. (WGS 84 datum)

RANGE IN CHARACTERISTICS:
The mean annual soil temperature (MAST) is 27 degrees C (81 degrees F). The difference between the mean summer and winter temperatures is less than 6 degrees C. Mean annual precipitation (MAP) is 3048 to 3683 millimeters (120 to 145 inches). Thickness of the organic layers above a mineral layer ranges from 63 to 99 centimeters (25 to 39 inches). The water table ranges from 30 centimeters (12 inches) above the surface to 15 centimeters (6 inches) below the surface. Rubbed fiber content throughout the surface and subsurface tiers ranges from 0 to 20 percent by volume. Some pedons have strata that are as much as 15 percent by volume mineral silt and clay. The surface layer is hemic or sapric material.

The Oa horizon has hue of 7.5YR or 10YR, value of 2 through 4, and chroma of 1 through 3. Reaction in calcium chloride is very strongly acid or strongly acid.

The 2C horizon is silt loam or silty clay loam. It has hue of 10YR, 2.5YR, or 5Y, value of 4 through 6, and chroma of 0 through 2. It is from 0 to 10 percent by volume coarse fragments. Reaction in 1:1 water is medium acid or slightly acid. The N value is more than 0.7.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Mesei soils are on very poorly drained valley bottoms near sea level. Slopes are nearly level. They formed in deposits of organic material overlying alluvium derived from upland soils on volcanic. Elevations are sea level to 6 feet. Mean annual rainfall ranges from 3048 to 3683 millimeters (120 to 145 inches), and the mean annual temperature is 27 degrees C (81 degrees F).

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dechel and Ngersuul soils. The Dechel soils are mineral soils that have textures and colors similar to Mesei's 2 C horizon. Ngersuul soils are poorly drained, mineral and alluvial soils.

DRAINAGE AND PERMEABILITY: Very poorly drained; very slow runoff; moderately slow permeability. A fluctuating water table ranges from 2.5 centimeters (1 inch) above soil surface to 15 centimeters (6 inches) below soil surface.

USE AND VEGETATION: The soil is used for the production of wetland taro. Unused areas are in hydrophytic grasses (Phragmytes sp.) and sedges.

DISTRIBUTION AND EXTENT: Mesei soils are in Palau and Yap Islands. They are of small extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Airai Municipality, Babelthuap Island, Palau, Western Caroline Islands, 1981.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Sapric material- the zone from a depth of 0 to 86 centimeters (Oa1, Oa2 and Oa3 horizons).
Hemic soil Material- the zone from a depth of 150 to 188 centimeters (3Oeb horizon).
Lithologic Discontinuities- the zone from a depth of 86 to 188 centimeters (2Cg and 3Oeb horizons).
Abrupt textural change- the zone from a depth of 86 to 188 centimeters (2Cg and 3Oeb horizons).
Aquic condition- the zone from a depth of 0 to 188 centimeters (Oa1, Oa2, Oa3 2Cg and 3Oeb horizons).

ADDITIONAL DATA: Typical pedon characterized by National Soil Survey Laboratory, Lincoln, Nebraska. Sample No. S80PB935005.

National Cooperative Soil Survey
U.S.A.