LOCATION DOLEN FM+PBEstablished Series
TAXONOMIC CLASS: Very-fine, parasesquic, isohyperthermic Typic Dystrudepts
TYPICAL PEDON: Dolen cobbly silt loam - on a 48 percent convex slope in agricultural forest. When described (2/15/79) the soil was moist throughout. (Colors are for moist soil. All textures are apparent field textures.)
A1--0 to 2 inches; dark brown (7.5YR 3/2) cobbly silt loam; strong fine and medium granular structure; very friable, slightly sticky and slightly plastic; many fine, medium, and common coarse roots; many very fine and fine interstitial pores and common very fine tubular pores; about 20 percent hard basalt cobbles; slightly acid (pH 6.4 in 1:1 water); clear wavy boundary. (2 to 12 inches thick)
B21--2 to 8 inches; dark yellowish brown (10YR 4/4) silty clay loam; moderate fine subangular blocky structure parting to strong fine and medium granular; friable, slightly sticky and plastic; many fine and medium roots; many very fine and fine tubular and interstitial pores; 10 percent cobbles; medium acid (pH 5.8 in 1:1 water); gradual wavy boundary. (5 to 10 inches thick)
B22--8 to 17 inches; dark yellowish brown (10YR 4/4) silty clay loam; moderate medium subangular blocky structure parting to strong very fine angular blocky; firm, slightly sticky and plastic; common fine and medium roots; common very fine and fine tubular and interstitial pores; 5 percent highly weathered pebbles; medium acid (pH 5.6 in 1:1 water); gradual wavy boundary. (3 to 12 inches thick)
B23--17 to 46 inches; yellowish brown (10YR 5/4) silty clay loam; moderate coarse subangular blocky structure parting to moderate fine and medium granular; firm, slightly sticky and plastic; common fine roots in upper part, decreasing to few in lower part; common very fine and fine tubular and interstitial pores; 5 percent highly weathered pebbles; strongly acid (pH 5.5 in 1:1 water); abrupt irregular boundary. (20 to 29 inches thick)
C--46 to 95 inches; dark brown (7.5YR 4/2) stony silty clay loam; weak medium and coarse subangular blocky structure; few very fine and medium roots; many very fine tubular pores; 35 percent basalt cobbles and stones; strongly acid (pH 5.5 in 1:1 water).
TYPE LOCATION: Sokehs Island, Ponape State, Federated States of Micronesia; about 1,968 feet from the beginning of the old Japanese road on the east side of Sokehs Island, cut back roadbank on left; lat. 6 degrees 57 minutes 41 seconds N. and long. 158 degrees 12 minutes 38 seconds E.
RANGE IN CHARACTERISTICS: Depth to highly weathered basic igneous rock ranges from 59 inches to over 78 inches. The thickness of the solum ranges from 27 to 49 inches.
The A horizon has moist color of 7.5YR 3/2, 3/4, 4/4; 10YR 3/3, 3/4, 4/4. The apparent field texture is silt loam or silty clay loam, and coarse fragments range from 0 to 25 percent cobbles and 0 to 5 percent stones. The reaction in 1:1 water ranges from slightly acid through strongly acid.
The B horizon has moist color of 7.5YR 4/4, 4/6; 10YR 4/4, 4/6, 5/4. The apparent field texture is silty clay loam, clay loam, silty clay, or clay. The coarse fragments range from 0 to 20 percent cobbles and 0 to 5 percent pebbles. The reaction in 1:1 water is medium acid or strongly acid.
The C horizon has moist color of 7.5YR 4/2, 4/4, 4/6; 10YR 4/4, 5/6. The apparent field texture is silty clay loam or silt loam. Coarse fragments range from 0 to 50 percent cobbles and stone, and 0 to 10 percent pebbles.
COMPETING SERIES: These are the Fomseng and Tolonier series in other families. Fomseng soils are shallow and high in organic matter. Tolonier soils are skeletal.
GEOGRAPHIC SETTING: Dolen soils are on foot slopes and on uplands. Slopes are 6 to 100 percent. These soils formed in colluvium and residuum derived from highly weathered basic igneous rock. Elevation is 17 to 1,968 feet. The mean annual rainfall is 143 to 255 inches and the mean annual temperature is about 77 to 81 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Tolonier soils.
DRAINAGE AND PERMEABILITY: Well drained; slow through rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Dolen soils are used for subsistence agriculture, woodland, watershed, and wildlife habitat. The main crops are breadfruit, banana, and coconut. The native vegetation is mainly mixed upland tropical rain forest.
DISTRIBUTION AND EXTENT: Upland areas of the islands of Kosrae, Ponape and Truk, East Caroline Islands. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Ponape, Federated States of Micronesia, 1981.
ADDITIONAL DATA: Two pedon of this series were sampled and laboratory analysis was performed by the SCS National Soil Survey Laboratory, Lincoln, Nebraska, in 1979 and 1980. Pedon numbers are S79 TQ-634-023 and S80 TQ-637-001.