LOCATION DWARF PREstablished Series
TAXONOMIC CLASS: Very-fine, mixed, isomesic Humic Haplaquox
TYPICAL PEDON: Dwarf muck - forest in Caribbean National Forest. (Colors are for moist soil conditions.)
Oa--0 to 4 inches; very dark grayish brown (10YR 3/2) muck; weak fine subangular blocky structure; very friable; many medium and coarse roots; common fine interstitial and tubular pores; very strongly acid; clear smooth boundary. (3 to 7 inches thick)
A--4 to 9 inches; dark brown (10YR 3/3) mucky sandy loam; weak fine subangular blocky structure; very friable; slightly sticky; slightly plastic; many fine and medium roots; common fine and medium interstitial and tubular pores; few faint dark brown (7.5YR 3/2 and 7.5YR 4/4) stains along root channels; few medium distinct grayish brown (2.5Y 5/2) areas of iron depletions; very strongly acid; abrupt smooth boundary. (5 to 10 inches thick)
Bg1--9 to 16 inches; dark grayish brown (2.5Y 4/2) silty clay loam; weak medium subangular blocky structure parting to weak fine subangular blocky; friable; slightly sticky; slightly plastic; common fine and medium roots; common fine and medium vesicular and tubular pores; many distinct dark brown (7.5YR 3/4) and strong brown (7.5YR 4/6) stains along root channels; common large worm casts filled with very dark grayish brown (10YR 3/2) material; very strongly acid; clear smooth boundary.
Bg2--16 to 26 inches; olive gray (5Y 4/2) silty clay; weak medium subangular blocky structure parting to weak fine subangular blocky; friable; slightly sticky; slightly plastic; common fine and medium roots; common fine and medium vesicular and tubular pores; few distinct coats of organic material in root channels and/or pores; common large worm casts filled with very dark grayish brown (10YR 3/2) material; common coarse distinct olive (5Y 4/4) and light olive brown (2.5Y 5/6) masses of iron accumulation; very strongly acid; clear smooth boundary. (Combined thickness of the Bg horizons is 6 to to 18 inches).
Bw--26 to 35 inches; olive (5Y 4/4) silty clay; weak coarse angular blocky structure; friable; sticky; plastic; few fine roots; few fine and medium vesicular and tubular pores; few distinct pressure faces on horizontal faces of peds; few coarse and common medium irregular-shaped iron-manganese concretions; many large worm casts filled with very dark grayish brown (2.5Y 3/2) silt; common fine distinct olive (5Y 5/6) and light olive brown (2.5Y 5/6) masses of iron accumulation, few coarse distinct greenish gray (5GY 5/1) areas of iron depeletions; very strongly acid; clear smooth boundary. (4 to 10 inches thick).
2BC--35 to 43 inches; olive brown (2.5Y 4/4) clay loam; and weak coarse angular blocky structure; firm; sticky; plastic; few fine and medium vesicular and tubular pores; few distinct pressure faces on horizontal faces of peds; common large worm casts; few distinct very dark grayish brown (2.5Y 3/2) stains and organic coatings on faces of peds; many medium prominent dark yellowish brown (10YR 4/4) masses of iron accumulation and common coarse prominent greenish gray (5GY 5/1) areas of iron depletions; very strongly acid; clear smooth boundary. (3 to 12 inches thick).
2C1--43 to 52 inches; olive (5Y 5/6) silt loam; massive; friable; slightly sticky; plastic; few fine and medium vesicular and tubular pores; few large worm holes filled with very dark grayish brown (2.5Y 3/2) and light olive brown (2.5Y 5/4) material; few coarse prominent strong brown (7.5YR 4/6) and few medium prominent yellowish brown (10YR 5/8) masses of iron accumulation; few fine distinct greenish gray (5GY 5/1), areas of iron depletions; very strongly acid; clear smooth boundary.
2C2--52 to 60 inches; about 70 percent strong brown (7.5YR 5/6) and about 30 percent yellowish brown (10YR 5/8) silty clay loam; massive; friable; slightly sticky; plastic; few fine and medium vesicular and tubular pores; few large worm holes filled with dark olive gray (5Y 3/2) material; few medium irregular-shaped iron-manganese concretions; many coarse prominent strong brown (7.5YR 5/8) masses of iron accumulation and few medium prominent very pale brown (10YR 8/3) areas of iron depletions; very strongly acid.
TYPE LOCATION: Rio Grande Municipio, Puerto Rico. Caribbean National Forest, Noreste SWCD; from the road junction of Road 191 and Forest Route (FR) 10, approximately 0.9 miles north on FR 10 about 20 feet on east side of FR 10, about 20 feet northeast from pullout to first electronic site building. El Yunque topographic quadrangle; lat. 18 degrees, 17 minutes, 37 seconds N., long. 66 degrees, 47 minutes, 44 seconds W.; PRD 1940.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 30 to 50 inches. Reaction ranges from extremely acid to strongly acid throughout the profile. Rock fragments range from 0 to 10 percent, by volume, throughout the profile.
The Oa horizon has hue of 10YR, value of 2 or 3, and chroma of 2 or less; or it is neutral with value of 2 or 3. Rubbed fiber content is less than 25 percent.
The A horizon has hue of 10YR or 2.5Y, value of 2 to 4, and chroma of 3 or less; or it is neutral with value of 2 or 3. Texture is mucky sandy loam, mucky silt loam, or mucky loam.
The Bg horizon has hue of 10YR to 5Y, value of 4 to 6, and chroma of 2 or less. Redoximorphic accumulations in shades of brown and yellow range from few to many. Texture is silt loam, silty clay loam, or silty clay.
The Bw horizon has hue of 2.5Y or 5Y, value of 4 or 5, and chroma of 3 or 4. Redoximorphic features in shades of yellow, brown, olive, and gray range from common to many. Texture is silty clay or clay.
The BC or 2BC horizon, where present, is similar in color to the Bw horizon. Texture ranges from sandy loam to clay.
The C or 2C horizon has hue of 7.5YR to 5GY, value of 4 to 6, and chroma of 1 to 8; or there is no dominant color and is multicolored in shades of yellow, brown, olive, and gray. Texture is sandy loam, silt loam, loam, silty clay loam, or clay loam.
COMPETING SERIES: There are no other competing series in this family.
GEOGRAPHIC SETTING: Dwarf soils are on ridges and side slopes of deeply dissected mountains. They formed in organic accumulations and residuum from volcanic sandstone rocks that been effected by soil creep. Slopes range from 5 to 65 percent. The climate is humid tropical. The average annual precipitation ranges from 200 to 270 inches and the average annual temperature ranges from 52 to 58 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These include Palm soils. Palm soils are on lower positions, are clayey-skeletal, have oxidic mineralogy, and are isothermic.
DRAINAGE AND PERMEABILITY: Poorly drained; moderately slowly permeability.
USE AND VEGETATION: Native forest land that is used for recreation and research. Over 200 native and introduced woody species.
DISTRIBUTION AND EXTENT: El Yunque, Caribbean National Forest in Puerto Rico. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.
SERIES ESTABLISHED: Caribbean National Forest and Liquillo Experimental Forest, Puerto Rico, 1992.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Histic epipedon - zone from 0 to 9 inches (Oa and A horizons).
Cambic horizon - zone from 9 to 43 inches (Bg, Bw, and 2BC horizons).
Acid feature - Very strongly acid reaction from 10 to 40 inches (Bg, Bw, and 2 BC horizons).
Aquic feature - perched water table; 0.5 to 1.0 feet; January through December.
Hydric soil indicatiors - A2, A7, A8, F1, F3.
ADDITIONAL DATA: Characterization pedon - Caribbean National Forest; Puerto Rico; S87PR-003-003 and Lincoln Lab No. 87P304. Sample by NSSL Lincoln, NE.
MLRA: 270.