LOCATION NENENUI HI

Established Series
MRK-RTG
06/2012

NENENUI SERIES

The Nenenui series consists of very shallow, well drained soils that formed in basic volcanic ash and cinders over pahoehoe lava. Slopes range from 2 to 20 percent. The mean annual rainfall is about 580 millimeters (23 inches), and the mean annual temperature is about 11 degrees C (51 degrees F).

TAXONOMIC CLASS: Cindery, mixed, isomesic Lithic Ustivitrands

TYPICAL PEDON: Nenenui extremely gravelly ashy loamy sand, on a southwest facing, 2 percent slope, under scattered shrubs at an elevation of 1588 meters (5209 feet). (Colors are for dry soil unless otherwise noted. All textures are "apparent field textures". When described on 9/8/94 the soil was slightly moist.)

C1/A--0 to 3 centimeters (0 to 1 inch); dark brown (7.5YR 3/3) extremely gravelly ashy loamy sand, dark brown (7.5YR 3/2) moist; weak very fine and fine subangular blocky structure; soft, very friable, nonsticky, nonplastic, and nonsmeary; few very fine roots; many fine interstitial pores; 70 percent gravel-size cinders and 5 percent pahoehoe stones; surface covered by 100 percent gravel-size cinders; C materials consist of cinders and unconsolidated pahoehoe lava fragments; neutral (pH 6.8); abrupt smooth boundary.

C2--3 to 15 centimeters (1 to 6 inches); black (N 2/0) cinders; single grain; loose when dry or moist, nonsticky and nonplastic; few very fine roots; many fine and medium interstitial pores; abrupt smooth boundary.

2R--15 centimeters (6 inches); hard pahoehoe lava.

TYPE LOCATION: Island of Hawaii, Hawaii County, Hawaii; from Ahu a Umi Heiau, pedon is located 61 meters (200 feet) at 320 degrees north-northwest. Hualalai Quadrangle; lat. 19 degrees 38 minutes 15.0 seconds N. and long. 155 degrees 47 minutes and 1.0 seconds W. (Old Hawaiian Datum)

RANGE IN CHARACTERISTICS:
Depth to bedrock: 5 to 25 centimeters (2 to 10 inches).
Mean annual soil temperature: 10 to 14 degrees C (50 to 58 degrees F).
Rock fragments: 80 to 100 percent by volume of the pedon and are gravel-size cinders.

C1/A horizon
Hue: 5YR to 10YR.
Value: 2 or 3 moist or dry.
Chroma: 2 or 3 moist or dry.
Texture: Very or extremely gravelly, ashy loamy sand or ashy sandy loam.
Structure: Weak to strong subangular blocky, granular, or single grain.
Soil reaction: Neutral (pH 6.6 to 7.3).

COMPETING SERIES: There are no competing series. Similar soils include the Ohianui series. Ohianui soils are ashy over cindery and have a lithic contact at 50 to 102 centimeters (20 to 40 inches).

GEOGRAPHIC SETTING: The Nenenui soils are in depressions of pahoehoe lava flows on high mountain slopes and in the saddle area between Hualalai and Mauna Loa volcanoes at elevations from 1585 to 2255 meters (5200 to 7400 feet). Slope gradients range from 2 to 20 percent. The soils formed in basic volcanic ash and cinders over pahoehoe lava. The mean annual rainfall ranges from 380 to 760 millimeters (15 to 30 inches). The mean annual pan evaporation ranges from 1020 to 1780 millimeters (40 to 70 inches). The mean annual air temperature ranges from 8 to 13 degrees C (47 to 55 degrees F). The mean summer and winter soil temperatures differ by less than 6 degrees C (11 degrees F).

GEOGRAPHICALLY ASSOCIATED SOILS: These are Huikau, Kealoha, Nawahine, and the similar Ohianui series. Huikau soils are ashy and greater than 102 centimeters (40 inches) deep. Kealoha soils are medial-skeletal and have a lithic contact from 50 to 102 centimeters (20 to 40 inches). Nawahine soils are medial-skeletal over cindery and have a lithic contact at greater than 102 centimeters (40 inches).

DRAINAGE AND PERMEABILITY: Well drained. Runoff is high. Permeability is rapid in the soil and very slow in the underlying bedrock.

USE AND VEGETATION: These soils are used for wildlife habitat. The natural vegetation is pukiawe (Styphelia tameiameiae, aalii (Dodonaea viscosa), and ohia lehua (Metrosideros polymorpha).

DISTRIBUTION AND EXTENT: High mountain slopes and saddle area between Hualalai and Mauna Loa volcanoes; MLRA 161B. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Island of Hawaii, Hawaii County, Hawaii, 2012. Proposed 1998.

REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon - from 0 to 3 centimeters (0 to 1 inch) (C1/A horizon).
Andic soil properties - from 0 to 15 centimeters (0 to 6 inches) (C1/A and C2 horizons).
Lithic contact - at 15 centimeters (6 inches) (2R horizon).

Soil moisture - usually moist, but dry for short intermittent periods totaling 90 or more days throughout the year in most years (Ustic moisture regime).

ADDITIONAL DATA: NASIS User Pedon ID 01HI601021.

Edit log: 2/08 MRK. Andic textural modifiers added.

National Cooperative Soil Survey
U.S.A.