LOCATION PUAULU HI
Established Series
Rev. KH-RTG
06/2012
PUAULU SERIES
The Puaulu series consists of deep and very deep, moderately well drained soils that formed in basic volcanic ash deposited over basic lava. Slopes range from 2 to 20 percent. The mean annual rainfall is about 3,685 millimeters (145 inches), and the mean annual air temperature is about 14 degrees C. (57 degrees F.)
TAXONOMIC CLASS: Medial over ashy, aniso, ferrihydritic over amorphic, isothermic Aquic Hapludands
TYPICAL PEDON: Puaulu hydrous silt loam, 4 percent slope under rain forest at an elevation of 1,160 meters (3,800 feet). (Colors are for moist soil unless otherwise noted. When described on 7/8/97 the soil was moist throughout. All textures are "apparent field textures". pH was measured using electrode in 1:1 water.)
A--0 to 8 centimeters (0 to 3 inches); dark reddish brown (5YR 3/2) hydrous silt loam; weak very fine subangular blocky structure; friable, slightly sticky and slightly plastic, weakly smeary; many very fine and fine roots; many very fine and fine interstitial pores; 10 percent gravel; strongly acid (pH 5.1); abrupt wavy boundary. (3 to 10 centimeters (1 to 4 inches) thick)
Bw--8 to 22 centimeters (3 to 9 inches); dark reddish brown (5YR 3/2) medial silt loam; weak medium subangular blocky structure; friable, slightly sticky and slightly plastic, weakly smeary; many very fine and fine roots; many very fine and fine interstitial pores; 5 percent gravel; strongly acid (pH 5.1); clear wavy boundary. (5 to 15 centimeters (2 to 6 inches) thick)
Cg--22 to 30 centimeters (9 to 12 inches); dark brown (7.5YR 3/2) ashy sandy loam; massive; friable, slightly sticky and slightly plastic, weakly smeary; many very fine and fine roots; many very fine and fine interstitial pores; common medium prominent irregular red (2.5YR 4/6) redox concentrations; slightly acid (pH 6.5); abrupt wavy boundary. (5 to 15 centimeters (2 to 6 inches) thick)
Cd1--30 to 38 centimeters (12 to 15 inches); lithochromic very dark grayish brown (10YR 3/2) ashy sand; massive; firm, nonsticky and nonplastic, nonsmeary; few very fine and fine roots; many very fine and fine interstitial pores; neutral (pH 7.0); abrupt discontinuous boundary.
Cd2--38 to 47 centimeters (15 to 18.5 inches); lithochromic black (10YR 2/1) ashy sand; massive; firm, nonsticky and nonplastic, nonsmeary; few very fine and fine roots; many very fine and fine interstitial pores; 10 percent subrounded gravel; neutral (pH 6.9); abrupt smooth boundary. (combined thickness of Cd horizons is 5 to 20 centimeters (2 to 8 inches))
2A/Bw--47 to 52 centimeters (18.5 to 20.5 inches); dark reddish gray (5YR 4/2) medial silt loam; weak very fine subangular blocky structure; friable, slightly sticky and slightly plastic, weakly smeary; common very fine and fine roots; many very fine and fine interstitial pores; neutral (pH 6.6); abrupt wavy boundary. (0 to 8 centimeters (0 to 3 inches) thick)
3A--52 to 55 centimeters (20.5 to 21.5 inches); black (N 2/0) medial silt loam; weak very fine subangular blocky structure; friable, moderately smeary, slightly sticky and slightly plastic; common very fine and fine roots, many very fine and fine interstitial pores; slightly acid (pH 6.4); clear wavy boundary. (0 to 5 centimeters (0 to 2 inches) thick)
3Bw1--55 to 61 centimeters (21.5 to 24 inches); dark reddish brown (5YR 2.5/2) medial silt loam; weak very fine subangular blocky structure; friable, slightly sticky and slightly plastic, weakly smeary; common very fine and fine roots, many very fine and fine interstitial pores; slightly acid (pH 6.5); abrupt smooth boundary. (3 to 10 centimeters (1 to 4 inches) thick)
3Bw2--61 to 71 centimeters (24 to 28 inches); dark reddish brown (5YR 2/2) medial sandy clay loam; weak fine subangular blocky structure; friable, slightly sticky and slightly plastic, weakly smeary; common very fine and fine roots; many very fine and fine interstitial pores; 3 percent gravel; neutral (pH 6.6); abrupt smooth boundary. (3 to 13 centimeters (1 to 5 inches) thick)
4A--71 to 75 centimeters (28 to 29.5 inches); black (10YR 2/1) hydrous silt loam; weak fine subangular blocky structure; friable, slightly sticky and slightly plastic, weakly smeary; few very fine and fine roots; many very fine and fine interstitial pores; neutral (pH 6.6); clear wavy boundary. (0 to 8 centimeters (0 to 3 inches) thick)
4Bw--75 to 78 centimeters (29.5 to 31 inches); dark reddish brown (5YR 3/2) medial silty clay loam; weak very fine subangular blocky structure; firm, moderately sticky and slightly plastic, moderately smeary; very few very fine roots, many very fine and fine interstitial pores; common patchy pressure faces; neutral (pH 6.6); clear smooth boundary. (0 to 5 centimeters (0 to 2 inches) thick)
5A--78 to 82 centimeters (31 to 32.5 inches); black (5YR 2.5/1) medial silty clay loam; weak very fine subangular blocky structure; firm, moderately sticky and slightly plastic, moderately smeary; many very fine and common fine roots; many very fine and fine interstitial pores; common distinct dark reddish brown (5YR 3/4) redox concentrations between peds; neutral (pH 6.6) clear smooth boundary. (0 to 5 centimeters (0 to 2 inches) thick)
5Bw--82 to 86 centimeters (32.5 to 34 inches); dark reddish brown (5YR 3/2) medial silt loam; weak fine and medium subangular blocky structure; friable, slightly sticky and slightly plastic, moderately smeary; many very fine and common medium roots; many very fine and fine interstitial pores; 5 percent gravel; moderately acid (pH 6.0); abrupt wavy boundary. (0 to 5 centimeters (0 to 2 inches) thick)
6A--86 to 89 centimeters (34 to 35 inches); black (5YR 2.5/1) medial silt loam; weak fine and medium subangular blocky structure; friable, slightly sticky and slightly plastic, weakly smeary; few very fine and fine roots; many very fine and fine interstitial pores; moderately acid (pH 5.7); abrupt wavy boundary. (0 to 5 centimeters (0 to 2 inches) thick)
6Bw--89 to 94 centimeters (35 to 37 inches); dark brown (7.5YR 3/3) medial very gravelly sandy clay loam; weak fine and medium subangular blocky structure; friable, moderately sticky and slightly plastic, moderately smeary; few very fine and fine roots; many very fine and fine interstitial pores; common fine and medium prominent yellowish red (5YR 4/6) redox concentrations in cracks; 50 percent gravel; moderately acid (pH 5.8); abrupt wavy boundary. (0 to 5 centimeters (0 to 2 inches) thick)
7A--94 to 96 centimeters (37 to 38 inches); black (5YR 2/1) hydrous silt loam; weak very fine granular structure; friable, slightly sticky and slightly plastic, weakly smeary; few very fine and fine roots; many very fine and fine interstitial pores; moderately acid (pH 5.6); abrupt broken boundary. (0 to 5 centimeters (0 to 2 inches) thick)
7Bw1--96 to 104 centimeters (38 to 41 inches); dark reddish brown (5YR 3/3) extremely gravelly medial sandy clay loam; massive; friable, moderately sticky and slightly plastic, moderately smeary; few very fine and fine roots; many very fine and fine interstitial pores; 70 percent gravel; moderately acid (pH 5.8); abrupt wavy boundary. (3 to 10 centimeters (1 to 4 inches) thick)
8Bw2--104 to 110 centimeters (41 to 43.5 inches); dark brown (7.5YR 3/2) hydrous silty clay loam; weak fine subangular blocky structure; friable, moderately sticky and slightly plastic, weakly smeary; few very fine and fine roots; many very fine and fine interstitial pores; many fine and medium faint dark reddish brown (5YR 3/3) redox concentrations throughout; moderately acid (pH 5.7); clear smooth boundary. (0 to 10 centimeters (0 to 4 inches) thick)
9Bw3--110 to 121 centimeters (43.5 to 47.5 inches); dark reddish brown (5YR 2/2) medial silty clay loam; weak fine subangular blocky structure; friable, moderately sticky and slightly plastic, weakly smeary; very few very fine and fine roots; many very fine and fine interstitial pores; strongly acid (pH 5.5); clear wavy boundary. (0 to 13 centimeters (0 to 5 inches) thick)
10Bw4--121 to 130 centimeters (47.5 to 51 inches); dark brown (7.5YR 3/3) medial sandy clay loam; massive; friable, weakly brittle; moderately sticky and slightly plastic, moderately smeary; very few very fine and fine roots; many very fine and fine interstitial pores; 5 percent gravel; moderately acid (pH 5.6); clear smooth boundary. (0 to 13 centimeters (0 to 5 inches) thick)
10Bw5--130 to 135 centimeters (51 to 53 inches); dark brown (7.5YR 3/3) medial sandy clay loam; massive; friable, moderately sticky and slightly plastic, moderately smeary; very few very fine and fine roots; many very fine and fine interstitial pores; moderately acid (pH 5.6); clear wavy boundary. (0 to 8 centimeters (0 to 3 inches) thick)
10Bw6--135 to 152 centimeters (53 to 60 inches); dark brown (7.5YR 3/3) medial sandy clay loam; weak fine subangular blocky structure; friable, moderately sticky and slightly plastic, moderately smeary; very few very fine and fine roots; many very fine and fine interstitial pores; strongly acid (pH 5.4);
TYPE LOCATION: Island of Hawaii, Hawaii; from State Hwy 11 travel 2.2 miles northwest on State Hwy. 148 (Wright Road) to the Olaa tract of Hawaii Volcanoes National Park; continue on State Hwy 148 for 0.1 mile to "road narrows" sign; walk east to fence, then north along fence for about 25 feet; cross fence at fallen tree and take 15 degrees magnetic heading about 22 feet to type location; Volcano Quadrangle; lat. 19 degrees 27 minutes 38.86 seconds N. and long. 155 degrees 14 minutes 51.84 seconds W. (Old Hawaiian Datum measured by GPS/PLGR).
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 15 to 18 degrees C. (59 to 64 degrees F.).
Rock fragments: Typically, less than 10 percent gravel or pumice; some B and C horizons have as much as 95 percent.
Buried horizon: Occurs in all pedons, but not all pedons have the same buried horizons.
Brittle horizon: Occurs in most pedons.
Indurated ash: Occurs in some pedons.
Soil reaction: Strongly acid to extremely acid in the surface and subsurface layers and neutral to strongly acid in the underlying layers.
A horizon
Hue: 5YR to 10YR, N.
Value: 2 to 4 moist.
Chroma: 1 or 2 moist.
Structure: Granular or subangular blocky.
B horizon
Hue: 5YR to 10YR.
Value: 2 to 4 moist.
Chroma: 2 to 4 moist.
Texture: Silt loam, sandy clay loam, silty clay loam, predominately medial but possibly ashy or hydrous.
Structure: Subangular blocky, granular, or single grain.
Bsm horizon: Occurs in some pedons and is stratigraphically located within the 10Bw horizon zone.
C horizon
Value: 2 or 3 moist.
Chroma: 1 or 2 moist.
Texture: Sand or loamy sand, predominately medial but possibly ashy.
Structure: Massive or single grain.
Cemented (Cm) horizon: Occurs in some pedons.
COMPETING SERIES: There are no competing series.
Eheuiki and
Hao soils are similar. Eheuiki soils are skeletal at depths below 20 inches. Hao soils have a placic horizon.
GEOGRAPHIC SETTING: Puaulu soils formed in three main volcanic ash packets: Keanakakoi base surge and ash, 200 to 600 years old, Uwekahuna ash, 2,000 to 3,000 years old, and an unnamed ash, about 10,000 years old. Puaulu soils are mainly on Mauna Loa landscapes approximately 10,000 years old at elevations 975 to 1,371 meters (3,200 to 4,500 feet). Slopes range from 2 to 10 percent. The mean annual rainfall is 2,795 to 4065 millimeters (110 to 160 inches), with about 75 percent of the rainfall occurring between November and May. The mean annual pan evaporation is 1,015 to 1,270 millimeters (40 to 50 inches). The mean annual air temperature is 13 to 16 degrees C. (55 to 60 degrees F.)
GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar
Eheuiki and
Hao soils.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is low to moderate. Permeability is moderate.
USE AND VEGETATION: These soils are used for National Park Service land, vegetable crops, and pasture. Vegetation is banana poka (Passiflora mollissima), kawau or Hawaiian Holly (Ilex anomala), loulu (Pritchardia beccariana), ohia lehua (Metrosideros polymorpha), olapa (Cheirodendron trigynum), naenae (Dubautia ciliolata), hapuu-pulu or tree fern (Cibotium glaucum), and yellow Himalayan raspberry (Rubus ellipticus).
DISTRIBUTION AND EXTENT: These soils occur in the Olaa portion of Hawaii Volcanoes National Park and the surrounding area; MLRA 159A. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Island of Hawaii, Hawaii County, Hawaii, 1971.
REMARKS: Diagnostic features and horizons recognized in this pedon are:
Andic soil properties - from 0 to 152 centimeters (60 inches).
Ochric epipedon - 0 to 22 centimeters (9 inches).
Densic Material - from 30 to 47 cm (12 to 18.5 inches).
Soil temperature - mean summer and mean winter soil temperatures differ by less than 6 degrees C. (iso temperature regime).
Soil moisture - precipitation exceeds evapotranspiration in all months of normal years (perudic moisture regime).
Ash packets - Keanakakoi ash is 0 to 47 centimeters (21 inches), Uwekahuna ash is 47 to 121 centimeters (21 to 48 inches), and an unnamed ash is 121 to 152 centimeters (48 to 60 inches).
This pedon could be Typic Endoaquands, but going with Aquic Hapludands based on location of redox features.
Edit Log: 12/03 KH. Added "hydrous", "medial", and "ashy" modifiers to textures.
9/99 KH. Changed type location. Changed classification due to changes in Taxonomy and new lab data. Was Medial over thixotropic, isothermic Typic Hydrandepts.
ADDITIONAL DATA: Puaulu NSSL sample S96HI-001-001 from type location.
Penetrometer measurements
Bw horizon = 0.25 tons/square foot
Cg horizon = 3.00 tons/square foot
Cd1 horizon > 4.00 tons/square foot
Cd2 horizon = 3.50 tons/square foot
2A/B horizon = 0.75 tons/square foot
3A horizon = 0.50 tons/square foot
3Bw1 horizon = 1.00 ton/square foot
3Bw2 horizon = 0.75 tons/square foot
4A horizon = 0.50 tons/square foot
4Bw horizon = 1.25 tons/square foot
5A horizon = 0.50 tons/square foot
5Bw horizon = 1.00 ton/square foot
8Bw2 horizon = 1.50 tons/square foot
9Bw3 horizon = 1.50 tons/square foot
10Bw4 horizon = 1.00 ton/square foot
10Bw5 horizon = 1.00 ton/square foot
10Bw6 horizon = 1.00 ton/square foot
National Cooperative Soil Survey
U.S.A.