Ecological Site Description
Ecological Site Characteristics
Site Identification
Site Type: Forestland
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Site ID: F164XY501HI
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MLRA: 164
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Colloquial Site Name: Ultrawet Dwarf Ohia Sphagnum Forest
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Official Site Name: Metrosideros polymorpha-Cheirodendron trigynum/Vaccinium calycinum-Myrsine sandwicensis
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Physiographic Features
This ecological site occurs on volcanic ash flows deposited over lava flows on sloping mountainsides of shield volcanoes. Volcanic ash flows range from deep to very deep on the underlying lava.
Landform: (1) volcanic ash flow
Landform: (2)
Landform: (3)
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Minimum
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Maximum
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Elevation (feet):
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1500
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4400
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Slope (percent):
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Water Table Depth (inches):
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Flooding:
Frequency:
Duration:
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|
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Ponding:
Depth (inches):
Frequency:
Duration:
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Runoff Class:
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low
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low
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Aspect: (1) NE
Aspect: (2)
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Climatic Features
Average annual precipitation ranges from 90 to 175 inches. Most of the precipitation falls from November through May, with December being the wettest month. Additional moisture is derived from condensation of fog on vegetation. Average annual temperature: no data. The climate generally can be classified as udic and tropical in nature. Interception of fog by vegetation adds considerable moisture to this ecological site (Juvik and Nullet 1993).
Climate Chart
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Minimum
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Maximum
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Frost Free Period (days):
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365
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365
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Freeze Free Period (days):
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365
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365
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Mean Annual Precipitation (inches):
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90
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175
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Monthly Precipitation (inches) and Temperature (0F)
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Month
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Jan
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Feb
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Mar
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Apr
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May
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Jun
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Jul
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Aug
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Sep
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Oct
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Nov
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Dec
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Precip. Avg.
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11.3
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11.8
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13.6
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14.9
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11.1
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9.7
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13.0
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15.4
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5.6
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7.9
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11.1
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16.5
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Temp. Min
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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Temp. Max
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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nd
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Climate Station: (1)
Climate Station: (2)
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East Honokane 183.2, 1949-1975
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Influencing Water Features
There are no water features influencing this site.
Representative Soil Features
Soils in this ecological site are formed in volcanic ash. Landscape surfaces in this ecological site are the oldest on the Island of Hawaii (120,000 to 500,000 years old). The soils are poorly drained. Available water capacity in most soils ranges from 6 to 9 inches. Available water capacity refers to the volume of water available to plants in the upper 40 inches of soil, including rocks, at field capacity. Permeability is rapid above the ironstone sheet. Runoff potential ranges is low. Moist colors range from dark gray to gray. Soil reactions (pH in CaCl2) range from 4.9 to 5.3 in surface horizons and 4.8 to 5.6 in subsurface horizons. Soil temperature regimes are isomesic. Soil moisture regimes are perudic (defined as a soil moisture regime in climates where precipitation exceeds evapotranspiration in all months of normal years, the moisture tension rarely reaches 100 kPa in the soil moisture control section, although there are occasional brief periods when stored moisture is used, and water moves through the soil in all months when it is not frozen).
Soils have a surface layer of live and decomposed sphagnum moss of variable thickness, underlain by a layer of gleyed, anaerobic mineral soil. Beneath this layer is an ironstone pan that perches water and acts as a barrier to root penetration.
Predominant Parent Materials:
Kind: volcanic ash
Origin:
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Surface Texture: (1) silt loam
Surface Texture: (2)
Subsurface Texture Group:
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Surface Fragments <=3" (%Cover): 0
Surface Fragments >3" (%Cover): 0
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Rock Fragments <=3" (%Volume): 0
Rock Fragments >3" (%Volume): 0
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Drainage Class: poorly
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Permeability Class: rapid above the ironstone sheet
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Minimum
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Maximum
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Depth (inches):
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20
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40
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Electrical Conductivity (mmhos/cm):
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Sodium Adsorption Ratio:
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Calcium Carbonate Equivalent (percent):
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Soil Reaction (1:1 Water):
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Soil Reaction (.0-1M CaC12):
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Available Water Capacity (inches):
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