The Cowardin Classification System is a descriptive method developed by the US Fish & Wildlife Service that categorizes and defines wetlands according to their landscape position and water source.
Within these broad classes fall types of wetlands known by common names, such as marshes, bogs, and swamps. (DLNR, FWS)
Hawaiian bogs occur primarily in montane zones (a mosaic of rainforest and shrublands) as isolated small patches on flat or gently sloping topography in high rainfall areas in cloud forests and other wet forests on all of the high islands between 3,500-5,500 feet elevation.
These bogs also occur in the subalpine zone 7,446 feet elevation on Maui, and as a low-elevation bog at 2,120 feet on Kauai. Soils remain saturated on a shallow to deep layer of peat (0.01-5 m), underlain by an impervious basal clay layer that impedes drainage.
A few sloping bogs occur on steeper terrain were precipitation is extremely high, such as in North Bog in the Wai‘ale‘ale summit region of Kauai, where soils remain saturated despite adequate drainage.
Two bogs are believed to have formed in former small lakes, one along the Wailuku River, Hawai`i (Treeless bog), the other the subalpine bog on East Maui (Flat Top bog). The low-elevation bog on Kauai occurs on shallow, poorly drained acidic peat. (NatureServe Explorer)
Bogs are one of the most distinctive kinds of wetlands. They are characterized by spongy peat deposits, acidic waters and a floor covered by a thick carpet of moss. They are typically treeless areas, surrounded by cloud forest.
Bogs receive all or most of their water from precipitation rather than from runoff, groundwater or streams. As a result, bogs are low in the nutrients needed for plant growth, a condition that is enhanced by peat mosses.
Bogs serve an important ecological function in preventing downstream flooding by absorbing precipitation. (EPA)
Hawaiian bogs are characterized by an extremely dwarfed growth of the species represented in the surrounding forest, and by a number of species practically endemic to the bogs.
Most of the plants are deeply embedded in cushions and hummocks (ground rising above a marsh) of mosses, hepatics, and turf-forming grasses and sedges. The area is saturated with water and there are often channels and pools. (Fosberg & Hosaka)
The more familiar bogs of the islands are those in Alakai swamp, Kauai; Kawela Swamp, Molokai; Puu Kukui, west Maui and northeastern Haleakalā, Maui; Kaala Bog, Kohala Mountains, Hawaii; and in the Koolau Mountains on Oahu. (Fosberg & Hosaka)
These marshes and bogs are found in depressions where rain or groundwater collects. Hawai‘i’s rare montane bogs take millions of years to form. (DLNR)
Ninika (a boggy region in the Laupāhoehoe-Maulua forest) (Maly) is at the seaward end of the Hakala Forest refuge in Honohina. This name was recorded by the surveyor D.H. Hitchcock (1874) based on information from his two informants.
Ku and Kalaualoha (both Boundary Commission witnesses for Piha and Honohina); he says “I found that most of the [coastal] gulches ended at Ninika, and [upland] gulches from mauka ended at swamp.”
Kalaualoha testified that from its upper point of origin “Nauhi gulch only runs a short distance into woods and there spreads out all around;” for the Honohina testimony, he states that the coastal “Nanue gulch ends at Ninika.” Kapou (witness for Hakalau Nui) also mentions Ninika: “I have heard that Kaiwiki reaches to the Ninika.” (Tuggle)
The Waikaumalo/Piha boundary runs “up gulch to Ninika to where Puuohua ends and Mauluanui bounds it to the mountain. Bird catchers from these two lands used to catch in common … Ninika is at mauka end of Puuohua, Kumuohia is on Piha.” (Hawaiian Place Names)
When we think of Hakalau Forest Refuge, we typically think and see native ohia and koa forest and lots of forest birds. However, below where people go, but still within the Refuge, is a somewhat different story. As described by Myra Tomonari-Tuggle in a report she did for the Refuge:
“The wet ‘Ôhi‘a zone covers essentially the entire seaward half of the refuge and is characterized by a forest dominated by ‘Ôhi‘a trees. … The groundcover is primarily ferns.”
“This low elevation area is cut by numerous streams and gullies and the ground surface is often bog-like, described by Stine as:”
“At the lowest elevation of the [Refuge] is the bog – ohia dieback community. This unit is actually a mosaic of open bog, matted fern and native shrub communities, and open to scattered wet ohia forest with many standing dead or partially defoliated trees.”
“The forest dieback in this area is believed to be a result of the poor rooting conditions found in this extremely wet habitat … The wet open boggy areas are dominated by introduced grass and sedge species with scattered native shrubs.” (Stine)
“Soil samples from the bog in the southern half of the refuge suggest that the bog may range from 8 to more than 12 feet deep; these samples were collected from six sites ranging in elevation from 4,405 to 5,040 feet asl.”
“A 19th century map of Honohina, one of the traditional Hawaiian land units within the refuge, gives the name ‘Ninika Swamp’ to this lower elevation bog.”
“This zone corresponds to the lower range of McEldowney’s montane rainforest zone, which she describes as an area largely used as a source of specialized forest resources such as a forest birds for feathers and dry or mesic hardwood species for crafts or construction.”
“Historically, the bog at the seaward edge of the refuge was called Ninika Swamp; it is probable that this swamp extends at this elevation across all of the ahupua‘a in the refuge.”
“A multitude of stream channels enter from the upper slopes, dissipate in the bog, then exit as new channels to the lower coastal slopes.” (Tomonari-Tuggle)
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