Print Report
G426 Carex alligata - Carex echinata - Racomitrium lanuginosum Hawaiian Bog Group
Type Concept Sentence: Hawaiian bogs are characterized by an uneven hummocky matrix of sedges, grasses and mosses with or without a woody layer of stunted Metrosideros polymorpha. Characteristic species include Carex alligata, Carex echinata, Carex montis-eeka, Carex thunbergii, Deschampsia nubigena, Dichanthelium spp., Oreobolus furcatus, Rhynchospora rugosa ssp. lavarum, and the moss Racomitrium lanuginosum.
Common (Translated Scientific) Name: Hawai`i Sedge - Star Sedge - Woolly Moss Hawaiian Bog Group
Colloquial Name: Hawaiian Bog
Hierarchy Level: Group
Type Concept: Hawaiian bogs are characterized by an uneven hummocky matrix of sedges and grasses often dominated by Oreobolus furcatus and Rhynchospora rugosa ssp. lavarum. Other characteristic species include the moss Racomitrium lanuginosum, sedges Carex alligata, Carex echinata, Carex montis-eeka, and Carex thunbergii, grasses Deschampsia nubigena, Dichanthelium cynodon, Dichanthelium hillebrandianum, and Dichanthelium isachnoides, and frequently stunted woody plants, including Metrosideros polymorpha, Coprosma ochracea, and Dubautia spp. Dwarfed or stunted woody plants can occur as scattered individuals, in clumps, or as a continuous layer. Associated ferns and herbs include Dicranopteris linearis, Polypodium spp., Sadleria spp., and, less commonly, Astelia spp., Athyrium spp., Elaphoglossum spp., Hymenophyllum spp., Machaerina spp., Lysimachia spp., Plantago spp., Schizaea robusta, Selaginella deflexa, Viola spp., and on Kaua`i Drosera anglica. Hawaiian bogs occur primarily in montane zones 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 1067 and 1670 m (3500-5500 feet) elevation. These bogs also occur in the subalpine zone at 2270 m (7446 feet) elevation on Maui, and as a low-elevation bog at 646 m (2120 feet) on Kaua`i. 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 Kaua`i, 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 Kaua`i occurs on shallow, poorly drained acidic peat.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: Hawaiian bogs form an uneven hummocky matrix of sedges and grasses that are typically dominated by Carex alligata, Carex echinata, Carex montis-eeka, Carex thunbergii, Deschampsia nubigena, Dichanthelium cynodon, Dichanthelium hillebrandianum, Dichanthelium isachnoides, Dichanthelium koolauense, Machaerina angustifolia, Oreobolus furcatus, and Rhynchospora rugosa ssp. lavarum, and stunted woody plants, including Metrosideros spp., Coprosma ochracea, and Dubautia spp. Substrates are organic, typically with an impermeable layer of clay that impedes drainage.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: This group is characterized by dense herbaceous cover of graminoids and mosses with or without a sparse to dense layer of stunted woody plants.
Floristics: Hawaiian bogs are characterized by an uneven hummocky matrix of sedges and grasses often dominated by Oreobolus furcatus and Rhynchospora rugosa ssp. lavarum (= Rhynchospora lavarum) with Carex alligata, Carex echinata, Carex montis-eeka, Carex thunbergii, Deschampsia nubigena (= Deschampsia australis), Dichanthelium cynodon, Dichanthelium hillebrandianum, Dichanthelium isachnoides, Dichanthelium koolauense, Machaerina angustifolia, and stunted woody plants, including Metrosideros spp., Coprosma ochracea, and Dubautia spp. (Vogel and Hendrickson 1971, Yoshinga 1978, Sohmer and Gustafson 1987, Gagne and Cuddihy 1990, Loope et al. 1991, Medeiros et al. 1991, Corn 1992). Dwarfed or stunted woody plants can occur as scattered individuals, in clumps, or as a continuous layer. Associated ferns, fern allies, mosses and herbs include Dicranopteris linearis, Polypodium spp., Sadleria spp., and, less commonly, Astelia spp., Athyrium spp., Drosera anglica, Elaphoglossum spp., Hymenophyllum spp., Lycopodiella cernua (= Lycopodium cernuum), Lysimachia spp., Machaerina spp., Racomitrium lanuginosum, Plantago spp., Schizaea robusta, Selaginella deflexa, Sphagnum palustre, and Viola spp. (Sohmer and Gustafson 1987, Gagne and Cuddihy 1990, Loope et al. 1991).
Dynamics: Although open bog habitat may be suitable for introduced species tolerant of saturated soils, few alien species appear capable of invading undisturbed bog vegetation. However, following disturbance by pigs several non-native species such as Ageratina adenophora, Andropogon virginicus, Conyza bonariensis, Cyperus haspan, Holcus lanatus, Hypochaeris radicata, Juncus planifolius, Melinis minutiflora, Sacciolepis indica, Schizachyrium condensatum, Senecio sylvaticus, and Sonchus oleraceus may establish (Sohmer and Gustafson 1987, Loope et al. 1991). Non-native seeds are dispersed along trail corridors by pigs and by humans (e.g., Holcus) or have wind-dispersed seeds (e.g., Andropogon, Conyza, Senecio, Sonchus). Although Holcus lanatus and Juncus planifolius appear to be aggressive exotic species, most exotic plants may eventually be crowded out by native bog species, if disturbance is eliminated. For example, after severe pig disturbance in Greensword Bog had 96% bare ground, and recovered to 10% bare ground after 3 years of protection (Loope et al. 1991). However, all bogs are threatened by feral pig rooting followed by invasion of exotic species and should be fenced to protect them and to allow disturbed bogs to recover from previous damage, by keeping pigs away.
Environmental Description: Hawaiian bogs occur primarily in montane zones as isolated small patches on generally flat or sometime gently sloping topography in high rainfall areas in cloud forests and other wet forests on all of the high islands between 1067 and 1670 m (3500-5500 feet) elevation, but range from the subalpine zone at 2270 m (7446 feet) on Maui to a low-elevation bog at 646 m (2120 feet) on Kaua`i. On flat and gently sloping terrain, the clay formation impedes drainage resulting in perched water on top of the clay. In addition, it has now been established that eolian clay mineral deposits accumulated on broad summits and ridges within high rainfall and cloud areas over a 200,000- to 500,000-year time span have also contributed to the formation of clay substrates that support Hawaiian bogs.
Climate: Climate is generally very wet (Zones 7) of the 7 Moisture Zones developed for the Hawaiian Islands by Price et al. (2007). Annual precipitation typically is over 4500 mm.
Soil/substrate/hydrology: 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 Kaua`i, 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 Kaua`i occurs on shallow, poorly drained acidic peat. Clay formation in Hawaiian bogs is typically a result of basaltic weathering under cool, wet conditions that permits an accumulation of humus. Peat layer generally exceeds 0.5 m (Mueller-Dombois and Fosberg 1998).
Climate: Climate is generally very wet (Zones 7) of the 7 Moisture Zones developed for the Hawaiian Islands by Price et al. (2007). Annual precipitation typically is over 4500 mm.
Soil/substrate/hydrology: 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 Kaua`i, 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 Kaua`i occurs on shallow, poorly drained acidic peat. Clay formation in Hawaiian bogs is typically a result of basaltic weathering under cool, wet conditions that permits an accumulation of humus. Peat layer generally exceeds 0.5 m (Mueller-Dombois and Fosberg 1998).
Geographic Range: Hawaiian bogs occur primarily in montane zones as isolated small patches on flat or gently sloping topography in high rainfall areas on Maui and Kaua`i.
Nations: US
States/Provinces: HI
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.860751
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 2 Shrub & Herb Vegetation Class | C02 | 2 |
| Subclass | 2.C Shrub & Herb Wetland Subclass | S44 | 2.C |
| Formation | 2.C.1 Tropical Bog & Fen Formation | F002 | 2.C.1 |
| Division | 2.C.1.Oa Polynesian Bog & Fen Division | D017 | 2.C.1.Oa |
| Macrogroup | 2.C.1.Oa.1 Hawaiian Bog & Fen Macrogroup | M238 | 2.C.1.Oa.1 |
| Group | 2.C.1.Oa.1.a Hawai`i Sedge - Star Sedge - Woolly Moss Hawaiian Bog Group | G426 | 2.C.1.Oa.1.a |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Montane Bogs (Loope et al. 1991)
= Montane Bogs (Medeiros et al. 1991a)
= Montane Bogs (Mueller-Dombois and Fosberg 1998)
> Montane Wet Herbland (Gagne and Cuddihy 1990)
> Montane Wet Mixed Communities (Gagne and Cuddihy 1990)
> Montane Wet Sedgeland (Gagne and Cuddihy 1990)
> Subalpine Wet Mixed Communities (Gagne and Cuddihy 1990)
= Montane Bogs (Medeiros et al. 1991a)
= Montane Bogs (Mueller-Dombois and Fosberg 1998)
> Montane Wet Herbland (Gagne and Cuddihy 1990)
> Montane Wet Mixed Communities (Gagne and Cuddihy 1990)
> Montane Wet Sedgeland (Gagne and Cuddihy 1990)
> Subalpine Wet Mixed Communities (Gagne and Cuddihy 1990)
- Corn, C. A. 1992. Kaala Natural Area Reserve, Mt. Kaala, Oahu. Department of Land and Natural Resources, Division of Forestry and Wildlife, State of Hawaii. 25 pp.
- Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2019a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
- Gagne, W. C., and L. W. Cuddihy. 1990. Vegetation. Pages 45-114 in: W. L. Wagner, D. R. Herbst, and S. H. Sohmer, editors. Manual of the Flowering Plants of Hawaii. 2 volumes. University of Hawaii Press, Honolulu.
- Loope, L. L., A. C. Medeiros, and B. H. Gagne. 1991. Aspects of the history and biology of the montane bogs. Technical Report 76. Studies in montane bogs of Haleakala National Park. University of Hawaii at Manoa and National Park Service. 30 pp. plus appendixes.
- Medeiros, A. C., L. L. Loope, and B. H. Gagne. 1991a. Degradation of vegetation in two montane bogs in Haleakala National Park: 1982-1988. Technical Report. University of Hawaii Cooperative National Park Resources Studies Unit, Honolulu. 31 pp.
- Medeiros, A. C., L. L. Loope, and B. H. Gagne. 1991b. Studies in the montane bogs of Haleakala National Park. Degradation of vegetation in two montane bogs: 1982-1988. Cooperative National Park Resources Study Unit, Department of Botany Technical Report 78. University of Hawaii, Honolulu.
- Mueller-Dombois, D., and F. R. Fosberg. 1998. Vegetation of the tropical Pacific islands. Springer-Verlag, New York. 733 pp.
- Price, J. P., S. M. Gon, III, J. D. Jacobi, and D. Matsuwaki. 2007. Mapping plant species ranges in the Hawaiian Islands: Developing a methodology and associated GIS layers. Hawai''i Cooperative Studies Unit. Technical Report HCSU-008. Pacific Aquaculture and Coastal Resources Center (PACRC), University of Hawai''i, Hilo. 58 pp., includes 16 figures and 6 tables.
- Sohmer, S. H., and R. Gustafson. 1987. Plants and flowers of Hawai''i. University of Hawaii Press.
- Vogel R. J., and J. Hendrickson. 1971. Vegetation of an alpine bog on east Maui, Hawaii. Pacific Science 25:475-483.
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- Yoshinga, A. Y. 1978. Vegetation of the Hana rainforest, Haleakala National Park. Pages 346-348 in: Proceedings Second Conference National Science, Hawaii Volcanoes National Park. June 1-3, 1978; Hawaii Field Research Center, Hawaii Volcanoes National Park.
- Ziegler, A. C. 2002. Hawaii natural history, ecology, and evolution. University of Hawaii Press, Honolulu. 477 pp