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G625 Metrosideros polymorpha - Acacia koa / Myrsine lessertiana Montane-Subalpine Mesic Forest Group
Type Concept Sentence: This mesic montane and lower subalpine forest group is characterized by an open to dense, mostly evergreen tree layer 10-35 m tall, that is dominated or codominated by Acacia koa, Metrosideros polymorpha, or Nestegis sandwicensis with an often diverse subcanopy that includes other trees such as Sapindus saponaria that are diagnostic species of this mesic group, and tall-shrub layers with lianas.
Common (Translated Scientific) Name: `Ohi`a - Koa / Kolea Lau Nui Montane-Subalpine Mesic Forest Group
Colloquial Name: Hawaiian Montane-Subalpine Mesic Forest
Hierarchy Level: Group
Type Concept: This mesic montane and lower subalpine forest group occurs on Kaua`i, Maui and Hawai`i. Vegetation is characterized by an open to dense, mostly evergreen tree layer 10-35 m tall. There are often diverse subcanopy and tall-shrub layers with lianas. Acacia koa, Metrosideros polymorpha, or Nestegis sandwicensis dominate or codominate with other trees (e.g., Santalum spp., Sapindus spp.). Sapindus saponaria is a diagnostic species of this mesic group. Other trees may be present such as Coprosma spp., Ilex anomala, Melicope spp., Myoporum sandwicense, Myrsine spp., Nothocestrum breviflorum, Pipturus albidus, Pisonia brunoniana, Pittosporum spp., Psychotria hawaiiensis, Zanthoxylum hawaiiense, and drier forest species such as Chamaesyce celastroides and Sophora chrysophylla. The understory is variable and may be dominated by sedges and ferns or shrubs. Tree ferns (Cibotium spp.) are typically much less prominent than in wet forest. Common shrubs include Clermontia spp., Cyanea spp., Dodonaea viscosa, Hedyotis spp., Rubus hawaiensis, Stenogyne spp., and Styphelia tameiameiae. Common ferns and fern allies present include Dryopteris wallichiana, Microlepia strigosa, Nephrolepis cordifolia, Melicope spp., Sadleria spp., and graminoids include Carex spp. and Uncinia uncinata. These higher elevation forests are restricted to the larger islands from 900-2000 m (2950-6560 feet) elevation. Stands are found in the mesic, seasonal wet zone between the dry leeward and wet windward climates. Sites are too dry to support rainforests, but do not experience extended periods of drought like the dry forests. These mesic sites have relatively even, moderate precipitation throughout the year or are wet with a seasonally dry period. Annual rainfall is generally 1000-2500 mm, with some areas experiencing a distinct dry period. Substrates include deep volcanic ash soils and trachyte, rocky mucks, and silty loams derived from weathered `a`â lava. Disturbed, lower elevation stands may have invasive, exotic trees present (such Morella faya, Psidium spp., and Schinus terebinthifolius), but not strongly dominant; otherwise such stands would be considered ruderal. Fire-adapted exotic grasses such as Holcus lanatus, Pennisetum clandestinum, and Pennisetum setaceum are invasive and threaten these forests by increasing fire intensity, frequency and size.
Diagnostic Characteristics: This mesic montane and lower subalpine forest group is characterized by an open to dense, mostly evergreen tree layer 10-35 m tall. There are often diverse subcanopy and tall-shrub layers with lianas. Acacia koa, Metrosideros polymorpha, or Nestegis sandwicensis dominate or codominate with other trees (e.g., Santalum spp., Sapindus spp.). Sapindus saponaria is a diagnostic species of this mesic group. Associated tree species include Coprosma spp., Ilex anomala, Melicope spp., Myoporum sandwicense, Myrsine spp., Nothocestrum breviflorum, Pipturus albidus, Pisonia brunoniana, Pittosporum spp., Psychotria hawaiiensis, Zanthoxylum hawaiiense, and drier forest species such as Chamaesyce celastroides and Sophora chrysophylla. Tree ferns (Cibotium spp.) are absent or much less prominent than in wet forest. Associated shrub species include Clermontia spp., Cyanea spp., Dodonaea viscosa, Hedyotis spp., Rubus hawaiensis, Stenogyne spp., and Styphelia tameiameiae. Common ferns and fern allies present include Dryopteris wallichiana, Microlepia strigosa, Nephrolepis cordifolia, Melicope spp., Sadleria spp., and graminoids include Carex spp. and Uncinia uncinata.
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This group grades into dry forest. Many constituent species are shared with mesic shrubland, dry shrubland, or dry forest. Exotic tree species such as Morella faya, Psidium spp., and Schinus terebinthifolius may be present in disturbed stands but do not dominate. Native overstory forests with understories strongly dominated (generally >90% cover) by exotic species such as Andropogon virginicus, Microlaena stipoides, Melinis spp., Nephrolepis multiflora, or Pennisetum clandestinum are considered ruderal and classified in ~Hawaiian Montane Ruderal Forest & Woodland Group (G626)$$.
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available
Floristics: Vegetation is characterized by an open to dense, mostly evergreen tree layer 10-35 m tall. There are often diverse subcanopy and tall-shrub layers with lianas. Acacia koa, Metrosideros polymorpha, or Nestegis sandwicensis dominate or codominate with other trees (e.g., Santalum spp., Sapindus spp.). Sapindus saponaria is a diagnostic species of this mesic group. Other trees may be present such as Coprosma spp., Ilex anomala, Melicope spp., Myoporum sandwicense, Myrsine spp., Nothocestrum breviflorum, Pipturus albidus, Pisonia brunoniana, Pittosporum spp., Psychotria hawaiiensis, Zanthoxylum hawaiiense, and drier forest species such as Chamaesyce celastroides and Sophora chrysophylla. The understory is variable and may be dominated by sedges and ferns or shrubs. Tree ferns (Cibotium spp.) are typically much less prominent than in wet forest. Common shrubs include Clermontia spp., Cyanea spp., Dodonaea viscosa, Hedyotis spp., Rubus hawaiensis, Stenogyne spp., and Styphelia tameiameiae. Common ferns and fern allies present include Dryopteris wallichiana, Microlepia strigosa, Nephrolepis cordifolia, Melicope spp. (= Pelaea spp.), Sadleria spp., and graminoids include Carex spp. and Uncinia uncinata. Exotic trees Morella faya, Psidium spp., and Schinus terebinthifolius may be present in disturbed, lower elevation stands, but do not dominate. Fire-adapted exotic grasses such as Holcus lanatus, Pennisetum clandestinum, and Pennisetum setaceum are invasive and threaten these forests by increasing fire intensity, frequency and size.
Dynamics: Major disturbances are storms, lava flow, and lava- or lightning-ignited fire.
Environmental Description: This forest group occurs on mesic montane and subalpine slopes of Kaua`i, Maui and Hawai`i, from 900-2000 m (2950-6560 feet) elevation.
Climate: This group occurs within the seasonally mesic and moist mesic zones (Zones 4 and 5) of the 7 Moisture Zones developed for the Hawaiian Islands by Price et al. (2007). Stands are found in the zone of mesic, seasonal precipitation between the dry leeward and wet windward climates. Sites are too dry to support rainforests, but do not experience extended periods of drought like the dry forests (Gagne and Cuddihy 1990). Annual rainfall is generally 1000-2500 mm, with some areas experiencing a distinct dry period.
Soil/substrate/hydrology: Substrates include deep volcanic ash soils and trachyte, rocky mucks, and silty loams derived from weathered `a`â lava (Gagne and Cuddihy 1990).
Climate: This group occurs within the seasonally mesic and moist mesic zones (Zones 4 and 5) of the 7 Moisture Zones developed for the Hawaiian Islands by Price et al. (2007). Stands are found in the zone of mesic, seasonal precipitation between the dry leeward and wet windward climates. Sites are too dry to support rainforests, but do not experience extended periods of drought like the dry forests (Gagne and Cuddihy 1990). Annual rainfall is generally 1000-2500 mm, with some areas experiencing a distinct dry period.
Soil/substrate/hydrology: Substrates include deep volcanic ash soils and trachyte, rocky mucks, and silty loams derived from weathered `a`â lava (Gagne and Cuddihy 1990).
Geographic Range: This mesic montane and lower subalpine forest group occurs on Kaua`i, Maui, Hawai`i, and possibly Moloka`i.
Nations: US
States/Provinces: HI
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.867659
Confidence Level: Moderate
Confidence Level Comments: No Data Available
Grank: GNR
Greasons: No Data Available
| Type | Name | Database Code | Classification Code |
|---|---|---|---|
| Class | 1 Forest & Woodland Class | C01 | 1 |
| Subclass | 1.A Tropical Forest & Woodland Subclass | S17 | 1.A |
| Formation | 1.A.3 Tropical Montane Humid Forest Formation | F004 | 1.A.3 |
| Division | 1.A.3.Oa Polynesian Montane & Cloud Forest Division | D068 | 1.A.3.Oa |
| Macrogroup | 1.A.3.Oa.1 Hawaiian Montane & Cloud Forest Macrogroup | M194 | 1.A.3.Oa.1 |
| Group | 1.A.3.Oa.1.b `Ohi`a - Koa / Kolea Lau Nui Montane-Subalpine Mesic Forest Group | G625 | 1.A.3.Oa.1.b |
Concept Lineage: No Data Available
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Montane Mesic Forest (Gagne and Cuddihy 1990)
- 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.
- 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.
- Wagner, W. L., D. R. Herbst, and S. H. Sohmer. 1999. Manual of the flowering plants of Hawaii. Revised edition. Volumes 1 and 2. University of Hawaii Press and Bishop Museum Press, Honolulu. 1919 pp.