Name:
Metrosideros polymorpha - Acacia koa / Myrsine lessertiana Montane-Subalpine Mesic Forest Group
Reference:
NatureServe Biotics 2019
Description:
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. <i>Acacia koa, Metrosideros polymorpha</i>, or <i>Nestegis sandwicensis</i> dominate or codominate with other trees (e.g., <i>Santalum</i> spp., <i>Sapindus</i> spp.). <i>Sapindus saponaria</i> is a diagnostic species of this mesic group. Other trees may be present such as <i>Coprosma</i> spp., <i>Ilex anomala, Melicope</i> spp., <i>Myoporum sandwicense, Myrsine</i> spp., <i>Nothocestrum breviflorum, Pipturus albidus, Pisonia brunoniana, Pittosporum</i> spp., <i>Psychotria hawaiiensis, Zanthoxylum hawaiiense</i>, and drier forest species such as <i>Chamaesyce celastroides</i> and <i>Sophora chrysophylla</i>. The understory is variable and may be dominated by sedges and ferns or shrubs. Tree ferns (<i>Cibotium</i> spp.) are typically much less prominent than in wet forest. Common shrubs include <i>Clermontia</i> spp., <i>Cyanea</i> spp., <i>Dodonaea viscosa, Hedyotis</i> spp., <i>Rubus hawaiensis, Stenogyne</i> spp., and <i>Styphelia tameiameiae</i>. Common ferns and fern allies present include <i>Dryopteris wallichiana, Microlepia strigosa, Nephrolepis cordifolia, Melicope</i> spp., <i>Sadleria</i> spp., and graminoids include <i>Carex</i> spp. and <i>Uncinia uncinata</i>. 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`รข lava. Disturbed, lower elevation stands may have invasive, exotic trees present (such <i>Morella faya, Psidium</i> spp., and <i>Schinus terebinthifolius</i>), but not strongly dominant; otherwise such stands would be considered ruderal. Fire-adapted exotic grasses such as <i>Holcus lanatus, Pennisetum clandestinum</i>, and <i>Pennisetum setaceum</i> are invasive and threaten these forests by increasing fire intensity, frequency and size.
Accession Code:
urn:lsid:vegbank.org:commConcept:40283-{08B5D8A0-2789-4134-BA50-47127B143DE7}
Plot-observations of this Community Concept:
0
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