Lowland Mesic System

Natural communities below 1,000 m (ca 3,000 ft) elevation, receiving bewteen 50 and 75 inches annual precipitation, or otherwise bearing prevailingly mesic substrate conditions comprise the lowland mesic system in the Hawaiian High Islands Ecoregion. This system is found on the islands of Hawai‘i, Maui, Moloka‘i, Lāna‘i, O‘ahu, and Kaua‘i, and may be found on both windward and leeward sides of the islands, for example, the Kona flank of Mauna Loa, the leeward flank of West Maui, the leeward side of East Moloka‘i, the slopes surrounding the summit of Lāna‘ihale (Lāna‘i), the lower slopes of the Wai‘anae Mountains (O‘ahu) and the leeward slopes of the Ko‘olau Mountains (O‘ahu), and the western slopes of Kaua‘i. It occurs typically below either the lowland wet system or the montane mesic system, and above the lowland dry system. There are a number of natural communities described within this system, including a variety of grasslands, shrublands, and forests. Biological diversity is high in this system, which is noted in particular for tree species diversity. A number of specialized plants and animals occur there, such as the Hawaiian bat, ‘Ōpe‘ape‘a ( Lasiurus cinereus semotus) and the native vine nuku‘i‘iwi (Strongylodon ruber). This system is of secondary importance for the forest bird concentration.

The Hawaiian bat, 'ōpe'ape'a, maintains highest densities in lowland mesic forest on all of the main islands.

Natural communities and species of this system are listed among nested targets via the appendices.

The distribution of the Lowland Mesic System across the Hawaiian High Islands Ecoregion is depicted below:

The Lowland Mesic System on Moloka'i (red above) typically occurs at mid-flank on the leeward slopes. It is threatened by feral ungulates and wildfires.

The Lowland Mesic System on O'ahu (red above) occurs in both Ko'olau (east) and Wai'anae (west) conservation areas, typically as remnant occurrences adjacent to agricultural and other developed lands.

The Lowland Mesic System on Kaua'i (red above) is restricted to the leeward (western) slopes of the island.

	Hawaiian High Islands Ecoregion This page last revised 02 September 2006 -- S.M.Gon III
Home Introduction Ecoregion Conservation Targets Viability Goals Portfolio TNC Action Sites Threats Strategies ▫ Tables Maps & Figures CPT Database Appendices Glossary Sources . The viney legume nuku'i'iwi (Strongylodon ruber) grows in mesic forest on several islands. The 'Elepaio is an endemic flycatchers that lives in lowland mesic forested areas. The endangered tree snail pupu kuahiwi (Achatinella mustelina) lives in lowland mesic habitat in the Wai'anae Mountains on O'ahu.	Lowland Mesic System Natural communities below 1,000 m (ca 3,000 ft) elevation, receiving bewteen 50 and 75 inches annual precipitation, or otherwise bearing prevailingly mesic substrate conditions comprise the lowland mesic system in the Hawaiian High Islands Ecoregion. This system is found on the islands of Hawai‘i, Maui, Moloka‘i, Lāna‘i, O‘ahu, and Kaua‘i, and may be found on both windward and leeward sides of the islands, for example, the Kona flank of Mauna Loa, the leeward flank of West Maui, the leeward side of East Moloka‘i, the slopes surrounding the summit of Lāna‘ihale (Lāna‘i), the lower slopes of the Wai‘anae Mountains (O‘ahu) and the leeward slopes of the Ko‘olau Mountains (O‘ahu), and the western slopes of Kaua‘i. It occurs typically below either the lowland wet system or the montane mesic system, and above the lowland dry system. There are a number of natural communities described within this system, including a variety of grasslands, shrublands, and forests. Biological diversity is high in this system, which is noted in particular for tree species diversity. A number of specialized plants and animals occur there, such as the Hawaiian bat, ‘Ōpe‘ape‘a ( Lasiurus cinereus semotus) and the native vine nuku‘i‘iwi (Strongylodon ruber). This system is of secondary importance for the forest bird concentration. The Hawaiian bat, 'ōpe'ape'a, maintains highest densities in lowland mesic forest on all of the main islands. Natural communities and species of this system are listed among nested targets via the appendices. The distribution of the Lowland Mesic System across the Hawaiian High Islands Ecoregion is depicted below: The Lowland Mesic System on Moloka'i (red above) typically occurs at mid-flank on the leeward slopes. It is threatened by feral ungulates and wildfires. The Lowland Mesic System on O'ahu (red above) occurs in both Ko'olau (east) and Wai'anae (west) conservation areas, typically as remnant occurrences adjacent to agricultural and other developed lands. The Lowland Mesic System on Kaua'i (red above) is restricted to the leeward (western) slopes of the island.	The Lowland Mesic System in Hawai‘i includes some of the most diverse forest communities in the ecoregion, and is a hotspot for endangered species recovery and restoration efforts. Above: Diverse mesic forest in the Wai'anae conservation area, O'ahu. The rare Hawaiian tree-thistle Hesperomannia grows in diverse mesic forest on the islands of O'ahu and Maui (West Maui). The Lowland Mesic System on Hawai‘i Island (red areas above) occurs in all six conservation areas, but is often reduced to remnant occurrences. The Lowland Mesic System on Maui (red above) occurs in both East Maui and West Maui conservation areas, typically as remnant occurrences adjacent to agricultural and other developed lands. The Lowland Mesic System on Lāna'i (red above) has been greatly degraded and fragmented by feral animals (especially deer).