Lowland Wet System

Natural communities below 1,000 m (ca 3,000 ft) elevation, receiving greater than 75 inches annual precipitation, or otherwise bearing prevailingly wet substrate conditions comprise the lowland wet 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 is best developed on the windward side of the highest islands (Maui and Hawai‘i) and the windward to summit regions of the lower islands, for example, the lower east flank of Mauna Kea, the northeast flank of Haleakalā (Maui), the heads of the northern valley systems of East Moloka‘i, the near-summit slopes of Lāna‘ihale (Lāna‘i), the slopes surrounding summit of Ka‘ala (Wai‘anae Mountains, O‘ahu), the majority of the Ko‘olau Mountains (O‘ahu), and the weet valleys and slopes adjacent to the summit plateau of Wai‘ale‘ale and Alaka‘i, Kaua‘i. It typically lies below the montane wet system and wet cliff system. There are a number of natural communities described within this system, including a variety of wet grasslands, shrublands, and forests. Biological diversity is high in this system, and specialized plants and animals occur there, such as tree snails (e.g., Achatinella and Partulina spp.) and endemic Cyrtandra spp.

The koli'i, an endemic lobeliad (Trematolobelia macrostachys), is a showy occupant of the lowland wet system, whose blossoms are pollinated by coadapted native forest birds.

Once excluded from the lowland wet forests by mosquito-borne diseases, the most common native honeycreepers, such as the 'apapane (Himatione sanguinea) are recolonizing the lowlands.

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

The Lowland Wet System on O'ahu (red areas above) is most prominent in the Ko'olau conservation area (right), but also occurs on slopes surrounding the montane wet summit of the Wai'anae conservation area (left), and on a few small peaks just below 1,000 m. (3,000 ft.) elevation.

The Lowland Wet System on Kaua'i (red areas above) dominates the windward (eastern) half of the island below 1,000 m. (3,000 ft.) elevation.

	Hawaiian High Islands Ecoregion This page last revised 23 August 2006 -- S.M.Gon III
Home Introduction Ecoregion Conservation Targets Viability Goals Portfolio TNC Action Sites Threats Strategies Acknowledgements ▫ Tables Maps & Figures CPT Database Appendices Glossary Sources . The 'amakihi is one of the few Hawaiian honeycreepers persisting in lowland wet and mesic systems. Rare plants of the lowland wet system include delicate ha'iwale (Cyrtandra spp.) Among the many invertebrates of the lowland wet system are endangered tree snails.	Lowland Wet System Natural communities below 1,000 m (ca 3,000 ft) elevation, receiving greater than 75 inches annual precipitation, or otherwise bearing prevailingly wet substrate conditions comprise the lowland wet 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 is best developed on the windward side of the highest islands (Maui and Hawai‘i) and the windward to summit regions of the lower islands, for example, the lower east flank of Mauna Kea, the northeast flank of Haleakalā (Maui), the heads of the northern valley systems of East Moloka‘i, the near-summit slopes of Lāna‘ihale (Lāna‘i), the slopes surrounding summit of Ka‘ala (Wai‘anae Mountains, O‘ahu), the majority of the Ko‘olau Mountains (O‘ahu), and the weet valleys and slopes adjacent to the summit plateau of Wai‘ale‘ale and Alaka‘i, Kaua‘i. It typically lies below the montane wet system and wet cliff system. There are a number of natural communities described within this system, including a variety of wet grasslands, shrublands, and forests. Biological diversity is high in this system, and specialized plants and animals occur there, such as tree snails (e.g., Achatinella and Partulina spp.) and endemic Cyrtandra spp. The koli'i, an endemic lobeliad (Trematolobelia macrostachys), is a showy occupant of the lowland wet system, whose blossoms are pollinated by coadapted native forest birds. Once excluded from the lowland wet forests by mosquito-borne diseases, the most common native honeycreepers, such as the 'apapane (Himatione sanguinea) are recolonizing the lowlands. Natural communities and species of this system are listed among nested targets via the appendices. The Lowland Wet System on O'ahu (red areas above) is most prominent in the Ko'olau conservation area (right), but also occurs on slopes surrounding the montane wet summit of the Wai'anae conservation area (left), and on a few small peaks just below 1,000 m. (3,000 ft.) elevation. The Lowland Wet System on Kaua'i (red areas above) dominates the windward (eastern) half of the island below 1,000 m. (3,000 ft.) elevation.	The Lowland Wet System in Hawai‘i includes wet forests of remarkable botanical diversity, such as this example in Lumaha'i Valley, Kaua'i. Distribution of the Lowland Wet System across the Hawaiian High Islands Ecoregion is depicted in the series of figures below: The Lowland Wet System on Hawai‘i Island(red areas above) occurs in five conservation areas (Kohala, Mauna Kea, Windward Mauna Loa, Ka‘ū-Kapāpala, and Kona) at <3,000 ft elev. The Lowland Wet System on Maui (red areas above) occurs along the windward flanks of both the East Maui and West Maui conservation areas below 1,000 m. (3,000 ft.) elevation. The Lowland Wet System on Lāna'i (red areas above) occurs immediately adjacent to the montane wet summit of the conservation area, below 1,000 m. (3,000 ft.) elevation. The Lowland Wet System on Moloka'i (red areas above) is prominent on the eastern half of the island's conservation area, but is being steadily degraded by uncontrolled feral ungulates such as pigs and deer below 1,000 m. (3,000 ft.) elevation.