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Hawaii tropical low shrublands (OC0702)

Hawaii tropical low shrublands
Near Maunaloa, Molokai, Hawaii, USA
Photograph by Comm. John Bortniak, NOAA Corps (ret.)


Tropical and Subtropical Grasslands, Savannas, and Shrublands

600 square miles (1,500 square kilometers) -- about half the size of Rhode Island

· One-of-a-Kind
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
· Looking Ahead


The Hawaiian Lowland Shrublands have an amazing amount of endemic plants that are found only in this ecoregion-more than 90 percent! Coastal and lowland dry shrublands occur on the lowest leeward slopes of the higher Hawaiian Islands and on all but the summit regions of Lana'i, Kaho'olawe, and Ni'ihau.

Special Features Special Features

Plant diversity is high, with more than 200 species. These include grassland species of Sporobolus and Lepturus, and mixed shrublands with species such as 'Ilima (Sida Cordifolio),
'A'ali'i (Dodonaea eriocarpa) and Maó (Gossypium sandwicense).

Did You Know?
Plant species in these shrublands often have very small distributions, with many restricted to single localities.

Wild Side

The weevil, Rhynehogonus giffardi, is known from only one acre of dry shrubland on the island of Hawaii. It feeds on A'ali'i. Many plants of this ecoregion have beautiful flowers including the bright orange blossoms of 'Ohai, and endemic pea, and the large yellow blossoms of Ma'o. Swezey's bug has an elongated head that looks like a thorn. These bugs feed on the the toxic sap of Euphorbia's and it is thought that the digestive track which extends into this part of the head is used to digest the toxins or store them for protection from predators.

Cause for Concern

Over 90 percent of this ecoregion has been lost due to human development and alien vegetation. Fire, weed invasions, feral animals, especially goats and deer, threaten this ecoregion. Only small pieces of natural habitat remain. Some of Hawaii's most endangered species of plants live in these shrublands. Many lowland and coastal shrub species have gone extinct. Many visitors to Hawaii may never see a native plant due to the disturbance of natural habitats.

For more information on this ecoregion, go to the World Wildlife Fund Scientific Report.

All text by World Wildlife Fund © 2001