Mamani forest, western slope of Mauna Kea, Hawaii, USA Photograph by David Olson   Oceania--Hawaiian Islands Tropical and Subtropical Dry Broadleaf Forests   2,500 square miles (6,600 square kilometers) -- about the size of Delaware and Rhode Island combined Critical/Endangered

· Dry Forest Surprise
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern

Dry Forest Surprise

Believe it or not, Hawaii has dry forests! The Hawaiian Dry Forests ecoregion harbors a number of specialist species that thrive with little rain, including native hibiscus trees and several rare shrubs such as Gouania, now represented only by a few individuals. Almost one-fourth of native Hawaiian plant species are found in these dry forests, which often get less than 10 inches (25 cm) of rain a year. Shrubland, grassland, and herbs also are found here.

Special Features

In contrast to the wet rain forests of Hawaii, the dry forests are found mostly on leeward mountain slopes and receive less than 50 inches (127 cm) (and often less than ten inches) of rainfall per year. They are also found on the mountaintops of the smaller islands.

	Close to 90 percent of the plants and almost all of the insects in Hawaii are found nowhere else on Earth.

Wild Side

Although the dry forests of Hawaii have fewer layers of vegetation and are structurally simpler than rain forests, their biodiversity rivals that of the most productive rain forests. These forests contain some of the rarest trees in Hawaii, such as the beautiful but nearly extinct Hibiscadelphus and Kokia. Many of the vines, shrubs, trees, and birds that fill these forests are threatened. Hawaiian owls can be seen hunting during the day. The endangered palila, a beautiful finch-like bird, feeds on the seeds and flowers of mamane trees high up on the volcanic slopes of Maunakea.

Cause for Concern

Although Hawaii is probably best known for its lush rain forests, the islands' dry forests are equally valuable -- and are in greater danger of extinction. An alarming 90 percent of Hawaii's dry forests have been destroyed, and what little habitat remains is highly fragmented. Clearing and burning of the forest began with the arrival of Polynesians, and the last remnants continue to be destroyed today though development, and expansion of agriculture and pastureland. One of the greatest problems in Hawaii is introduced plants and animals such as rats, deer, and pigs, as well as African fountain grass and molasses grass. The pigs were brought to these islands from elsewhere in Polynesia and Europe, and since their arrival they have destroyed native vegetation, caused soil erosion, eaten bird eggs and nestlings, spread weeds and diseases, and polluted water supplies.Most of the dry forest that remains is now dominated by bunch grass and rats.

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