Endangered Species in the Pacific Islands
Recovery Plan for the Mauna Kea Silversword
Habitat & Distribution:
Currently, the species has been reduced to a single naturally occurring population in Waipahoehoe Gulch. Between 1973 and 1982, the State of Hawai‘i outplanted silverswords in three exclosures within in the Mauna Kea Forest Reserve near Pu'u Nanaha at 9,086 feet (2,770 meters) elevation, near skyline jeep trail at 9,184 feet (2,970 meters), and at Waipahoehoe Gulch at 9,184 feet (2,800 meters). Additional reintroduction efforts have increased the numbers to approximately 8,000 individuals.
There are several distinct vegetational and climatic zones of Mauna Kea. The upper region from 11,152 to 12,464 feet (3,400 to 3,800 meters) elevation is barren alpine cinder desert. The region between
The annual rainfall is between 19.5 and 31.2 inches (500 and 800 millimeters) a year, and annual mean temperature is about 11 degrees celcius.
The Hawai‘i Department of Land and Natural Resources Division of Forestry and Wildlife has been actively involved in the preservation and restoration of the Mauna Kea silversword by building fences and exclosure, and outplanting. The vegetation of Mauna Kea was not protected until 1935, when a fence was constructed along the lower boundary of the Forest Reserve. Beginning 1974, the silversword seed was germinated and plants were greenhouse-grown at Hawai‘i Volcanoes National Park. Additional reintroduction efforts have increased the number of founders from 2 to 6, and the numbers from 800 to 8,000. The silversword has been extensively studied by scientists at the University of Hawai‘i (Manoa), the University of California (Davis), and the University of British Columbia, Vancouver.
Actions identified in this recovery plan are protecting all remaining plants from feral ungulates, fire and human-related disturbances; monitor and research existing populations; develop and implement a program to enhance regeneration within existing populations; and reestablish the silversword within areas of historic abundance, and verify recovery objectives.