Control of Alien Plants on Nature Conservancy Preserves

The Nature Conservancy of Hawai`i is currently (1989) engaged in active alien plant control on two large montane forest and shrubland preserves on the islands of Moloka`i and Maui. The national Conservancy organization is in the process of developing comprehensive guidelines for the use of pesticides in alien species control and is producing an Element Stewardship Abstract database to assemble pertinent information on management of key alien species. Strategy for alien plant control in Hawai`i follows that of Hawai`i Volcanoes National Park in prioritizing control tasks but is highly reliant on volunteer labor and interagency collaborative research effort. Conservancy managers view effective ungulate control as a necessary prerequisite to long-term alien plant control. Current alien plant control priorities are localized infestations of highly invasive weeds (e.g., Rubus argutus and Clidemia hirta on Moloka`i) and development of control methods for more widespread invasive plants that threaten preserve integrity. Interagency cooperation to eliminate new alien plant populations before they spread to key natural areas and research on revegetation and weed control through use of native plants are recommended. INTRODUCTION The Nature Conservancy is a private, nonprofit conservation organization dedicated to establishing managed, protected habitat for the full array of the earth's remaining natural communities and species. To that end, the Conservancy has set aside more than 31 million acres (12 million ha) of land in the United States, Canada, Latin America, and the Caribbean since the early 1950s. Today The Conservancy manages more than 1.3 million acres (526,000 ha) itself in about 1,630 Conservancy nature preserves nationwide. Programs of the Conservancy for the control of alien plant species on nature preserves nationally and in Hawai`i are described in this paper.