Ka‘upulehu Restoration Project

The North Kona Dryland Forest Working Group was organized in 1993 to pursue long-term protection and management of the dryland forests in the North Kona district of the State of Hawai‘i, particularly in the Huehue, Kealakehe, Kaloko, Kau, Ka‘upulehu, Pu‘uanahulu and Pu‘uwa‘awa‘a land divisions. Click here to view map.

After an assessment of remnant dryland forests in the area, the Working Group decided to focus its initial efforts on a 7-acre “mauka” parcel at Ka‘upulehu which was leased by Kamehameha Schools to the National Tropical Botanical Garden. This site had the advantage of having been fenced for a number of decades, and both the landowner and lessee were supportive of Working Group involvement. A summary of the results is posted on this site.

Although weed control, fire break maintenance and other activities continue at the mauka site, focus has shifted to a 70-acre “makai” site at Ka‘upulehu. Also owned by Kamehameha Schools, this parcel is leased to PIA Kona Limited Partnership.

Among the goals of the working group is to demonstrate cost-effective dryland forest restoration measures which can be undertaken over large parcels of land by other landowners. Thousands of acres in Kona are subject to the same threats experienced at Ka‘upulehu—invasive weeds, particularly fountain grass; wildfires; grazing by cattle and goats; and seed and seedling predation by rats, among others. However, public and private landowners lack information on ways to effectively address these threats. It is hoped that the Working Group’s efforts will provide the technical and economic information needed to encourage widespread dryland forest restoration.

Rats are controlled with baited traps. Ungulates have been fenced out. Firebreaks and a water source are key in protecting the site from wildfires. The most difficult problem to address, however, has been fountain grass. Treatments such as aerial spraying of Fusilade (a grass-specific herbicide), shading, and scraping with a bulldozer blade have been attempted. Controlled grazing was considered, but the terrain is too rough for cattle, and the native species too vulnerable. To date, the most successful method for eliminating fountain grass continues to be labor-intensive physical cutting with a weed-eater, followed by repeated applications of Roundup herbicide. As this is not a feasible control method for large parcels, experimentation will continue, possibly on other sites.

Another objective at Ka‘upulehu is to increase the number and the health of native Hawaiian dryland forest species on site, both plant and animal. Nine endangered plant species grow at Ka‘upulehu, and the site is also home to the endangered Blackburn’s sphinx moth. After extensive outplantings of the endangered seedlings, Ka‘upulehu is now home to more of certain species than exist in the wild. Common dryland species are also being planted, in an effort to recreate a balanced ecosystem.

Due to the quality of the remnant native forest at Ka‘upulehu, its accessibility and the continued interest of the landowner and lessee, the Working Group has shifted its emphasis on the makai portion of the project toward increasing its educational value. Over 3,000 native seedlings, many of which are endangered species, have been planted on site by volunteers and Working Group members, and are the subject of interpretive materials. Plants are being labeled, and a trail which offers opportunities for lessons in geology, cultural history, and botany has been constructed. By prior arrangement, school and community groups are using the site as an outdoor classroom, contributing volunteer labor during their visits.

Scientific research remains an important activity at Ka‘upulehu, as well. Examinations of water use by native and invasive plants, dormancy periods for native seeds, and methods of fountain grass control continue. Cooperation among state and local government agencies, non-profit organizations and universities is significantly augmenting scientific knowledge of dryland forest ecosystems.