Like secret agents in on a mission, a dozen or so conservationists, business executives and government officials, spades in hand, planted saplings Wednesday under a canopy of trees near a stream more than 1,000 feet above sea level.
Their goal: to bring a native Hawaiian gardenia back from the brink of extinction.
The 30 saplings were transferred from plastic pots into holes surrounded by a wire fence to keep out predatory wild pigs and cattle. The precise location on Oahu is secret so as to avoid intruders.
"It gives me hope," said Sam ‘Ohu Gon, senior scientist and cultural adviser with the Nature Conservancy of Hawaii. "I think the whole idea of biocultural restoration is bringing back living parts of the culture in the form of these trees. That can only help the community to re-establish their identity and connections with the land."
The Hawaiian nanu, known scientifically as the Gardenia brighamii and sometimes called nau, has bright yellow-orange pulp that was used by the Hawaiians for dye, Gon said. It is also part of a chant about the blazing Waianae sunset.
Nanu is different from most gardenias that mature into shrubs. A mature nanu is a tree about 20 feet high, becoming a part of the native canopy, with a trunk about a foot in diameter.
Only one mature tree exists in the wild on Oahu — in Nanakuli, conservationists say.
Raising the Hawaiian nanu from cuttings to saplings took four years of work by a number of groups and government entities. The preparation for planting the saplings involved hundreds of hours of work, although putting a dollar estimate on the effort would be difficult, organizers said.
The Nature Conservancy contributed the cuttings from a plant that grew in the wild but which has since died. The Lyon Arboretum grew the cuttings into saplings with the help of a horticulturalist funded by the state Department of Land and Natural Resources.
U.S. Fish and Wildlife officials also had a hand in the replanting, which was supported by contributions from the Hawaiian Springs bottled water company.
To create a protected area, workers cleared the land of weeds, including guinea grass, an invasive species used to feed cattle. It develops into a dense matted undergrowth that chokes out native plants and creates a potential for brush fires.
"It is a major scourge," Gon said. "It nibbles away at the native forest."
Gon said the Hawaiian nanu once grew in an area of Leeward Oahu but repeated brush fires have destroyed them, while the guinea grass has been quick to re-establish itself. He said planting the Hawaiian nanu in a wetter area helps to prevent it from becoming a victim of brush fires.
Susan Ching, the Oahu plant coordinator for the Plant Extinction Prevention Program, part of the state Division of Forestry and Wildlife, said there are Hawaiian nanu species being grown at various arboretums on Oahu and Kauai and some are sold at garden stores.
But she said the cuttings come from a wild stock on Oahu thought to be more robust.
Plant experts said the ground planting Wednesday was the second done on Oahu of the wild stock, with the intent of preserving the wild genes in the population and using the trees as a seed source.
Gon said the hope is to eventually take back the area from guinea grass and re-establish the Hawaiian dry land forest, helping to increase rain and groundwater recharge.
"The more forest you can establish, especially in those areas that are marginal between wet and dry — that just pushes the wet down lower into the dry area … You’re coaxing the water back into the lowlands."
Success with the nanu would mark a major victory in the battle against extinction in Hawaii. Of the 667 plants on the federal endangered species list, 363 or 54 percent live on the brink of extinction in Hawaii, according to the U.S. Fish and Wildlife Service.
