Protecting Rare Native Plants in Wao Kele o Puna


The isles of Ka Pae ʻĀina Hawaiʻi are among the most isolated land masses on Earth, and are a biological hotspot where approximately 90% of native flora is endemic (found nowhere else in the world).

On the southeast side of Moku o Keawe, in the district of Puna, portions of the ahupuaʻa Waiakahiula and Kaʻohe are home to the Office of Hawaiian Affairs’ (OHA) Wao Kele o Puna (WKOP) Forest Reserve.

A wao kele is aptly defined as a rain belt or an upland forest, and WKOP is home to a number of endemic species, in the forest on a very young slope of Kīlauea. About a third of the forest floor is 1,500 to 3,000 years old, but the majority is less than 750 years old, and includes a branch of the 2015 flow that stopped on the doorstep of Pāhoa. The 40 square miles of WKOP is a bit smaller than Kahoʻolawe, and is zoned conservation. Its lack of money-earning potential and its location, difficult to access, perhaps makes stewarding WKOP a challenge.

Although the substrate is young, abundant rains have allowed native forest to grow and thrive, but that forest and its native wildlife are under siege from the impacts of feral pigs, as well as competition from alien invasive plants such as waiawī ʻulaʻula (guava), Miconia (a fast-growing weedy tree), and alien grasses.

Rats and slugs eat plants, including seed pods, destroying any hope for natural regeneration of future generations. Endemic birds such as ʻio, ʻamakihi, ʻapapane, and ʻōmaʻo also suffer from rat predation of eggs, avian pox and malaria, and loss of habitat because of invasive species.

That bleak reality is tempered by the work of dedicated field staff who toil in a harsh environment, working through thickets of uluhe fern and their knife-sharp broken stems, while being on the lookout for deep cracks in the forest floor obscured by vegetation. They search for and monitor rare native plants and birds, locally eradicate invasive pests, and do their best, with limited resources, to honor the ʻāina and its cultural heritage.

The rarest of rare plants survive in places inaccessible to alien invaders: collapsed lava tube trenches or their skylights, the sides of deep cracks, or perhaps in communities in the bottoms of lua poho (pit craters).

Photo: Forest Solutions staff
L-R, Joshua Pang-Ching (DOFAW), Robbie Justice (Forest Solutions), Alex Wang (DOFAW), Grace Tredinnick (US Forest Service), Lori Walker (OHA), Sarah Knox (Akaka Foundation), Kirk Derasin (Forest Solutions)

In October 2022, the U.S. Fish and Wildlife Service awarded OHA a $231,000 grant to construct a fence to protect rare and endangered plants in WKOP. Contractor Forest Solutions will construct the 4,000-foot-long fence to enclose 17 acres of forest with the goal of protecting a population of the endangered Cyrtandra nanawaleensis, haʻiwale Nānāwale that was discovered in 2021.

The Plant Extinction Prevention Program (PEPP), is a project of the Pacific Cooperative Studies Unit of the University of Hawaiʻi at Mānoa and is supported by state and federal funds, grants, and donations from public and private institutions. PEPPʻs kuleana extends to any endangered plant with fewer than 50 individuals in the wild. Although haʻiwale Nānāwale in WKOP has a total of just under 100 individuals, excessive threats from feral pigs and the potential of lava flows have the many cooperating partners on high alert to protect this species.

Haʻiwale Nānāwale is a member of the Gesneriaceae family, the same as African violets. Scientists believe that a single ancestor has evolved into about 60 different species in Hawaiʻi, all of them endemic. Most have extremely limited ranges, many to a single island or location on that island. Nānū, Gardenia remyi, also apparently grows in WKOP, but its existence is uncertain, with perhaps five wild individuals remaining. Once the fence is completed, field surveys will be undertaken by PEPP staff within the enclosure, searching for nānū.

Forest Solutions staff will monitor the completed fence monthly and conduct repairs as needed for two years. Theyʻll remove pigs and other hooved mammals from inside the fence using traps, and those traps will be monitored monthly at minimum. Annual reports will include photos, maps, and progress updates.

Another partner, the Hawaiʻi Division of Forestry and Wildlife, is collaborating with this effort. Their staff will survey for rare plants, and also for ʻaʻo (Newellʻs shearwater, Puffinus newelli, a sea bird), and our ʻōpeʻapeʻa, the endemic Hawaiian bat. Others will complete comprehensive rare plant surveys, and collect species for propagation at the Volcano Rare Plant Facility. There, plants will be grown by rare-plant permitted specialists, until keiki are big enough to be outplanted.

We are filled with immense gratitude, and send our mahalo piha to our many cooperating partners, their field staff and volunteers, and donors. Collectively, they demonstrate their aloha for our ʻāina by working tirelessly, often unseen, to improve conditions for all.