Saving Koke‘e’s Native Flora

By Léo Azambuja

Kaua‘i Resource Conservation Program field crew, left to right, Kupu intern Jorell Hancock, Makamae Compoc-Dela Cruz, field crew leader Matt Dery, and Amaya Simao.

Anyone can make a difference alone, but when you gather the support of the community and bring in the right partnerships, that difference can reach thousands of acres.

Almost a quarter century ago, a woman started a volunteer-based program to preserve Koke‘e’s native flora. Today, nearly 13,000 acres of Hawai‘i’s most beautiful and important state parks would have looked much different if it weren’t for the efforts of tens of thousands of volunteers who joined Kaua‘i Resource Conservation Program along the years.

“The natural resources of Hawai‘i contain magnificent ecosystems that are unique in the world, and include culturally valuable plants, and need protection immediately,” said KRCP founder Katie Cassel, adding the program works on the ground to preserve the upland forests of Koke‘e, while involving the community in natural resource conservation.

Cassel started KRCP in January 1998, under Hui o Laka/Koke‘e Natural History Museum. In those days, when she used to work for the museum, Hui o Laka would offer volunteer training series for hiking guides, which would involve a workday in the forest pulling invasive weeds.

“I saw that everyone really enjoyed the workdays, being in the forest with like-minded people even if they didn’t like pulling weeds in their yards at home,” Cassel said. “Even visitors enjoyed the interactions with local people and helping to preserve the beauty they came here to see.”

Cassel knew invasive weeds were gaining a big foothold in Koke‘e, threatening the survival of some of Hawai‘i’s most unique and endangered plants. She thought the volunteer workdays should become a regular program where people would give back to the community and preserve the native forest.

The kolokolo kuahiwi (Lysimachia hillebrandii) is an endemic shrub found on Kaua‘i, O‘ahu, Molokai, Lana‘i and Maui. Photo by Spencer Kashiwa

“She took a grant writing course, she wrote a grant to do weed control up in Koke‘e, and she got her first grant. So, with a $10,000 grant and her little car, she just started the program, and we are where we are today,” said Matt Dery, KRCP Field Technician Crew Leader.

Cassel said the program grew “amazingly well” because it addresses a critical need, which is preserving the unique biodiversity of Koke‘e. And this can only be achieved by keeping pressure on invasive species.

The work of KRCP is mostly invasive weed control to prevent habitats from becoming completely dominated by invasive species, according to Dery.

An invasive species is something that was introduced to Hawai‘i, either intentionally or unintentionally. Dery said invasive species originally come from areas with heavy competition for survival and propagation, so they naturally evolved to handle this intense competition. Once in Hawai‘i, those plants don’t have much competition, and therefore their aggressiveness for survival makes them really successful against native plants. Left unchecked, invasive species can create areas that are called monotypic stands — plantings dominated by a single species.

“When you go to a native forest, we have a large diversity of plants; we have a canopy, a sub canopy and an understory,” Dery said. “We don’t find that when we get to a strawberry guava forest; all we find is strawberry guava.”

KRCP founder Katie Cassel, fourth from left, is seen here with the field crew and volunteers on this undated photo.

Monotypic stands are considered poor models for rainwater to properly percolate into an aquifer — a body of porous soil saturated with groundwater that eventually resurfaces through springs or wells. If rainwater goes through an area populated by a single plant species, the soil will likely erode. But if there are mosses, ferns and other vegetation layers typically found in our native forests, the water will eventually make its way down to the ground, slowly percolating through the soil and into the aquifer, Dery said.

Loss of native flora affects more than the aquifer, it also affects native fauna. For example, Dery said, the native ‘i‘iwi — a bright red honeycreeper fairly common in Koke‘e — evolved to suck the nectar of the cyanea flower. While feeding on the cyanea’s nectar, the top of the bird’s curved beak touches the flower’s pollen, carrying it to next flower, and becoming the plant’s major pollinator. Both species ensure the survival of each other.

All non-native plant species are targeted for removal by KRCP when they work in a given area — there are more than 130 non-native plants in Koke‘e — and a few of them can cause quite some damage. In Koke‘e, some of the most troublesome “habitat modifiers,” as KRCP Field Operations Manager Spencer Kashiwa called them, are the Himalayan ginger (Hedychium gardnerianum), strawberry guava (Psidium cattleianum), Australian tree fern (Sphaeropteris cooperi), sawtooth blackberry (Rubus argutus), and a handful of grass species (i.e Guinea grass, vasey grass, bushbeard grass, broomsedge, molasses grass, etc.).

The koki‘o ‘ula ‘ula (Hibiscus saintjohnianus) is a hibiscus native to northwestern Kaua‘i. In early Hawai‘i, it was used for medicinal purposes — to purify the blood, as a laxative and to strengthen a weakened child. Photo by Spencer Kashiwa

“For Koke‘e State Park specifically, the butterfly bush (Buddleja madagascarensis) is a growing concern and difficult to manage. This sprawling vining species is overtaking understories and canopies and it is starting to spread into new areas,” Kashiwa said.

The northwestern region of Kaua‘i has the oldest forests in the Main Hawaiian Islands, and there are numerous species that are unique to these forests (single-island endemics), according to Kashiwa.

“With the uniqueness, there are also many species that are federally listed as threatened, endangered, or critically endangered, and their rarity makes encounters very special, and it is sad to think that I may be the last generation to see some of these species,” said Kashiwa. He added there are some species teetering on the brink of extinction, and others only known to occur in a very limited area.

“Finding or seeing something new always drove me to push a little further and knowing that there is still more uniqueness to be found and seen. The collectiveness of all the flora and fauna species is what make these forest overwhelmingly unique,” Kashiwa said.

One of KRCP’s main challenges, Cassel said, is picking which areas they will work.

“We gradually realized that we should choose areas that were still primarily native, which allowed us to save more acres. It was also important to choose areas that included endangered plants in order to save them, and areas that were accessible for locals to access their culturally valuable plants,” Cassel said.

KRCP founder Katie Cassel. Contributed photo

Dery said it’s important to prioritize right. One plant he thinks is a big threat is bushbeard; a sedge that looks like a big grass clump. This invasive species is spreading through the Nature Loop in mile marker 8 and threatening native plants such as the iliau.

“That just grows uncontrollably because the amount of seed dispersal, and then the herbicides that we currently have and the tools that we’re currently using aren’t extremely effective on it,” said Dery, adding that as the bushbeard matures and seeds, it turns brown. You may think you have killed it, but it’s just seeding.

Also, clearing an area riddled with invasive species doesn’t necessarily mean it will be quickly overtaken by native species.

“When we attack a big thicket of ginger, we do get some native regeneration, but a lot of what comes back is ginger, and we need to go back again and work on it,” Dery said. “Complete eradication is a big effort.”

To deter invasive species from coming back on a cleared area, the KRCP field crew — Dery, Makamae Compoc-Dela Cruz, Amaya Simao and Kupu intern Jorell Hancock — is pushing hard for out-planting native species.

“The crew that’s out right now, they’re doing weeding as well as out-planting. So, not only are they removing the invasive plants, but they’re putting in native plants that were once found in the area,” Dery said of his field crew.

KRCP volunteers and field crew are seen here in Koke‘e’s bog forest. Contributed photo

The work may seem endless, but KRCP has had a lot of help over the years. Since 1998, KRCP has cleared more than 12,650 acres in Koke‘e, all with the help about 33,000 volunteers who pulled nearly 14 million weeds during 180,000 hours of field work.

These numbers reflect the core of Cassel’s vision for KRCP: its volunteer program.

“The strategy of experiential education, where volunteers learn by going out in the field and working side-by-side with experienced and knowledgeable field staff along with passionate local citizens, offers a win-win opportunity for all,” Cassel said. “This approach has proven to be one of the most effective and reliable methods for raising public awareness of and appreciation for the remaining and highly fragile ecological resources of the island.”

This is because volunteers make deep personal connections with the land they help to protect and with each other as co-workers, according to Cassel. Field staff and naturalists, she said, share the gratification of passing along vital knowledge and practical skills concerning invasive weed identification and eradication.

The relationship between staff and volunteers benefits the entire region as more people become part of the solution, joining as active partners in native forest conservation, she said. Usually, local residents account for 60-70 percent of the volunteers, but during the pandemic, the local volunteers swelled to 85 percent. Many volunteers are schoolchildren on field trips.

KRCP volunteers at Kilohana Lookout. Contributed photo

Volunteer work usually focuses on invasive weed control in selective forested areas. But Kashiwa said projects can also include work in their native nursery, out-planting of native species and trail maintenance.

“Mahalo nui loa to our many volunteers both individuals and groups as well as our conservation partners that have volunteered and continue to support KRCP. They are the heart of this program, and we are grateful for their generous contribution of time and hard work,” said Cassel, who retired a couple years ago but still remains an integral part of the program, assisting the staff with some project planning and helping with a few volunteer groups coming to Koke‘e.

KRCP operates under their fiscal sponsor, the Garden Island Resource Conservation & Development, Inc. The program is funded through donations and contracts with several organizations, including the Hawai‘i Department of Land and Natural Resources, State Parks Division/Division of Forestry and Wildlife, The Nature Conservancy, USDA Natural Resources Conservation Service and the Natural Area Reserves System.

Visit www.krcp.org for more information on how to volunteer or to donate. Donations can also be made by check via mail to P.O. Box 1108, Waimea HI 96796.