ABOVE: Mahina Patterson, coordinator for the Kohala Watershed Partnership (KWP) walks a fence line in the Puu o Umi Natural Area Reserve.
"A healthy forest is like an ohana," says Mahina Patterson, framed by fern fronds as she explains the analogy to family. "Ohana has kupuna [elders] and makua [parents] and keiki [children]—all of those generations. In the forest, that's what you want to see. You want to see the young plants, you want to see mature plants and then you want to see the hundreds-of-years-old plants."
Patterson says this while standing on the floor of a robust, multigenerational cloud forest near the summit of Kohala volcano, the oldest of Hawaii Island's five volcanoes. The canopy of endemic ohia lehua trees towers above, letting dappled light in to feed the midstory. Patterson stands beside a hapuu fern on spongy native sphagnum moss; olapa keiki (shoots) surround her feet and reach for the sky. This family is thriving because the forest is actively managed: Work crews keep the suffocating invasive plant species at bay, and fences keep out pigs that would otherwise chomp and stomp tender young plants.
"In a forest with pigs, it's that young generation that's impacted. They are missing and unable to grow." Patterson has a special interest in ensuring that the young generation of this forest can grow. She's coordinator for the Kohala Watershed Partnership (KWP), an organization comprising the largest individual landowners in Kohala, all collaborating toward one goal: protecting Kohala's water. While the remote windward side of the volcano is lush, the populated leeward side sits in an arid rain shadow. High-quality water depends on the natural water cycle, in which healthy native forest plays a crucial role. This year marks KWP's twentieth anniversary, and its efforts have shown promise. The proof is in the plants.
Patterson carefully crouches, ducks and crawls along a forest transect. "A healthy forest is a difficult forest to walk through!" she jokes. A transect is an imaginary line on a map, marked in actuality by tape tied to tree branches. Patterson follows the fluorescent flags denoting the transect points, where she stops to make observations. Repeated measurements at these same points help to reliably track changes in the forest over time.
A keiki (young) endemic ohia lehua ready for planting.
Patterson honors NARS program manager Nicholas Agorastos with a lei made from ohia planted by KWP.
Patterson with her father, Mike Gomes, in front of a flowering ohia in leeward Kohala.
This ten-acre section of forest has never been grazed, logged or planted with sugarcane, like so much of the rest of leeward Kohala, so it was one of the first areas KWP set out to protect in 2004. A crew from the state's Natural Area Reserve System (NARS) has been managing this location ever since, mostly by removing invasive plants and animals and planting native species. The understory is now thick with what managers call indicator species, native and endemic plants that indicate the absence of predators or feral ungulates: Lacy akolea ferns, showy oha wai (lobelia), twisting maile vines and silvery painiu (lilies) congregate closely together. Fallen seeds rest atop a healthy layer of leaf litter. Tree sprouts unfurl from the duff, tiny saplings that will eventually replace the towering canopy that harbors the entire forest ohana.
Native forests are essential to the water cycle in myriad ways. Leaves and branches capture moisture from passing clouds, and this fog drip helps recharge the aquifer. Organic matter collects on the forest floor to create a sponge-like layer that retains water. The forest canopy reduces evaporation and protects the ground from overheating. Roots prevent soil erosion and runoff. The forested summit of Kohala is the source of the headwaters for many streams, and the entire system acts as a filter so that stream water remains clean.
Kanaka Oiwi (Native Hawaiians) have long understood the role forests play in the water cycle. Around the 1400s, as the increasing population of the Islands put pressure on its resources, an Oahu chief named Mailikukahi devised a system to protect the watershed: Land was divided into ahupuaa—units based on watersheds from the mountain ridges to the sea—and each ahupuaa was carefully managed for sustainability. This system was adopted across the island chain.
"I think about aloha aina [love of the land] a lot, and I truly do feel like that needs to be a kakou [collaborative] thing. It needs to be a community effort," says Patterson, seen above driving past a stand of outplanted Acacia koaia, a cousin of koa, on her way to the Kohala summit. The invasive kikuyu grass in the foreground was introduced to Hawaii for cattle fodder and has since spread throughout the Islands.
That changed in 1848, when land parcels were allowed to be bought and sold. New property lines cut across ahupuaa and bisected watersheds. Industries and plantations strained water supplies. Introduced pigs, cattle, deer and mouflon sheep multiplied, eating their way through what was essentially a predator-free all-you-can-eat salad bar. The saplings of native species like koa were especially vulnerable, and the forests that once blanketed the slopes of Hawaii Island's volcanoes were slowly stripped bare. The ranching industry emerged in part to manage feral cattle; the paniolo (cowboys) who fenced forests and tamed cattle through the nineteenth century noted declining water quantity and quality.
By 1877 the Kingdom of Hawaii recognized the need to protect Kohala's forests. King David Kalakaua created a commission that toured the Islands, surveying available resources. It reported that "The forests on the Kohala Mountains are dying rapidly" and suggested that "the government, if it would wish to preserve that part of the Island of Hawaii from serious injury, must take some steps for reclaiming the forests."
In 1924, Hawaii's supervisor of forestry, CS Judd, wrote to then-Governor Farrington, "Forestry is practiced in the Territory of Hawaii primarily, not for timber production, but for the conservation of water. Probably in no other section of the world is the relation between a satisfactory forest cover on the mountains and the supply of water for domestic and agricultural uses better or more ably demonstrated."
The eleven partners of KWP are doing two things: protecting intact forests and growing new ones on former pasture land. Protecting intact forests means removing non-native plants, fencing out non-native mammals and preventing new invasive species from gaining a foothold. Creating new forest means planting trees in areas that are not ideal for grazing cattle, such as steep gulches and cinder cones.
Members and their ohana celebrated KWP's twentieth anniversary by planting ohia together at one of the partnership's collaborative watershed management projects. Forest restoration is critical to a healthy watershed, as native Hawaiian plants capture moisture that feeds Kohala's streams and recharges its aquifers.
Zach Judd (no relation to CS) is forestry manager for Parker Ranch, a KWP partner and the oldest ranch in Hawaii. Founded in Waimea in 1847 and nestled at the foot of Kohala, no single business entity has witnessed more changes to the Kohala watershed over time. In 2017 the ranch brought its forestry management efforts in-house when it hired its first forestry manager. Judd took over the forestry manager position in 2021. Under Judd's direction, reforestation efforts have increased. "It's a really exciting time to balance conservation and agricultural production," Judd says in his Waimea office. "My hope is that we can do both on the same piece of land and blur the lines of ag production and conservation, or ag production and forestry."
To date, Parker Ranch has planted about 32,000 trees, and in the past fifteen months or so has managed weeds on four hundred of the some 130,000 acres of the ranch's land. "It doesn't seem like a whole lot in the grand scheme of things," Judd says, "but it's more than we've done in several decades."
Ranches are not the only entities interested in the health of Kohala's forests. Queen Emma Land Company, Kamehameha Schools, the Department of Hawaiian Home Lands and The Kohala Center are among the KWP partners and associate partners. Jake Merkel, the field crew leader for The Kohala Center's cloud forest team, spent the early years of his career reforesting a pasture area about twenty miles south of Kohala. When he returned fifteen years later, he was in disbelief. "I was just awestruck. ... I saw these koa trees that were already three or four feet in diameter at the base. I would never have thought that was going to happen."
One of KWP's goals is to reconnect high-elevation cloud forest to low-elevation dry forest. To that end, the partners designated a corridor and fenced out cattle so the land could be replanted. In the restoration corridor, Merkel noted the return of other indicator species: native forest birds. "Already, you see amakihi and apapane coming out of the cloud forest down into that corridor, almost using that as a little flyway to get further down the mountain." Luckily, farther down the mountain is still above the "mosquito line" at about 4,500 feet in elevation. Above that, mosquitos cannot survive the cold, and avian malaria—a significant driver of native bird extinction—cannot spread. The tree line currently sits at about 4,800 feet above the corridor, so if the tree line were to come down a few hundred feet, it would provide much more habitat for forest birds.
Cattle graze in a pasture at Parker Ranch, the largest ranch in Hawaii and a KWP partner.
KWP field project technician Woodlin Nelson with a native akala (Hawaiian raspberry).
Parker Ranch forestry manager Zachary Judd tends to koa seedlings destined for outplanting on ranch land at the state tree nursery in Waimea.
Near the bottom of the corridor and abutting Kohala Mountain Road sits what might be the very first fenced Kohala restoration project, the Koaia Tree Sanctuary, a KWP project managed by the state Department of Land and Natural Resources Division of Forestry and Wildlife (DOFAW). Pulling her work vehicle into the newly paved parking area, Patterson recounts the origins of the unit in the 1950s. "Then-territorial forester LW Bryan had the foresight to see that there were still native species left in this area," she says, "and they went ahead and protected it with a fence." In the almost seventy-five years since, the tree sanctuary has grown abundantly, largely due to volunteer sweat equity. Regular community workdays help to maintain the trails, remove invasives and plant natives. The sanctuary is under DOFAW jurisdiction and open to the public. It's the best place for the people to see what the leeward slopes of Kohala might have looked like before they were overrun with grasses from Africa.
While fountain grass may be here to stay, new invasive species can be kept out. Invasive species, by definition, are introduced to an area and cause harm to the environment, the economy or human health. While keeping invasives out entirely is probably impossible, KWP's interventions do help mitigate their impact. "Researchers have studied different scenarios, specifically on Kohala mountain, of what would happen to our native forests without active management," says Patterson, explaining what might happen if no action were taken at all. "One study showed that our native forests would convert to an invaded, non-native forest within fifty years, which is really scary and really quick." That scenario is why the KWP partners keep up the laborious work.
Recent discoveries, however, have blown winds of hope in everyone's sails. In October 2019 a burrow of uau (Hawaiian petrel) was found on the valley slopes of a protected forest in Kohala, "the first known burrow to be recorded in Kohala in Western times," says Bret Mossman, natural resource management specialist for NARS. The state has set up a grid to protect the birds from predators like cats, rats and mongooses so that a more robust seabird population has a chance to grow in Kohala.
Three generations—a mother, daughter and grandson—plant the future forest canopy. The seeds of the ohia they're planting were collected in Kohala, grown by Maui Native Nursery and are now returning to their home on windward slopes of Kohala.
Another ray of hope above the valley slopes and on KWP partner property is a previously unrecorded population of kahuli, native tree snails. At one time around 750 species of these colorful tree snails inhabited forests across the archipelago. The kahuli found in Kohala is the last remaining species of native tree snail on Hawaii Island, and it's found only in Kohala. Patterson has helped secure funding to install a predator-proof fence, lovingly referred to as a "snail jail," around the kahuli population.
Patterson takes pride in KWP's accomplishments over the past twenty years. The greatest lesson learned might be the power of collaboration: Many ranchers once believed that removing feral cattle was a lost cause, but acting in concert the KWP partners have mostly eliminated cattle from the upper watershed. The KWP partners continue to secure funding to protect and expand forests.
Patterson reflects on her work from her office at the end of an eleven-hour day. "I think about aloha aina [love of the land] a lot, and I truly do feel like that needs to be a kakou [collaborative] thing. It needs to be a community effort. It needs to be a part of our lives whether you're a hunter, a fisherman, a realtor or whatever you do. All of us who depend on the water of Kohala should be involved in stewarding our place and our source of water."
