|
story by Dennis Hollier
The great wiliwili tree in my front yard is blighted. Its crown bristles with dried twigs. Leaves still grow on the lower branches, but in twisted, stunted bunches. They’re gnarled and pocked with galls. The old tree is dying — another victim in a statewide epidemic of parasitic Erythrina gall wasps. These invasive wasps were first noted in Hawai‘i less than two years ago. Now, throughout the Islands, almost every type of tree in the Erythrina genus is infested, including both native wiliwili and ornamental imports such as the Indian Coral Tree. On the street behind my house, a windbreak of tall wiliwili stands leafless in the sun. These were once venerable trees. Now, to paraphrase Samuel Beckett, they’re more than venerable; they’re dead. Despite the best efforts of the state’s botanists, there’s still no treatment for the gall wasps. No known pests for bio-control. No poisons to apply. No mutations to muddle the genome of these destructive pests. Fearing the worst—that the blight may only end with the extinction of the wiliwili in Hawai‘i—scientists throughout the state are methodically stocking up on seeds. In the back of Manoa Valley, the botanists at Lyon Arboretum’s Rare Hawaiian Plants Program have ninety pounds of wiliwili seeds on ice. For after the apocalypse. Of course, the crisis of the wiliwili, although sudden and dramatic, is only the latest episode in the long story of loss and extinction here in Hawai‘i. There are about 1,000 native plant species in Hawai‘i, ninety percent of which exist nowhere else in the world. Hundreds of these species are endangered. Hawai‘i accounts for about a quarter of the federally listed endangered plant species in the country, while countless other unlisted species also teeter on the brink of extinction. Over the last few years, a network of organizations and conservation professionals has emerged, seeking to preserve these fragile plants. The very public efforts to save the wiliwili simply highlight the largely anonymous work being done to protect Hawai‘i’s other rare and endangered plants. Scientists in white coats toil at their microscopes. Administrators scramble for funding. And high on the windy, perilous ridges of the Ko‘olau Mountains, intrepid field biologists nurture the last dwindling communities of these rare Hawaiian plants. But the nexus of all this quiet work can be found in two unobtrusive laboratories at Lyon Arboretum. Alvin Yoshinaga runs the seed bank at the Arboretum. He’s a slight, soft-spoken man with a graying mustache and glasses. When you ask him a question about biology, he often defers to other experts, sometimes quickly pulling up their Web sites on the Internet. But his quiet manner belies a real passion for plant conservation: Yoshinaga’s experience at the seed bank has made him the expert on Hawaiian seed. The protocols for seed storage and propagation of most agricultural plants are well-known. For rare native plants, though, these processes are more mysterious. Science knows little about the pollination biology of many of the plants coming into the seed bank. Yoshinaga and his associates spend much of their time researching the intimate details of plant sex. They look for the conditions under which a plant germinates best. They store seeds at different combinations of temperature and humidity to find the ideal climate. Using sandpaper, razors, acids and dental tools, they examine the effects of scarification on seed. Yoshinaga is especially interested in identifying storage techniques that extend the useful lifespan of seeds. “Because most tropical seed cannot be frozen,” he notes, “people assumed that was true for Hawaiian plants, too.” But surprisingly, Yoshinaga has discovered that many Hawaiian seeds can be successfully frozen. Others survive better if only refrigerated. A few do best if stored at room temperature. This information is critical: Yoshinaga points out that a seed that remains viable for one year at room temperature might last 100 years if it can be frozen. Many of the seeds stored in Lyon’s seed bank will need that kind of shelf life. “There are two kinds of seed banks,” says Yoshinaga. “One—what I call a working seed bank—is something like a passbook savings account. You deposit the seeds of native plants so that you can withdraw them later—for habitat restoration, perhaps.” The seed bank serves this role for many of its customers: the Army Natural Resources Program, the state Department of Land and Natural Resources and The Nature Conservancy, among others. The other type of seed bank preserves germplasm in perpetuity. Yoshinaga calls it “a kind of Noah’s Ark.” For this aspect of the work, the bank conserves not just the species, but also its genetic diversity. Sometimes, the survival of certain plants in the wild is so tenuous that special measures are taken to preserve their genome in the seed bank, in case a natural catastrophe or wildfire takes out the last surviving plants. Also, as individual specimens of a plant become rare, it’s critical to conserve the genetic diversity of every one of them. The seed bank at Lyon Arboretum is a true bank: It doesn’t own the seed in its collection; it merely serves as a vault for the material deposited there by other organizations. Only the organization that makes the deposit can remove or use that plant material. The refrigerators and freezers are full of carefully labeled foil packets and vials of seeds. Each package contains the seeds of a single plant collected at a single time. When future researchers propagate these seeds, this kind of recordkeeping will allow them to manage the population genetics of the plants. The accession of seeds to the collection is a detailed process. The seeds often come in fruit or pods that must be removed. Then the seeds themselves require specialized treatment to prepare them for storage. Often, they must be dried in a controlled climate so that they don’t rot later. Different kinds of seeds also require different temperatures and humidity levels during storage, and all require periodic testing and maintenance. The seeds themselves come in a wide range of sizes. Wiliwili seeds, which are sometimes strung into lei, are about the size of a black-eyed pea. Other seeds, though, are like motes of dust. A film vial might hold thousands of them. And each species can have its own storage and germination protocols. To make sure seeds in the collection are still viable, Yoshinaga periodically checks each sample for germination rates. He uses several incubators as grow chambers in the lab at Lyon, and also has a couple at the Army’s Natural Resource Management Base near Wheeler. At any given time, he may have 300 to 400 tiny plants in various stages of germination. But not all plants are suitable for propagation from seed. Sometimes, botanists are unsure of the protocols for getting seeds to germinate. More often, it’s impossible to collect mature, viable seeds from extremely rare plants. Upstairs from the seed bank, Nellie Sugii runs Lyon Arboretum’s astonishing tissue culture—or micro-propagation—lab. Here, Nellie and her staff laboriously tend a garden of Hawai‘i’s rarest plants. But it’s a most unusual garden.In a small, brightly lit room lined with wire rack shelves, thousands of tiny plants grow in test tubes and beakers. A glance at any one of them reveals a perfectly formed plant in miniature. All these plants have been grown from the tissue samples—leaf cuttings, immature seeds, roots and etc.—of specific plants. As at the seed bank, each plant is carefully labeled with its collection site and date, the collector’s name and the plant number. For the rarest plants, Sugii makes sure to have a tiny specimen grown from the tissue of every known wild individual. In many cases, that might mean just a handful of plants. Surprisingly, Sugii also grows plants that are extinct in the wild—plants that only continue to exist inside her carefully tended test tubes.
The work of the tissue culture lab is even more exacting than the seed bank. Out front, Sugii’s assistants manage the routine maintenance of about 10,000 plants. Under specially ventilated glass hoods designed to prevent contamination, technicians carefully remove the tiny plants, one by one, from their test tubes and meticulously trim them using scalpels. After working with each plant specimen, they sterilize their blades in the flames of a small lamp. They constantly monitor the collection for disease or dead tissue. The test tubes are periodically refilled with fresh growth medium, a clear potion concocted by Sugii. Raising plants this way is labor intensive, but seeing the garden of the tissue culture lab has a real psychological effect on the visitor. In the seed lab, the collection is packed tightly in refrigerators and freezers, so it’s hard to grasp its full nature. The tissue culture lab, on the other hand, is more like a library: You can browse the aisles to get a sense of the desperate straits of Hawai‘i’s flora. Sugii points out a small collection of plants of the genus Cyanea, known as haha in Hawaiian. One Ane Bakutis and her assistant, Hina Kneubuhl, spearhead the quixotic efforts of PEP on O‘ahu. Other organizations certainly work on rare and endangered plants, but they tend to focus on habitats or remediation; PEP focuses only on the conservation of species of plants with fewer than fifty specimens surviving in the wild. Their objective is to collect and preserve the seeds or tissue from as many of these plants as possible. PEP used to be known as the Genetic Safety Net. It was an unpopular name, but it aptly describes the team’s mission.Bakutis and Kneubuhl prowl the high ridges of the Ko‘olau and Wai‘anae mountains, keeping tabs on small populations of rare and endangered plants littered along the spine of O‘ahu. These plants are almost always in remote and difficult locations, so the work is both dangerous and physical. Bakutis describes the wild setting overlooking Windward O‘ahu as “the most beautiful office in the world.” It’s serious work, though. Even with the help of a helicopter, they often have to hike for hours to reach their sites. Once there, they collect seed and tissue; they monitor plant development and health; they keep data on every individual plant under their supervision. Every plant has a tag and a number. The numbers are depressingly low.
On one typical afternoon, I took a helicopter ride with them to the crest of the Ko‘olau to check on the status of a population of about twenty Cyanea st. johnii, another member of the haha group. On a previous visit, Bakutis had noticed that these tiny plants were fruiting; now she wanted to see if it was time to collect their seeds. Because the winds were too high to land safely near the crest, the helicopter dropped us on a small knoll below the site. From there, we hiked a quarter mile up a narrow ridge, thick with stunted ‘ohia, sphagnum moss and ‘uki sedges. At one point, I lost my footing and ended up straddling the ridge, neck deep in the moist ‘ohia. When I reached down to find a handhold, the ridge was only the width of my palm. The drop-off on either side was a couple hundred feet. Nevertheless, Bakutis and Kneubuhl, wearing spiked tabi, made their way confidently along the narrow ridges. At one point, Bakutis walked out on a nearly vertical slope to check the status of one of her haha. In the high wind, she signaled its condition to Kneubuhl by slashing her finger across her throat. Bakutis had taken the precaution on her last visit to wrap the fruit of these plants in small, green mesh bags. This kept the rats from eating them, or the seeds from dispersing in the wind if the fruit had matured before she had a chance to return. Laying prone in the tall grass surrounding plant number twenty-two, she gently pulled the bag back to check the fruit. No luck. They were still green—there would be nothing to deliver to the seed bank from this trip. One by one, Bakutis and Kneubuhl surveyed their precious plants, but none were ready to harvest. On one plant, the main stalk had died, leaving only a sucker at its base. And plant number seven, on the windward side of the crest of the Ko‘olaus, had disappeared altogether. Two or three peaks over, the last Cyanea truncata disappeared in the 1990s. After coming down from the mountains, I asked Bakutis if the work depressed her. Instead, she and Kneubuhl seem to find it heartwarming. Bakutis, a local girl who grew up in Wai‘anae and earned degrees in both botany and Hawaiian Studies at the University of Hawai‘i, says she wishes every Hawaiian kid had the opportunity to see that you can make a living like this. Her enthusiasm reminds me of something Nellie Sugii told me back at Lyon Arboretum. “Sometimes people don’t realize what they have in their own back yard,” she said, gesturing to the tiny plants in her improbable garden. “This is like a dream job. It’s the best thing that ever happened to me.” |
|||
