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The Species Race

The world is losing plants faster than scientists can find them

By Virginia Stuart '75, '80G
Photography by Lisa Nugent

On a Sunday morning in August, 20 crack biologists from around the world descend on a concrete pier in New Castle, N.H. Wrapped in an early morning mist, the floating pier undulates gently with the motion of the water. Some of the scientists lie on their stomachs in a row, like so many curious children, staring into the waters and pulling out treasures: a rosy starfish the size of a Frisbee, a mussel encrusted with smaller shells and a delicate red seaweed. The researchers call out scientific names to a record keeper--"Homarus americanus," "Neosiphonia harveyi"--and seal specimens in plastic bags.

The scientists, including UNH seaweed expert Art Mathieson, are performing a "rapid assessment." Over the course of a week they are collecting and recording all the marine plant and animal species they can find in a series of one-hour stops along the New England coast. Every afternoon they return to a nearby lab and work into the evening, analyzing and preserving specimens. Twenty-five percent of the organisms identified three years ago in the first Northeast Rapid Assessment were species known to have come from afar, perhaps in a ship's ballast or an oyster's shell. Some of the imports may be innocuous; others are not. Take, for example, the Asian green seaweed known as dead man's fingers (Codium fragile ssp. tomentosoides). With its spongy, jointed leaves that resemble skeletal fingers, the plant has been spreading along the East Coast since the 1950s, smothering shellfish in their beds and crowding out native seaweeds.

On their quest to protect coastal New England from such scourges, the scientists appear to be armed with nothing more than Ziploc bags, kitchen strainers, eye droppers and a couple of butterfly nets. But their ultimate weapon is something much more powerful--the ability to take a six-foot-long seaweed or an orange blob of a sea squirt and give it a name.

The long list of Latin names that came out of the first rapid assessment has already helped states start tracking existing invasions, while officials from Long Island to Canada are collaborating on a plan to prevent further contamination of harbors, perhaps by disinfecting ballast water or discharging it in the open ocean.

The biologists participating in the rapid assessment are experts in taxonomy--the identification, classification and naming of organisms. An endeavor that's as old as Aristotle, taxonomy is now more important than ever as scientists strive to catalog and protect the rapidly diminishing diversity of life on Earth. For Judith Pederson of MIT's Sea Grant program, the hardest part of coordinating the rapid assessment has been finding botanists, like Mathieson, and zoologists trained in taxonomy. It seems that taxonomists are themselves an endangered species.

So many species, so little time

More than 100 years ago, Charles Darwin suggested that diverse ecosystems were superior to monocultures. Today the majority of biologists believe that biodiversity is critical to human survival. In a 1998 nationwide survey by the American Museum of Natural History, most biologists agreed we are in the midst of the largest and only human-induced mass extinction of plants and animals. It is estimated that extinctions are now occurring 100 to 1,000 times faster than normal.

The scientists considered the loss of biodiversity more serious than depletion of the ozone layer, global warming or pollution. The anticipated effects included destruction of natural systems that cleanse air and water; an increase in flooding, drought and infectious disease; elimination of potential new medications; and damage to agriculture, fisheries and the world's economies.

Out of an estimated 10 to 30 million species on Earth today, a mere 1.5 million have been described to date. Scientists clearly have their work cut out for them.

Garrett Crow, the chair of the plant biology department, is a botanist-of-the-world in the mold of the great taxonomists of the past. He has "botanized" in places like Tierra Del Fuego, Bolivia, Siberia, Labrador and the Amazon. He has waded waist-deep into tropical waters, studying giant water lilies with leaves the size of small trampolines, climbed to alpine meadows in the Crimea where the wild cousins of tulips and peonies grow and marveled at carnivorous bladderworts growing in the trees of the Costa Rican cloud forest. He dismisses as mere annoyances the mythic-sounding trials he has endured, from blood-sucking leeches to the scrutiny of the KGB. Wherever he goes, he gathers plant specimens in a temporary field press of newspaper and cardboard, and like Darwin and so many other naturalists before him, he describes the plants and habitats in his journal.

An internationally known expert on aquatic plants, Crow is co-author (with C. Barre Hellquist '65, '66G) of the definitive book on aquatic plants in northeastern North America and author of a similar book on aquatic plants in Costa Rica. In 1993, he published an article on a surprising discovery he made when comparing aquatic environments in Costa Rica and New England. He found that, contrary to the pattern among terrestrial plants, New England's aquatic environments are as diverse as those in tropical Costa Rica--or more so. Subsequent work with then-doctoral student Nur Ritter '92, '00G in Bolivia and a recent trip to the Amazon revealed a similar pattern. A solid, patient man who takes the long view, Crow suspects the retreat of glaciers from northeastern North America more than 13,000 years ago contributed to our diversity in aquatic plants by leaving behind so many different types of aquatic environments.

Crow believes his discovery emphasizes the need to "preserve what we have." He and his students have advised consultants on ways to enhance diversity of created wetlands and avoid the introduction of non-native species.

Preserved plant specimens, and the standardized Latin names used to identify them, allow botanists like Crow to make comparisons across geographic borders--or across time periods. Art Mathieson has, in effect, collaborated with a Victorian botanist named Frank Collins, who died in 1920.

A self-taught but scholarly amateur from Massachusetts, Collins made an extensive seaweed collection that has enabled Mathieson to compare the flora in Maine harbors then and now. The 77,000 specimens Mathieson has collected over 30 years at 1,000 sites in New England will, in turn, present an important historical record for future ecologists. Since today's botanists have analyzed the DNA from fragments of specimens collected 200 years ago, Mathieson knows his collection could be used in ways he can't even imagine today. Even a simple list of the plants growing in an area in the past can make all the difference in efforts to restore the habitat for an endangered species--like the masked bobwhite quail successfully reintroduced in Arizona.

In this corner--the botanists

Writing in the journal Science in 1997, James Blackburn, head of the United Kingdom Society of Systematists, estimated that there were only 7,000 biological taxonomists in the world, a number he termed "clearly inadequate." The National Science Foundation, also recognizing the loss of taxonomists at a time when they are most needed, has established a program to encourage the training of new taxonomists.

The number of taxonomists has been dwindling for several reasons. Many, like Art Mathieson and Garrett Crow, are nearing retirement age, and few young faculty members are coming into the field. Crow explains why taxonomists are underappreciated: "We're detail people, we make collections and we make students memorize." Take Janet Sullivan, for example. An adjunct professor of botany and editor of the journal Rhodora, she teaches the UNH course in plant systematics: taxonomy with an emphasis on evolutionary relationships. She estimates that students in her course must memorize 350 terms used in plant identification plus the Latin names of about 150 plant families and genera, as well as some terms from related fields like molecular biology.

A thoughtful person, Sullivan measures her words carefully, just as she has measured thousands of plant parts for the herbarium, a library of dried plant specimens. She is a leading authority on the genus Physalis, which includes roadside weeds called ground cherries as well as the Mexican husked tomato called a tomatillo. Details are her stock in trade.

Sullivan has used more than 40 characteristics to redefine some of the species in Physalis. She has examined thousands of specimens, measuring the pedicels (stalks that support flowers) and describing the maculations (spots) on their petals. She has analyzed the chemical composition of these plants, hybridized them, observed bees' behavior around them and scanned their pollen with an electron microscope. Among the characteristics she studied, her favorite may be the "lovely little branching hairs" on the undersides of the leaves in some species. She and a German colleague did extensive research on the morphology and development of these tiny hairs, which look like crisscrossing glass filaments under a dissecting microscope.

Advances in molecular biology have taken the minutiae of taxonomic research to even more minute levels, and some long-standing taxonomical problems are being resolved as a result. Working in collaboration with plant biologist Chris Neefus, molecular biologist Anita Klein, and graduate student Troy Bray, Art Mathieson has used molecular methods to study seaweeds in the genus Porphyra, which includes the nori used in sushi. DNA sequencing has helped the researchers discern the differences among five species that were previously considered one species.

While taxonomic work can look like counting angels on the head of a pin--literally splitting hairs, or even DNA--the practical implications can be profound. Porphyra, whether destined for sushi or pigments used in scientific research, is being cultivated around the world. Failure to distinguish among these species when

propagating plants for aquaculture could lead to the introduction of an alien species into some areas. When Caulerpa taxifolia, a cultivated aquarium plant, escaped from a museum in Monaco in 1984, few people recognized the danger it posed. The plant, dubbed the killer algae, has since spread at the expense of native flora and fauna. Today it carpets 60,000 acres of the Mediterranean Ocean floor and is considered beyond control.

Slicing and dicing DNA

Ironically, advances in molecular biology appear to be simultaneously helping and hurting the field of botanical taxonomy. In addition to elucidating differences among closely related species, molecular research has increasingly enabled taxonomists to make evolutionary relationships the basis of their classification systems. "If your classification scheme tells you something about evolutionary relatedness," Sullivan explains, "you can make predictions about how something will grow, what its chemical makeup will be and whether its use will be positive or negative." Since the 1970s, for example, researchers have been looking for ways of producing the cancer drug Taxol without destroying thousands of the Pacific yew trees in which it was first discovered. Scientists had only to look for closely related species within the same genus. A number of cultivated species of yews produce the necessary chemical in their needles, which unlike the bark of 100-year-old trees, is an easily renewable resource.

Unfortunately the cutting-edge work of slicing and dicing DNA makes traditional taxonomic pursuits like slogging through a bog or measuring pedicels in a herbarium seem antiquated. Money for molecular equipment may come at the expense of important resources like the herbarium, and the push to produce scientists with molecular training is reducing the number of scientists skilled in fieldwork. Grant money also comes more easily to DNA-related research.

"Every time a new technology is introduced there's a bandwagon factor," explains Sullivan. "But there probably isn't one technique that's going to give us The Truth." She believes systematics research should combine up-to-the-minute techniques with knowledge of plants in their natural environment, plus an understanding of earlier attempts at classification.

Molecular work is "only as good as the taxonomy that goes with it," insists Mathieson, who has seen genetic research in a major database applied not only to the wrong species, but even the wrong genus. "There are fewer and fewer people doing active fieldwork," he laments. Although the students he works with in marine ecology learn molecular methods in the lab, he makes sure that they also get plenty of experience in the field--and the herbarium.

What's in a name?

Garrett Crow also gives his students extensive training in fieldwork, often in wetlands and sometimes in remote areas-like the Bolivian rain forest or Lake Umbagog National Wildlife Refuge in northern New Hampshire, where Mare Nazaire '03 has been studying the vegetation in two of the state's largest bogs. On her early morning commute by boat down the Magalloway River, the evergreen boreal forest bulges out over the riverbanks, mirrored in the glassy water. At the bog called Harpers Meadow, she is more likely to see signs of moose than humans as she sets out over the hummocks and hollows of what is, in effect, a 350-acre, sodden sphagnum sponge. She gets her feet wet immediately. Although she never knows exactly how deep she'll sink with her next step, she has learned that she is much less likely to leave a sneaker behind in the muck if she avoids the muddy moose paths.

In July, delicate fringed pink orchids called rose pogonias appear among the pitcher plants and unripe cranberries in the bog. When Nazaire notices several rose pogonias that have been trampled by moose, she reflects on the human activity of naming. She wonders if we value this beautiful flower even more because we have given it the name "orchid."

It is Nazaire's job to identify--with Latin names--all the plants in the bog, so that even the smallest flowers and berries underfoot can be recognized and protected by the refuge. From the earliest times, people have believed that to know the name of someone or something is to have power over that person or thing. In Genesis, God asked Adam to name all the newly created creatures and plants, Sullivan reminds her students on the first day of plant systematics class. Thus, according to the Judeo-Christian tradition, man was given dominion over the natural world. Taxonomists from Aristotle, with his Great Chain of Being, to the present have been interested in the rightful relationships between different species. Crow believes that "Adam's naming gave creatures value, and having 'dominion' was actually about stewardship, not power. Humans have largely abused the responsibility laid down in Genesis."

Nazaire's work will help the Umbagog refuge to fulfill that responsibility, according to wildlife biologist Laurie Wunder. "Harpers Meadow is a National Natural Landmark," she explains, "so we have a responsibility to be a good steward. There are some rare plant species in the bog. Mare will give us a detailed survey map of the plant communities there, and then we will set up permanent monitoring plots to see how we're doing and whether fluctuating water levels are having an impact on the plants."

The Art of Science

What toils, what science would be more wearisome and painful than Botany" wrote the great 18th-century botanist Carl Linnaeus, acknowledging the challenges of the profession he embraced. Nazaire has spent two summers in the great bogs at Umbagog, marking off plots, identifying plants within them, and assessing the degree of dominance of different species. Since many plants need to be flowering or fruiting for accurate identification, she must comb through the same plant communities again and again. When she gets back to the refuge headquarters at the end of the day, her feet are wrinkled from standing in water--and then it's time to begin pressing and identifying the specimens she has collected.

But Linnaeus also described the "singular spell" that botanists fall under in their devotion to plants. Crow says simply, "You have to love the work," and Nazaire clearly does. She loves being far away from civilization early in the morning in a desolate landscape of stunted tamarack trees where the only sound she hears is the haunting laugh of the loon. The refuge already protects the loon by adjusting the lake's water levels. She knows her hard work will help the refuge protect endangered or threatened plants as well.

Nazaire, who received her first undergraduate degree from the Portland School of Art, was an artist before she became a scientist. "I think art and science are very deeply connected," she says. "They both have to do with the observation of things. What drew me to plants is geometry. Most of my paintings worked with geometry. And I have always been interested in the relationship between order and chaos."

Out in Harpers Meadow, the cargo pockets on Nazaire's tan vest bulge with the tools of her trade. As she turns to examine a plot she has roped off, the sun breaks through the clouds, revealing a pattern in the vast meadow that only moments ago seemed like a chaotic blend of broad- and narrow-leaved sedges. Now the broader blades stand out, leaning in one direction, shining in the light. For an instant, it seems as though Nazaire could be holding a pallet and paintbrush instead of a field press and compass. She is painting a picture, after all, preserving this shining moment in Harpers Meadow for the people who will come after her, as well as for the moose and the loons. ~ Return to UNH Magazine Features