Surveying Vietnam

Vietnam harbors an astonishing range of habitats, from rain forests and dry forests to mangroves and coral reefs, and is home to an unusually rich array of plants and animals. The reasons for Vietnam’s extraordinarily rich biodiversity are complex, and that complexity captivates biodiversity scientists. 

Biodiversity science in Vietnam is a young and rapidly expanding endeavor. For decades, the country’s troubled political history prohibited biologists, Vietnamese and foreign alike, from exploring its biological wealth. In recent years, an increasing number of scientists have searched Vietnam for new species, and their efforts have been rewarded. For example, botanists working in Vietnam have described more than 100 new species of plants in the past ten years. Even large mammals are turning up, among them two new species of muntjac, which are also called barking deer; a striped rabbit; and the saola, a member of a previously unknown genus related to oxen. The discovery of the saola in 1992 captured the attention of biologists around the world. Finding a new species of large mammal is exciting, but to discover a new genus is doubly so. How could such a large mammal, representing a previously unknown branch of evolution, have remained hidden for so long? Discoveries like these lend an air of excitement to field biology and systematics (the study of how species are related to one another through evolution) in Vietnam.  Biologists understand that they have only begun to appreciate the nation’s tremendous biodiversity.  

Between 1998 and 2000, an international team of scientists—from the Center for Biodiversity and Conservation (CBC) at the American Museum of Natural History; the Missouri Botanical Garden (MBG); and the Institute for Ecology and Biological Resources (IEBR) in Vietnam—carried out a series of expeditions to further document and study a wide range of biodiversity in Vietnam, including fishes, reptiles, birds, amphibians, mammals, invertebrates, and plants. For plant scientists, the trips were particularly rewarding: the team discovered dozens of plant species new to science, including several new varieties of cycad, an unusual group of plants sometimes referred to as “living fossils” because their evolutionary roots trace back more than 280 million years. Vietnam is a center of cycad diversity; its 24 species exceeds the diversity of cycads in any other Asian country. “Thanks to the expanding collaboration between Vietnam and other countries, we pay attention to more botanical groups,” says Phan Ke Loc, a botanist with IEBR. “Cycads are one of the groups that we really care about. They are very rare and precious.”

Biological discoveries depend a great deal on who does the looking and whether anyone has bothered to look in a particular place before. “We have collected over 50 new species of fern, simply because we are the first ones to actually focus on collecting them,” says Dan Harder of the Missouri Botanical Garden. Having the right scientist on your team—an expert on cycads, for example—can also greatly improve the chances of identifying new species. The more you look and the better trained you are, the more species you’re likely to find.

Field biologists observe biological diversity firsthand. They visit habitats around the world and explore the plants and animals found there: reptiles, amphibians, birds, mammals, insects, worms, fungi, algae, down to the smallest living thing. These scientists collect and identify specimens, and then carefully archive them for future researchers to study. The work can be exciting, fueling a researcher with the hope of perhaps finding a species—of deer, mosquito, barnacle, or bird—never before named by science. Like any job, it also involves plenty of drudgery: long, soggy days searching for insects in a swamp; late nights typing page after page of data into a computer. Botanists on the plant-finding expedition to Vietnam spent their time hiking, climbing trees, digging roots, and clipping branches. They collected stems, leaves, fruits, flowers, bark, and anything else that helped them distinguish one species from another. Each day they gathered anywhere from 50 to 150 specimens. At night, back at base camp, they sat together examining each plant and noting its color, smell, and oils—“the things you would encounter in the plant if you saw it fresh,” Harder says.

By collecting and identifying all kinds of species, scientists aim to infer important biogeographical patterns: where species, particularly rare ones, are to be found; which habitats are central to the survival of those species; and which regions contain the most biological diversity. Coupled with other information, scientists and conservation managers can identify important regions under immediate threat from development, pollution, poaching, or other human activities. This information in turn is critical to conservation efforts, both in Vietnam and around the world. The more that is known about the number of species and where they live, the easier it is to figure out how best to conserve them.

Biodiversity scientists working in Vietnam have made a remarkable number of discoveries in recent years. Of the more than 155 amphibians known to live in Vietnam, 26 have been described since 1997. More than 200 mammals have been recorded in Vietnam, several of which—including a wild pig; a striped rabbit; three species of barking deer; the Tonkin snub-nosed monkey; and the saola, a recently described wild oxen — are found only in Vietnam or neighboring countries such as Laos, Cambodia, and China. Botanists have identified and cataloged 9,000 of the more than 12,000 plant species thought to exist in Vietnam. Of these, perhaps as many as 10 percent are believed to grow only within the country’s borders. Analysis of these collections has yielded 200 previously undescribed taxa.  In addition, Vietnam is home to nearly 900 species of birds. And discoveries of new species continue: in the past 10 years, three new large mammal species and three new birds species have been discovered in the Truong Son mountain region of central Vietnam. “The extraordinary richness of Vietnam’s biodiversity is only starting to be fully appreciated, as ongoing discoveries are being made at a rapid pace,” says Raoul Bain, a biodiversity specialist with the Center for Biodiversity and Conservation at the American Museum of Natural History. “Its rich biodiversity is due to Vietnam’s diversity of habitats.”

The diversity of habitats in turn is the product of geological and climatic changes that have unfolded over millions of years. Vietnam lies in the tropics, between 8 and 23 degrees north latitude. Through geologic time, when glaciers periodically wiped out the flora and fauna at high altitudes and high latitude areas, tropical lowlands have remained warm, moist nurseries and havens for evolving plants and animals. This is one reason tropical areas support more species than similarly sized areas farther to the north or south.

In addition, Vietnam is situated at the meeting place of three converging continental plates: the Eurasian, the Indo-Australian, and the Philippine Sea. Over hundreds of millions of years, these plates migrated across Earth’s surface and collided, bringing together a disparate assortment of plant and animal species. Over subsequent eons, the sea level rose and fell; mountains grew upward, then shrank through erosion; river courses naturally shifted; and the variety, size, and locations of forests changed with alterations in the climate. Vietnam’s habitats and environments have been evolutionary nurseries for new and unique species. Understanding the relationship among species, where they are found, and the environments where they evolved is termed “biogeography.” 

Having pieced together Vietnam’s biogeographic history, and with it some understanding of how the country’s known species came to live where they do, biologists are better equipped to pinpoint biogeographic zones where new species might be found. One such zone is the Truong Son mountain range, which lies in western Vietnam along the border with Laos and Cambodia. Monsoon rains from the South China Sea fall year-round on the eastern slopes, enabling lush, evergreen forests to grow at high elevations. The western slopes, which are sheltered from the rain, support plants and animals that have adapted to a drier, more seasonal climate.

The Kon Tum Plateau, a region of steep mountains and wet forests in Vietnam’s central highlands, also supports tremendous biological diversity. Many of the species found there appear related to animals and plants in Malaysia and tropical Indonesia, an indication that they all share common evolutionary roots.

Because it is home to diverse species from a number of distinct groups including invertebrates, mammals, birds, fish, reptiles, and frogs, Vietnam offers a unique opportunity for conservation. By conducting biological surveys, scientists hope to identify regions within Vietnam whose high biodiversity value calls out for aggressive conservation measures. “The areas of remaining forest in our country are not large,” says Phan Ke Loc, a botanist with Vietnam’s Institute of Ecology and Biological Resources. “So we must carry out the work of inventory very quickly, the faster the better. Vietnam is pushing for botanical diversity because we understand that every effort of humankind, has always been and always will be, utterly dependent on biological diversity.”

In recent years and in increasing numbers, scientists from around the world have been joining Vietnamese scientists in exploring and studying Vietnam’s biological riches. But even as this biodiversity is being revealed, it is under growing threat from expanding development and human activity. Scientists are racing to accomplish their studies before many species and their habitats disappear from the Vietnamese landscape.

As of 2003, the World Conservation Union had listed 284 species of plants and animals found in Vietnam as threatened with extinction. Birds and mammals are the best-studied groups with respect to likely extinctions. Thirty-nine of Vietnam’s birds, about 14 percent of all bird species found there, are threatened with extinction. Forty-five of Vietnam’s mammal species—almost 20 percent of the country’s total—are listed as threatened. Of those, 5 are among the 25 most endangered primates in the world: Delacour's leaf monkey (Trachypithecus delacouri); the Cat Ba leaf monkey (T. poliocephalus);the Tonkin leaf monkey (T. francoisi); the gray-shanked douc (Pygathrix nemaeus cinerea); and the Tonkin snub-nosed monkey (Rhinopithecus avunculus). Four of these are endemic to Vietnam. In addition, 27 of Vietnam’s reptile species—most of them turtles—are listed as vulnerable, endangered, or critically endangered. “The task of conserving nature in Vietnam is very urgent,” says Phan Ke Loc, a botanist with the Institute for Ecological and Biological Resources, in Vietnam. 

Political history has not been kind to Vietnam’s rich biological heritage. In the 19th century, after France claimed Vietnam as a colony, Europe began to exploit the country’s natural resources, particularly nonnative rubber, and quickly carved large plantations into the landscape. French rule lasted until 1954; its end overlapped with a series of military conflicts stretching from the 1940s to the 1970s—conflicts that did long-term damage to the environment. Only in recent years has the political situation been stable enough to allow biologists—both foreign and Vietnamese—to inventory and study the nation’s biological resources.

Vietnam’s economic situation has also improved significantly. The nation is now a major exporter of crude oil, coal, rice, coffee, textiles, cashews, and rubber. But extracting nonrenewable resources and growing cash crops demand large amounts of land, and the country’s swelling population—80 million people who subsist largely by farming, clearing land, and grazing livestock—has taken a heavy toll on the forests. Because most farming takes place in the lowlands, almost no undisturbed forest remains at low elevations in Vietnam; most remaining pristine forests in Vietnam are isolated patches on remote mountain peaks.  

Hunting, poaching, firewood collection, slash-and-burn agriculture, and large-scale land clearing for cash crops all diminish the ecological integrity of forests, which are broken up and reduced to islands of degraded forest habitat amid a widening sea of human activity. Conservation scientists working in Vietnam are alarmed by both the ongoing deforestation and the forest fragmentation, because small fragments of forest cannot support the same biological diversity that a larger forest patch can. Many large mammals need tens or hundreds of square miles of contiguous forest in which to roam, feed, and mate. Thirty years ago, the forests of Vietnam supported elephant, rhinoceros, tiger, wild cattle, and buffalo. Today these animals are all but extinct, largely because of the loss or subdivision of their habitat. In 1980, an estimated 1,500 to 2,000 elephants roamed the forests of Vietnam; by 2000, the population had dropped to between 85 and 114. Illegal poaching was partly responsible for the steep decline. But the major cause was the fragmentation of the elephants’ forest habitat. “The forest areas in Vietnam have decreased seriously, not only in terms of quantity but also in terms of quality,” says Loc. “Nowadays the forest is not continuous in a large area. Here’s a patch, over there is another one. Animals cannot move around in such small areas.”

The fragmentation of habitat in Vietnam also creates a serious challenge for scientists trying to decipher the patterns and origins of the country’s biological diversity. Especially with species only recently identified, it is virtually impossible to determine whether distribution patterns observed today reflect those species’ original, natural ranges. Some species may occupy only a small patch of forest or mountain range, not because of ecological or evolutionary reasons but simply because recent human activity has isolated them there. The same holds true for many of the biogeographic patterns that scientists see elsewhere on the planet. It is a challenge to understand the distribution of species around the world when humans have substantially reduced or degraded the habitats of those species. This added uncertainty makes the effective protection of endangered species and habitats still more difficult.

The Ngoc Linh Nature Reserve lies deep in central Vietnam on the Kon Tum Plateau, a region of lush forests isolated from most human traffic. This unique ecosystem is separated from surrounding habitats by a series of high mountains. Smaller than 50 square kilometers (about 19 square miles) in size, the existing Ngoc Linh Nature Reserve contains a wealth of biodiversity. Biological surveys conducted in the area by several institutions, including the American Museum of Natural History, the Missouri Botanical Garden and the Institute of Ecological and Biological Resources in Vietnam, have recorded 385 plant species, 51 mammals, 171 birds, 15 reptiles and 25 amphibians; and many more species remain to be discovered. Sixteen globally threatened plant species live here, as does the Annamite muntjac (Muntiacus truongsonensis), a recently discovered relative of deer that is found in only two other areas of Vietnam. One bird species, the golden-winged laughing thrush (Garrulax ngoclinhensis), is found nowhere in the world except on the slopes of one mountain in the area.         

Planners would like to expand the boundaries of the Ngoc Linh Nature Reserve as part of an ambitious effort by the government of Vietnam to address environmental degradation within the nation’s borders. As of 1990, more than 90 protected areas, covering some 4 percent of the country, had been placed under government protection. The government aims to increase the total land area protected to 6 percent within the next several years. Some regions have higher biodiversity than others, however, and not all the areas currently under protection merit the status they’ve been given. Various institutions and conservation groups from around the world are working with the Vietnamese government to make sure that newly protected environments live up to their promise: providing habitat for plants and animals that are most immediately threatened by human activity. If established, the Ngoc Linh Nature Reserve in Quang Nam province would connect to three additional reserves in Kon Tum province to the south of Quang Nam: Ngoc Linh Nature Reserve (this reserve, though it has the same name, is in a different province and has already been established), Kon Ka Kinh Nature Reserve, and Kon Cha Rang Nature Reserve. If conservation planners can succeed, the large, contiguous protected area would be elevated to the status of a national park. 

Protected areas are one means of ensuring the survival of critically endangered species.  In Vietnam, the Tonkin snub-nosed monkey (Rhinopitheus avunculus) is found at only a handful of sites. Although these reserves are recognized and protected by the government, they are ultimately too small for the primate’s needs.  Unless these areas are expanded, as some conservation groups have urged, the animal will not survive in the long run. BirdLife International, a non-profit conservation organization, has identified 63 areas in Vietnam that merit expansion and protection in order to ensure the survival of numerous bird species threatened by development. Of course, these Important Bird Areas (IBAs) would benefit many other animals and plants. Nonetheless, the main goal of the IBAs is to preserve habitat for a specific group of organisms.

Habitat-based conservation takes a wider view: it aims to protect unique types of habitats and, as a result, the communities of plants and animals that live in them. In Vietnam, conservation groups such as the World Wildlife Fund, BirdLife International, and the Center for Biodiversity and Conservation at the American Museum of Natural History, hope to connect the many separated patches of forest into wildlife “corridors” that would enable animals to roam farther and more freely. Animals such as tigers, which require large hunting ranges, would benefit from such corridors, as would many species of birds. The proposed Ngoc Linh Nature Reserve in Quang Nam province is attractive precisely because it augments an existing reserve in the adjacent Kon Tum province with a relatively large stretch of intact forest. In fact, it spans several different types of forest between 150 meters to 2,600 meters (about 490 to 8,530 feet) in elevationthe longest uninterrupted stretch of different-elevation habitat types remaining in Vietnam.  And since the proposed reserve is adjacent to other protected areas, the cumulative effect of these neighboring areas would be greater than protecting each of them singly.

A third approach to conservation takes the widest view of all. It aims for the preservation of whole “ecoregions”, large contiguous areas of land that encompass many different kinds of habitats within a fairly uniform climate.  Ecoregions often span international borders; the Central Truong Son ecoregion, for example, straddles the borders of Vietnam, Laos and Cambodia. Ecoregional conservation plans have the potential to protect not one but many distinct habitats, each with its own suite of unique and threatened plants and animals. Expanding the Ngoc Linh Reserve system would provide substantial protection to an important ecoregion that is rich in biodiversity.  Its extensive network of forested river valleys make the region surrounding Ngoc Linh particularly interesting to planners, because intact river systems--rivers whose paths have not been cleared of vegetation--are among the most threatened habitats in Southeast Asia. The proposed National Park would form one of the largest uninterrupted areas under conservation protection in Vietnam 

Because ecoregions can be large, their effective management requires that careful attention be paid to socioeconomic development. Research suggests that the proposed Ngoc Linh National Park would benefit the lives of the people who live downstream. For example, protecting the forests would greatly minimize soil erosion during times of heavy rain; erosion not only harms agriculture (because the rich topsoil is washed away), it also clogs rivers and streams, which villages farther away depend on for irrigation and drinking water. Intact forests also delay the runoff of rainwater and so help reduce the likelihood and severity of flooding. Forests also ensure that water is available in streams even during periods of low rainfall. Thus, water supplies would be ensured for cash crops at critical times of the year when rainfall is lacking.

“Vietnam is pushing for diversity,” says Phan Ke Loc, a botanist with the Institute for Ecological and Biological Resources, “because we understand that every effort of humankind has always been, and will always be, utterly dependent on biological diversity.”