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Biodiversity in the Crossfire

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.

The Tonkin Snub-nosed Monkey, Rhinopithecus avunculus, is one of the 25 most endangered primates in the world. It is found only in northern Vietnam.Tilo Nadler

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.