Destruction of Rain Forests, Warns a Conservationist, Is Endangering Many Species—including Our Own

updated 11/28/1988 AT 01:00 AM EST

originally published 11/28/1988 AT 01:00 AM EST

"Wonder, astonishment and sublime devotion fill and elevate the mind, "the evolutionist Charles Darwin wrote in 1832 after a visit to a rain forest in Brazil. Today tropical rain forests around the world are under siege. Fifty acres are destroyed every minute. An area the size of the state of New York is burned or cleared every year. Within five to 10 years, Haiti and El Salvador will have virtually no forests left. Recent devastating floods in Bangladesh have been aggravated by deforestation.

This loss of tropical rain forests—jungle that receives at least 80 inches of rain a year—may have profound meaning for the future of mankind. Scientists generally agree that the burning of rain forests is contributing to the "greenhouse effect, "in which increasing levels of carbon dioxide in the atmosphere trap the sun's heat, preventing it from radiating back into space. The result is a gradual warming of the atmosphere. Many scientists suspect that the greenhouse effect contributed to making this past summer the hottest in more than half a century.

One of the most energetic champions of rain forests is 38-year-old conservationist Dr. Russell Mittermeier. Trained as a primatologist at Harvard, Mittermeier is the vice-president for science of the World Wildlife Fund and an associate professor of anatomical sciences at the State University of New York at Stony Brook. As a child, Mittermeier wanted to be a jungle explorer. Today he spends more than a third of the year in the wild, tracking rare primates and overseeing conservation programs. He spoke with senior writer Harriet Shapiro.

Why are we losing so much rain forest?

There is a variety of factors, among them slash-and-burn agriculture, timber extraction, mining, hydroelectric projects, clearing for plantation agriculture and cattle ranching. And intimately linked with all of this is the ever-expanding human population, which is putting enormous pressure on the tropical forests.

What exactly do you mean by slash-and-burn agriculture?

This is a practice whereby trees are cut down by farmers and then burned where they lie. The problem is that most of the nutrients are in the living organisms, the trees, not in the top-soil. So if the forest is cut down and burned, there is a very thin layer of ash in which you can grow crops for a few years. But once the nutrients have been picked up by the crops that have been grown for food or been washed away by the warm rains, the land becomes virtually worthless, a wasteland.

How does burning rain forests contribute to the greenhouse effect?

It's kind of a double whammy. First, the burning itself releases huge amounts of carbon dioxide. Second, since trees absorb carbon dioxide, the loss of the rain forest destroys one of the great natural sinks for this gas. Together, the burning and the destruction have almost certainly contributed to an increased global warming or, as it is commonly called, the greenhouse effect.

In addition to combating the greenhouse effect, what other reasons are there for saving the rain forests?

The forests are critical to the conservation of biological diversity, that is, the vast wealth of species and ecosystems that makes our planet what it is. In the Amazon, a single pond the size of a tennis court contains more species of fish than all the rivers of Europe combined. Rain forests cover only 8 percent of the earth's land surface, yet at least 70 percent of the world's plants, insects and animals live within their boundaries. By protecting tropical forests, we're protecting most species on the planet.

What about plant life?

People often forget that not all valuable chemical compounds are invented in laboratories. Many are discovered in nature. In rain forests, the possibilities are limitless. So far we've looked at less than 2 percent of tropical forest plants to see what valuable compounds they might contain. Alkaloids from the rosy periwinkle, a small plant that originated in Madagascar, are very effective in treating Hodgkin's disease and childhood leukemia. Curare, an Indian arrow poison that is made from a plant that grows only in the Amazon, is used in heart operations as a muscle relaxant. For all we know, solutions to health problems like cancer and AIDS may well exist in tropical forests.

How do rain forests affect our everyday lives?

Think about what we eat. Some food, such as Brazil nuts, grows only in rain forests, while others—coffee, sugarcane and cocoa—originated in rain forests. They are now grown elsewhere, but many commercial crops have a very small genetic base. If a pest of one kind or another attacked, they could be wiped out. So we have to be able to go back to the rain forests in order to crossbreed commercial crops with their relatives from the wild.

How valuable is the rain forest in economic terms?

One study, done by Charles Peters, a scientist at the New York Botanical Garden, stated that the fruit, latex and timber alone on an acre of Amazon rain forest in Peru is worth approximately $3,600. The same land would be worth only around $1,300 if used for cattle pasture or a wood-pulp plantation. And Peters was just examining fruits and a few other products, not the medicinal plants and the animals.

What is happening to the indigenous people living in the rain forests?

As soon as there is contact with the outside world, the process of cultural disintegration begins. And looking at it from a purely economic point of view, the knowledge these people have developed over thousands of years is tremendously valuable. Their shamans—or medicine men—discovered beneficial uses for quinine and curare long before the civilized world. The knowledge of how to utilize forest plants is disappearing much faster than the plants themselves.

What other effects might deforestation have?

The threat to some animals is severe. Ninety percent of all primates, for example, live in tropical forests, and their populations are rapidly declining around the world. Of the 227 species of primates on the planet today, 113 are currently considered either endangered, vulnerable or rare. Fifteen to 20 species could very well be extinct by the turn of the century if we don't take action now to reverse those trends.

What are some of these species?

In Madagascar, the mysterious aye-aye, a nocturnal lemur, and the spectacular indri, which looks like a cross between a giant panda and a teddy bear, are in danger of becoming extinct. In South America, the muriqui, the largest monkey on that continent; the golden lion tamarin, a squirrel-size monkey with brilliant golden fur and a lionlike mane; and the grotesque white uakari are all down to just a few hundred individuals in the wild.

Why should anyone care about preserving rain forest animals?

We put millions of dollars into conserving the works of our own species in museums, but we are not very good at conserving nature's works of art. Even severe pollution is reversible, but species extinction is irreversible. Once a certain species is gone, it's gone forever. In the words of the naturalist William Beebe, "Another heaven and another earth must pass before such a one can be again."

How serious is the threat of extinction for rain forest species?

At this point all we can do is guess, but the crisis we're facing right now is comparable to the extinction of the dinosaurs. If some of the trends continue, we stand to lose thousands of species before the turn of the century. It's difficult to estimate extinction rates when perhaps 90 percent of certain groups in the tropics, like insects, have yet to be described by scientists.

How is the international community responding to the tropical forest crisis?

Over the past few years there has been an amazing growth of interest on the part of organizations like the World Bank and agencies like USAID and the Norwegian NORAD. There's a growing recognition that we can't have long-term sustainable development without conserving global biological resources, and that includes the rain forests.

What can be done to save rain forests?

Public awareness is part of the solution. We must greatly increase the interest in tropical-forest and species conservation and make it the truly global issue it deserves to be. We must also increase the political visibility of conservation worldwide. To some extent, this is already happening. Brazil, for instance, which is home to more species than any other country on earth, is now including a major section on conservation and the protection of its ecosystems in its constitution.

After all the talk about life in other solar systems, this is still the only place where we know for certain that life exists in the whole vast universe. So we should appreciate life in its many magnificent manifestations and do everything possible to ensure that the earth remains a living planet in the fullest sense of the word.

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