Saving El Imposible: A Biodiversity Puzzle

Part of the Biodiversity Counts Curriculum Collection.

How do people decide to set aside a piece of land for conservation? What kinds of things have to be considered? Can biodiversity be protected at the same time as the land is used for research, recreation, and growing food? When there is a conflict between nature and people, how is it resolved? Can compromises be made?
Trees in front of verdant mountain ridges inside El Imposible National Park in El Salvador
Photo by ElmerGuevara via Wikimedia Commons

These are among the questions faced by Salvanatura, a nongovernmental organization that manages a large national park on behalf of the government in El Salvador. Because the same questions might be asked about site preservation anywhere in the world, we asked Carlos Ramirez-Sosa, who served on a committee that advised Salvanatura, to tell us about the decision-making process.

In 1979, the government of El Salvador created a new national park called El Imposible—The Impossible One—covering 5,000 hectares in the department of Ahuachapan, which borders on Guatemala. (A hectare equals 10,000 square meters, or a little less than 2.5 acres.) "This park is on the Pacific coast of Central America, an area that has basically been destroyed," Carlos explained. "A lot more people live there than on the Atlantic coast, where the lowland rain forest is found. This area is dry forest, which means it’s easier to burn and manage than rain forest. Over the years most of the forest has been cleared for coffee, sugarcane, and cotton plantations. What little remains has been called the Jewel of Central America, because outside of Mexico it is probably the largest remaining old-growth forest," he said.

The area designated as a national park contains the following:

  • 5,000 hectares of land.
  • 35 families, some of whom have been there all of their lives. They farm small plots to grow food for their own use and cut wood in the forest to use as fuel.
  • 18 archaeological sites that may be 3,000 years old and contain evidence of ancient Maya civilization.
  • 8 different vegetation types, including old-growth forest, new forest, and land cleared for agriculture.
  • 6 separate rivers and many small streams. It is one of the most important nonpolluted watersheds in the country.
  • 400 species of trees, including Guapira witsbergeri, a tree that is found nowhere else in the world.
  • An undetermined number of species of herbaceous plants and shrubs, including orchids and plants with healing properties.
  • 31 species of fish, 263 species of birds, 31 species of mammals (not counting bats or rodents), 25 species of snakes, and 10 species of amphibians. Many migrant birds from North America winter there.

The land inside the national park combines the last bit of old-growth forest with abandoned coffee plantations and cattle ranches taken over by the government nearly 20 years ago. "It has been estimated that there are 400 species of trees there, a very high diversity for that type of land in El Salvador. Even in the time since the plantations and ranches were abandoned, the forest is recovering, and many of the original tree species are coming back."

But why is it called El Imposible, we asked. "The name was given because the terrain is so broken, with very steep mountains, that you cannot drive through it. You have to go on horseback or foot to traverse the entire forest," Carlos explained.

In the early 1990s, an advisory committee was formed to study the park and make recommendations for how it should be managed. "I was hired to look at how diverse the flora (plant life) is. Another scientist looked at the fauna (animal life). There was also an archaeologist because there are 18 archaeological sites within the park, and a sociologist to study the people who make the park their home." Carlos explained that when the park was established, 65 families of agricultural workers were permitted to remain on the land. "They had been born there and they had nowhere else to go, no jobs, no way of earning a livelihood. There was an oral agreement that they could remain there, but no one else could move in and they couldn’t build new houses or grow more crops than they needed for their own use." Over the years, the population has shrunk to 35 families, and Salvanatura was considering evicting them.

Each specialist studied one aspect, and then everyone met to decide on recommendations. There were disagreements, of course, but Carlos said that a compromise was finally reached. "Some people thought it was most important to protect the old-growth forest, which is only a very small area of the park. Others, including me, felt that biodiversity includes everything that is there, even newer plants, which are still part of the ecosystem."

In Carlos’s opinion, the reason for the very high level of biodiversity of both plants and animals is that there has been a lot of change, creating what Carlos calls "succession levels" over the years. "Some forested areas are 100 years old, some are only 30 or 40. You find different species at different succession levels." For example, he said, "In the early stages of forest recovery, there will be more butterflies and birds because the open lands and the type of plants that grow in those areas attract them. In old-growth forest, it’s too dark and there are more predators, so there won’t be as many butterflies and birds.

"If we want to keep biodiversity as it exists today, we have to maintain those systems." The way to do that, he believes, is by selectively pruning, cutting, or burning trees. As surprising as it may sound, Carlos says that "If we let the forest continue to grow, biodiversity will decrease."

Up until now, El Imposible has not been open to the public, but park administrators soon plan to open some areas for day visitors and overnight campers, while reserving other areas for special use.

"The park will be divided into three main zones," Carlos Ramirez-Sosa told us. "One will be open to anyone who wants to go there. A second section will be more restricted; visitors will have to go with a guide provided by the park. Then there will be portions of the park that are open only to scientists who are doing research. These are areas where the terrain is very fragile and could be easily damaged by foot traffic or where there are archaeological sites that might be looted."

Picnic and camping areas will be located where the abandoned plantations once stood. "Since this land has already been cleared, putting parking lots and other visitor facilities here will cause the least amount of disturbance to the environment," Carlos explained.

One of the biggest questions was whether the park inhabitants have a negative or positive impact on the land. "Our conclusions were ambiguous," Carlos said. "It really is a many-sided question." On one hand, the small-scale farming they do still includes the use of pesticides and fertilizers, some of which is applied by young children and all of which is harmful to the ecosystem. Furthermore, it was assumed that the wood they cut for fuel would alter the forest in negative ways. However, Carlos discovered that the types of trees the inhabitants cut resprout, so there is no danger of depletion. He also suggested encouraging adoption of farming methods that would reduce pesticide and fertilizer use, such as planting species that repel insects and others that add nitrogen, an important fertilizer ingredient, to the soil. "Legumes—peas, beans, and peanuts—are nitrogen-fixers. And there are many tropical plants that naturally repel insects, similar to the marigold here in the United States," he said. Aside from replicas of plants and taxidermy mounts of animals, dioramas contain landforms such as hills and cliffs, rivers and ponds, rocks and possibly even features made by people. The backgrounds are painted on curved walls to give depth to the diorama so viewers feel as if they are looking out on a landscape through a window.

Carlos also believes that the human inhabitants of the area are an important resource. "They know the forest in a way that no one else does. They could work as guides in the park and assist in the biodiversity inventory. Furthermore, they are part of our cultural heritage. Some of their houses are of a type found nowhere else in El Salvador, and their way of life, which is the way people have lived in El Salvador for hundreds of years, has totally disappeared everywhere else in the country. If we kick them out, all of that will be lost."

Carlos sees a lesson in the archaeological sites found in the park. "They tell us that people have been there for centuries. And I believe that the park is the way it is because people, as well as natural forces, have played a major role. There have been fires, there have been hurricanes, just as there have been plantations and settlements, but the forest regenerates itself if we let it."


Here are highlights of what the advisory committee recommended:

  • Inventory the biodiversity of the park.
  • Protect old-growth forest from fires and human intervention.
  • Monitor species populations, especially those such as butterflies that are targets of poachers.
  • Open selected areas of the park to the public.
  • Monitor the effect of public use of the park.
  • Promote scientific research in the park, including the establishment of a biological research station.