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"Biodiversity" encompasses not only the variety of distinct species within a given area but also two other important factors:
- genetic diversity or variability within a given species population and
- the variety of ecosystems across a geographic area.
Ecological health depends on maintaining a diversity of life forms. Diversity indicates a system's resilience or its ability to adapt and cope with change. Healthy, intact ecosystems also build soil, prevent erosion, store and cycle nutrients, and provide economic benefits through such valuable products as wood fiber, foodstuffs, dyes, resins, and oils.
The National Park System houses a rich diversity of species and ecosystems that can be of great value to society. Parks may even serve as reservoirs of plants and animals that can repopulate lands where species have been extirpated.
The benefits derived from just one type of ecosystem, coral reefs, illustrates the implied costs of losing intact ecosystems. Although they constitute only 0.2 percent of the ocean, coral reefs shelter a quarter of all marine fish, making reefs the foundation of the $2.5-billion-dollar U.S. fishing industry. Reefs also protect coastal areas from storm damage, erosion, and flooding by buffering the impact of powerful waves.
Healthy reefs worldwide strengthen local economies by attracting tourists. Protection of reefs is vital: 10 percent of U.S. reefs have disappeared in recent years, and another two-thirds are in immediate danger. If current trends continue, 40 percent of coral reefs worldwide could be lost within two to ten years.
Protecting a reservoir of genetic traits in plants and animals benefits humankind through agriculture and medicine. Enzymes isolated from organisms living in the hot pools of Yellowstone National Park became the basis for the technique of DNA fingerprinting.
Almost a quarter of all prescription drugs sold in the United States contain natural substances. One of the best-known natural drugs is penicillin, derived from Penicillium mold. Other examples include the use of fish-liver oil for dietary supplements, the blood of horseshoe crabs for testing vaccines, and extracts from the Pacific yew for fighting breast cancer. Biomedical research on native plants and animals is continuing with hope of new discoveries. Protecting biodiversity is critical to preserving our options in the field of bio-medical research.
Aldo Leopold, one of the great thinkers of conservation, observed more than half a century ago the importance of protecting species. "To keep every cog and wheel is the first precaution of intelligent tinkering," he wrote. Losing species is like throwing away one by one the engine parts of an airplane while flying.
Recent studies indicate that the cogs and wheels within the national parks are poorly known. Biologists have not even identified all of the species we are losing. The All-Taxa Biodiversity Inventory at Great Smoky Mountains National Park, which seeks to tally all of the park's plants and animals, has revealed more than 280 species new to science.
During spring 2002, North American butterfly experts identified 860 butterfly and moth species in the park, breaking the previous record of 720 set two years earlier. Of those 860, 138 were new for the park and 51 were new to science. If researchers can discover this many species in a park previously thought to be well-studied, then even greater biological unknowns remain in scores of other national parks, none of  which, because of inadequate funding, have undertaken all-taxa surveys—Great Smoky Mountains is the first and still only to do so. |
