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### National Park Service U.S. Department of the Interior

## Table of Contents

- The Eroding Foundation ofLife
- The Stuff of Life: DNA andGenetic Diversity
- Diversity and itsValues
- Nature's Harvest
- New Medicines
- Benefits to Industry
- Parks and Diversity
- Stewards of the Land
- World View
- The World's Heritage

### The Eroding Foundation ofLife

Almost unnoticed, the earth's living wealth is slipping away. Ashuman populations expand and intensify their use of the land,species of wild things and their habitats disappear. With them gonot only the beauty and variety of life created over millions ofyears but also environmental stability and untold potential forsupplying human needs. Wild plants and animals are the basis of ourfood, many of our medicines, and countless industrial products. Aswildlife vanishes, our own life is impoverished, if notimperiled.

When scientists speak of biological diversity they simply meanvariety of life: variety of species and their genetic variation,and variety of communities of plants and animals. Over billions ofyears, the earth has been enriched with an abundance of life forms.As different forms of life evolved, others died out--becameextinct. Sometimes cataclysmic events like asteroid strikes, abruptclimate changes, or the advance of ice sheets caused massextinctions. When this happened, new species evolved that wereadapted to the changed environment.

Today we are witnessing another extinction of unprecedentedproportions, this one caused by humans. People are rapidly alteringand destroying environments that have fostered a wondrous diversityof organisms. By early next century, at present rates of loss, aquarter of the world's existing plant and animal species (estimatedat five million but possibly several times that number) may havevanished forever, many before they are identified and described.Some experts think that species are dying out at the rate of 100 aday. Overharvesting or direct human exploitation is only partly toblame.

The main reason for this decline is loss of habitat, especiallyin the tropics, which support perhaps three-fourths of alllife-forms. Each year in those regions a forested area the size ofPennsylvania is cleared. The Amazon basin, for example, is theworld's single richest region in species diversity. Deforestationthreatens the basin's million or more species. Deforestation alsothreatens the indigenous people and their traditional way of life,which from pre-Columbian times has been compatible with thesustainable and productive use of the forests. Things are a littlebetter in the industrialized countries, where every year thousandsof square miles of natural habitat are converted to urban andagricultural uses, and pollutants released into the air and waterdegrade much of the living space that is left.

This destruction of nature is loaded with lasting consequencesfor our own species. If unchecked, the accelerating extinctions nowgoing on seem likely to transform the workings of the biosphere,and in ways not beneficial to humans. The complex array ofrelationships among life-forms will be disrupted. The loss ofspecies is certain to divest us of resources and influence foreverthe course of evolution.

If there is to be change for the better, it must begin withchanged thinking, and that must be based on understanding.Throughout history, enlightened people have seen theinterconnectedness of all life. The ancient Greeks thought of theearth as a living organism. Buddhists teach that "each thing hasits own intrinsic value, and is related to everything else infunction and position." Tribal groups on all continents have livedthis belief. The chief of the Kuna Indians in Panama recentlyexpressed it this way: "The land is our mother, and all livingthings that live on her are brothers. We must live in a harmoniousmanner on her; because the extinction of one living thing is alsothe end of another." Affirming this age-old view, modern ecologistshave shown the linkages in all communities of life.

National parks and other protected places are samples of theworld's natural variety, often the last bastion of the earth's wildwealth. They are vital to our future well-being.

### The Stuff of Life: DNA and GeneticDiversity

Biological diversity rests ultimately on genetic diversity. Thisis because the survival of a species is intimately related to itsability to adapt, through variations in its genetic inheritance, toinevitable change in its environment.

Genetic diversity is the foundation of several levels ofdiversity. At the top are ecosystems, which are associations ofplants and animals interacting with their physical environments.Forests of many kinds, deserts hot and cold, grasslands, tundra,lakes, streams--all are examples of ecosystems that supportdistinct groups of plants and animals in an intricate mosaic oflife.

Ecosystems are composed of communities, species, populationswith species, individual organisms, and genes of organisms. Whenbiologists speak of a species, they mean a group of similar,related individuals that can breed and produce fertile offspring. Aspecies may be further separated into local breeding populationsthat differ somewhat from each other in appearance or geneticstructure. Individuals within populations to some degree alsodiffer from each other in traits, the way people differ in hair oreye color.

At the base of all this variation is the gene. It is the genes,acting within the constraints of environment, that controlvariation in living things. Genes are composed of the nucleic acidDNA, a complex chemical molecule that encodes all the informationnecessary for an organism to produce progeny that are essentiallyidentical to it. Genes control the development of particular traitsor characteristics. Bacteria have about 1,000 genes, a mouse about100,000, some flowering plants about 400,000.

So great is the information stored within the genes of a singleorganism that when we lose a species it is equivalent to losing anentire library of books of which there are no other copies. Even ifa species is not extinguished but only drastically reduced innumbers, there is still cause for concern, because it will havelost much of its natural genetic variation. Because of this loss,it will be less able to adapt to environmental change through themechanism of natural selection. Those individuals with genetictraits suited to life in a changed environment tend to survive andpass on their beneficial traits to succeeding generations. Numerousand diverse populations thus make it more likely that a specieswill have the genetic variety needed to escape extinction from slowenvironmental change, and the numbers to recover from naturalcatastrophes or human impacts. Conserving biodiversity is not,therefore, a matter of saving a few remnants. Many largepopulations of each species are essential--and to preserve largepopulations, we must preserve sufficient habitat. National parksand other protected areas help provide that habitat.

### Diversity and itsValues

The loss of biological diversity is an accelerating worldwidephenomenon. The aurochs, the wild ancestor of domestic cattle,disappeared in Europe in 1627. In central Asia, the tarpan,ancestor of the domestic horse, became extinct in the mid-1800's.As habitats in the Old World were increasingly altered, so wildspecies increasingly disappeared.

Here in North America our resources were once thoughtinexhaustible. Explorers describe the American frontier asboundless, but in time prairies were tilled and forests leveled.Some species like the gray wolf were extirpated over most of theirrange and others like the passenger pigeon became extinct.Extinctions continue today, threatening little-known species likethe noonday snail as well as spectacular ones like the grizzlybear.

Out of the relentless conversion of nature on this continentarose a movement for conservation. In 1872 the American peopleundertook a novel experiment. Yellowstone was set aside in "itsnatural condition" as the world's first national park. There aretoday more than 360 parks in the U.S. National Park System and morethan 3,600 areas under similar protection around the globe.National parks and other public lands shelter well over half of theplant and animal species in North America. More than 80 countrieshave established several hundred biosphere reserves specifically toprotect biological diversity.

The values of this diversity in parks are legion: the value ofnature for its own sake, a source of wonder and enjoyment; thevalue of learning about the workings of nature in places largelyfree of human influence, for comparison with landscapes dominatedby humans; the survival value of multitudes of wild species thatflourish as natural systems helping regulate climate, air quality,and cycles of carbon, nitrogen, oxygen, mineral elements, andwater--all fundamental to life on earth. There is economic value inthese same plants and animals. They are potential sources of food,medicine, and industrial products. Parks protect the species andtheir communities that underlie these values--serving if necessaryas reservoirs of seed stock for restoring species lostelsewhere.

### Nature's Harvest

Nearly all the food in the supermarket was originally derivedfrom wild sources. Of an estimated 80,000 types of plants know tobe edible, only about 150 are extensively cultivated. A mere threecrops--corn, wheat, and rice, all of wild origin--supply two-thirdsof the world's total grain harvest.

Wild species are necessary to ensure the continued productivityof our cultivated foods. The potato blight in Ireland during the1840s led to the starvation of two million people and prompted massemigration to the United States. Eventually, the potato wascrossbred with several of its wild, disease-resistant relatives,producing the many reliable varieties in use today.

Wild animal resources are also important. Commercial fishing, a$75 billion-a-year industry worldwide, relies on natural systems,including coastal estuaries protected by many national seashores.On land, breeding domestic cattle with such genetically compatiblewild species as the American bison may give us new breeds hardierand more productive than current beef cattle.

Biological diversity is thus a form of insurance. If cultivatedvarieties of food fail because of events like disease or globalwarming, we can look for genetic infusions from the natural world.National parks and other preserves help ensure that vital wildresources and their genetic information will continue to exist.

### New Medicines

Among other things, nature resembles a giant drug store. Almostone-quarter of all prescription drugs sold in the United States (an$8 billion-a-year market) contain natural substances. Alkaloids,plant substances especially common in tropical plants, are used incancer-fighting drugs, painkillers, blood-pressure boosters,anti-malarial drugs, and muscle-relaxants. Probably the best knownnatural drug is penicillin, derived from *Penicillium* mold, aclose relative of common bread molds. Aspirin also had a naturalorigin. Even when synthetic versions of drugs are developed, givingus substitutes for penicillin or aspirin, they are usually createdby following the "blueprints" of natural chemical compounds. Yet ofearth's hundreds of thousands of species or higher plants(estimates range between 250,000 and 750,000) only a relativehandful have been exhaustively studied for their medicinal value.The world's flora surely holds many more cures for human ills.

Wild animals are also sources of many valuable medicinalproperties. Fish liver oil, rich in vitamins A and D, is well knownas a dietary supplemental and for its uses as a soothing ointmentfor skin rashes. The horseshoe crab, *Limulus polyphemus*,found in waters off many of our national seashores, has acopper-based "blue" blood that is sensitive to some toxins;extracts of this animal's blood are used to test vaccines andintravenous fluids for contamination and to diagnose humandiseases. 

### Benefits to Industry

When a space shuttle returns to earth, the first part to touchdown is its tires made of natural rubber. Once just another plantin the jungle with a peculiar latex sap, the rubber tree becameindispensable with the advent of the industrial age.

Rubber comes from trees native to the tropics of thishemisphere. Though petroleum-based synthetics have been developed,natural rubber is still essential in tires, especially aviation andtruck tires, and vital in many other industrial products. In WorldWars I and II scientists pressed the search for other naturalsources of rubber. One likely candidate was guayule, *Partheniumargentatum*, a shrub that grows in many places in the AmericanSouthwest, including Big Bend National Park. Guayule was plantedand harvested successfully in the Southwest in the 1940s. Becausethe plant also yields hydrocarbons, researchers have an interest inguayule as an alternative source of petroleum. Examples abound ofsuccessful products derived from other plants. George WashingtonCarver, commemorated at George Washington Carver National Monumentin Missouri, developed numerous products from plants during thefirst decades of the 20th century. Cloth from tomato vines, aplastic from soybeans, and cosmetics from peanut oil are samples ofhis ingenuity.

Life in a technical age is unimaginable without many otherproducts that come from natural sources. Trees supply wood, paper,pulp, chemicals, and other products worth well over $100 billionannually worldwide. Rayon, derived from wood chemicals, isimportant to making cloth. Ethanol, derived from fermenting corn,sorghum, or sugar cane, may well become an important source of fuelin a world short of petroleum. Industrial oils and waxes can beobtained from many plants and some animal species.

Nature is our security. By sustaining natural diversity throughthe establishment of national parks and other reserves, we protectpotential genetic sources of economic wealth for the future. 

### Parks and Diversity

The land managers of America range from large public agencies totimber companies, ranchers, farmers, owners of private sanctuaries,even city dwellers who tend their shrubbery, yards, and gardens.They each have a role in maintaining biological diversity.

Of the public agencies, one of the most visible is the NationalPark Service, manager of 79 million acres of parkland. Its primaryconservation mission in natural areas is to minimize humaninfluences so that park ecosystems are governed by naturalprocesses alone. Managers have learned that park boundaries are notbarriers and that they must sometimes intervene to help naturefollow its own course. Lightning fires, for example, are allowed toburn in certain areas if they do not threaten property or publicsafety, and some parks conduct controlled burning to restoreconditions as they were before fires were suppressed. This practicehelps maintain the natural variety of vegetation in its variousstages of recovery from disturbance, along with the animals adaptedto those stages. Another instance is predators. In former times,they were frequently removed from parks; now they are protected asnatural elements of ecosystems and sometimes restored ifmissing.

When managers, with the help of research, understand how parksfunction as biological systems, they can take measures to maintainor restore native flora and fauna. These measures include:

- controlling exotic species that may compete with, prey on, oralter native species;
- restoring lost or depleted native species (bighorn sheep inYosemite, for example);
- restoring natural habitats (tallgrass prairie in manymidwestern parks);
- finding out the habitat needs of endangered species (themanatee, panther, and snail kite at Everglades NP);
- participating in regional management of migratory orfar-ranging animals. An example involving Yellowstone and otherparks is the Interagency Grizzly Bear Committee with federal,state, and Canadian members.

Historic genetic resources are also conserved in parks. Rareorchard stocks are maintained at John Muir National Historic Sitein California and several other parks. George Washington BirthplaceNational Monument in Virginia keeps globally rare Hog Island sheepand Ossabow hogs, once raised on sea islands along the Virginia andGeorgia coasts.

Contrary to the popular phrase, parks are not places apart. Theyexist in regional settings. Park managers must work with theirneighbors to lessen the impact of surrounding development. Equallycritical are the long-term consequences of influences that arecontinental, if not global, in scope. The threats of acid rain andglobal warming are perhaps the best known. Parks can no longer bethought of as islands of nature. They share the fate of thebiosphere.

### Stewards of the Land

By far the largest single landowner in the United States is thefederal government.

The Fish and Wildlife Service manages 90 million acres of wildliferefuges and, among other duties, administers the Endangered SpeciesAct, designed to restore species threatened with extinction.

The Bureau of Land Management, like other federal agencies, must bylaw identify any endangered species and take measures to safeguardthem on land it administers. Though grazing, mining, and timberingare allowed on most of its 300-million-acre domain, the Bureaurestricts use in habitats especially important to threatenedspecies--the Snake River Birds of Prey Area in Idaho, forexample.

The Forest Service is responsible for 191 million acres of nationalforests, habitat for a majority of the country's plant andvertebrate species. The agency's goal is to maintain the existingplant and animal diversity in national forests even as timberharvesting and other uses go on.

Other federal agencies protect significant amounts of wildlifehabitat. The Defense Department is the custodian of 25 millionacres. Hunting is allowed, but care is taken to protect rare orthreatened species. The National Oceanic and Atmospheric Administration administerssome 270,000 nautical square miles of marine and estuarinesanctuaries. Some 54 million acres of tribal land held in trust bythe federal government but managed by Native Americans providesvaried habitat in many parts of the country.

In the private sphere, numerous organizations work to protectand sustain biological diversity. Two organizations notable fortheir effectiveness take different approaches to the task. The Nature Conservancy, widely known for rescuing many significantnatural areas from development, conducts Natural HeritageInventories to identify the locations of rare species so they canbe protected. The Center for Plant Conservation, a consortium of 19 botanicalgardens, is assembling a National Collection of Endangered Plantsfor research and restocking.

Yet no single organization, public or private, can alone assurebiodiversity. Coordination is important. An example of this is theYellowstone region, composed of two national parks, six nationalforests, four wildlife refuges, and numerous private holdings. Its10 million acres make it one of the largest wildland tracts in theearth's temperate zone, large enough to support sizable populationsof the wide-ranging grizzly bear, the rare trumpeter swan, andmigratory elk. At least 25 different federal and state agencieshave administrative responsibilities for this region, many of themoverlapping. Remoteness once protected this land. Today itsecological health is dependent on thoughtful and well coordinatedmanagement by many groups.

### World View

In many developing countries, conservation must be combined withhelp for the people. Until their basic needs are met, few peopleare likely to care about biodiversity. But wildlife has needs too.National parks and similar protected areas are the only refuge forplants and animals that wane in human proximity. The golden liontamarin (a small monkey) survives only in protected forests onBrazil's heavily developed southeastern coast. The tiger depends onsimilar protection in densely populated India. Parks shouldtherefore be part of regional economic development.

In 1971 UNESCO created another type of protected area, thebiosphere reserve, to serve both conservation and development.These reserves have (1) core zones that remain natural to conservediversity and (2) surrounding zones in which (often) traditionallife continues and research is conducted on the sustainable use offorests, grassland, and other resources. Such zones often protectthe much-needed genetic diversity of crops and livestock used intraditional agriculture.

In 1992, there were 311 biosphere reserves in 81 countries, 47in the United States alone. The goal is to establish at least onebiosphere reserve in each of the world's land and coastal/marineregions.

Only 3 percent of the world's land area is now devoted to thepreservation of nature for its own sake. Some countries have setaside as much as 38 percent of their territory; a few, nothing. Forthe United States the figure is 8 percent. Parks and reserves arevital but by themselves are not likely to be decisive in the questto sustain diversity. If this quest is to succeed, much of it mustalso come about on lands used for many purposes.

### The World's Heritage

Some places transcend time and national boundaries and becomethe common inheritance of mankind. These places are now giveninternational recognition as World Heritage Sites or BiosphereReserves. Of the nearly 400 World Heritage Sites, over 100 aresignificant for their natural resources. The Galapagos Islands(Ecuador) and the Everglades (U.S.) are well known examples.Biosphere Reserves (numbering hundreds worldwide) are places inwhich traditional life, conservation, and research go hand-in-hand.A good example is the Southern Appalachian Biosphere Reserve, whichlinks a number of parks and research sites.

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