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BioDiversity PART 2 HUMAN DEPENDENCE ON BIOLOGICAL DIVERSITY
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BioDiversity A Young Yanomami Indian women in the Amazon rain forest relaxes while preparing an armadillo for a future meal. A tame trumpeter bird searches for food in the background. Photo courtesy of Victor Englebert. © 1982 Time-Life Books B.V. from the Peoples of the Wild series.
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BioDiversity CHAPTER 8 DEEP ECOLOGY MEETS THE DEVELOPING WORLD JAMES D.NATIONS Director of Research, Center for Human Ecology, Austin, Texas There is a movement afoot in the United States that environmentalists call deep ecology (Tobias, 1985). In a nutshell, its basic tenet is that all living things have a right to exist—that human beings have no right to bring other creatures to extinction or to play God by deciding which species serve us and should therefore be allowed to live. Deep ecology rejects the anthropocentric view that humankind lies at the center of all that is worthwhile and that other creatures are valuable only as long as they serve us. Deep ecology says, instead, that all living things have an inherent value—animals, plants, bacteria, viruses—and that animals are no more important than plants and that mammals are no more valuable than insects (Blea, 1986). Deep ecology is similar to many Eastern religions in holding that all living things are sacred. As a conservationist, I am attracted to the core philosophy of deep ecology. Like the Buddhists, and Taoists, and supporters of the Earth First! movement, I also believe that all living things are sacred. When human activities drive one of our fellow species to extinction, I consider that a betrayal of our obligation to protect all life on the only planet we have. Where I run into trouble with the philosophy of deep ecology is in places like rural Central America or on the agricultural frontier in Ecuadorian Amazonia—places where human beings themselves are living on the edge of life. I have never tried to tell a Latin American farmer that he has no right to burn forest for farmland because the trees and wildlife are as inherently valuable as he and his children are. As an anthropologist and as a father, I am not prepared to take on that job. You could call this the dilemma of deep ecology meeting the developing world. The dilemma is softened somewhat by the realization that the farmer in the developing world probably appreciates the value of forest and wildlife better than we do in our society of microwave ovens and airplanes and plastic money. The Third-World farmer appreciates his dependence on biological diversity because that
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BioDiversity dependence is so highly visible to him. He knows that his life is based on the living organisms that surround him. From the biological diversity that forms his natural environment he gathers edible fruit, wild animals for protein, fiber for clothing and ropes, incense for religious ceremonies, natural insecticides, fish poisons, wood for houses, furniture, and canoes, and medicinal plants that may cure a toothache or a snakebite. There are indigenous peoples in some parts of the world who have an appreciation for biological diversity that puts our own conservation theorists to shame. I stayed once in southeastern Mexico with a Maya farmer who expressed his view this way: “The outsiders come into our forest,” he said, “and they cut the mahogany and kill the birds and burn everything. Then they bring in cattle, and the cattle eat the jungle. I think they hate the forest. But I plant my crops and weed them, and I watch the animals, and I watch the forest to know when to plant my corn. As for me, I guard the forest.” Today, that Maya farmer lives in a small remnant of rain forest surrounded by the fields and cattle pastures of 100,000 immigrant colonists. He is subjected to the development plans of a nation hungry for farmland and foreign exchange. The colonists have been forced by population pressure and the need for land reform to colonize a tropical forest they know nothing about. The social and economic realities of a modern global economy are leading them and their national leaders to destroy the very biological resources their lives are based upon. The colonists are fine people who are quick to invite you to share their meager meal. But if you want to talk with them about protecting the biological diversity that still surrounds them, be prepared to talk about how it will affect them directly. If you look a frontier farmer in the eye and tell him that he must not clear forest or hunt in a wildlife reserve and that the reason he must not do these things is because you are trying to preserve the planet’s biological diversity, he will very politely perform the cultural equivalent of rolling his eyes and saying, “Sure.” But he will not believe you. Instead, you should be prepared to demonstrate how he can produce more food and earn more money by protecting the biological resources on his land. The developing world colonist may understand his dependence on biological diversity, but his interest in protecting that diversity lies in how it can improve his life and the lives of his children. Colonists on the agricultural frontier do not have the luxury of debating the finer points of deep ecology. The same thing can be said for the government planner in the nation where the pioneer farmer lives and the development banker in Washington, D.C. The planner and the banker may appreciate the moral and aesthetic values of biological diversity. They may lament the eradication of wilderness and wildlife. But if you want them to protect a critical area of forest or place their hydroelectric dam outside a protected area, be prepared to talk about the economic value of watersheds, income from tourism, and cost-benefit analysis. In the developing world, as well as in our overdeveloped world, we are obligated to present economic, utilitarian arguments to preserve the biological diversity that ultimately benefits us all. Deep ecology makes interesting conversation over the seminar table, but it won’t fly on the agricultural frontier of the Third World or in the board rooms of the Inter-American Development Bank.
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BioDiversity The day may come when ethical considerations about biological diversity become our most important reason for species conservation. But in the meantime, if we want to hold on to our planet’s biological diversity, we have to speak the vernacular. And the vernacular is utility, economics, and the well-being of individual human beings. In the 1980s, the question seems to be, “What has biological diversity done for me lately?” The good news is that the answer to that question is, “Plenty, and more than you realize.” Our lives are full of examples of the logic of preserving the plants and animals that we depend upon as a species. Our food is a good example. Human beings eat a wealth of plants and animals in the home-cooked meals and restaurant dinners that we live on day-to-day. Yet one of the most immediate threats posed by the loss of biodiversity is the shrinkage of plant gene pools available to farmers and agricultural scientists. During the past several decades, we have increased our ability to produce large quantities of food, but we have simultaneously increased our dependence on just a few crops and our dependence on fewer types of those crops. As much as 80% of the world food supply may be based on fewer than two dozen species of plants and animals (CEQ, 1981). We are eroding the genetic diversity of the crops we increasingly depend upon, and we are eradicating the wild ancestors of those crops as we destroy wilderness habitats around the world. We are dependent on biological diversity in ways less visible than the plants and animals we eat and wear. We also depend on them for raw materials and medicines. We depend on the diversity of plants and animals for industrial fibers, gums, spices, dyes, resins, oils, lumber, cellulose, and wood biomass. We chemically screen wild plants in search of new drugs that may be beneficial to humankind. We import millions of dollars worth of medicinal plants into the United States and use them to produce billions of dollars worth of medicines (OTA, 1984). We use animals in medical research as well, though sometimes with brutal results. We import tens of thousands of primates for drug safety tests and drug production (OTA, 1984). We use Texas armadillos in research on leprosy. When human activities threaten the survival of these animals and their wild habitats, they threaten human welfare as well. At the same time, we have to acknowledge that we will never be able to demonstrate an immediate, utilitarian reason for preserving every species on Earth. Some of them may have no use for humankind beyond being part of the great mystery. But who will tell us which species are unimportant? Who can tell us which level of extinction will seriously disrupt the web of life that we depend upon as human beings? Environmental writer Erik Eckholm says that one of the key tasks facing both scientists and governments is to identify and protect the species whose ecological functions are especially important to human societies. And “in the meantime,” Eckholm continues, “prudence dictates giving existing organisms as much benefit of the doubt as possible” (Eckholm, 1978). One of the important factors in providing those species with the benefit of the doubt they deserve is educating ourselves and our governments’ policy makers about our dependence, as human beings, on biological diversity. That education tends
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BioDiversity to emphasize the utilitarian value of species protection. One of the results is that there is a growing, pragmatic ethic among scientists and conservationists. It is an ethic that centers on the realization that our ability to preserve biological diversity depends on our ability to demonstrate the benefits that diversity brings to human beings (Fisher and Myers, 1986). On one level, these benefits take the form of immediate economic income through activities like wildlife harvesting, tourism, and maintaining agricultural production. On another level, they focus on unfulfilled potential—new crops, new medicines, new industrial products. Taken together, the benefits of biological diversity provide short-term income to individual people and improve the long-term well-being of our species as a whole. These two levels of benefits work together in the sense that if we hope to see the long-term benefits of biological diversity, we have to focus first—or least simultaneously—on the immediate, short-term benefits to individual people. Few of the wild gene pools—the raw materials for future medicines, food, and fuels—are likely to survive intact in places where people have to struggle simply to provide their basic, daily needs (Wolf, 1985). One of our long-term goals as a species is to enjoy the uncounted benefits that our planet’s biological diversity can eventually bring us. But in the short term, at a minimum for the next few decades, our basic strategy must concentrate on ensuring that people here and on the frontiers of the developing world receive material incentives that will allow them to prosper by protecting biological diversity rather than by destroying it (Cartwright, 1985). That done, we can return to the ethical and aesthetic arguments of deep ecology with the knowledge that when we look up from our discussion, there will still be biological diversity left to experience and enjoy. The authors of the three chapters that follow are counted among the most successful and most dedicated of the scientists now working to point out the short-term and long-term benefits of biological diversity—three scientists who are working as quickly as possible to discover the unread books of our planet’s genetic diversity and to translate those discoveries into practical advantages for their fellow human beings. REFERENCES Blea, C. 1986. Individualism and ecology. Earth First! Journal 6(6):21, 23. Cartwright, J. 1985. The politics of preserving natural areas in third world states. Environmentalist 5(3):179–186. CEQ (Council on Environmental Quality). 1981. The Global 2000 Report to the President, Vol. II. Council on Environmental Quality and the U.S. Department of State, Washington, D.C. Eckholm, E. 1978. Disappearing Species: The Social Challenge. Worldwatch Paper 22. Worldwatch Institute, Washington, D.C. 38 pp. Fisher, J., and N.Myers. 1986. What we must do to save wildlife. Int. Wild. 16(3):12–15. OTA (Office of Technology Assessment). 1984. Technologies to Sustain Tropical Forest Resources. OTA-F-214. Office of Technology Assessment, U.S. Congress, Washington, D.C. 344 pp. Tobias, M., ed. 1985. Deep Ecology. Avant Books, San Diego, Calif. 285 pp. Wolf, E.C. 1985. Challenges and priorities in conserving biological diversity. Interciencia 10(5):236–242.
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BioDiversity CHAPTER 9 SCREENING PLANTS FOR NEW MEDICINES NORMAN R.FARNSWORTH Research Professor of Pharmacognosy, Program for Collaborative Research in the Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois The U.S. pharmaceutical industry spent a record $4.1 billion on research and development in 1985, an increase of 11.6% from 1984 (Anonymous, 1986). In the same year, the American consumer purchased in excess of $8 billion in community pharmacies for prescriptions whose active constituents are still extracted from higher plants (Farnsworth and Soejarto, 1985). For the past 25 years, 25% of all prescriptions dispensed from community pharmacies in the United States contained active principles that are still extracted from higher plants, and this percentage has not varied more than 1.0% during that period (Farnsworth and Morris, 1976). Despite these data, not a single pharmaceutical firm in the United States currently has an active research program designed to discover new drugs from higher plants. THE GLOBAL IMPORTANCE OF PLANT-DERIVED DRUGS Approximately 119 pure chemical substances extracted from higher plants are used in medicine throughout the world (Farnsworth et al., 1985) (see Table 9–1). At least 46 of these drugs have never been used in the United States. For the most part, the discovery of the drugs stems from knowledge that their extracts are used to treat one or more diseases in humans. The more interesting of the extracts are then subjected to pharmacological and chemical tests to determine the nature of the active components. Therefore, it should be of interest to ascertain just how important plant drugs are throughout the world when used in the form of crude extracts. The World Health Organization estimates that 80% of the people in
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BioDiversity TABLE 9–1 Secondary Plant Constituents Used as Drugs Throughout the World, Their Sources and Uses Compound Name Therapeutic Category in Medical Science Plant Sources Plant Uses in Traditional Medicine Correlation Between Two Usesa Acetyldigitoxin Cardiotonic Digitalis lanata Ehrh. (Grecian foxglove) Not used Indirect Adoniside Cardiotonic Adonis vernalis L. (Pheasant’s eye) Heart conditions Yes Aescin Antiinflammatory Aesculus hippocastanum L. (Horse chestnut) Inflammations Yes Aesculetin Antidysentery Fraxinus rhynchophylla Hance (variety of Fraxinus chinensis Roxb.) Dysentery Yes Agrimophol Anthelmintic Agrimonia eupatoria L. (Common agrimony) Anthelmintic Yes Ajmalicine Circulatory stimulant Rauvolfia serpentina (L.) Benth. ex Kurz (Indian snakeroot) Tranquilizer Indirect Allantoinb Vulnerary Several plants Not used No Allyl isothiocyanateb Rubefacient Brassica nigra (L.) Koch (Black mustard) Rubefacient Yes Anabasine Skeletal muscle relaxant Anabasis aphylla L. (Tumbleweed) Not used No Andrographolide Antibacterial Andrographis paniculata Nees. (Karyat) Dysentery Yes Anisodamine Anticholinergic Anisodus tanguticus (Maxim.) Pascher (Zàng qiè) Meningitis symptoms Yes Anisodine Anticholinergic Anisodus tanguticus (Maxim.) Pascher (Zàng qiè) Meningitis symptoms Yes Arecoline Anthelmintic Areca catechu L. (Betel-nut palm) Anthelmintic Yes Asiaticoside Vulnerary Centella asiatica (L.) Urban (Indian pennywort) Vulnerary Yes Atropine Anticholinergic Atropa belladonna L. (Belladonna) Dilate pupil of eye Yes Benzyl benzoateb Scabicide Several plants Not used No Berberine Antibacterial Berberis vulgaris L. (Barberry) Gastric ailments Yes Bergenin Antitussive Ardisia japonica Thunb. (Japanese ardisia) Chronic bronchitis Yes
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BioDiversity Borneolb Antipyretic; analgesic; antiinflammatory Several plants Not used No Bromelain Antiinflammatory; proteolytic Ananas comosus (L.) Merrill (Pineapple) Not used Indirect Caffeine Central nervous system stimulant Camellia sinensis (L.) Kuntze (Tea) Stimulant Yes Camphor Rubefacient Cinnamomum camphora (L.) Nees & Eberm. (Camphor tree) Not used No (+)-Catechin Hemostatic Potentilla fragarioides L. (Cinquefoil) Hemostatic Yes Chymopapain Proteolytic; mucolytic Carica papaya L. (Papaya) Digestant Yes Cocaine Local anesthetic Erythroxylum coca Lam. (Coca) Appetite suppressant; stimulant Yes Codeine Analgesic; antitussive Papaver somniferum L. (Opium poppy) Analgesic; sedative Yes Colchiceine amide Antitumor agent Colchicum autumnale L. (Autumn crocus) Gout No Colchicine Antitumor agent; anti-gout Colchicum autumnale L. (Autumn crocus) Gout Yes Convallatoxin Cardiotonic Convallaria majalis L. (Lily-of-the-valley) Cardiotonic Yes Curcumin Choleretic Curcuma longa L. (Turmeric) Choleretic Yes Cynarin Choleretic Cynara scolymus L. (Artichoke) Choleretic Yes Danthron (1,8-dihydroxyanthraquinone)b Laxative Cassia species (Senna) Laxative Yes Demecolcine Antitumor agent Colchicum autumnale L. (Autumn crocus) Gout No Deserpidine Antihypertensive; tranquilizer Rauvolfia tetraphylla L. (Snakeroot) Not used Indirect Deslanoside Cardiotonic Digitalis lanata Ehrh. (Grecian foxglove) Not used Indirect Digitalin Cardiotonic Digitalis purpurea L. (Common foxglove) Cardiotonic Yes Digitoxin Cardiotonic Digitalis purpurea L. (Common foxglove) Cardiotonic Yes Digoxin Cardiotonic Digitalis lanata Ehrh. (Grecian foxglove) Not used Indirect
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BioDiversity Compound Name Therapeutic Category in Medical Science Plant Sources Plant Uses in Traditional Medicine Correlation Between Two Usesa L-Dopab Antiparkinsonism Mucuna deeringiana (Bort) Merr. (Velvet bean) Not used No Emetine Amebicide; emetic Cephaelis ipecacuanha (Botero) A. Richard (Ipecac) Amebicide; emetic Yes Ephedrineb Sympathomimetic Ephedra sinica Stapf (Ma-Huang) Chronic bronchitis Yes Etoposideb Antitumor agent Podophyllum peltatum L. (May apple) Cancer Yes Galanthyamine Cholinesterase inhibitor Lycoris squamigera Maxim. (Ressurection lily; magic lily) Not used No Gitalin Cardiotonic Digitalis purpurea L. (Common foxglove) Cardiotonic Yes Glaucarubin Amebicide Simaruba glauca DC. (Paradise tree) Amebicide Yes Glaucine Antitussive Glaucium flavum Crantz (Horned poppy, sea poppy) Not used No Glaziovine Antidepressant Ocotea glaziovii Mez (Yellow cinnamon) Not used No Glycyrrhizin (Glycyrrhetic acid) Sweetener Glycyrrhiza glabra L. (Licorice) Sweetener Yes Gossypol Male contraceptive Gossypium species (Cotton) Decreased fertility observed Yes Hemsleyadin Antibacterial; antipyretic Hemsleya amabilis Diels (Luó guō di) Dysentery Yes Hesperidin Capillary antihemorrhagic Citrus species (Citrus, e.g., orange, lemon) Not used No Hydrastine Hemostatic; astringent Hydrastis canadensis L. (Golden seal) Astringent Yes Hyoscyamine Anticholinergic Hyoscyamus niger L. (Henbane) Sedative Yes Kainic acid Ascaricide Digenea simplex (Wulf.) Agardh (Red alga) Anthelmintic Yes
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BioDiversity Kawainb Tranquilizer Piper methysticum Forst. f. (Kava) Euphoriant Yes Khellin Bronchodilator Ammi visnaga (L.) Lamk. (toothpick plant) Asthma Yes Lanatosides A, B, C Cardiotonic Digitalis lanata Ehrh. (Grecian foxglove) Not used Indirect Lobeline Respiratory stimulant Lobelia inflata L. (Indian tobacco) Expectorant Yes Mentholb Rubefacient Mentha species (Mint, e.g., peppermint, spearmint) Carminative No Methyl salicylateb Rubefacient Gaultheria procumbens L. (Wintergreen) Carminative No Monocrotaline Antitumor agent (topical) Crotalaria spectabilis Roth (Rattlebox) Skin cancer Yes Morphine Analgesic Papaver somniferum L. (Opium poppy) Analgesic; sedative Yes Neoandrographolide Antibacterial Andrographis paniculata Nees (Karyat) Dysentery Yes Nicotine Insecticide Nicotiana tabacum L. (Tobacco) Narcotic No Nordihydroguaiaretic acid Antioxidant (lard) Larrea divaricata Cav. (Creosote bush) Antitussive No Noscapine (narcotine) Antitussive Papaver somniferum L. (Opium poppy) Analgesic; sedative Yes Ouabain Cardiotonic Strophanthus gratus (Hook.) Baill. (Twisted flower) Arrow poison Indirect Pachycarpine [(+)-sparteine] Oxytocic Sophora pachycarpa Schrenk ex C. A. Meyer (Pagoda tree) Not used No Palmatine (fibraurine) Antipyretic; detoxicant Coptis japonica Makino (Goldthread) Not used No Papain Proteolytic; mucolytic Carica papaya L. (Papaya) Digestant Yes Papaverineb Smooth muscle relaxant Papaver somniferum L. (Opium poppy) Sedative; analgesic No Phyllodulcin Sweetener Hydrangea macrophylla (Thunb.) Seringe (Hydrangea) Sweetener Yes Physostigmine (eserine) Anticholinesterase Physostigma venenosum Balf. (Ordeal bean) Ordeal poison Indirect
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BioDiversity CHAPTER 11 THE OUTLOOK FOR NEW AGRICULTURAL AND INDUSTRIAL PRODUCTS FROM THE TROPICS MARK J.PLOTKIN Director, Plant Conservation, World Wildlife Fund-U.S., Washington, D.C., and Research Associate, Harvard Botanical Museum, Cambridge, Massachusetts Many of the initial international wildlife conservation efforts focused on attractive species of endangered mammals—the so-called charismatic megafauna. Although a number of these programs have proven to be extremely successful, the modus operandi was clearly not entirely applicable to the conservation of all organisms: “Save the Sedges!” is just not as stirring a battle cry as “Save the Tiger!” We cannot save the pandas, however, unless we save the bamboos on which they feed. Furthermore, human existence is much more dependent on the plant kingdom than on animals. Plants are indeed the roots of life. Because of the sheer diversity of plant life—especially in the tropics—many conservationists in the recent past have had some difficulty trying to decide where to begin. Faced with an area like the Amazon, home to tens of thousands of species of plants, many of which have yet to be discovered by modern scientists, it is clearly impractical to evaluate the conservation status and potential utility of each species on an individual basis. Consequently, there has been a perceptible shift in emphasis toward plants that are either useful or potentially useful to people. The concept of protecting a plant because it shows promise for aiding human well-being seems to have a much wider appeal than preserving a species for purely aesthetic or academic purposes. Conservationists generally divide useful plants into three categories: medicinal, agricultural, and industrial. Of these three groupings, medicinal plants tend to attract the most attention from the media. There is no denying the appeal of the modern ethnobotanist’s ventures into the jungle to work with witch doctors to find healing herbs. Due to a variety of factors—factors that are expected to change in
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BioDiversity the near future—there has been relatively little development of new wonder drugs from tropical plants during the last decade (Tyler, 1986; see also Farnsworth, Chapter 9 of this volume). The recent history and predicted future for new agriculture and industrial plant products from the tropics have been very positive (Balick, 1985; Schultes, 1979). AGRICULTURE The greatest service which can be rendered any country is to add a useful plant to its culture. From Thomas Jefferson, 1821. A hungry people listen not to reason, nor care for justice, nor are bent by prayers. From Seneca, ca. 60 A.D. A hungry mob is an angry mob. From Bob Marley, 1979. Tropical forest plants can be of use to modern agriculture in three different ways: as sources of new crops that can be brought into cultivation; as source material for breeding improved plant varieties; and as sources of new biodegradable pesticides. NEW CROPS Only a very small proportion of the world’s plants have ever been used as a food source on a large scale. Of the several thousand species known to be edible, only about 150 have ever become important enough to enter into world commerce (R.E.Schultes, Harvard Botanical Museum, personal communication, 1986). In the movement toward a global economy, there has been a trend to concentrate on fewer and fewer species. Today, less than 20 plant species produce most of the world’s food (Vietmeyer, 1986b). Furthermore, the four major carbohydrate crop species—wheat, corn, rice, and potatoes—feed more people than the next 26 most important crops combined (Witt, 1985). The obvious place to turn for new crops to reduce our heavy reliance on such a relatively small number of species is the tropics. North America north of Mexico has contributed relatively little to the storehouse of economically important crop plants. If we had to live on plants that originated in the United States, our diet would consist of pecans, sunflower seeds, cranberries, blueberries, grapes, wild rice, pumpkins, squashes, and Jerusalem artichokes. Caufield (1982) estimated that 98% of U.S. crop production is based on species that originated outside our borders. Of our common foodstuffs, corn, rice, potatoes, sweet potatoes, sugar, citrus fruit, bananas, tomatoes, coconuts, peanuts, red pepper, black pepper, nutmeg, mace, pineapples, chocolate, coffee, and vanilla all originated in tropical countries. A typical American breakfast of cornflakes, bananas, sugar, coffee, orange juice, hot chocolate, and hash brown potatoes is based entirely on tropical plant products. Few people realize how much of our diet today has been determined by exploitation patterns developed when tropical countries were colonies of Europe. In many cases, the advantage that some current crop staples have over other, less-exploited tropical species is the disproportionate amount of research to which they have been subjected. Under the colonial system, only a few key species were chosen for export, and the establishment of a market for these species determined future cultivation
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BioDiversity The author collecting medicinal plants with local Indian guide, in southern Suriname. and research priorities, which excluded lesser-known species. This overreliance on a few species was maintained even after independence, since developing countries had to depend on preexisting markets and technicians trained in temperate countries (NRC, 1975). Many currently underexploited tropical species will become common sights in the produce sections of our supermarkets during the next decade. Because those species are often best known to aboriginal or peasant peoples, they have often been stigmatized as slave foods in their country of origin. This has impeded the development of these crops, which often tend to be robust, productive, self-reliant, free of indigestible compounds with relatively high nutritive value, and suitable for growing in some sort of agricultural system. The demand for tropical cuisine continues to grow in this country. The Los Angeles area is said to have more than 200 Thai restaurants, and Mexican fast-food outlets have become a $1.6 billion industry (Vietmeyer, 1986a). Even a short walk down M Street in Washington, D.C., will take you past Chinese, Vietnamese, Thai, Filipino, Mexican, Central American, and South American restaurants. Kiwi fruit from China was not introduced into this country until 1962, yet last year they were purchased by more than 10 million Americans. Furthermore, do-
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BioDiversity mestic demographic trends will add to the demand for tropical produce: the U.S. population has increased 17% since 1970, whereas the Hispanic population has risen 87% and the Asian population, 127% (Vietmeyer, 1986a). The more promising species include the following: The uvilla (Pourouma cecropiaefolia; family Moraceae). The uvilla is a medium-size tree native to the western Amazon. Both harvested from the wild and cultivated by local Indians as a doorstep crop, it yields fruit in only 3 years time. The tasty fruits can be eaten raw or made into a wine (Balick, 1985; Prance, 1982). The lulo (Solanum quitoense; family Solanaceae). The lulo, or naranjilla, is one of the most highly prized fruits in Colombia and Ecuador. It is a shrubby perennial bearing pubescent, yellow-orange fruits. The greenish flesh is made into an exceptionally delicious drink. The lulo has already been introduced in Panama, Costa Rica, and Guatemala, where it is being marketed as a frozen concentrate (Heiser, 1985). The pupunha (Bactris gasipaes; family Palmae). Native to the northwest Amazon, the pupunha, or peach palm, is a 20-meter-tall palm widely cultivated in both South and Central America. Each year this palm can yield up to 13 bunches of fruit, which contains carbohydrates, protein, oil, minerals, and vitamins in nearly perfect proportions for the human diet. Under cultivation, the tree will produce more carbohydrate and protein per hectare than does corn (Balick, 1985; NRC, 1975; Vietmeyer, 1986b). The amaranths (Amaranthus spp.; family Amaranthaceae). The three major species of amaranths (Amaranthus caudatus, A. cruentus, and A. hypochondriachus) are rapidly growing cereal-like plants that have been cultivated in Central and South America since Pre-Columbian times. The ancient Aztecs considered amaranth a sacred plant and consumed cakes made of ground amaranth seeds and human blood. Because of this religious practice, the Spanish severely suppressed the cultivation of this plant. Amaranth seeds have extremely high levels of total protein and of the nutritionally essential amino acid lysine, which is usually lacking in plant protein (NRC, 1984; Vietmeyer, 1986b). Amaranth is currently being marketed in this country as breakfast cereal and is now being sold in many health food stores. The guanabana (Annona muricata; family Annonaceae). The guanabana, or soursop, is a medium-size tree native to tropical America. Throughout the year the tree produces fruit whose delicious white flesh has a unique smell and a texture that can be best described as a sort of fibrous pineapple custard. Already popular in China, Australia, Africa, and the Philippines, guanabana can be eaten raw or made into a delicious drink or yogurt (NRC, 1975). The buriti palm (Mauritia flexuosa; family Palmae). A veritable tree of life to many Amazonian Indians, the buriti palm produces a fruit said to be as rich as citrus in vitamin C content. Its pulp oil is believed to contain as much vitamin A as carrots and spinach. A starch extracted from the pith is used to make bread. An edible palm heart can be extracted from the shoots. The Indians also make wine from its fruit, sap, and inflorescences (NRC, 1975). A strong fiber is obtained from the young leaves, and a useful cork-like material is extracted from the petioles.
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BioDiversity The wood of the trunk is used in light construction. Furthermore, the buriti palm thrives in Amazonian swamps of little use for intensive agriculture (Schultes, 1979). IMPROVEMENT OF CROP SPECIES THROUGH CROSS-BREEDING Relatives of commercial species must continuously be crossbred with these species to improve crop yield, nutritional quality, durability, responsiveness to different soils and climates, and resistance to pests and diseases (IUCN, 1980). Since many of the world’s most important crop species originated in the tropics, we must look to the equatorial regions for wild or semidomesticated relatives of commercial species to maintain or improve our crops. A barley plant from Ethiopia has already provided a gene that protects a $160-million barley crop in California from the lethal yellow dwarf virus. A wild relative discovered by Iltis in the Peruvian Andes has increased the sugar content of the domestic tomato which has resulted in an increased commercial value estimated at $5 to $8 million per year (Witt, 1985; see also Iltis, Chapter 10 of this volume). In fact, tomatoes are one of the world’s most important crops, yet they could not be grown commercially in the United States without the genes provided by wild relatives (Harlan, 1984). Rice grown in Asia is protected from the four main rice diseases by genes provided by a single wild species from India. In both Africa and India, yields of cassava—one of the most important crops throughout the tropics—have been increased up to 18 times because of the disease resistance provided by genes from wild Brazilian cassava. Disease resistance provided by wild Asian species of sugarcane have saved the sugarcane industry in the southeastern United States from total collapse (Prescott-Allen and Prescott-Allen, 1983). Perennial corn, discovered by Guzmán in Mexico in 1977, has proven to be immune or resistant to the seven major diseases of domesticated corn (Witt, 1985). Although the use of wild and semidomesticated relatives is already extensive, it will undoubtedly increase in the near future because of the wider availability of these plants and the growing documentation of their potential utility (Frankel, 1983; Prescott-Allen and Prescott-Allen, 1983). Rapid advances in genetic engineering will also provide greater access to certain gene pools, which can now only be taken advantage of with special techniques (Frankel, 1983). Following are some good examples of the types of plants that may prove useful for future breeding purposes: Coffee (Coffea spp.; family Rubiaceae) is a mainstay of the economy of several tropical countries, yet it is rather susceptible to certain fungal diseases. Although Africa is home to most commercial species (particularly C. arabica from Ethiopia), the island of Madagascar has approximately 50 wild species of Coffea. Some of these species may prove important for commercial breeding not only for their potential resistance to fungal infections but also because they produce beans with little or no caffeine (Guillaumet, 1984; Plotkin et al., 1985). Two wild species of potatoes (Solanum spp.; family Solanaceae) have leaves that produce a sticky substance that traps predatory insects, which subsequently
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BioDiversity die of starvation. This type of self-defense could conceivably reduce or negate the need for using pesticides on cultivated potatoes (Gibson, 1979; Harlan, 1984). Formerly one of the most important timber trees of western coastal Ecuador, Persea theobromifolia, also called Caryodaphnopsis theobromifolia (family Lauraceae) has been pushed to the very brink of extinction by overexploitation. When it was finally described in 1979, it was found to be a relative of the common avocado (Persea americana) and might one day prove useful as rot-resistant root graft stock for the cultivated species (Gentry and Wettach, 1986). NATURAL PESTICIDES Many tropical plants have developed chemical defenses to deter predation by herbivorous animals. Tropical people possess a sophisticated knowledge of these plants, often using them as medicines or poisons. The calabar bean (Physostigma venenosum) was traditionally used as an ordeal poison in West Africa, and studies of the active principle of this species led to the development of methyl carbamate insecticides. World trade in daisy flowers (Chrysanthemum cinerariaefolium), the source of insecticidal pyrethrum extracts, is a multimillion dollar business (Oldfield, 1984). This plant was first discovered because of its use by African tribal peoples to control insect pests. South American Indians use Lonchocarpus, a forest vine, as a poison to stun fish. Today we import the roots of this plant as a source of rotenone, a biodegradable pesticide. Other plants used by tribal people as fish poisons have yet to be evaluated for their potential as pesticides. Plants used to make arrow poisons or curares also bear looking into, since one such species, Chondrodendron tomentosum already provides us with d-tubocurarine—an anesthetic administered during abdominal surgery. Not only do we need to investigate the individual components used in the manufacture of the many different types of curare but we must also study the interactions among different species that are sometimes used together. In the northeast Amazon, the preparation of an arrow poison may involve the mixing of seven different species, and the Indians insist that each plant changes and amplifies the toxicity of the poison. Yet another category of potentially useful natural pesticides are allelochemicals. These are chemicals produced by plants that inhibit the growth of other plants and of soil microorganisms. Allelochemicals include a number of different types of chemicals and may one day be used directly or serve as models for seminatural or wholly synthetic compounds (Balandrin et al., 1985). Species that might prove useful as sources of biodegradable pesticides in the future include the following: Piquiá (Caryocar spp.; family Caryocaraceae). One Amazonian species of Caryocar produces a compound that seems to be toxic to the dreaded leaf-cutter ant (Atta spp.). This insect is the scourge of South American agriculture, causing millions of dollars of damage each year. Guaraná (Paullinia cupana; family Sapindaceae). This woody vine is native to central Brazil. It is grown on plantations near Manaus for use in Brazilian soft
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BioDiversity drinks. Guaraná contains three times as much caffeine as does coffee, and recent tests at Harvard have shown that caffeine and some synthetic analogs can kill or inhibit the growth of mosquitoes and other insects (J.Nathanson, Harvard, personal communication, 1986). Should further testing prove caffeine to be an effective insecticide, guaraná could become a major crop throughout the tropics. INDUSTRY Development of native indigenous plants, particularly with reference to tropical and subtropical soils, will be beneficial at a variety of economies of scale. In some instances, their development will be small and amenable to utilization by individual farmers or farming groups. On the other hand, there will be instances where development will be large scale and have international implications. From McKell, 1980. During the Arab oil embargo of 1973, the U.S. community was faced not only with the loss of a major energy source but also with the loss of its most important raw material for the manufacture of innumerable synthetic products. Few realize how many of our everyday products are made from petroleum and petroleum by-products, such as plastics, fertilizers, lubricants, and adhesives, to name only a few. It has recently been estimated that almost one-fifth of the petroleum used in this country is devoted to industrial nonfuel purposes (White, 1979). Between 1973 and 1976, the annual use of petroleum-based chemicals in the United States was more than 100 billion pounds (Princen, 1977), yet the majority of these substances can now be synthesized from plant products (Wang and Huffman, 1981). These so-called botanochemicals are destined to become increasingly important as raw materials for industry. Until 1985, the reasons for reducing our dependence on fossil fuels were obvious. At present, the price of oil has dropped sharply, and there are those who believe that the heyday of the OPEC cartel is over. Nonetheless, experts disagree sharply about predictions of future price trends for petroleum. Since oil is a nonrenewable resource, and since the largest reserves lie in one of the most politically unstable regions of the world, we should try to reduce our dependence on petroleum whenever it is economically feasible. FATS AND OILS Approximately 3 million tons of vegetable fats and oils are used each year in the manufacture of coatings, lubricants, plasticizers, and many other products (Prescott-Allen and Prescott-Allen, 1982). In the past, industrial usage of these vegetable products has suffered from competition with cheap synthetic petroleum products (Wang and Huffman, 1981), but this trend is expected to change due to the uncertainty about the future of the petroleum market. Between 1973 and 1981, the price of petrochemicals increased more than 700%, whereas that of vegetable oils rose less than 100% (Prescott-Allen and Prescott-Allen, 1982). Even in the industrialized world, commercial demand for oils for use as a food and in industry continues to grow, and demand often exceeds supply (Schultes, 1979).
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BioDiversity The supply of edible oils is seriously inadequate to meet human nutrition requirements, especially in underdeveloped tropical regions. However, several tropical forest species have been used by tribal peoples as sources of edible oils for thousands of years. These oils contain vitamins and minerals and are necessary for cooking in areas where butter or lard are either unavailable or in short supply. There has been little attempt to domesticate some of these species, although ambitious efforts are under way in Brazil, Colombia, and Malaysia (M.Balick, New York Botanical Garden, personal communication, 1986). Domestication would increase yield, lower production costs, and reduce or eliminate characteristics that might inhibit harvesting on a commercial scale while providing a steady supply of edible and/or industrial oils. Some of these plants, e.g., bacabá (Oenocarpus bacaba) and patauá (Jessenia bataua), can grow in both the forest and on semiforested plantations and thus seem to be potential crop species of great importance in the tropics. Some of the more promising tropical oil plants include the following: The patauá palm (Jessenia bataua; family Palmae). The patauá palm grows to a height of 20 meters and is found in the lowlands of tropical South America. The oil of the fruit is almost identical to olive oil in its chemical and physical properties, and the biological value of its protein is almost 40% higher than that of soybean protein (Balick, 1985; Balick and Gershoff, 1981). The babassú palm (Orbignya spp.; family Palmae). The South American babassú palm may reach 60 meters in height. A single tree may produce up to a half ton of a fruit that resembles the coconut, although babassú has a higher oil content. This oil can be refined into an edible oil or used to make plastics, detergents, soap, margarine, and shortening. The seedcake is 27% protein and is an excellent fertilizer and animal feed. Its ability to colonize and thrive in deforested areas makes it an ideal species for turning degraded areas into productive lands (Balick, 1985; Schultes, 1979). The vine (Fevillea; family Cucurbitaceae). Seeds of the fruits of these vines have a higher oil content than that of any other dicotyledenous plant. Gentry and Wettach (1986) theorized that if naturally occurring lianas in a rain forest were cut and replaced by Fevillea, a per-acre oil yield comparable to those obtained in the most productive plantations might be obtained without felling a single tree. FIBERS Fiber plants are second only to food plants in terms of their usefulness to humans and their influence on the advancement of civilization. Tropical people use plant fibers for housing, clothing, hammocks, nets, baskets, fishing lines, and bowstrings. Even in our industrialized society, we use a wide variety of natural plant fibers: for ropes, brooms, brushes, and baskets. In fact the so-called synthetic fibers now providing much of our clothing are only reconstituted cellulose of plant origin. [Cellulose is produced in far greater quantities by the world’s plants than any other organic compound—up to 3 billion tons a day, according to R.E.Schultes of the Harvard Botanical Museum (personal communication, 1986)]. Several trees in
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BioDiversity tropical South America could be exploited for the fiber that they produce; their commercial potential is, at this point, unrealized. Promising species include: The tucúm palm (Astrocaryum tucuma; family Palmae). The tucum palm reaches a height of 20 meters and is native to the western Amazon. Its fiber is considered to be among the finest and most durable of the plant kingdom and is highly valued by Amazonian Indians. Furthermore, the tucúm produces an edible palm heart and a fruit that contains three times more vitamin A than do carrots (Balick, 1985; Schultes, 1977). Rattans (Demoncus spp.; family Palmae). Rattans are climbing palms native to the Asian tropics. Trade in rattan end products amounts to more than $1 billion a year. Unable to afford imported rattan, Peruvian peasants have begun to use Demoncus, a local climbing palm that has proven to be a very satisfactory substitute (A.Gentry, Missouri Botanical Garden, personal communication, 1986). THE ROLE OF THE ETHNOBOTANIST Tropical forest peoples are the key to understanding, utilizing, and protecting tropical plant diversity. Virtually every plant mentioned in this paper—not only the lesser-known species like the tucum palm and the buriti but also the well-known ones like corn and chocolate—were first discovered and utilized by indigenous peoples. Although it may come as a surprise to many that modern botanists are learning about useful plants from primitive peoples (the science known as ethnobotany), we are in fact just getting started. A single tribe of Amazonian Indians may use more than 100 different species of plants for medicinal purposes alone, yet very few tribal populations have been subjected to a complete ethnobotanical analysis and the need to do so becomes more urgent with each passing year. As we struggle to protect the dwindling tropical rain forest and find new and useful plant species for the benefit of modern human beings, the people who best understand these forests are dying out. More than 90 different Amazonian tribes are said to have disappeared since the turn of the century (G.Prance, New York Botanical Garden, personal communication, 1986). Through extinction and tribal acculturation, true forest peoples are dying out, and their oral traditions are disappearing with them. Each time a medicine man dies, it is as if a library has burned down. Conservationists often talk about the problem of disappearing species, but the knowledge of how to use these species is disappearing much faster than the species themselves. In order to collect this information, we need to expand ethnobotanical field research. Organizations like the World Wildlife Fund and the National Geographic Society, together with leading botanical institutes like the Harvard Botanical Museum, the New York Botanical Garden, and the Missouri Botanical Garden, are working to document ethnobotanical lore (Figure 11–1). The results of this type of research are not only lists of useful species but also data on potentially useful wild and cultivated varieties as well as ecological information on how to best utilize tropical ecosystems in a sustainable manner. The collection of this type of information, combined with expanded programs bringing some of the more
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BioDiversity promising species into cultivation, will eventually enrich our diets, and reduce our overdependence on current crop species and nonrenewable industrial materials. REFERENCES Balandrin, M., J.Klocke, F.E.Wurtele, and W.Bollinger. 1985. Natural plant chemicals: Sources of industrial and medicinal materials. Science 228:1154–1160. Balick, M. 1985. Useful plants of Amazonia: A resource of global importance. Pp. 339–368 in G. Prance and R.Lovejoy, eds. Key Environments—Amazonia. Pergamon Press, Oxford. Balick, M., and S.Gershoff. 1981. Nutritional evaluation of Jessenia bataua: Source of high quality protein and oil from Tropical America. Econ. Bot. 35(3):261–271. Caufield, C. 1982. Tropical Moist Forests: The Resource, the People, the Threat. International Institute for Environment and Development, London. 67 pp. Frankel, O. 1983. Genetic principles of in-situ preservation of plant resources. Pp. 55–65 in S.Jain and K.Mehra, eds. Conservation of Tropical Plant Resources. Proceedings of the Regional Workshop on Conservation of Tropical Plant Resources in South’East Asia, New Delhi, March 8–12, 1982. Botanical Survey of India, Howrah. Gentry, A., and R.Wettach. 1986. Fevillea—A new oil seed from Amazonian Peru. Econ. Bot. 40(2):177–185. Gibson, R. 1979. The geographical distribution, inheritance and pest-resisting properties of stick-tipped foliar hairs on potato species. Potato Res. 22:223–236. Guillaumet, J.L. 1984. The vegetation: An extraordinary diversity. Pp. 27–54 in A.Jolly, P. Ogberle, and R.Albignac, eds. Key Environments—Madagascar. Pergamon Press, Oxford. Harlan, J. 1984. Evaluation of wild relatives of crop plants. Pp. 212–222 in J.Holden and J.Williams, eds. Crop Genetic Resources: Conservation and Evaluation. Allen and Anwin, London. Heiser, C. 1985. Ethnobotany of the naranjilla (Solanum quitoense) and its relatives. Econ. Bot. 39(1):4–11. IUCN (International Union for the Conservation of Nature). 1980. World Conservation Strategy. International Union for the Conservation of Nature, Gland, Switzerland. 55 pp. McKell, C.M. 1980. Native plants: An innovative approach to increasing tropical food production. Pp. 349–382 in Background Papers for Innovative Biological Technologies for Lesser Developed Countries. Office of Technology Assessment, Washington, D.C. NRC (National Research Council). 1975. Underexploited Tropical Plants with Promising Economic Value. National Academy of Sciences, Washington, D.C. 187 pp. NRC (National Research Council). 1984. Amaranth: Modern Prospects for an Ancient Crop. National Academy Press, Washington, D.C. 76 pp. Oldfield, M. 1984. The Value of Conserving Genetic Resources. U.S. Department of the Interior, National Park Service, Washington, D.C. 360 pp. Plotkin, M., V.Randrianasolo, L.Sussman, and N.Marshall. 1985. Ethnobotany in Madagascar. Report submitted to the International Union for the Conservation of Nature, Merges, Switzerland. 657 pp. Prance, G. 1982. The increased importance of ethnobotany and underexploited plants in a changing Amazon. Pp. 129–136 in J.Hemming, ed. Change in the Amazon Basin. Vol. I: Man’s Impact on Forests and Rivers. Manchester Press, Manchester. Prescott-Allen, R., and C.Prescott-Allen. 1982. What’s Wildlife Worth? Economic Contributions of Wild Plants and Animals to Developing Countries. International Institute for Environment and Development, London. 92 pp. Prescott-Allen, R., and C. Prescott-Allen. 1983. Genes from the Wild. Using Genetic Resources for Food and Raw Materials. International Institute for Environment and Development, London. 101 pp. Princen, L. 1977. Potential wealth in new crops: Research and development. Pp. 134–148 in D. Siegler, ed. Crop Resources. Proceedings of the 17th Annual Meeting of the Society for Economic Botany, the University of Illinois, Urbana, June 13–17, 1976. Academic Press, New York. Schultes, R.E., 1977. Promising structural fiber palms of the Colombian Amazon. Principes 21(2):72–82. Schultes, R.E. 1979. The Amazonia as a source of new economic plants. Econ. Bot. 33(3):259–266.
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BioDiversity Tyler, V. 1986. Plant drugs in the twenty-first century. Econ. Bot. 40(3):279–288. Vietmeyer, N. 1986a. Exotic edibles are altering America’s diet and agriculture. Smithsonian 16(9):34–43. Vietmeyer, N. 1986b. Lesser-known plants of potential use in agriculture and forestry. Science 232:1379–1384. Wang, S., and J.B.Huffman. 1981. Botanochemicals: Supplements to petrochemicals. Econ. Bot. 35(4):369–382. White, J. 1979. The growing dependency of wood products on adhesives and other chemicals. For. Prod. J. 29:14–20. Witt, S. 1985. Biotechnology and Genetic Diversity. California Agricultural Lands Project, San Francisco. 145 pp.
Representative terms from entire chapter: