Background As early as 1789, naturalists such as Gilbert White de- scribed the many sequences of animals eating plants, and animals being eaten by other animals. However, the use of the term “food chain” dates from 1927, when Charles S. Elton described the implications of the food chain and food web concept in a clear man- ner.His solid exposition advanced the study of two im- portant biological concepts: the complex organiza- tion and interrelatedness of nature, and energy flow through ecosystems. Food Chains in Ecosystem Description Stephen AlfredForbes,founderofthe Illinois Natural History Survey, contended in 1887 that a lake com- prises a system in which no organism or process can be understood unless its relationship to all the parts is understood. Forty years later, Elton’s food chains pro- vided an accurate way to diagram these relationships. Since most organisms feed on several fooditems,food chains were cross-linked into complex webs with pre- dictive power. For instance, algae in a lake might sup- port an insect that in turn is food for bluegill. If unfa- vorable conditions eliminate this algae, the insect might also disappear. However, the bluegill, which feeds on a wider range of insects, survives because the loss of this algae merely increases the pressure on the other food sources. This detailed linkage of food chains advanced agriculture and wildlife management and gave scientists a solid overview of living systems. When Arthur G. Tansley penned the term “ecosys- tem” in 1939, it was food-chain relationships that de- scribed much of the equilibrium of the ecosystem. Most people still think of food chains as the basis for the “balance of nature.” This phrase dates from the controversial 1960 work of Nelson G. Hairston, Frederick E. Smith, and Lawrence B. Slobodkin. They proposed that if only grazers and plants are present, grazing limits the plants. However, with predators present, grazers are limited by predation, and the plants are free to grow to the limits of the nutrients available. Such explanations of the “balance of nature” were commonly taught in biology books throughout the 1960’s and 1970’s. Food Chains in Production Biology Elton’sexplanation of food chains came only one year after Edgar Nelson Transeau of Ohio State University presented his calculations on the efficiency with which corn plants converted sunlight into plant tissue. Ecol - ogists traced this flow of stored chemical energy up the food chain to herbivores that ate plants and on to carnivores that ate herbivores. Food chains therefore undergirded the new “production biology” that placed all organisms at various trophic levels and calculated the extent to which energy was lost or preserved as it passed up the food chain. With data accumulating from many ecologists, Elton extended food chains into a pyramid of num- bers. The food pyramid in which much plant tissue supports some herbivores that are in turn eaten by fewer carnivores is stillreferred to as an“Eltonian pyr- amid.” In 1939, August Thienemann added “decom- posers” to reduce unconsumed tissues and return the nutrients of all levels back to the plants. Early pyra- mids were basedontheamountof living tissues or bio- mass. Calculations based on the amount of chemical en- ergy at each level, as measured by the heat released (calories) when food is burned, provided even more accurate budgets. Because so much energy is lost at each stage in a food chain, it became obvious that this inefficiency is the reason food chains are rarely more than five or sixlinkslongand why large, fierce animals are uncommon. It also became evident that because the Earth intercepts a limited amount of sunlight en- ergy per year, there is a limit on the amount of plant life—and ultimately upon the amount of animal life and decomposers—that can be fed. Food chains are also important in the accounting of carbon, nitrogen, and water cycling. Value of Food Chains in Environmental Science Unlike calories, which are dramatically reduced at each step in a food chain, some toxic substances be- come more concentrated as the molecules are passed along. The concentration of molecules along the food chain was first noticed by the Atomic Energy Commis- sion, which found that radioactive iodine and stron- tium released in the Columbia River was concentrated in tissue of birds and fish. However, the pesticide dichloro-diphenyl-trichloroethane (DDT) provided the most notorious example of biological magnifica- tion: DDT was found to be deposited in animal body fat in ever-increasing concentrations as it moved up the food chain to ospreys, pelicans, and peregrine falcons. High levels of DDT in these birds broke down steroid hormones and interfered with eggshell formation. Because humans are omnivores able to feed at sev - 448 • Food chain Global Resources eral levels on the food chain, it has been suggested that a higherworld population could be supported by humans moving down the food chain and becoming only vegetarians. A problem with this argument isthat much grazing land worldwide is unfit for cultivation, and therefore the cessation of pig or cattle farming does not necessarily free up substantial land to grow crops. While the food chain and food web concepts are convenient theoretical ways to summarize feeding in- teractions among organisms, real field situations have proved far more complex and difficult to measure. Animals often switch diets between larval and adult stages, and they are often able to shift food sources widely. In real life, it is often difficult to draw the boundaries of food chains and food webs. John Richard Schrock Further Reading Colinvaux, Paul. “The Efficiency of Life.” In Why Big Fierce Animals Are Rare: An Ecologist’s Perspective. Princeton, N.J.: Princeton University Press, 1978. Golley, Frank Benjamin. A History of the Ecosystem Con- cept in Ecology: More than the Sum ofthe Parts. New Ha- ven, Conn.: Yale University Press, 1993. Lowenfels, Jeff, and Wayne Lewis. Teaming with Mi- crobes: A Gardener’s Guide to the Soil Food Web. Port- land, Oreg.: Timber Press, 2006. Pimm, Stuart L. Food Webs. New York: Chapman and Hall, 1982. Reprint. Chicago: University of Chi- cago Press, 2002. Rooney, N., K. S. McCann, and D. L. G. Noakes, eds. From Energetics to Ecosystems: The Dynamics and Struc- ture of Ecological Systems. Dordrecht, the Nether- lands: Springer, 2007. Schilthuizen, Menno. The Loom of Life: Unravelling Eco- systems. Berlin: Springer, 2008. See also: Biosphere; Carbon cycle; Ecology; Ecosys- tems; Lithosphere; Nitrogen cycle; Phosphorus cycle; Sulfur cycle. Food shortages Category: Social, economic, and political issues Throughout human history, civilizations have been plagued by malnutrition, hunger, and famine. The growth of the human population, the ecological disas - ters the world is facing, and continued warfare and civil strife have all been named as contributors to the problem in modern times. Background The procurement of food is one of the necessities of all societies. For thousands of years this was accom- plished by hunting and gathering. While people were able to find and to use a variety of types of food, they were not always able to acquire the items they needed in the quantities that were required. With the onset of the agricultural revolution and the advent of orga- nized farming, the problem was alleviated to a certain extent. Individuals and societies had more control over what their food supply might be at a given time. While this fact did not eradicate the problems caused by natural disasters that could destroy food sources, it did help to mitigate those catastrophes. Other important developments were the scientific and technological advances that occurred beginning in the sixteenth century. The results of this scientific progress were applied to agricultural endeavors,med- ical practice, and industry. The knowledge gleaned from science enabled farmers togrow additional crops and to increase the productivity of the land on which they grew them. The advances in medical science in- creasedthelifeexpectancy of people and thuscreated additional demands for the foodstuffs that were pro- duced. The Industrial Revolution also led to the in- vention of fuels and machines. These fuels provided the energy to run the factories that created farm equipment and machinery. They later served as a source of energy for farm equipment. Population By 2009, the global population was approximately 6.8 billion. Very poor people continue to have large fami- lies for a variety of cultural and religious reasons. Large families provide labor; in some countries chil- dren asyoungassix years of age are part of the family’s labor pool. Besides providing more income, having many family members may mean more clout in com- munity affairs. Extra children also provide additional hands to care for parents in their old age. It would be tempting simply to blame the problem of food shortages on the world’s increasing popula- tion, but population increase alone is by no means re - sponsible for the hunger that exists in the world. Rather, food shortages are caused by a combination of Global Resources Food shortages • 449 450 • Food shortages Global Resources 8070605040302010 Source: United Nations, Millennium Development Goals Indicators, 2009. Congo, Democratic Republic of the Eritrea Burundi Haiti Comoros Sierra Leone Angola Ethiopia Zambia Central African Republic Liberia Rwanda Zimbabwe Chad Mozambique Madagascar Togo Tanzania Tajikistan Djibouti Guinea-Bissau Kenya North Korea Yemen Gambia 76 68 63 58 52 47 46 46 45 43 40 40 40 39 38 37 37 35 34 32 32 32 32 32 30 Undernourished Population (%) World’s Hungriest Nations, 2004 elements that contribute to block access to the tools that would enable people or cultural groups to break the cycle of hunger. Extent and Causes of Hunger Estimates indicate that at least one billion people are hungry at any given time. Almost sixteen thousand children die of hunger-related diseases each day. Mal- nutrition, or not getting the proper nutrients, is one of these related syndromes. Malnutrition often leads to other diseases, such as goiter, as is the case in Ban- gladesh, where people have great iodine deficiencies. Pellagra, another malnutrition-related disease, is caused by a lack of the amino acid tryptophan. Pellagra is found in countries where the diet consists mainly of maize and jowah, a type of sorghum eaten mainly in India. Nutritional blind- ness also is a side effect of malnutrition. Infantile marasmus and kwashiorkor are two protein-deficiency diseases that cause lethargy, edema, and a number of other medical problems. These are brought on by a lack of protein in the diet and are prevalent in West Africa. One of the easiest methods of ascer- taining the extent of hunger worldwide is to examine infantmortality rates. Incoun- tries where hunger is greatest, the infant mortality rate tends to be high. It is often as high as 50 deaths per every 1,000 births; in Angola, the infantmortality rate is 180. In developed countries, in contrast, the rate is far lower. Singapore has the lowest rate at 2.31. In less developed countries, the infant mortality rate averages 90 per 1,000; in more developed countries it av- erages 8. (In all countries the rate varies from area to area.) The developed, or highly industrialized, countries are able to feed their own populations and gener- ally have additional supplies of food to send to other nations. Developing coun- tries, however, include more than two- thirds of the world’s population and ac- count for more than 90 percent of the hunger that exists in the world. Estimates indicate that 14 to 18 million people die each year from hunger. The World Health Organization states that more than 820 million people in developing countries suffer from malnutrition. There are a number of explanations for hunger throughout the world.Many experts believethat hun- ger arises not so much from overpopulation as from the inequitable distribution of food supplies. In other words, a small number of people are responsible for the production of food and are obliged to apportion it to the world. Political scientist Susan George argues this viewpoint and states that it is not only the ineffec- tive or inequitable distribution of food that leads to hunger; in addition, the inequitable income distri- Global Resources Food shortages • 451 Women in Pakistan buy rice discounted for Ramadan. The reduced price of the rice is a humanitarian gesture by the government of a country beset by food shortages. (Mohsin Raza/Reuters/Landov) bution among the peoples ofthe worldleads tothe in - ability to purchase food. Poverty leads to hunger, and the causes of poverty throughout the world are many. Large numbers of people are poor because they have no access to land or to themeans of production. Many people have no way to earn a living, and many are forced to migrate to other places—which often offer no relief for theirsuffering. Hunger occurswhen there are societal dislocations; Arline T. Golkin summarizes these as “disorders in food production, distribution, earning capacity, medical care, and levels of develop- ment.” Hunger exists in rich nations as well as poor. Environmental factors such as soil erosion, defor- estation, and desertification lead to a diminution of farmland, a situation that eventually leads to food shortages and hunger. Deforestation leads to the wash- ing away of soil. Forests are often destroyed toprovide fuel; in other cases, forests are reduced or washed away completely by flooding. The Food and Agricul- ture Organization of the United Nations estimates that some 70 percent of global drylands, which are 30 percent of the globe, are already degraded, with much of the farmland becoming desert annually. De- sertification is caused by periods of exceptional dry- ness in an already tenuous climate. Desertification is found in a number of African countries as well as in Russia, Ecuador, Nepal, and other nations. For all these reasons there is a shortage of usable farmland, which translates into hunger as a chronic condition for millions of people throughout the world. When hunger persists in a region for an extended period of time and leads to increased mortality from disease or starvation, famine exists. These periods can last for several years, and often more than a food shortage is involved. Major famines have occurred throughout history. Since 1970, famines have occurred in Ethiopia, Nigeria, the Democratic Republic of the Congo, Sudan, the Sahel region in northern Africa, and North Korea. In Ethiopia, the cause was drought. In the Democratic Republic of the Congo and Nige- ria, civil war was primarily responsible. Frequently, a famine is indicative of many underlying structural malfunctions within a society. A long and deep reces- sion inarural area, for example,cancause dislocation in employment, income, andproduction. The people who are most subject to displacement by this process are those who own no land, artisans, and those who trade in goods and services. In times of famine, people are unable to pay for ar - tisans’ services and products. As John Osgood Field states, “famine occurs not only because a chain of events disposes to a famine outcome but also because nothing, or at least nothing effective, is done to break the process.” Most of the countries that are subject to famine do not have the resources with which to break the cycle of famine, and often the ecosystem is out of balance in a number of ways. While societal problems may lead to famines,they can also be the outgrowth of famines. When groups of people suffer from famine, they frequently migrate elsewhere if they are able; they then become part of the throng of people in overcrowded cities. The result can be significant num- bers of people hoarding, huge increases in the price of food, and concomitant violence. Judy Arlis Chesen Further Reading Bennett, Jon. The Hunger Machine: The Politics of Food. New York: Polity Press in association with B. Black- well, 1987. Devereux, Stephen, ed. The New Famines: Why Famines Persist in an Era of Globalization. New York: Rout- ledge, 2007. Field, John Osgood, ed. The Challenge of Famine: Recent Experience, Lessons Learned. West Hartford, Conn.: Kumarian Press, 1993. George, Susan. How the Other Half Dies: The Real Rea- sons for World Hunger. New York: Penguin, 1976. George, Susan, and Nigel Paige. Food for Beginners. New York: W. W. Norton, 1982. Golkin, Arline T. Famine, a Heritage of Hunger: A Guide to Issues and References. Claremont, Calif.: Regina Books, 1987. Patel, Rajeev. Stuffed and Starved: Markets, Power, and the Hidden Battle for the World Food System. Toronto: HarperCollins, 2007. Roberts, Paul. The End of Food. Boston: Houghton Miff- lin, 2008. Southgate, Douglas, Douglas H. Graham, and Luther Tweeten. The World Food Economy. Malden, Mass.: Blackwell, 2007. Stanford, Claire, ed. World Hunger. Bronx, N.Y.: H. W. Wilson, 2007. See also: Desertification; Developing countries; Drought; Earth First!; Earth Summit; Environmental degradation, resource exploitation and; Green Revo- lution; Land ethic; Land-use regulation and control; United Nations Convention to Combat Desertifica - tion. 452 • Food shortages Global Resources Ford, Henry Category: People Born: July 30, 1863; Springwells township (now Dearborn), Michigan Died: April 7, 1947; Dearborn, Michigan The “automobile age” of the twentieth century owes its existence largely to Henry Ford’s vision of the automo- bile as a utility vehicle for the masses rather than as a wealthy individual’s luxury. Ford’s development of the Model T instituted some of the greatest and most rapid changes in the history of modern civilization. Biographical Background Henry Ford’s conception of mass-produced automo- biles manufactured at a rapid rate changed the world’s concept of crucial resources. An American inventor, world-famous industrialist, and technologi- cal genius, Ford learned about internal combustion engines when he was nineteen. In 1896, he built his first “horseless carriage,” the four-horsepower Quad- ricycle. In 1899, he formed the Detroit Automobile Company (later reorganized as the Henry Ford Com- pany) and built several racing cars, including the “999.” Ford left the Detroit Automobile Company to start the Ford Motor Company, which was incorporated in 1903. The company’s first automobile on the market was the Model A, built in 1903. Realizing the Model A was not the car that he believed the United States needed, he declared, “I will build a motor car for the great multitude.” In October, 1908, he announced the birth of the Model T, an automobile that was built with the most advanced production technology con- ceived to thatpoint.Thecar arrived on the market the following year. The establishment of a constantly moving main production line in Highland Park, Michigan, that eventually reduced the assembly time of a car from twelve hours to one and one-half was the cause of the spectacular success of the Model T, of which nearly seventeen million were sold over a period of nineteen years. It took a number of years to perfect this assem- bly line. Ford’s production methods were intensively studied. In 1914, afterthe Model T was asuccess, Ford startled the world by announcing a $5 daily wage (compared with an average of $2.34). Ford established small village factories and built schools that emphasized vocational training. His hold- ings eventually went into the Ford Foundation, the richest private foundation in the world. Henry Ford worked intuitively, and he spent most of his life mak- ing headlines, both positive and negative. Impact on Resource Use Without the twenty-four-hour assembly line and its utilization in thecreation of millions of affordable au- tomobiles, resourcessuchas petroleum, rubber (both natural and artificial), and the metalsusedto produce automotive components would not have the impor- tance they do in contemporary society. Ford’s influ- ence reached far beyond the automotive world, in that other industries adapted his efficient assembly- line technique to their own needs. Mysore Narayanan See also: Gasoline and other petroleum fuels; Inter - nal combustion engine; Oil industry; Rockefeller, John D.; Rubber, natural; Steel. Global Resources Ford, Henry • 453 Henry Ford’s technological contribution to the transportation in- dustry helped generate America’s love affair with the automobile. (Library of Congress) Forest fires Category: Environment, conservation, and resource management Forest fires can be natural or caused by humans. They destroy life and property and devastate thousands of hectares, but they are also vital to the health of the forest. Background Evidence of forest fires is routinely found in soil sam- ples and treeborings.The first major North American fires in the historical record were the Miramichi and Piscataquis fires of 1825. Together, they burned more than 1 million hectares in Maine and New Brunswick. Other U.S. fires of significance were the Peshtigo fire in 1871, which raged over 500,000 hectares and took fourteen hundred livesin Wisconsin; the fire that dev- astated northern Idaho and northwestern Montana in 1910 and killed at least seventy-nine firefighters; a series of fires that joined forces to sweepacross a third of YellowstoneNationalParkin1988;and the “Station Fire” of 2009, the largest in the history of Los Angeles County. Fire Behavior Fires need heat, fuel, and oxygen. They spread hori- zontally by igniting particles at their edge. At first, flames burn at one point, then move outward, accu- mulating enough heat to keep burning on their own. Topography and weather affect fire behavior. Fires go uphill faster thandownhill because warm air rises and preheats the uphill fuels. Vegetation on south- and west-facing slopes receives more sunlight and so is drier and burns more easily. Steep, narrow canyons will pull heat up them like a chimney, increasing heat intensity. For several reasons, only one-third of the vegeta- tion within a large fire usually burns. This mosaic ef- fect may be caused by variedtree species that burn dif- ferently, old burns that stop fire, strong winds that blow the fire to the leeward side of trees, and varied fuel moisture. Forest Management One of the early criteria of forest management was fire protection. In the second quarter of the twentieth century, lookout towers, firebreaks, and trails were built to locate fires as quickly as possible. Low fires that typically wouldhave burned through the forest at ground level and cleared out brush every five to twenty-five years were suppressed. As a result, the nat- ural cycle of frequent fires moving through an area was broken. Fallen trees, needles, cones, and other debris collected as kindling on the forest floor rather than being incinerated every few years. It took foresters and ecologists fifty years to realize that too much fire suppression was as bad as too little. Accumulated kindling burns hot and fast and ex- plodes into treetops. The result is a devastating crown fire, a large fire thatadvances as a single front. Burning embers of seed cones, as well as sparks borne by hot, strong winds created within the fire, are tossed into unburned areas to start more fires. In the 1970’s, prescribed burning was added to forest management techniques used to keep forests healthy. Fires set by lightning are allowed to burn when the weather is cool, the area isolated, and the risk of the fire exploding into a major fire low. More than 70 percent of prescribed burning takes place in the southeastern states, where natural fires would burn through an area more frequently than in the West. Causes of Fires Forest fires may becaused bynatural events or human activity. Most natural fires are started by lightning strikes. Dozens of strikes can be recorded from one lightning storm. When a strike seems likely, fire spot- ters watch for columns of smoke, and small spotter planes will fly over the area looking for smoke. Many of the small fires simply smolder and go out, but if the forest is dry because of drought or any period of hot, dry weather, multiple fires can erupt from a single lightning storm. The majority of forest fires are human-caused, and most are the result of carelessness rather than arson. Careless campers may leave a campsite without squelching their campfire completely, and winds may then whip the glowing embers into flames; a smoker may toss a cigarette butt from a car window; sparks from a flat tire riding on the hub may set fire to vegeta- tion alongside the highway; and the Sun shining through a piece of broken glass left by litterers may ig- nite dry leaves. Prescribed fires may be natural or human-caused. In some areas they are set in an attempt to re-create the natural sequence of fire, as in Florida, where 454 • Forest fires Global Resources prescribed burns provide wildlife habitat and open up groves to encourage healthy growth. Other pre- scribed fires start accidentally but are allowed to burn until they reach a predetermined size. Benefits of Fire Some tree species require very high temperatures for their seed casings to split for germination. When fire periodically sweeps through the forest, seeds will ger- minate. Other species, such as the fire-resistant pon- derosa pine, require a shallow layer of decaying vege- table matter in which to root. Fires burn excess debris and small trees of competing species, leaving an open environment suitable for germination. Dead material on the forest floor is processed into nutrients more quickly by fire than by decay, and in a layer of rich soil, plants will sprout within days to replace those de- stroyed in the fire, thus providing feed for wildlife. Fire intervals vary. Without human intervention, spacious ponderosa pine forests will burn every five to twenty-five years. Lodgepole pine, which grows in dense stands, will burn every two hundred to four hundred years. Southern pines, if fire is not sup- pressed, are cleared every three to five years. Disadvantages Erosion is one of the devastating effects of a fire. If the fuels burn hot, tree oils and resins can be baked into the soil, creating a hard shell that will not absorb water. When it rains, the water runoff gathers mud and debris, creating flash floods and extreme stream sedimentation. Culverts and storm drains fill with silt, and streams flood and change course. Fish habitat isdestroyed, veg- etation sheltering stream banks is ripped away, and property many kilo- meters downstream from the forest is affected. When a fire passes through tim- ber, it generally leaves pockets of green, although weakened, stands. Forest pests such as the bark beetle are attracted to theburned trees and soon move to the surviving trees, weakening them further and destroy- ing them. Healthy trees outside the burn area may also fall to pest infes - tation unless the burned trees are salvaged before pests can take hold. The ash and smoke from hot, fast-burning forest fires can be trans- ported for kilometers, affecting the air quality of cities many kilometers from the actual fire. Relationship to Timber Resources Although a prescribed fire is an attempt to duplicate natural fire, it is not as efficient, because private and commercial property within the fire path must be pro- tected. Once a fire has occurred, burned timber dete- riorates quickly, through either insect infestation or blueing—a mold that stains the wood. Private land- owners can move quickly to salvage fire-damaged trees and plant new seedlings to harness erosion. On federal land, regulations governing the salvage of trees can delay loggingof theburned snags untildete- rioration makes it uneconomical to harvest them. Fire Fighting Bulldozers are used to cut fire lines ahead of the ap- proaching fire,andfuelsbetween this line and the fire are backburned. Helicopters and tanker planes drop water with a fire-retardant additive or bentonite, a clay, at the head of the fire to smother fuels. Fire- fighters are equipped with fire shelters in the form of aluminized pup tents, which they can pull over them- selves if a fire outruns them. Despitetechnological ad- vances, one of the best tools for fighting fires—along Global Resources Forest fires • 455 A firefighter gives directions as a backfire is set during the devastating Station Fire that burned uncontrollably in the Los Angeles National Forest during the summer of 2009. (AP/Wide World Photos) with the shovel—remains the Pulaski, a combination ax and hoe, first produced commercially in 1920. This tool, in the hands of on-the-ground firefighters, is used to cut firebreaks and to throwdirt on smoldering debris. Public Policy and Public Awareness Beginning in the early twentieth century, forest fires engendered public policy. In the aftermath of major fires in 1903 and 1908 in Maine and New York, state fire organizations and private timber protective asso- ciations were formed toprovide fire protection. These, in turn, contributed to the Weeks Act of 1911, which permitted cooperative fire protection between fed- eral and state governments. People who make their homes in woodland set- tings in or near forests face the danger of forest fire, and government agencies provide information to help the public safeguard themselves and their property. Homes near forests should be designed and land- scaped with fire safety in mind, using fire-resistant, noncombustible materials on the roof and exterior. Landscaping should include a clear safety zone around the house, and hardwood trees, less flamma- ble than conifers, should be planted. Jill A. Cooper Further Reading Carle, David. Burning Questions: America’s Fight with Nature’s Fire. Westport, Conn.: Praeger, 2002. Fuller, Margaret. Forest Fires: An Introduction to Wild- land Fire Behavior, Management, Firefighting, and Pre- vention. New York: Wiley, 1991. Omi, Philip N. Forest Fires: A Reference Handbook. Santa Barbara, Calif.: ABC-CLIO, 2005. Pyne, Stephen J. Awful Splendour: A Fire History of Can- ada. Vancouver: Universityof British ColumbiaPress, 2007. _______. Fire in America: A Cultural History of Wildland and Rural Fire. 1982. Reprint. Princeton, N.J.: Princeton University Press, 1988. _______. Smokechasing. Tucson: University of Arizona Press, 2003. Rothman, Hal K. Blazing Heritage: A History ofWildland Fire in the National Parks. New York: Oxford Univer- sity Press, 2007. Wuerthner, George, ed. The Wildfire Reader: A Century of Failed Forest Policy.Washington, D.C.: IslandPress, 2006. Web Site National Interagency Fire Center Fire Information: Wildland Fire Statistics http://www.nifc.gov/fire_info/fire_stats.htm See also: Erosion and erosion control; Fires; Forest management; Forestry. Forest management Category: Environment, conservation, and resource management Forest management is theprocessof planning, organiz- ing, and implementing activities designed to produce and maintain a mix of resources in the forest that will meet the goals and objectives of landowners and so- ciety. Background In 1967, the Society of American Foresters defined forestry as “the science, the art, and the practice of managing and using for humanbenefitthenaturalre- sources that occur on and in association with for- estlands.” In 1971, the same organization redefined forest management as “generally, the application of scientific, economic, and social principles to the ad- ministration and working of a forest estate for speci- fied objectives” and “more particularly, the branch of forestry concerned with a) the overall administrative, economic, legal, and social aspects, and b)with the es- sentially scientific and technical aspects, especially silviculture, protection, and forest regulation.” Forests include or provide many things of value to humans: water, wildlife, grazing, timber, and recre- ation. Forest structure and composition can be de- signed to produce different mixtures of these things; one aspect of forest management is the determina- tion of the mixture of goods and services that will best satisfy the goals and objectives of landowners and soci- ety. Forest managers have the responsibility to plan, schedule, and implement activities in the forest to achieve the management objectives. Silviculture Ralph Nyland, in Silviculture: Concepts and Applications (2d ed., 2001), defines silviculture as “the science and art of growing and tending forest crops” and particu - 456 • Forest management Global Resources larly as “the theory and practice of controlling the es- tablishment, composition, character, and growth of forest stands to satisfy specific objectives.” Silviculture is distinct from forest management. Forest manage- ment is concerned with the establishment of manage- ment goals and objectives and the administrative ac- tivity to support the achievement of these goals, while silviculture is concerned with the detailed prescrip- tions forindividualforest management units required to achieve the goals set for the larger area. The types of resources to emphasize and the mix of goods and services to produce are forest management decisions; specific measures to achieve these goals and the devel - opment of prescriptions for individual areas are the province of silviculture. Protection Forest protection is the branch of forestry concerned with minimizing damage to forests from both abiotic and biotic factors. Abiotic factorssuch as wind,floods, and fire can directly kill trees and affect the achieve- ment of management goals. Biotic factors such as pests, pathogens, herbivores, livestock, and humans also affect tree mortality and health. The amount and type of material and human resources to allocate to fire protection, for example, are management deci- sions. Forest management is concerned with the allo- cation of financial, material, and human resources to manage all of these risk factors in such a way as to bal - ance the costsof control measures with thebenefits of maintaining forest health and productivity. Global Resources Forest management • 457 Environmental Effects of Select Silvicultural Methods Silvicultural methodsLong-term effects Short-term effects Converting mixed forest stands to monoculture Soil acidification Fertilizing Increased leaching of nutrients, especially nitrogen Forest machines leave the residues in heaps, often on wet sites Clear-cutting Increased water runoffSoil erosion Soil scarification Draining Increased amount of organic material and metals (Fe, Al, Hg) in water and ecosystems; secondary effects on fish Decreased number of plant and animal species of the forests, mires, and fens Short rotation intervals Decreased number of old and dead trees Foreign speciesDecreased number of forest plant and animal species Source: Bioenergy and the EnvironmentAdapted from I. Stjernquist, “Modern Wood Fuels,” in , edited by Pasztor and Kristoferson, 1990. . procurement of food is one of the necessities of all societies. For thousands of years this was accom- plished by hunting and gathering. While people were able to find and to use a variety of types of. process.” Most of the countries that are subject to famine do not have the resources with which to break the cycle of famine, and often the ecosystem is out of balance in a number of ways. While. distribution of food that leads to hunger; in addition, the inequitable income distri- Global Resources Food shortages • 451 Women in Pakistan buy rice discounted for Ramadan. The reduced price of the