Klyza, Christopher McGrory, and David J. Sousa. American Environmental Policy, 1990-2006: Beyond Gridlock. Cambridge, Mass.: MIT Press, 2008. Landy, Marc Karnis, Marc J. Roberts, and Stephen R. Thomas. TheEnvironmental ProtectionAgency: Asking the Wrong Questions from Nixon to Clinton. New York: Oxford University Press, 1994. McMahon, Robert. The Environmental Protection Agency: Structuring Motivation in a Green Bureaucracy— the Conflict Between Regulatory Style and Cultural Identity. Portland, Oreg.: Sussex Academic Press, 2006. Portney, Paul R., and Robert N. Stavins, eds. Public Pol- icies for Environmental Protection. 2d ed. Washington, D.C.: Resources for the Future, 2000. Rosenbaum, WalterA.Environmental Politics and Policy. 7th ed. Washington, D.C.: CQ Press, 2008. Samuel, Peter. Lead Astray: Inside an EPA Superfund Di- saster. San Francisco: Pacific Research Institute, 2002. Yeager, Peter Cleary. The Limits of Law: The Public Regu- lation of Private Pollution. New York: Cambridge University Press, 1991. Web Site U.S. Environmental Protection Agency http://www.epa.gov See also: Carbon; Clean Air Act; Clean WaterAct; Cli- mate Change and Sustainable Energy Act; Ecosystem services; Endangered species; Environment and Nat- ural Resources Division; Environmental impact state- ment; Environmental law in the United States; Haz- ardous waste disposal; National Environmental Policy Act; Superfund legislation and cleanup activities; United Nations Convention on Long-Range Trans- boundary Air Pollution; Watt, James. Erosion and erosion control Category: Environment, conservation, and resource management Erosion is the gradual wearing away of the land sur- face by natural agents of water, wind, and ice. Eroded sediments are a major water pollutant. The land is de - graded because the soil that remainsis of lower produc - tivity, and the sediment may damage crops or aquatic environments. Therefore, the control of erosion is an important soil conservation and water quality protec- tion practice. Background Erosion is a natural process in which water, wind, and ice remove soil particles from the land surface and re- deposit them somewhere else. Sediment pollution is the water pollutant comprising the largest volume or mass. Erosion also causes the soil to be less productive because the remaining soil is more coarsely textured and of lower fertility. Nutrients and pesticides can be released from eroded sediments into streams and lakes. There are three erosion processes: detachment, transportation, and deposition. Detachment is the re- moval of soil particles from the soil mass. Transporta- tion carries detached particles away from the soil mass. The distance can be a few centimeters or hun- dreds of kilometers. After the soil is transported, the particles are then redeposited somewhere else (depo- sition). Classification of Erosion Erosion can be classified in a number of ways. Geo- logical erosion is the natural, slow rate of erosion that occurs when the land is protected by its native vegeta- tion. Rates are in the range of grams to a few kilo- grams per hectare per year. This kind of erosion is responsible for many important present-day land for- mations. Accelerated erosion is the rapid erosion that occurs when the native vegetation is removed. These rates are in the range of metric tons per hectare per year. The two most important agents of accelerated ero- sion are water and wind. Kinds of water erosion are raindrop splash, sheet, rill, and gully erosion. Rain- drop splash occurs when raindrops strike soil particles and dislodge them from the rest of the soil mass. Falling raindrops have considerable kinetic energy and can easily dislodge particles from bare soils. In sheet erosion a thin layer of soil is removed fairly uni- formly across the land surface. Rill erosion occurs when small channels (rills) forminthesoil. These rills are usually parallel to one another, are narrow and shallow, and can be easily removed by ordinary tillage and cultivation practices. Rill erosion is responsible for the greatestquantities of soil loss. Gully erosion oc - curs when deep, wide channels form that cannot be removed by ordinary tillage and cultivation practices. 398 • Erosion and erosion control Global Resources It is the most spectacular because the gullies are easily seen. Wind erosion is classified according to the way the soil particles are transported. Surface creep is a roll- ing of large particles across the surface. Saltation is a bouncing of intermediate-sized particles and is re- sponsible for the largest amount of erosion by wind. Suspension occurs when small particles are picked up by the wind and carried long distances. It is the most spectacular because the resulting dust cloud is easily seen. Erosion damage occurs both on-site and off-site. On-site damage occurs because the eroded land is de- graded by the removal of the most productive parts of the soil. The eroded parts are usually finer textured and higher in organic matter than the remaining parts. The soil that is left behind is usually coarser textured. Off-site damage occurs because the trans- ported soil causes damage somewhere else. Examples are smothered crops, decreased storage of drinking water reservoirs, and the filling in of harbors. Sedi - ment also drastically alters the aquatic life of rivers and lakes. The costs for correcting some of these off- site effects are usually borne by society. Erosion Control Strategies for erosion control involve preventing de- tachment or encouraging deposition before the soil travels veryfar.The most effectiveand cheapest meth- ods of erosion control are to keep the soil in place and reduce water runoff. Erosion control methods may be divided into cultural practices and mechanical con- trol. Cultural practices include cropping rotations, tillage methods, and residue management. Mechani- cal control includes terraces,sediment control basins, and silt fences. A guiding principle in erosion control is to keep the soil covered, either with growing vegeta- tion or with the remains of vegetation in the form of mulch. Another principle is to shorten the slope length. Reducing the steepness of a slope is not prac- tical. Erosion control in farming includes contouring, whereby all tillage, planting, and harvesting opera - tions are done across the slope instead of up and Global Resources Erosion and erosion control • 399 Following a June, 2008, flood, this cornfield in Indiana suffered significant erosion. (AP/Wide World Photos) down the slope. This practice is most effective for gen - tle slopes, with a gradient of between 2 and 6 percent. Strip cropping is alternately planting a strip of a row crop such as corn,soybeans, or cotton and then a strip of a close-growing crop such as small grain or forage. Field strip cropping is planting the strips straight and parallel without regard to the slope. Contour strip cropping, planting the strips across the contour of the slope, will provide erosion control for steeper slopes up to about 18 percent. Terraces are constructed channels across a slope that reduce the slope length. The channel is at a slight grade so the water is re- moved slowly and safely. Terraces may be cropped or in permanent vegetation. Grassed waterways are vegetated channels con- structed where water would cause a gully. The chan- nel is at a slight grade; the grass stabilizes the soil. A water and sediment control basin is a riser pipe con- nected to a subsurface drain. A small dam and an ori- fice plate in the riser pipe allow the water to pond for no more than twenty-four hours, which allows sedi- mentation before the water enters the riser pipe. Con- servation tillage is a method of planting crops in which last year’s old crop residue (in the form of straw, stalks, and so on) is not completely incorpo- rated into the soil but instead is left on the surface as a mulch. At least 30 percent of the soil surface must be covered by residue to qualify as conservation tillage. No-till is a form of conservation tillage where the crop is planted without any previous tillage. Special plant- ing equipment is necessary in order to plant through the crop residue. Weed pests are controlled by herbi- cides rather than by cultivation. No-till is very effective at reducing soil loss. Erosion control for developments and construction sites includes saving existing vegetation and disturb- ing only as much land as can be reasonably developed in a few months. Other methods include temporary seedings, straw mulch, sedimentation basins, silt fences (plastic sheets staked into the ground), and straw bales staked in erosive channels. Tom L. Zimmerman Further Reading Blanco-Canqui, Humberto, and Lal Rattan. Principles of Soil Conservation and Management. London: Springer, 2008. Brady, Nyle C., and Ray R. Weil. The Nature and Prop - erties of Soils. 14th ed. Upper Saddle River, N.J.: Prentice Hall, 2008. Montgomery, David R. Dirt: The Erosion of Civilizations. Berkeley: University of California Press, 2007. Morgan, R. P. C. Soil Erosion and Conservation.3ded. Malden, Mass.: Blackwell, 2005. Schwab, Glenn O., Delmar D. Fangmeier, and Wil- liam J. Elliot. Soil and Water Management Systems. 4th ed. New York: Wiley, 1996. Toy, Terrence J., George R. Foster, and Kenneth G. Renard. Soil Erosion: Processes, Prediction, Measure- ment, and Control. New York: John Wiley & Sons, 2002. Web Sites School of Geography, Queen’s University Belfast, Northern Ireland Soil Erosion Site http://soilerosion.net U.S. Department of Agriculture Soil Quality Resource Concerns: Soil Erosion http://soils.usda.gov/SQI/publications/files/ sq_two_1.pdf U.S. Geological Survey Erosion http://www.usgs.gov/science/ science.php?term=353 See also: Conservation; Deforestation; Dust Bowl; Environmental degradation, resource exploitation and; Farmland; Land management; Soil; Soil man- agement. Ethanol Categories: Products from resources; plant and animal resources Where Found Ethanol, a biofuel, is produced by carbohydrate fer- mentation processes, hydration of ethylene, and, to a lesser extent, reduction of acetaldehyde obtained from acetylene. Primary Uses Ethanol—also known as ethyl alcohol, grain alcohol, or spirits—has traditionally found many uses in the chemical industry: for the preparation of numerous esters vital to many polymer industries, for the pro - 400 • Ethanol Global Resources duction of diethyl ether (also called ether or ethyl ether), and as a major solvent and extractant. How- ever, it has been best known for thousands of years as the primary alcohol component in alcoholic bever- ages and, since the 1970’s, as a potentially significant source of transportation fuel, either as a gasoline re- placement or as a blend fuel stretching available pe- troleum supplies. Technical Definition Ethanol is a colorless liquid with a mild and character- istic aroma and taste. It has a boiling point of 78.3° Celsius and a melting point of −114.5° Celsius. At 20° Celsius it has a density of 0.7894 gram per milliliter and a refractive index of 1.3614. Its molar mass is 46.07 grams. Ethanol is completely soluble in water and most organic solvents. It has a flash point of 8° Celsius and is thus highly flammable. Description, Distribution, and Forms Alcohol obtained from fermentationprocesses is gen- erally included with other fermentation products and extracts from the carbohydrate-rich grains, fruits, and so on that are the raw materials for the multitudinous alcoholic beverages produced and consumed on Earth. Alcohol produced by yeast fermentation is ob- tained at a maximum concentration of 14 percent; therefore, alcoholic beverages other than beer and nonfortified wines require the addition of concen- trated alcohol, which is obtained by distilling dilute alcohol from the fermentation of molasses and other sugar sources. In the United States and other highly industrialized countries, the alcohol added to bever- ages has increasingly been produced by other methods. Ethanol is also used in largequantitiesforchemical synthesis in the organic chemical industry. It is used for the preparation of numerous esters vital to many polymer industries and for the production of diethyl ether (also called ether or ethyl ether), a major sol- vent and extractant. Other synthetic procedures lead to the manufacture of acetaldehyde, acetic acid, ethyl halides, and acetonitrile, which are in turn employed for the preparation of drugs, explosives, adhesives, pesticides, detergents, synthetic fibers, and other sub- stances. Ethanol itself is used in vast quantities as an extractant or solvent. For some time, ethanol has been added to gasoline in winter to reduce air pollution, an advantage of eth - anol that has been viewed as particularly valuable since the Kyoto Protocol (1997) and other interna - tional agreements obligated their signors to reduce the carbon emissions associated with internal com- bustion engines. Thus, the United States and other oil-importing countries have frequently explored and, to some degree, pursued the “gasohol” option of com- bining ethanol with varying amounts of gasoline. History The fermentationof various fruitsandother products of the soil into drinking alcohol can produce pleasant tastes and, in the minds of people throughout the globe and for a very long partof history, a pleasurable effect. Based on archaeological discoveries, there is evidence of alcoholic imbibing as early as the sixth century b.c.e. Historically, ethanol has been used as a home fuel source, albeit more recently than as a beverage. In the 1820’s, for example, a blend of ethanol and turpen- tine was utilized as lamp fuel in the majority of Ameri- can homes. Subsequently, natural gas and electricity displaced ethanol in home use in the United States and Europe, but it is still used in rural areas of the de- veloping world for lighting and cooking. It is also widely employed as a part of everyday life in American and European homes as rubbing alcohol and as a sol- vent in chemical products. Ethanol was used to power cars—especially in West- ern Europe—well before the Model T rolled off the first assembly line in 1908, driven by a motor based on an 1860 internal combustion engine developed in Germany to run on ethanol. However, before the first Model T was produced, the discovery of oil in the United States in the 1880’s and the high tax that Con- gress enacted on industrial alcohol during the Civil War had combined to render the production of etha- nol for transportation purposes both uneconomical and unnecessary. Both the Prohibition era in the United States (1919-1933), which tainted the home production of ethanol for fuel purposes as “closet moonshining,” and the discovery of deep pools of cheap oil in the Middle East during the period be- tween World War I and World War II pushed ethanol further off the market as a source of transportation fuel until the 1973 energy crisis. Obtaining Ethanol Beverage alcohol is produced from a great variety of sources, including grains, potatoes, and fruit, but fer - mentation-based industrial alcohol is almost entirely Global Resources Ethanol • 401 obtained by yeast fermentation of molasses. Molasses (50 percent sucrose residue from sugar processing or cornstarch) is diluted with water to approximately 15 percent and under slightly acidic conditions is fer- mented by yeast to give 14 percent ethanol. Fractional distillation of the solution yields the commercial product: 95 percent ethanol. Approximately 9 liters of blackstrap molasses are needed to make 3.785 liters of 190-proof ethanol. Although ethylene hydration was known in the early part of the nineteenth century, it did not be- come an industrial process until 1929; today, it is the dominant method of producing ethanol. Ethylene, obtained from the thermal cracking of petroleum fractions or from natural gas separation processes, is treated with complex phosphoric acid-based catalysts at temperatures above 300° Celsius and steam at pres- sures of thousands of kilograms per square centime- ter. The ethanol can be fractionally distilled, and the residual ethylene can be recycled. Ethylene can also be passed into concentrated sulfuric acid, and after hydrolysis, the ethanol can be distilled from the diluted sulfuric acid. Uses of Ethanol Despite ethanol’s importance in the produc- tion of alcoholic beverages and its continued employment in various sectors of the chemi- cal industry, its utility as a means of reducing petroleum dependency has commanded the most commentary and controversy since 1973, when Arab states embargoed oil ship- ments to countries supporting Israel in the Yom Kippur War. Whether corn or sugarcane is used as eth- anol’s feedstock, concern exists that the ex- panded cultivation of both of these crops will greatly increase both air and water pollution. The indictment is especially levied against corn, because its cultivation requires the most pesticides and insecticides of any crop grown in the United States. The “pesticide cock- tail”—composed of four weed killers, three insecticides, and two fungicides—produces a toxic effect known to kill wildlife, and its runoff damages subsoil streams and, hence, threatens U.S. supply of drinking water. In- creasing the production of ethanol increases environmental costs. So too does burning it in internal combustion engines, in which— depending on the gasohol mixture of ethanol and petroleum—ethanol fuels can produce more than twice as much ground ozone as gasoline. Meanwhile, in the short term, reallocating existing corn produc- tion to meet a growing demand for ethanol inflates the cost of corn and of everything depending on it. This includes the price of corn-fed beef, milk drawn from corn-feddairy cows, and the powdered milk that the United States exports to meet nourishment needs in poor countries of the developing world. Nonethe- less, the United States, which has subsidized biofuels since 1978, is committed, under its Energy Indepen- dence and Security Act of 2007, to the goal of produc- ing 136 billion liters of ethanol by 2022—a fourfold increase over the amount produced in 2008. Issues also exist concerning the actual fuel savings available from an E90 (10 percent ethanol, 90 percent petroleum) gasohol mixture used in the United States. Planting and harvesting corn and processing it into ethanol involve significant use of fuel, which has to be considered in assessing overall petroleum sav - 402 • Ethanol Global Resources A worker in Brazil harvests sugarcane, which can be used to produce ethanol fuel. (AP/Wide World Photos) ings through the widespread use of ethanol-petroleum solutions as gasoline. There is also the issue of kilometers-per-liter savings in ethanol versus conven- tional gasoline. Ethanol burns cleaner than tradi- tional gasoline in terms of carbon gases, but it also burns faster, meaning that it requires more energy to provide the same energy output as its fossil-fuel kin. Brazil has evaded these efficiency issues by utilizing sugarcane harvested by cheap labor as its feedstock and by mandating the sale after 2007 of only flexible fuel vehicles (FFVs) capable of burning fuels con- taining very high levels of ethanol (up to 85 percent ethanol and beyond). Consequently, coupled with its domestic oil production, Brazil has become indepen- dent of foreign oil. For other countries, and especially those locked into E90 or even E85 mixtures, concerns over actual fuel savings as well as environmental dam- age from the use of corn-and sugarcane- derived etha- nol continue to linger. In the democratic world of pluralistic bargaining in public policy, these feedstocks that have nonetheless been favored over the use of switchgrass and other cel- lulosic sources of ethanol in the production of gaso- line, despite the two to three times greater reduction in greenhouse gases possible by using cellulosic biofuels. Existing internal-combustion-engine automobiles and trucks can run, without major modifications, on E85, so the automotive industry has had reasons to support the development of the fuel, especially when alterna- tives have involved government mandates to retool to produce solar- or electric-powered cars. The petro- leum industry, too, supports ethanol, which will main- tain the demand for petroleum, as opposed to alterna- tive energy technologies in the transportation field, in which more than one-half of all petroleum used in the United States is consumed. Above all, agricultural states with an interest in reviving their sagging agricul- tural communities and the large farming corporations that own most farming land in the United States have had reason to lobby diligently on behalf of the ethanol industry. Thus, whenever the focus has been on the high cost of imported fuels or reducing carbon emis- sions associated with automobile use, bills requiring the use of corn-based ethanol have been introduced in the U.S. Congress and have been enacted into law. William J. Wasserman, updated by Joseph R. Rudolph, Jr. Further Reading Blume, David. Alcohol Can Be a Gas! Fueling an Ethanol Revolution for the Twenty-first Century. Santa Cruz, Calif.: International Institute for Ecological Agri - culture, 2007. Boudreaux, Terry. Ethanol and Biodiesel: What You Need to Know. McLean, Va.: Hart Energy, 2007. Brune, Michael. Coming Clean: Breaking America’s Ad- diction to Oil and Coal. San Francisco: Sierra Club Books, 2008. Freudenberger, Richard. Alcohol Fuel: A Guide to Mak- ing and Using Ethanol as a Renewable Fuel. Gabriola Island, B.C.: New Society, 2009. Goettemoeller, Jeffrey, and Adrian Goettemoeller. Sus- tainable Ethanol: Biofuels, Biorefineries, Cellulosic Bio- mass, Flex-Fuel Vehicles, and Sustainable Farming for En- ergyIndependence.Maryville, Mo.: Prairie Oak, 2007. Minteer, Shelley, ed. Alcoholic Fuels. Boca Raton, Fla.: CRC/Taylor & Francis, 2006. Mousdale, David M. Biofuels: Biotechnology, Chemistry, and Sustainable Development. Boca Raton, Fla.: CRC Press, 2008. Pahl, Greg. Biodiesel: Growing a New Energy Economy.2d ed. White River Junction, Vt.: Chelsea Green,2008. Paul, J. K., ed. Ethyl Alcohol Production and Use as a Motor Fuel. Park Ridge, N.J.: Noyes Data, 1979. Rothman, Harry, Rod Greenshields, and Francisco Rosillo Callé. Energy from Alcohol: The Brazilian Expe- rience. Lexington: University Press of Kentucky, 1983. Shaffer, Brenda. Energy Politics. Philadelphia: Univer- sity of Pennsylvania Press, 2009. Web Sites Alternative Fuels and Advanced Vehicles Data Center, U.S. Department of Energy Ethanol http://www.afdc.energy.gov/afdc/ethanol/ index.html Economic Research Service, U.S. Department of Agriculture Ethanol Expansion in the United States: How Will the Agricultural Sector Adjust? http://www.ers.usda.gov/Publications/FDS/2007/ 05May/FDS07D01/fds07D01.pdf See also: Biofuels; Brazil; Corn; Energy economics; Energy Policy Act; Gasoline and other petroleum fu- els; Internal combustion engine; Oil and natural gas chemistry; Peak oil; Petrochemical products; Petro- leum refining and processing; Plant domestication and breeding; Resources for the Future; Synthetic Fuels Corporation. Global Resources Ethanol • 403 European Union Natura 2000 Categories: Laws and conventions; organizations, agencies, and programs Date: Birds Directive, April 2, 1979; Habitats Directive, May 21, 1992 Natura 2000 was established to protect endangered species and regions in the European Union. Background The geography of the European Union includes nine different biogeographical regions. This largediversity of European ecosystems and landscapes offers a vari- ety of different habitats for fauna and flora: arctic and high-alpine rocks and glaciers, areas of moderate cli- mate, marine ecosystems, and arid areas and deserts. Estimates indicate that more than 40 percent of mam- mals, 15 percent of bird species, and 45 percent of reptiles in Europe are endangered or threatened. While policies for environmental protection and nature conservation in protected areas have a rather long history, environmental protection and nature conservation policies were not accounted for in the founding documents of the European Union, such as the Treaty of Rome (1958). At the beginning of the 1970’s, after the United Nations Conference on the Human Environment in Stockholm, the European Commission finally developed environmental policy programs. The Single European Act (1985) and, later, the Treaty of Amsterdam (1997) included environ- mental protection in the Europeantreaties. The Birds Directive, emphasizing the conservation of birds, was passed in 1979; however, the Habitats Directive, estab- lishing a European network of protected areas, was not established until 1992. Hence, the European Union’s Natura 2000 stipulations are part of the Euro- pean Union’s Sustainable Development Strategy and of the Environment Action Programme of the Euro- pean Community, the latter of which has multiple edi- tions. The importance of biodiversity conservation also has been widely acknowledged in many Euro- pean Union policies of other fields, such as in the Eu- ropean Spatial Planning Strategy and the Common Agricultural Policy. Provisions The Birds Directive and the Habitats Directive can be considered the fundamental documents of joint Eu - ropean Union nature conservation policies. The Hab - itats Directive is based on two policies. A network of protected areas (Natura 2000 network) has been es- tablished in all member countries, and a strict frame- work for species conservation has been instituted. In- dividual member countries are no longer free to decide which nature conservation policies should be pursued if the ecosystems or species endangered or threatened are of community interest. However, all member states established their own legal regulations regarding nature conservation much earlier than the joint European framework. The Habitats Directive aims at maintaining biodi- versity by means of a common framework for the con- servation of wildlife (fauna and flora) and of habitats of community interest. Member states are obliged to protect “special protection areas” (SPAs) and “sites of community interest” (SCIs). The directive includes several appendixes where biodiversity elements of community interest are listed, such as natural habi- tats, animal and plant species, and the definition of “priority” or “strict protection” habitats and species. European Union member countries who find habitats or species of community interest on their territoryare obliged to set up conservation areas and management plans and to report to the European Commission about the concrete conservation policies. For in- stance, SPAs (Natura 2000 sites) are established based on the annex of the Habitats Directive, reported by the member state to the European Commission, which includes the site in a list of habitats of commu- nity interest. When this has been done, the area is es- tablished as protected. Failure of any EU member country to report sites of community interest is sub- ject to chargesbefore the European Court of Justice. An important provision of Natura 2000 is that member states are obliged to guarantee that habitats of community interest are conserved and any deterio- ration of the habitat is avoided. Member states also have to initiate the management of landscapes and habitats of special importance for the migration, dis- persal, and genetic exchange of wildlife; establish strict protection of threatened fauna and flora; ex- plore possibilities of reintroducing extinct wildlife; and prevent the nonselective taking, killing, or cap- turing of wildlife listed in the directive. Even if the member state does not formally establish a Natura 2000 site for a priority habitat or species, it is neverthe - less protected under European Union law. The Natura 2000 regulations not only provide for 404 • European Union Natura 2000 Global Resources the conservation of biodiversity but also establish the possibilities for co-financing conservation measures. Implementation of Natura 2000 is estimated to cost about 6.1 billion euros ($8.6 billion) per year. One of the financial instrumentssetup for co-financing is the “LIFE+ Nature and Biodiversity” program. It is specifi- cally designed to contribute to the implementation of Natura 2000 in member states and to support the es- tablishment and management of protected areas. The European Union and its member states are sig- natories of the Convention on Biological Diversity (CBD). The European Union has also committed it- self to the goal of halting biodiversity loss. In order to support this goal, the European Commission adopted a Biodiversity Action Plan in 2006, which followed earlier strategies such as the Biodiversity Strategy of 1998. The strategy encompasses the European Union’s commitment to conserving global biodiversity, ad- dressing issues of biodiversity and climate change, and implementing a comprehensive knowledge base regarding the conservation of biodiversity. Natura 2000 may serve as a nature conservation model for other parts of the world. Impact on Resource Use The Natura 2000 regulations are progressive in terms of their strict regulatory framework and the concept of establishing a consistent, coherent, and representa- tive European ecological network of protected areas. Furthermore, the number of sites set up is impressive. The following are based on 2008 figures: In terms of the Birds Directive, there are 5,044 SPAs covering an area of 517,896 square kilometers (10.5 percent of the area of the European Union and 531 marine sites cov- ering 66,084 square kilometers. The Habitats Direc- tive has 21,612 SCIs covering an area of 655,968 square kilometers (13.3 percent of the area of the Eu- ropean Union) and 1,294 marine sites covering an area of 87,505 square kilometers. However, the appli- cation of the directives in the individual member states varies and ranges from around 7 percent of the national territory for SCIs (United Kingdom) up to 31.4 percent (Slovenia). While the Natura 2000 frameworks provide a coherent and strong basis for conserving biodiversity, they need to be implemented effectively in all member states. Many areas of com- munity interest are still “paper parks” without con- crete management plans or funds for administering the European Union directives’ requirements. The Biodiversity Action Plans, published assessments of the EU’s biodiversity policies, revealed that it was un- likely that the European Union would be able to meet its aims of halting biodiversity loss by 2010. Policies therefore have to concentrate on the finalization of the Natura 2000 network, provide adequate financial resourcesfor establishing and managing the sites, and implement the necessary action and management plans in the member countries. Of specific impor- tance in this context is the support of Natura 2000 sites in the new European Union member countries in Central and Eastern Europe that significantly con- tribute to the natural endowment of the European Union. Funding programs for capacity building is im- portant because the management of protected areas is an emerging interdisciplinary professional field. Michael Getzner Further Reading Bromley, Peter. Nature Conservation in Europe: Policy and Practice. New York: Spon, 1997. European Communities. The European Union’s Biodi- versity Action Plan: Halting the Loss of Biodiversity by 2010—and Beyond. Luxembourg: Office for Offi- cial Publications of the European Communities, 2008. Keulartz, Jozef, and Gilbert Leistra, eds. Legitimacy in European Nature Conservation Policy: Case Studies in Multilevel Governance. New York: Springer, 2008. Rosa, H. D., and J. M. Silva. “From Environmental Eth- ics to Nature Conservation Policy: Natura 2000 and the Burden of Proof.” Journal of Agricultural and En- vironmental Ethics 18, no. 2 (2005): 107-130. Web Sites Eionet The European Topic Centre on Biological Diversity http://biodiversity.eionet.europa.eu/ European Commission Nature and Biodiversity http://ec.europa.eu/environment/nature/ index_en.htm See also: Austria; Belgium; Biodiversity; Denmark; Endangered species; France; Germany; Greece; Italy; The Netherlands; Norway; Poland; Portugal; Spain; Sweden; United Kingdom. Global Resources European Union Natura 2000 • 405 Eutrophication Category: Pollution and waste disposal Eutrophication is the overenrichment of water by nutri- ents; it causes excessive plant growth and stagnation, which leads to the death of other aquatic life such as fish. Definition The word “eutrophic” comes from the Greek eu, which means “good” or “well,” and trophikos, which means “food” or “nutrition.” Eutrophic waters are well nour- ished and rich in nutrients; they support abundant life. Eutrophication refers to a condition in aquatic systems (ponds, lakes, and streams) in which nutrients are so abundant that plants and algae grow uncontrol- lably and become a problem. The plants die and de- compose, and the water becomes stagnant. This ulti- mately causes the death of other aquatic animals, particularly fish, that cannot tolerate such conditions. Eutrophication is a major problem in watersheds and waterways such as the Great Lakes and Chesapeake Bay that are surrounded by urban populations. Overview The stagnation that occurs during eutrophication is attributable to the activity of microorganisms growing on the dead and dying plant material in water. As they decompose the plant material, microbes con- sume oxygen faster than it can be resupplied by the at- mosphere. Fish, which need oxygen in the water to breathe, become starved for oxygen and suffocate. In addition, noxious gases such as hydrogen sulfide (H 2 S) can be released during the decay of the plant material. The hallmark of a eutrophic environment is one that is plant-filled, littered with dead aquatic life, and smelly. Eutrophication is actually a natural process that oc- curs as lakes age and fill with sediment, as deltas form, and as rivers seek new channels. The main concern with eutrophication in natural resource conservation is that human activity can accelerate the process and can cause it to occur in previously clean but nutrient- poor water. This is sometimes referred to as “cultural eutrophication.” For example, there is great concern with eutrophication in Lake Tahoe. Much of Lake Tahoe’s appeal is its crystal-clear water. However, de- velopment around Lake Tahoe is causing excess nu - trients to flow into the lake and damaging the very thing that attracts people to the lake. The nutrients that cause eutrophication usually come from surface runoff of soil and fertilizer associ- ated with mismanaged agriculture or from domestic and industrial wastes discharged into rivers and lakes. Phosphorus(P)and nitrogen (N) are two of the nutri- ents most limiting to plant growth in water. When they are supplied, plant growth can explode and eutrophi- cation can occur. Phosphorus was one of the major causes of eutrophication in Lake Erie during the 1960’s. Before preventative action was taken, the lake was considered to be dying. These preventative actions included banning phosphates from laundry detergent and imposing stricter conservation practices on farm- ers to reduce soil erosion in the watersheds draining into Lake Erie. Many areas now restrict the total amount of phosphorusthat can be applied to land that drains into waterways. Preventative action also forced sewage treatment facilities to start chemically remov- ing phosphorus from the water they discharged. As a result of these actions, phosphorus loading into Lake Erie was cut in half from the 1960’s to the early 1990’s; however, total phosphorus content in Lake Erie rose slightly over the subsequent decade and a half. Mark S. Coyne See also: Ecosystems; Erosion and erosion control; Lakes; Streams and rivers. Evaporites Category: Mineral and other nonliving resources Evaporites are sedimentary deposits of salt minerals that crystallize from marine and continental brines. Common evaporite minerals include halite (sodium chloride, or table salt), gypsum (hydrated calcium sul- fate), calcite (calcium carbonate), dolomite (calcium- magnesium carbonate), and various borate minerals. Definition Evaporites form in environments where evaporative water loss from a body of water exceeds, at least peri- odically, the rate of inflow to the body. Evaporites oc- cur in all the major continents; the most extensive de- posits are found in North and South America, Europe, and the Middle East. Notable North American locali - ties are the Michigan Basin and the Permian Basin of Texas and New Mexico. Most rock salt (halite) is mined 406 • Eutrophication Global Resources from evaporites, as is the gypsum used in wallboard and other constructionmaterials.Borate minerals are used in cleaning agents and in other industrial uses. Other evaporite minerals are important sources for industrial metals such as magnesium and strontium. Overview Evaporites are stratified sedimentary deposits consist- ing of minerals precipitated from salt brines (highly concentrated salt water). These deposits have formed on every continent and throughout geologic time, al- though the Silurian (438 to 408 million years ago) and Permian (286 to 248 million years ago) periods were the most prolific times of evaporite formation. In re- cent times evaporite deposition has been relatively rare. The chief factors influencing evaporite formation are aridity and a closed basin environment in which water inflow is restricted. High air temperatures gen- erally accompany these conditions, but this is not al- ways the case. For example, recent minor evaporites are known from the arid regions of Antarctica. Evaporite minerals crystallize from seawater in a certain order, depending on their relative solubilities. Calcite generally crystallizes first as the amount of water is reduced by evaporation. Gypsum follows, with halite precipitating when only about one tenth of the original solution is left. More soluble minerals crystal- lize in the final liquid, including sylvite (potassium chloride). This process produces concentrated crys- talline layers that consist of only one or two major minerals. World evaporite bodies can be divided into marine deposits, the thickest and most extensive in origin, and continental deposits. Marine evaporites may form in marginal lagoons closed off from the sea by a sandbar or other barrier. Another importantenviron- ment is the sabkha, a shallow margin of a sea or ocean in an extremely arid climate, as occurs, for example, in the Persian Gulf. Continental deposits most com- monly form in temporary desert lakes called playas. Evaporite minerals in playas are derived from streams that leach marine brines trapped in sedimentary rocks from surrounding mountains. Major evaporite localities in North America are the Michigan Basin (Salina deposits), the Permian Basin of Texas and New Mexico, the Midcontinent field cen- tered in Kansas and adjacent states, and the borate de- posits of Death Valley and adjacent areas. The first three of these localities are mostly known for halite and gypsum production. They are primarily marine deposits formed in shallow continental seas during Si- lurian times (Michigan Basin) or during the Permian period (Permian Basin and Midcontinent). The Death Valley area is famous for its borate deposits, minerals that were deposited in playas. John L. Berkley See also: Borax; Boron; Carbonate minerals; Deserts; Gypsum; Limestone; Magnesium; Oceans; Salt; Salt domes; Sedimentary processes, rocks, and mineral deposits; Strontium; Water. Exclusive economic zones Category: Government and resources Date: December 10, 1982 Although the concept of a conservation zone off na- tional coasts was not new, the exclusive economic zone (EEZ), created by the United Nations Convention on the Law of the Sea, was a legal and political achieve- ment because it was the result of a consensus by all the world’s states. Background Part V of the United Nations Convention on the Law of the Sea of December 10, 1982, established the ex - clusive economic zone of a coastal state as “an area be - yond and adjacent to the territorial sea” which is un - Global Resources Exclusive economic zones • 407 Gypsum-selenite is one example of an evaporite. (USGS) . according to the way the soil particles are transported. Surface creep is a roll- ing of large particles across the surface. Saltation is a bouncing of intermediate-sized particles and is re- sponsible. damage occurs both on-site and off-site. On-site damage occurs because the eroded land is de- graded by the removal of the most productive parts of the soil. The eroded parts are usually finer textured and. storage of drinking water reservoirs, and the filling in of harbors. Sedi - ment also drastically alters the aquatic life of rivers and lakes. The costs for correcting some of these off- site