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Interest Grabber continued

Section 6-1 Section 6-1

1. Choose an animal other than a human and describe at least two ways Leaving a Mark on the World in which it may change its environment.

Have you ever seen very old photographs of the town or city in which you now live? Has your area changed? Perhaps there are more buildings or 2. What events might have led to the changes that occurred in your town than there were many years ago. Maybe your town or city has more or city? trees and flowers now than it had years ago. Humans, like all , have an effect on their environment. 3. What positive effect have humans had on their environment? What negative effect have humans had on their environment?

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Section Outline

Section 6-1

6–1 A Changing Settling of Hawaii A. as an Island B. Human Activities • Hawaii was first settled 1600 years ago by the Polynesians. C. Hunting and Gathering • Polynesians were respectful for the limited that D. they had. 1. From Traditional to Modern Agriculture – Every palm tree that was cut down, two were planted in its 2. The Green Revolution place. 3. Challenges for the Future – They could not catch certain types of fish during the E. Industrial Growth and Urban Development spawning season. • However, their actions (Clearing for farmland and introducing nonnative and animals) caused major changes resulting in the extinction of native plants and animals.

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Hawaii today Earth as an Island

• In the late 1700’s, Americans, Europeans, and Asians began • The history of humans on Hawaii offers an important lesson for the to populate the Hawaiian Islands continuing to change the 21st century. ecosystems. • Consider Earth as an island. All living things must share the • Many native animals are becoming scarce. limited resources that are available for their survival. • Agricultural practices have seriously depleted drinking in certain areas. • has caused some fish to become very rare. • Important necessities including were Imported.

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1 Human Activities Hunting and Gathering

• Humans depend on certain ecological -support systems to • Our early ancestors obtained food by hunting and gathering. give us some basic needs such as , breathable • They hunted mammals and caught fish. air, and fertile . • They collected wild seeds, fruits, and nuts. •We need to be aware that our actions can change the local • These actions have been believed to cause mass extinction of and global environments. animals such as the woolly mammoth, giant ground sloth, and • Among human activities that affect the are hunting saber-tooth cats. and gathering, agriculture, industry and urban development.

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Hunting today Agriculture

• Some people still survive using • Early hunters and gatherers began to understand how plants grow. the hunting and gathering ways • About 11,000 years ago, they started the practice of farming, or of the past. These people make agriculture. little demands on the • Soon, people all over the world were growing , , and potatoes. environment. • The development of agriculture also included raising animals such as • These people are called sheep, goats, cows, pigs, and horses. subsistence hunters. • Agriculture was one of the most important developments in human history. • Most hunters today use • It provides humans with a dependable supply of food. modern technologies such as • Humans began to gather in larger settlements rather than search for food. guns, recreational vehicles, or manufactured goods.

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From Traditional to Modern Agriculture The Green Revolution

• Farmers gradually acquired machinery, • By the 1950’s, agriculture has come a long way from the primitive such as plows and seed drills, to help with techniques used in the past. cultivation. • However, there were still many food shortages in many parts of the world. • Exploration led to the exchange of crops around the world. • Governments and scientists began a major effort to increase food production in those countries. • In the 1800 and 1900’s, modern advances led to and machinery for plowing, • breeders developed highly productive “Miracle Strains” of wheat and planting, and harvesting that led to higher rice. yields of crops. • This effort came to be called the Green Revolution. • Farming techniques, such as (planting large fields with only one type of crop), , and also led to greater yields.

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2 Challenges for the Future Industrial Growth and Urban Development

• Although the advances in modern agriculture has increased our world • The major impact humans have caused on the biosphere occurred during food supply, major concerns for our environment have risen. the Industrial Revolution, which added many machines and factories. • Large scale monoculture can lead to problems with pests and disease. • Some advances include the ability to build the homes we live in, clothes • What will happen to a population of corn-eating insects in a large we wear, electronic devices, mass-production equipment, and field of corn? automobiles. • However, these things require to make and use. • The population of insects will grow rapidly. Farmers will be forced to increase the amount of pesticides used. • Most of this energy comes from fossil , coal, oil, and natural gas. • What effects will this have?

• Pesticides can damage beneficial insects, contaminate water supplies, and accumulate in the environment.

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Concept Map

Section 6-1

Human Industrial Growth and Urban Development Activities that have changed the biosphere include • For years, cities and industries discarded wastes from manufacturing, energy production, and other sources into our air, water, and . Hunting and Industrial Urban gathering Agriculture growth development • Meanwhile, the cities became crowded and people began to move to the may have once caused often relies on the methods of the suburbs. have resulted in • What effects could this cause to our ecosystem? Extinctions of Green large animals revolution High standard Increased of living pollution • Many ecologists are concerned with effects of human activity both locally which increased and globally. • pollute air, water, and soil. Dense human populations create wastes that must be disposed of. Suburban growth consumes Food supply use Monoculture use farmland and natural habitat.

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Interest Grabber Interest Grabber continued

Section 6-2 Section 6-2

1. Examine the list of natural resources shown below. Then, classify each natural as either renewable or nonrenewable. Where Do Natural Resources Come From? a. Natural resources are materials that are supplied by nature. A renewable b. Fossil fuels resource is one that is replaceable. A nonrenewable resource is one that c. Aluminum cannot be replenished by natural processes. Once a nonrenewable d. Wool e. Gold resource is used up, it is gone forever.

2. Describe the impact that the loss of nonrenewable resources would have on the environment.

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3 Section Outline

Section 6-2

Tale of the 6–2 Renewable and Nonrenewable Resources A. Classifying Resources • English villagers were able to graze their cattle in a pasture that all could B. use called the Commons. C. Resources • The people put as many cattle as they could afford on that land. D. Resources E. Resources • Eventually, there were more cattle than the pasture could supply food for. 1. Overfishing • The villagers didn’t care, because it wasn’t theirs to protect. 2. Sustainable Development • In the end, there were so many cattle that the commons were ruined 3. Aquaculture F. Air Resources G. Freshwater Resources • Today, environmentalists use the phrase,”” to describe resources that are available to everyone that may one day be destroyed. • Examples: ground water and fish

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Classifying Resources Sustainable Development

• Environmental goods and services may be classified as either • Sustainable Development: a way of using natural resources renewable or nonrenewable. without depleting them and of providing for human needs without • Renewable Resources: can regenerate if they are alive or can be causing long-term environmental harm. replenished by bio-chemical cycles if they are nonliving. • Human activities can affect the quality and supply of renewable • Example: and trees resources such as land, forests, , air, and fresh water. • Nonrenewable Resources: are one that cannot be replenished • Example: Using insects to control insect pests. by natural processes. • Examples: Fossil fuels

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Land Resources Midwest Prairie

• Land is a resource that provides space for human communities, • Produced and maintained a raw materials for industry, and soils in which crops are grown. meter or more of very fertile • Managed properly, soil is a renewable resource. topsoil. • Food crops grow best in fertile soils that include a mixture of sand, • Deep roots of grasses held soil clay, rock particles, and humus. in place against and . • Most humus is found in the upper most layer of soil called topsoil. • Plowing the land removed – Absorbs and retains moisture those roots which cause soil . – Allows excess water to drain. – Wearing away of surface – Rich in and low in salts soil by wind and rain.

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4 Desertification Forest Resources

• In certain parts of the world with • Forests are an important resource for the products they provide and for dry climates, a combination of the ecological functions they perform. farming, , and has turned once productive areas • They provide us with wood to build homes, make , and other into deserts. products. • This process is called • The wood can be burned to provide us with heat for our homes and desertification. cooking. • Ways to prevent this: • They are called “the lungs of the Earth” because they remove the – Leaving roots and stems of dioxide and produce . previous year’s crops. • Forests also store nutrients, provide habitats and food for organisms, – Contour plowing (Growing moderate climate, limit , and protect freshwater supplies. crops perpendicular to the slope of the land.)

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Are Forests Renewable Resources?

• Forests of the Northeastern can be considered renewable. • It is the loss of forests • Most of these forests have been logged at least once in the past and have grown back naturally. • It can lead to severe erosion because the soil is exposed to the weather. • Erosion can wash away the nutrients found in the topsoil. • Other forests, such as those in Alaska and the Pacific Northwest, are • Grazing and plowing after deforestation can cause permanent changes called “old-growth forests.” that could prevent the regrowth of trees. – They have never been cut • Because these forests take centuries to grow, they are considered nonrenewable. • These forests contain a rich variety of species. If they were logged, some of these species might be lost.

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Forest Management Fishery Resources

• There are several ways to manage • Fish and other animals that live in water are a valuable source of forest growth: food. 1. Selectively harvest mature trees to promote the growth of • However, there has been occasions where these water have been younger trees. in danger. 2. Plant new trees where logging has occurred.

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5 Overfishing Sustainable Development

• Overfishing is harvesting fish faster than they can be replaced by • The US National Marine Fisheries reproduction. Service (USNMFS) used researched data to create guidelines for United • Between 1950 and 1990, the world fish catch grew from 19 million State commercial fishing. to more than 90 million tons. • Guidelines state how many fish and of •Researchers feared the cod and haddock populations could what size could be caught in various parts of the ocean. disappear from the sea. • Scientists are also trying a technique • This is a classic example of the tragedy of the commons. called aquaculture, the raising of aquatic animals for human consumption.

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Growth of Fish Catch

Section 6-2

Air Resources World Fish Catch World Fish Catch per Person • The preservation of air quality remains a challenge for modern society. • Big cities are faced with smog, a mixture of chemicals that occurs as a gray-brownish haze in the atmosphere. • Smog is caused by automobile exhaust and industrial emissions. (kilograms) Total Catch Total (million tons) • Burning of fossil fuels release chemicals such as nitrates, sulfates, and particulates (microscopic particles of ash and dust) into the Amount of Fish per Person Year Year atmosphere. • These particles can cause health problems over a long period of time. • When these particles mix with water vapor, they form drops of nitric and sulfuric acid which is called acid rain.

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Freshwater Resources Freshwater Resources

• Americans use billions of liters of freshwater daily for drinking, washing, • One way to ensure that our water watering crops, and making steel. supply stays clean is to protect the • Water is a renewable resource, but it is limited. natural systems involved in the • There are several ways water can become polluted: water cycles, such as wetlands. • Wetlands act as a natural filter for 1. Improperly discarded chemicals can enter streams and rivers. freshwater. 2. Wastes discarded on land can seep through soil and enter underground water supplies. 3. Domestic (sinks and toilets) contain nitrates and that could promote algae and bacteria growth. 4. Raw sewage contains microorganisms that could spread disease.

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6 Figure 6-12 The Formation of Acid Rain Interest Grabber

Section 6-2 Section 6-3

Chemical Transformation Condensation Nitric acid What Is ? Emissions to Atmosphere Sulfuric acid oxides Sulfur dioxide Biodiversity is the sum total of the variety of organisms in the biosphere. Dry Fallout Precipitation Sometimes humans can reduce biodiversity, which is considered a natural particulates, gases Acid rain, fog, resource. snow, and mist

Industry Transportation Ore smelting Power generation

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Interest Grabber continued Section Outline

Section 6-3 Section 6-3

6–3 Biodiversity A. The Value of Biodiversity 1. List three ways in which other organisms have proved to be a benefit B. Threats to Biodiversity to humans. C. Habitat Alteration D. Demand for Products 2. Compare biodiversity with other natural resources, such as wood and E. Pollution fossil fuels. Do you think biodiversity is a renewable or a nonrenewable F. Introduced Species resource? Explain your answer. G. Conserving Biodiversity 1. Strategies for Conservation 3. What can be done to preserve the biodiversity of organisms? 2. Challenges in Conservation

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• Biodiversity is one of Earth’s greatest natural resources. The Value of Biodiversity The Value of Biodiversity • Species of many kinds have • Biodiversity - the sum total of the genetically based variety of all provided us with , organisms in the biosphere. industrial products, and medicines: • Ecosystem diversity - the variety of habitats, communities, and ecological processes in the living world. – Painkillers, antibiotics, heart drugs, • Species diversity - the number of different species in the antidepressants, biosphere. anticancer drugs. – Scientists have identified 1.5 million species. • Example: Rosy periwinkle is a – Millions more may be discovered. source for a substance that is • Genetic Diversity - the sum total of all the different forms of used to treat certain types of genetic information carried by all organisms living on Earth. cancer.

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7 Species Diversity

Section 6-3

Threats to Biodiversity Insects 54.4% • Human activity can reduce biodiversity by altering habitats, hunting species to extinction, introducing toxic compounds into food webs, and introducing foreign species to new environments. Protists Other Animals 4.2% 19.7% • Extinction - occurs when a species no longer exists on this Plants planet. 18% • - a species whose population size is declining in a way that places it in danger of extinction. Bacteria • As an ES population decreases, so does the genetic diversity. Fungi 0.3% 3.4%

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Habitat Alteration Demand for Wildlife Products

• When land is developed, a species habitat may be destroyed. • Throughout history, humans have pushed species into extinction by • This habitat is a limited resource for these species. hunting them for food or other products. • If the habitat is not preserved, the species existence may be in jeopardy. – Carolina parakeet • Habitat Fragmentation - the splitting of habitats into pieces due to – Passenger pigeon development. • Today, the U.S. has protected endangered species from being hunted. • This can cause biological “islands”. • However, other countries in Africa, South America, are still • Example: New York City’s Central Park hunting rare animals for meat, , hides, or they believe their parts have medicinal properties. • The Convention on International Trade in Endangered Species (CITES) bans international trade in products derived from a list of endangered species.

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Figure 6-16 Biological Magnification of DDT

Section 6-3 Magnification of Fish-Eating Birds DDT Concentration 10,000,000 Pollution Large • Many forms of pollution can threaten biodiversity. Fish 1,000,000 • One of the most serious problems occurs when toxic compounds accumulate in the tissue of organisms. Small Fish 100,000

• The best example is the use of DDT in the mid 1900’s. Zooplankton 10,000 • This build up of toxins can lead to biological magnification. Producers 1000

Water 1

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8 Introduced Species Conserving Biodiversity

• One of the most important threats to biodiversity comes from apparently • Most people would like to preserve Earth’s biodiversity. harmless plants and animals that humans around the world. • Conservation - the wise management of natural resources, including • Introduced into new habitats, these plants and animals reproduce rapidly. the preservation of habitats and wildlife. • They are called invasive species, because they do not have any • In order to do this, scientists need to know: parasites or predators to control their population size. 1. Ways natural populations use their habitats • Examples: 2. Integrating information from other scientific disciplines, such as – Nutria genetics, geography, and management. – Zebra mussels – Leafy spurge

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Biodiversity Hot Spots Strategies for Conservation

• Many conservation efforts are aimed at managing individual species to keep them from becoming extinct. • Zoos have established captive breeding programs. • Today, conservation efforts focus on protecting entire ecosystems as well as single species. • Protecting an ecosystem will ensure that the natural habitats and the interactions of many different species are preserved at the same time.

• There are national parks, forest, and other protected area.

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Interest Grabber

Section 6-4

Conservation Challenges

• Protecting resources for the future can require people to change the way How Much Should It Cost? they earn their living today. • Example: Fishing regulations You may have read that when something becomes hard to obtain, its price usually increases. Such is the case for materials like gold and diamonds, • A little bit of a hardship now will preserve these occupation for the future. which are nonrenewable resources. Using similar thinking, some researchers believe that all the valuable services provided by a healthy ecosystem should be assigned a dollar value.

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9 Interest Grabber continued Section Outline Section 6-4 Section 6-4

Rank the following items in order of their importance to you. Then, next to 6–4 Charting a Course for the Future each item, write down how much you would be willing to pay for it. A. 1. Fresh, clean drinking water B. Global 2. Clean air to breathe 1. Evidence of Global Warming 3. An endangered plant containing a substance that can cure cancer 2. Possible Effects of Global Warming C. The Value of a Healthy Biosphere 4. Gas for your family car

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Sustainable Agriculture Figure 6-22 Ecosystem Services

Section 6-4 Section 6-4

Solar energy

Production of oxygen Storage and of nutrients Cover Crops Controlled Grazing Biological Pest Control Regulation of climate Legumes, grasses, and other By managing graze periods and herd The use of predators and parasites cover crops recycle soil nutrients, densities, farmers can improve to control destructive insects Purification of water and air reduce need, and cycling, increase the effectiveness of minimizes pesticide use as well as prevent weed growth. precipitation, and increase the carrying crop damage Storage and distribution of capacity of pastures. A B C fresh water Food production Contour Plowing Yr. 1 Contour plowing reduces corn oats alfalfa Nursery habits for wildlife soil erosion from land runoff. Different crops use and On hilly areas, plowing is done Yr. 2 replenish different nutrients. Detoxification of human and alfalfa By rotating crops, the loss industrial waste across the hill rather than corn alfalfa (plowed straight up and down. in) of important plant nutrients Natural pest and disease is decreased. control Yr. 3 oats alfalfa corn Management of soil erosion and runoff

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Video Go Online

Interactive test How Does Everything Fit?

Articles on natural resources and pollution

For links on , go to www.SciLinks.org and enter the Web Code as follows: cbn-2061. For links on biodiversity, go to www.SciLinks.org and enter the Web Code as follows: cbn-2063. For links on global warming, go to www.SciLinks.org and enter the Web Code Click the image to play the video segment. as follows: cbn-2064.

10 Interest Grabber Answers Interest Grabber Answers

1. Choose an animal other than a human and describe at least two ways in 1. Examine the list of natural resources shown below. Then, classify each which it may change its environment. natural resource as either renewable or nonrenewable. Sample answers: A beaver both removes wood from a forest and dams a a. Wood Renewable; new trees can be grown body of water. A dog digs a hole and may damage plants, but also may b. Fossil fuels Nonrenewable; once depleted they are gone unearth worms and turn the soil. c. Aluminum Nonrenewable; although recyclable, once depleted the 2. What events might have led to the changes that occurred in your town or resource is gone city? d. Wool Renewable; sheep can grow new fleece e. Gold Nonrenewable; once gold ores are depleted no more Sample answers: increase or decrease in population and industry. gold can be made 3. What positive effect have humans had on their environment? What negative effect have humans had on their environment? 2. Describe the impact that the loss of nonrenewable resources would have on the environment. Humans preserve, conserve, and restore the natural environment as well as construct facilities that improve human health. Humans pollute the air, Sample answers: fossil fuels; limited energy, which impacts on industry, water, and land with materials that can harm humans and other organisms. quality of life, economy; gold and aluminum; decrease in components for technology, which also impacts on industry, quality of life, economy.

Interest Grabber Answers Interest Grabber Answers

1. List three ways in which other organisms have proved to be a benefit Rank the following items in order of their importance to you. Then, next to to humans. each item, write down how much you would be willing to pay for it. They provide food, medicine, building materials, and clothing. 1. Fresh, clean drinking water 2. Compare biodiversity with other natural resources, such as wood and fossil 2. Clean air to breathe fuels. Do you think biodiversity is a renewable or a nonrenewable 3. An endangered plant containing a substance that can cure cancer resource? Explain your answer. 4. Gas for your family car Nonrenewable, because once species of organisms are extinct, they cannot be brought back to life by any natural processes. Students’ answers will depend on how important the items are to them. 3. What can be done to preserve the biodiversity of organisms? Students may suggest protecting endangered species and ecosystems.

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