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Name Class Date 6.1 A Changing Landscape Lesson Objectives Describe human activities that can affect the biosphere. Describe the relationship between resource use and sustainable development. Lesson Summary The Effect of Human Activity Humans and other organisms change the environment when they obtain food, eliminate wastes, and prepare places to live. Because Earth is like an island, life is limited to the resources that are here. Humans affect regional and global environments through three major activities: agriculture, particularly monoculture, which is the cultivation of a single crop development of cities and suburbs, including conversion of farmland and destruction of habitats for other organisms industrial growth, which consumes energy and emits pollutants Sustainable Development In economic terms, ecosystems are providers of goods and services (natural resources). Healthy ecosystems produce or replace renewable resources. Humans must be careful about the use of nonrenewable resources, such as fossil fuels, which cannot be replaced. Sustainable development provides for human needs while preserving the ecosystems that provide renewable resources. The Effect of Human Activity 1. What three human activities have transformed the biosphere? 2. What is monoculture? 3. List three resources used in agriculture. 4. How does urban and suburban development affect the environment and habitats? 5. What source provides most of the energy for industrial production? 82 Name Class Date 6. Complete the table to show some consequences of human activities on global ecology. Consequences of Some Human Activities Activity Positive Consequences Negative Consequences Agriculture Development Industrial Growth Sustainable Development 7. Complete the Venn diagram to compare renewable and nonrenewable resources. Renewable Resources Raw materials for building, manufacturing, fuels, and food Nonrenewable Resources 8. How can development be sustainable? Apply the Big idea 9. The human population (currently around 7 billion) may reach 9 billion by 2100. Most of those people will live in cities. Predict the impact of city growth on natural ecosystems and farmland. What will happen if sustainable development is not achieved? 6.2 Using Resources Wisely Lesson Objectives Describe how human activities affect soil and land. Describe how human activities affect water resources. Describe how human activities affect air resources. Lesson Summary Soil Resources Soil is a renewable resource, but it must be managed properly. Soil erosion is the wearing away of surface soil by water and wind. In dry climates, farming and overgrazing change farmland into deserts, a process called desertification. Deforestation is loss of forests. Because healthy forests hold soil in place, deforestation increases erosion. Sustainable uses include leaving stems and roots of previous crops in place, crop rotation, contour plowing, terracing, selectively harvesting mature trees, and tree farms. Freshwater Resources The amount of fresh water is limited, and some sources cannot be replaced. A pollutant is a harmful material that can enter the biosphere. Water pollutants come from industrial chemicals, residential sewage, and other sources. Many chemical pollutants become concentrated in organisms at higher trophic levels of the food chain through biological magnification. Sustainable uses include conservation, pollution control, and watershed protection. Atmospheric Resources Clean air is important to human health and Earth’s climate. Pollution reduces air quality. Smog is a mixture of chemicals formed from emissions from cars and industry. Burning fossil fuels releases compounds that join with water in air, forming acid rain. Greenhouse gases, such as carbon dioxide and methane, can cause global warming. Particulates are microscopic particles that cause health problems. One way of sustaining air quality is controlling automobile emissions. Soil Resources 1. What is topsoil? 2. How does topsoil form? 84 Name Class Date 3. What is soil erosion? 4. How does plowing land increase the rate of soil erosion? 5. What happens to farmland during desertification? 6. Are mature forests a renewable resource? Why or why not? 7. What happens to soil when rain forest is cut down? 8. Complete the graphic organizer to give examples of sustainable uses of soil. Sustainable Soil Use Examples 85 Name Class Date Freshwater Resources Use this diagram to answer Questions 9–11. 9. THINK VISUALLY The diagram shows the typical impact of a chemical pollutant in an aquatic ecosystem. 10. Name and describe the process that this diagram is illustrating. 11. Describe an example of biological magnification 86 Name Class Date 12. What is a “dead zone,” and what is its cause? 13. Why is watershed management important to maintaining good water quality in a large river or lake? Atmospheric Resources For Questions 14–17, write the letter of the correct answer on the line at the left. 14. Which is the name for the mixture of chemicals that forms as a graybrown haze in the atmosphere? A. dust C. ozone B. smog D. radiation 15. Which component of acid rain kills plants and harms soil? A. carbon dioxide and water C. nitric and sulfuric acids B. CFCs and fossil fuels D. ozone and particulates 16. Which is the name for the bits of ash and dust put into the air by certain kinds of diesel engines? A. particulates C. ozone layer B. precipitation D. greenhouse gases 17. Which is a pollutant of soil and water that is now dropping steadily due to laws that affected the automobile industry? A. carbon C. nitrogen B. lead D. ozone Apply the Big idea 18. The citizens of Ecotown want to protect the quality of their soil, fresh water, and air. Suggest a plan for Ecotown that includes steps for achieving sustainable use of each of those three categories of resources. 6.3 Biodiversity Lesson Objectives Define biodiversity and explain its value. Identify current threats to biodiversity. Describe how biodiversity can be preserved. Lesson Summary The Value of Biodiversity The sum of all the genetic diversity among all the organisms in the biosphere is called biodiversity. There are three general types of biodiversity: Ecosystem diversity is the variety of habitats, communities, and ecological processes in the biosphere. Species diversity is the number of different species in an area or in the biosphere. Genetic diversity is the total of all genetic information carried in living things. Biodiversity benefits humans through its contributions to medicine and agriculture and through the provision of ecological goods and services. Threats to Biodiversity Human activities threaten biodiversity. Development splits ecosystems into pieces, resulting in habitat fragmentation. The smaller the pieces of a habitat, the less likely that species in the habitat can survive. Other threats to biodiversity include hunting, introduced species, pollution, and climate change. Conserving Biodiversity Conservation efforts are focused on three things: Protecting single species is the focus of groups such as the Association of Zoos and Aquariums (AZA), which oversees species survival plans (SSPs). Protecting habitats and ecosystems is the main thrust of global efforts. Biologists are particularly concerned about ecological hot spots, which are places where significant numbers of habitats and species are in immediate danger of extinction. Considering local interests is part of developing plans to replace harmful activities with ones that conserve environments and biodiversity. The Value of Biodiversity 1. What is biodiversity? 2. Why is biodiversity one of Earth’s greatest natural resources? 88 Name Class Date 3. Complete the table to define the types of biodiversity. Diversity in the Biosphere Type of Diversity Definition Ecosystem diversity Species diversity Genetic diversity Threats to Biodiversity For Questions 4–8, write True if the statement is true. If the statement is false, change the underlined word or words to make the statement true. 4. The current rate of species loss is 10 times the typical rate of extinction. 5. The smaller a habitat “island,” the larger the number of species that can live there. 6. Habitat fragmentation increases the impact of hunting on endangered species. 7. Endangered species can become invasive and threaten biodiversity. 8. The increased concentration of carbon dioxide in air is making oceans more acidic and putting stress on coral reefs. 9. What are five ways that human activity reduces biodiversity? 10. Identify three reasons why endangered species are hunted. 89 Name Class Date 11. How can introduced species lead to economic losses? 12. How does climate change threaten biodiversity? Conserving Biodiversity 13. What is the main purpose of biodiversity conservation today? 14. Why have ecologists identified ecological hot spots? 15. What are some of the challenges that conservationists face? 16. What are some strategies that encourage conservation? Provide an example of one of these strategies. Apply the Big idea 17. Why is preserving entire ecosystems a better idea than protecting single species from extinction? 6.4 Meeting Ecological Challenges Lesson Objectives Explain the concept of ecological footprint. Identify the role of ecology in a sustainable future Lesson Summary Ecological Footprints The ecological footprint of an individual or a population is the amount of land and water needed to provide resources, absorb wastes, and render the wastes harmless. Ecology in Action Three case studies illustrate the three steps of ecology in action: (1) recognize a change in the environment, (2) determine the cause of that change, and (3) change behavior to have a positive impact. Case Study 1: Atmospheric Ozone This gas blocks ultraviolet (UV) radiation. Ozone gas blocks ultraviolet (UV) rediation. The ozone layer is an area of relatively high concentration of ozone in the atmosphere, between 20 and 50 kilometers above Earth’s surface. In the 1970s, a hole in the layer was observed. Regulations reduced CFC use, and the hole may be slowly disappearing. Case Study 2: North Atlantic Fisheries Commercial fish catches have declined in recent years. The cause is overfishing. Regulations closed some fishing grounds to allow fish stocks to replenish. In the mean time, aquaculture, or fish farming, also can provide food for people. Case Study 3: Climate Change Global warming, the rise in the biosphere’s average temperature, and climate change, a shift in Earth’s overall weather patterns, has occurred. Physical evidence includes rising sea levels due to melting ice. Biological evidence includes temperature-related behavior changes in organisms. Using less fossil fuel will reduce greenhouse gases in the atmosphere. Ecological Footprints For Questions 1–2, refer to the Visual Analogy that shows examples of factors that contribute to a population’s ecological footprint. 1. VISUAL ANALOGY Why do you think ecologists use the term footprint to describe the total resources a population uses and its wastes that must be absorbed? Name Class Date 2. Explain this statement: The average American has an ecological footprint more than four times larger than the global average. Ecology in Action 3. List three factors that will affect the future of the biosphere. 4. Complete the table to summarize how the basic principles of ecology can lead to positive impacts on the environment. Examples of Ecology in Action Environmental Change Cause Behavior Change Needed Hole in the ozone layer Declining numbers of fish in the oceans Global warming and climate change Case Study 1: Atmospheric Ozone For Questions 5–7, complete each statement by writing the correct word or words. 5. The ozone layer is a high concentration of ozone at about Earth’s surface. above 6. The ozone layer is important to humans because it protects against exposure to from the sun. 7. UV radiation causes ,damages eyes, and reduces resistance to disease. Case Study 2: North Atlantic Fisheries For Questions 8–10, complete each statement by writing the correct word or words. 8. Technologies that have led to large increases in the mass of ocean fish caught include large boats and high-tech equipment. 9. caused the decline in fish catches since 1997. 10. An alternative to commercial fishing is ,which produces large amounts of food with minimal environmental damage if properly managed. 92 Name Class Date Case Study 3: Climate Change Use the graph to answer Questions 11–12. 11. How does the change in global temperature between 1850 and 2000 compare with the change that occurred between 1850 and 1880? 12. List three factors that may have contributed to the trend shown in the graph. 13. Suggest three possible effects of global warming on the future of the biosphere. Apply the Big idea 14. Explain why populations with the largest ecological footprints change the biosphere the most. Chapter Vocabulary Review For Questions 1–10, match the term with its definition. Definition Term 1. Cultivation of a single, highly productive crop over a large area A. aquaculture 2. The removal of soil by water or wind C. ecological footprint 3. A loss in land productivity caused by drought, overgrazing, and farming D. monoculture 4. The process in which pollutants become more concentrated in the bodies of high trophic level organisms F. ecological hot spot 5. The total of all genetically based variation in all organisms in the biosphere B. ozone layer E. biological magnification G. global warming H. desertification I. biodiversity 6. An area where ecosystems and species face severe J. erosion threat of destruction or extinction 7. The amount of land and water needed to provide resources and process wastes for an individual or a nation 8. A part of the atmosphere that blocks UV rays of the sun from reaching Earth’s surface 9. The farming of fish and other aquatic organisms for food 10. A rise in Earth’s average temperature For Questions 11–17, complete each statement by writing in the correct word or words. 11. A resource that can be produced or replaced by a healthy ecosystem is a(n) resource. 12. Fossil fuels are examples of 13. resources. can lead to severe soil erosion, especially on mountainsides. 14. Any harmful material that enters the biosphere is a(n) . 15. The mixture of chemicals that forms a gray-brown haze in the air of cities is . 16. The variety of habitats, communities, and ecological processes in the biosphere is . 17. The number of different species in an area is .