Leaving a Mark on the World Section 6-1 Leaving a Mark on the World 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 roads than there were many years ago. Maybe your town or city has more trees and flowers now than it had years ago. Humans, like all organisms, have an effect on their environment.

Interest Grabber continued Section 6-1 1. Choose an animal other than a human and describe at least two ways in which it may change its environment. 2. What events might have led to the changes that occurred in your town or city? 3. What positive effect have humans had on their environment? What negative effect have humans had on their environment?

Section Outline 6–1 A Changing Landscape A. Earth as an Island B. Human Activities C. Hunting and Gathering D. Agriculture 1. From Traditional to Modern Agriculture 2. The Green Revolution 3. Challenges for the Future E. Industrial Growth and Urban Development

Concept Map Human Activities Section 6-1 Hunting and gathering that have changed the biosphere include Hunting and gathering Agriculture Industrial growth Urban development may have once caused often relies on the methods of the have resulted in Extinctions of large animals Green revolution High standard of living Increased pollution which increased Food supply Pesticide use Monoculture use

Where Do Natural Resources Come From? Interest Grabber Section 6-2 Where Do Natural Resources Come From? Natural resources are materials that are supplied by nature. A renewable resource is one that is replaceable. A nonrenewable resource is one that cannot be replenished by natural processes. Once a nonrenewable resource is used up, it is gone forever.

Interest Grabber continued Section 6-2 1. Examine the list of natural resources shown below. Then, classify each natural resource as either renewable or nonrenewable. a. Wood b. Fossil fuels c. Aluminum d. Wool e. Gold 2. Describe the impact that the loss of nonrenewable resources would have on the environment.

Section Outline 6–2 Renewable and Nonrenewable Resources A. Classifying Resources B. Sustainable Development C. Land Resources D. Forest Resources E. Fishery Resources 1. Overfishing 2. Sustainable Development 3. Aquaculture F. Air Resources G. Freshwater Resources

Amount of Fish per Person Growth of Fish Catch Section 6-2 World Fish Catch World Fish Catch per Person Total Catch (million tons) Amount of Fish per Person (kilograms) Year Year

Chemical Transformation Emissions to Atmosphere Figure 6-12 The Formation of Acid Rain Section 6-2 Chemical Transformation Nitric acid Sulfuric acid Condensation Emissions to Atmosphere Nitrogen oxides Sulfur dioxide Dry Fallout Precipitation Acid rain, fog, snow, and mist particulates, gases Industry Transportation Ore smelting Power generation

Interest Grabber What Is Biodiversity? Section 6-3 What Is Biodiversity? Biodiversity is the sum total of the variety of organisms in the biosphere. Sometimes humans can reduce biodiversity, which is considered a natural resource.

Interest Grabber continued Section 6-3 1. List three ways in which other organisms have proved to be a benefit to humans. 2. Compare biodiversity with other natural resources, such as wood and fossil fuels. Do you think biodiversity is a renewable or a nonrenewable resource? Explain your answer. 3. What can be done to preserve the biodiversity of organisms?

Section Outline 6–3 Biodiversity A. The Value of Biodiversity B. Threats to Biodiversity C. Habitat Alteration D. Demand for Wildlife Products E. Pollution F. Introduced Species G. Conserving Biodiversity 1. Strategies for Conservation 2. Challenges in Conservation

Species Diversity Insects Protists Other Animals Plants Bacteria Fungi Section 6-3 Insects 54.4% Protists Other Animals 4.2% 19.7% Plants 18% Bacteria Fungi 0.3% 3.4%

Figure 6-16 Biological Magnification of DDT Section 6-3 Magnification of DDT Concentration Fish-Eating Birds 10,000,000 Large Fish 1,000,000 100,000 Small Fish 10,000 Zooplankton 1000 Producers Water 1

Interest Grabber How Much Should It Cost? Section 6-4 How Much Should It Cost? 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, 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.

Interest Grabber continued Section 6-4 Rank the following items in order of their importance to you. Then, next to each item, write down how much you would be willing to pay for it. 1. Fresh, clean drinking water 2. Clean air to breathe 3. An endangered plant containing a substance that can cure cancer 4. Gas for your family car

Section Outline 6–4 Charting a Course for the Future A. Ozone Depletion B. Global Climate Change 1. Evidence of Global Warming 2. Possible Effects of Global Warming C. The Value of a Healthy Biosphere

Sustainable Agriculture Section 6-4 Cover Crops Legumes, grasses, and other cover crops recycle soil nutrients, reduce fertilizer need, and prevent weed growth. Controlled Grazing By managing graze periods and herd densities, farmers can improve nutrient cycling, increase the effectiveness of precipitation, and increase the carrying capacity of pastures. Biological Pest Control The use of predators and parasites to control destructive insects minimizes pesticide use as well as crop damage A B C Contour Plowing Contour plowing reduces soil erosion from land runoff. On hilly areas, plowing is done across the hill rather than straight up and down. Yr. 1 Crop Rotation Different crops use and replenish different nutrients. By rotating crops, the loss of important plant nutrients is decreased. corn oats alfalfa Yr. 2 alfalfa (plowed in) corn alfalfa Yr. 3 oats alfalfa corn

Figure 6-22 Ecosystem Services Section 6-4 Solar energy Production of oxygen Storage and recycling of nutrients Regulation of climate Purification of water and air Storage and distribution of fresh water Food production Nursery habits for wildlife Detoxification of human and industrial waste Natural pest and disease control Management of soil erosion and runoff

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Go Online Interactive test Articles on natural resources and pollution For links on sustainable agriculture, 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 as follows: cbn-2064. Internet

Interest Grabber Answers 1. Choose an animal other than a human and describe at least two ways in which it may change its environment. Sample answers: A beaver both removes wood from a forest and dams a body of water. A dog digs a hole and may damage plants, but also may unearth worms and turn the soil. 2. What events might have led to the changes that occurred in your town or city? Sample answers: increase or decrease in population and industry. 3. What positive effect have humans had on their environment? What negative effect have humans had on their environment? Humans preserve, conserve, and restore the natural environment as well as construct facilities that improve human health. Humans pollute the air, water, and land with materials that can harm humans and other organisms. Section 1 Answers

Interest Grabber Answers 1. Examine the list of natural resources shown below. Then, classify each natural resource as either renewable or nonrenewable. a. Wood Renewable; new trees can be grown b. Fossil fuels Nonrenewable; once depleted they are gone c. Aluminum Nonrenewable; although recyclable, once depleted the resource is gone d. Wool Renewable; sheep can grow new fleece e. Gold Nonrenewable; once gold ores are depleted no more gold can be made 2. Describe the impact that the loss of nonrenewable resources would have on the environment. Sample answers: fossil fuels; limited energy, which impacts on industry, quality of life, economy; gold and aluminum; decrease in components for technology, which also impacts on industry, quality of life, economy. Section 2 Answers

Interest Grabber Answers 1. List three ways in which other organisms have proved to be a benefit to humans. They provide food, medicine, building materials, and clothing. 2. Compare biodiversity with other natural resources, such as wood and fossil fuels. Do you think biodiversity is a renewable or a nonrenewable resource? Explain your answer. Nonrenewable, because once species of organisms are extinct, they cannot be brought back to life by any natural processes. 3. What can be done to preserve the biodiversity of organisms? Students may suggest protecting endangered species and ecosystems. Section 3 Answers

Interest Grabber Answers Rank the following items in order of their importance to you. Then, next to each item, write down how much you would be willing to pay for it. 1. Fresh, clean drinking water 2. Clean air to breathe 3. An endangered plant containing a substance that can cure cancer 4. Gas for your family car Students’ answers will depend on how important the items are to them. Section 4 Answers

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