1. Living Resources Environmental Issues Forests and Fisheries Biodiversity The Search for New Medicines Table of Contents

2. Living Resources Types of Environmental Issues Three general categories of environmental issues are of major concern: Resource use, Population growth, and Pollution.

3. Living Resources Resource Use Determining how to use our natural resources is a major concern. Natural resource —anything in the environment that is used by people. -Renewable resources —resources that are either always available or naturally replaced in a relatively short period of time. Ex: sunlight, wind, fresh water, trees -Nonrenewable resources —resources that are not replaced in a useful timeframe. Ex: oil, coal, natural gas and minerals.

4. Living Resources Population Growth Human population growth is another major concern. -Human population grew very slowly until about A.D. 1650. After that, improvements in medicine, agriculture and waste disposal have allowed it to grow much faster. -Today, 6 billion people live on this Earth. -Will we have enough resources to support them all?

5. Living Resources Pollution Pollution is yet another major environmental concern. Pollution is the contamination of Earth’s land, water or air. -Causes: chemicals, wastes, noise, heat and light -Related to both resource use and population growth. Example: burning fuels Example: fertilizer use to feed growing population

6. Living Resources Making Environmental Decisions Deciding how to deal with these environmental issues is no easy task. Decisions must be made on many different levels: personal local national global In all cases, the costs and benefits of every proposal must be weighed carefully. This often involves scientists, lawmakers and citizens. Read pages 85-87

7. Living Resources Main Idea Detail Identifying Main Ideas As you read the section “Types of Environmental Issues,” write the main idea in a graphic organizer like the one below. Then write three supporting details that give examples of the main idea. Three types of environmental issues are… Resource usePopulation growthPollution - Environmental Issues

8. Living Resources Links on the Environment Click the SciLinks button for links on the environment. - Environmental Issues

9. Living Resources End of Section: Environmental Issues

10. Living Resources Chapter 3 is devoted to our living resources. We will look at 1. Managing our forests and our fisheries 2. Maintaining biodiversity throughout the world. This Giant catfish is 9’ long and weighs 646 lbs. Found in the Mekong River, it may be the biggest freshwater fish ever recorded (Source: NYTimes). The large stump is from an old- growth California redwood tree. It takes 400-500 yrs to get this large.

11. Living Resources Forest Resources The value of our forests: 1. lumber 2. paper 3. household products 4. food 5. prevent flooding and soil erosion 6. produce oxygen 7. absorb carbon dioxide

12. Living Resources Managing Forests Question: How much of the total land area of the United States is covered with forests? Answer: about 1/3 (300 million hectares) Question: Are forests renewable or nonrenewable resources? Answer: renewable However, to maintain our forests as a renewable resource we must develop proper logging methods.

13. Living Resources Logging Methods There are two major methods of logging: 1. Clear-cutting —cut down all the trees in an are at once. This is quick, easy and safe for the loggers. However, it is very damaging to the environment. 2. Selective cutting —cut down only some trees, leaving a mix of tree sizes and species. This causes less damage to the environment. However, it is more expensive and more dangerous for the loggers.

14. Living Resources Managing Forests Clear-cutting involves cutting down all the trees in an area at once. Selective cutting involves cutting down only some trees. - Forests and Fisheries

15. Living Resources Sustainable Forestry The goal in managing forests is to provide a sustainable yield. Sustainable yield —an amount of trees that can be harvested regularly without reducing the future supply. To do this we must: 1. plant new trees to replace harvested trees 2. harvest only at a rate that does not exceed the growth replacement 3. log only small patches of forest each year

16. Living Resources Logging Methods Activity Click the Active Art button to open a browser window and access Active Art about logging methods. - Forests and Fisheries

17. Living Resources Fisheries Fishery —an area with a large population of valuable ocean organisms. Examples: Grand Banks, Newfoundland Georges Bank, New England Monterey Canyon, California

18. Living Resources Question: Are fish renewable or nonrenewable resources? Answer: renewable Question: Is it possible to “over-fish” an area? Answer: Yes: Scientists estimate 70% of the world’s major fisheries have been over-fished.

19. Living Resources Developing a Sustainable Yield Techniques for managing a sustainable yield for fisheries include: 1. Setting fishing limits —on number and size 2. Changing fishing methods —ban cyanide poisoning and dynamite fishing; use nets with larger mesh 3. Developing aquaculture —create fish farms 4. Finding new resources —find new fish species that are good to eat

20. Living Resources What You Know What You Learned Before you read, write what you know about forests and fish resources in a graphic organizer like the one below. As you read, write what you learn. 1.Forests provide people with lumber and paper. 2.Commercial fishing boats harvest large amounts of fish. 1.Forests can be renewable resources. 2.Setting fishing limits, changing fishing methods, and developing aquaculture techniques are ways to manage fisheries for sustainable yields. - Forests and Fisheries Using Prior Knowledge

21. Living Resources End of Section: Forests and Fisheries

22. Living Resources Diversity of Species The number of different species in an area is called its biodiversity. - Biodiversity

23. Living Resources The Value of Biodiversity There are many reasons why we should protect the diversity of organisms on earth: Economic value —plants, animals, and other living organisms provide us with food, clothing, medicines and other products. Protecting their ecosystems can also have economic value in tourism as well.

24. Living Resources Ecologic value —all living things depend on other living things to stay alive. This keeps ecosystems in balance. *Keystone species —a species that influences the survival of many other species in an ecosystem. Example: Sea otters (eat sea urchins---sea urchins eat kelp----when otters were hunted to almost extinction the kelp died off too)

25. Living Resources Factors Affecting Biodiversity Factors that affect biodiversity include: Area —the larger the area; the more diversity. Climate —diversity increases from the pole to the equator. Tropical climates seem to support more diversity. Niche Diversity —more niches supports more diversity. Example: coral reef vs. sand bar

26. Living Resources Factors Affecting Biodiversity Factors that affect biodiversity in an ecosystem include area, climate, and diversity of niches. - Biodiversity

27. Living Resources Gene Pool Diversity Gene Pool Diversity refers to diversity within a species. -Genes —structures in an organism’s cell that carry hereditary information. -Gene Pool —All the different variations in the genes of all the members of a species. -Individual members of a species should be genetically different from other members. -Genetic differences such as differences in color, size, and ability to fight disease will allow a species to adapt better to changes in its environment.

28. Living Resources Extinction of Species Extinction —the disappearance of all the members of a species. It is a natural process---but seems to be increasing dramatically in the last few centuries. Endangered species —a species in danger of becoming extinct in the near future. Threatened species —a species that could become endangered in the near future.

29. Living Resources Causes of Extinction 1. Habitat Destruction —this is the major cause of extinction of most species. Ex: Natural catastrophic event Clear-cutting forests for lumber Clearing land for city expansion or farming Filling in wetlands 2. Habitat Fragmentation —breaking up a larger habitat into smaller pieces Ex: Road construction through a forest

30. Living Resources Causes of Extinction 3. Poaching —illegal killing or removal of wildlife species from their habitat. 4. Pollution —pollutants can build-up in organisms and be passed through the food chain. They can kill or weaken organisms or cause birth defects.

31. Living Resources 5. Exotic Species —non-native species introduced into a habitat can out-compete with the native species and push them to extinction. Rats accidentally brought by sailors to Hawaii—ate Nene goose eggs Mongoose intentionally brought to Hawaii to kill rats. Ate Nene goose eggs instead---easier. Nene Goose, Hawaii’s state bird is now endangered.

32. Living Resources Endangered Species Click the Video button to watch a movie about endangered species. - Biodiversity

33. Living Resources Protecting Biodiversity To protect biodiversity we can either protect the individual species or protect an entire ecosystem. Three approaches to doing this are: Captive Breeding —the mating of animals in zoos or wildlife preserves. (Can be expensive). Laws and Treaties —Endangered Species Act and the Convention on International Trade in Endangered Species have both saved many species from extinction. (Can be hard to enforce) Habitat Preservation —protect the whole ecosystem by establishing parks and refuges. (Must be large area, control pollution, poaching and exotic species)

34. Living Resources California Peregrine Falcon Recovery The peregrine falcon, the world’s fastest bird of prey, was nearly extinct in the United States in 1970. The pesticide DDT was weakening peregrine eggshells, so eggs rarely hatched. In 1972, the United States banned DDT. Use the graph to answer questions about the peregrine population in California. - Biodiversity

35. Living Resources California Peregrine Falcon Recovery Time interval in years is on the x-axis. Number of breeding pairs of peregrine falcons is on the y-axis. Reading Graphs: What variable is plotted on the x-axis? What variable is plotted on the y-axis? - Biodiversity

36. Living Resources California Peregrine Falcon Recovery The population grew steadily, except for a brief drop around 1980, until 1994, when the number of breeding pairs remained the same for the four following years. Interpreting Data: How did California’s peregrine population change from 1976 to 1998? - Biodiversity

37. Living Resources California Peregrine Falcon Recovery There were only a few breeding pairs at first, and they could produce only a few young. These, in turn, had to grow up before they had a chance to breed. As more pairs grew to breeding age, more and more young could be produced. Inferring: Why do you think the peregrine population grew fairly slowly at first? - Biodiversity

38. Living Resources California Peregrine Falcon Recovery The graph probably would have sloped downward from left to right, possibly reaching zero breeding pairs. Predicting: What might this graph have looked like if DDT had not been banned? - Biodiversity

39. Living Resources Biodiversity Medicine -Almost one half of all medicines sold today contain chemicals originally found in wild organisms. Ex: aspirin----bark of willow tree digitalis for heart disease-----foxglove vincristine for leukemia----rosy periwinkle vinblastine for Hodgkin’s—rosy periwinkle taxol for cancer---bark of Pacific Yew tree -Most of these medicines are now made in a laboratory so destruction of the plants are no longer necessary. But without the plants, we would not have been able to develop the medicines.

40. Living Resources More on Biodiversity Click the Planet Diary button for an activity about biodiversity. - Biodiversity

41. Living Resources Building Vocabulary After you read this section, reread the paragraphs that contain definitions of Key Terms. Use all the information you have learned to write a meaningful sentence using each Key Term. - Biodiversity Key Terms:Examples: biodiversityThe biodiversity of ecosystems can have great economic value. keystone speciesA keystone species is a species that influences the survival of many other species in an ecosystem. geneGenes are the structures in an organism’s cells that carry its hereditary information. extinctionThe disappearance of all members of a species from Earth is called extinction. endangered speciesSpecies in danger of becoming extinct in the near future are called endangered species. Key Terms:Examples: threatened species habitat destruction habitat fragmentation poaching captive breeding Species that could become endangered in the near future are called threatened species. The major cause of extinction is habitat destruction. Breaking larger habitats into smaller, isolated pieces, or fragments, is called habitat fragmentation. The illegal killing or removal of wildlife species from their habitats is called poaching. Captive breeding is the mating of animals in zoos or wildlife preserves.

42. Living Resources End of Section: Biodiversity

43. Living Resources QuestionAnswer Asking Questions Before you read, preview the red headings. In a graphic organizer like the one below, ask a what, how, who, when, or where question for each heading. As you read, write the answers to your questions. Why is biodiversity important to medicine? Biodiversity is important because there may be undiscovered medicines that exist in nature. What is the story of taxol? Taxol is a cancer treatment drug that comes from the bark of the Pacific yew tree. Scientists are concerned about the supply of this tree. How can we increase the supply of taxol? Today taxol can be reproduced in the lab. - The Search for New Medicines

44. Living Resources Links on Medicines From Plants Click the SciLinks button for links on medicines from plants. - The Search for New Medicines

45. Living Resources End of Section: The Search for New Medicines

46. Living Resources Graphic Organizer Ecological value Biodiversity is valued for is threatened by can be protected by Economic value Habitat destruction Pollution Laws Captive breeding Habitat preservation Poaching

47. Living Resources End of Section: Graphic Organizer