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Chapter Contents – page vii

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Chapter Contents – page vii

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  1. Chapter Contents – page vii Chapter 5Biological Diversity and Conservation 5.1:Vanishing Species 5.1:Section Check 5.2:Conservation of Biodiversity 5.2:Section Check Chapter 5Summary Chapter 5Assessment

  2. Chapter Intro-page 110 What You’ll Learn You will explain the importance of biological diversity. You will distinguish environmental changes that may result in the loss of species. You will describe the work of conservation biologists.

  3. 5.1 Section Objectives – page 111 Section Objectives: • Explain biodiversity and its importance. • Relate various threats to the loss of biodiversity.

  4. Section 5.1 Summary – pages 111-120 Biological Diversity • Biodiversity refers to the variety of species in a specific area. • The simplest and most common measure of biodiversity is the number of different species that live in a certain area.

  5. Section 5.1 Summary – pages 111-120 Where is biodiversity found? • Areas around the world differ in biodiversity. • Biodiversity increases as you move toward the equator.

  6. Section 5.1 Summary – pages 111-120 Where is biodiversity found? • Tropical regions contain two-thirds of all land species on Earth.

  7. Section 5.1 Summary – pages 111-120 Where is biodiversity found? • The richest environments for biodiversity all seem to be warm places: tropical rain forests, coral reefs, and large tropical lakes.

  8. Section 5.1 Summary – pages 111-120 Studying biodiversity • How do ecologists perform experiments related to biodiversity? • Today you can read about projects in rain forests that require scientists to live 150 meters up in the canopy for weeks while they collect species that live only at that level.

  9. Section 5.1 Summary – pages 111-120 Studying biodiversity • Other researchers catalogue the organisms that live in coral reefs and others attach radio collars to sea turtles.

  10. Section 5.1 Summary – pages 111-120 Studying biodiversity • Still others work in laboratories comparing the DNA of members of isolated populations to see how or if these populations might be changing.

  11. Section 5.1 Summary – pages 111-120 Importance to nature • Living things are interdependent. • Living things can be niches for other living things. • Populations are adapted to live together in communities.

  12. Section 5.1 Summary – pages 111-120 Importance to nature • Scientists do know that if a species is lost from an ecosystem, the loss may have consequences for other living things in the area.

  13. Section 5.1 Summary – pages 111-120 Biodiversity brings stability • Biodiversity can bring stability to an ecosystem. • A pest could easily destroy all the corn in a farmer’s field, but it would be far more difficult for a single type of insect or disease to destroy all individuals of a plant species in a rain forest. • Ecosystems are stable if their biodiversity is maintained.

  14. Section 5.1 Summary – pages 111-120 Importance to people • Humans depend on other organisms for their needs. • Yet only a few species of plants and animals supply the major portion of the food eaten by the human population. • Biodiversity could help breeders produce additional food crops.

  15. Section 5.1 Summary – pages 111-120 Importance to people • Another important reason for maintaining biodiversity is that it can be used to improve people’s health. • Living things supply the world pharmacy. Penicillium

  16. Section 5.1 Summary – pages 111-120 Importance to people • Preserving biodiversity ensures there will be a supply of living things, some of which may provide future drugs. Penicillium

  17. Section 5.1 Summary – pages 111-120 Loss of Biodiversity • Extinction is the disappearance of a species when the last of its members dies. • Extinction is a natural process and Earth has experienced several mass extinctions during its history.

  18. Section 5.1 Summary – pages 111-120 Loss of Biodiversity • There is also a certain level of natural extinction, called background extinction, that goes on. • Scientists estimate that background extinction accounts for the loss of one to ten species per year. • However, the current rate of extinction exceeds that by many times.

  19. Section 5.1 Summary – pages 111-120 Loss of Biodiversity • A species is considered to be an endangered species when its numbers become so low that extinction is possible.

  20. Section 5.1 Summary – pages 111-120 Loss of Biodiversity • When the population of a species is likely to become endangered, it is said to be a threatened species.

  21. Section 5.1 Summary – pages 111-120 Threats to Biodiversity • Complex interactions among species make each ecosystem unique. • Changes to habitats can therefore threaten organisms with extinction.

  22. Section 5.1 Summary – pages 111-120 Habitat loss • One of the biggest reasons for decline in biodiversity is habitat loss.

  23. Section 5.1 Summary – pages 111-120 Habitat fragmentation • Habitat fragmentation is the separation of wilderness areas from other wilderness areas.

  24. Section 5.1 Summary – pages 111-120 Habitat fragmentation Habitat fragmentation has been found to contribute to: • increased extinction of local species. • changes in overall biodiversity. • disruption of ecological processes. • new opportunities for invasions by unwanted or exotic species. • increased risk of fire.

  25. Section 5.1 Summary – pages 111-120 Habitat fragmentation • The smaller the fragment, the less biodiversity the area can support. • Geographic isolation can lead to genetic isolation. • Habitat fragmentation also makes it difficult for species to reestablish themselves in an area.

  26. Section 5.1 Summary – pages 111-120 Edge and size • The edge of a habitat or ecosystem is where one habitat or ecosystem meets another.

  27. Section 5.1 Summary – pages 111-120 Edge and size • The different conditions along the boundaries of an ecosystem are called edge effects. • Different organisms might live along the edge of a forest instead of in the interior of the forest.

  28. Section 5.1 Summary – pages 111-120 Edge and size • If a road is cut through a wooded area, the shape of the wooded area changes and the edge is changed. • Now there is less distance between the edge and the interior. Some plants might die out.

  29. Section 5.1 Summary – pages 111-120 Edge and size • When an edge changes, animals might migrate because there isn’t enough space from which to gather food. • As a result, biodiversity of that area changes.

  30. Section 5.1 Summary – pages 111-120 Habitat degradation • Another threat to biodiversity is habitat degradation, the damage to a habitat by pollution. • Three types of pollution are air, water, and land pollution.

  31. Section 5.1 Summary – pages 111-120 Habitat degradation • Pollutants enter the atmosphere in many ways—including volcanic eruptions and forest fires.

  32. Section 5.1 Summary – pages 111-120 Habitat degradation • Burning fossil fuels is also a major source of air pollutants such as sulfur dioxide. • Acid precipitation—rain, snow, sleet, and fog with low pH values—has been linked to the deterioration of some forests and lakes.

  33. Section 5.1 Summary – pages 111-120 Habitat degradation • Ultraviolet waves emitted by the Sun also can cause damage to living organisms. • Ozone, a compound consisting of three oxygen atoms, is found mainly in a region of Earth’s atmosphere between about 15 km and 35 km altitude.

  34. Section 5.1 Summary – pages 111-120 Habitat degradation • The ozone in this region—known as the ozone layer—absorbs some of the ultraviolet waves striking the atmosphere, reducing the ultraviolet radiation reaching Earth’s surface. Click image to view movie.

  35. Section 5.1 Summary – pages 111-120 Water pollution • Water pollution degrades aquatic habitats in streams, rivers, lakes, and oceans. • A variety of pollutants can affect aquatic life.

  36. Section 5.1 Summary – pages 111-120 Water pollution • Excess fertilizers and animal wastes are often carried by rain into streams and lakes. • The sudden availability of nutrients causes algal blooms, the excessive growth of algae.

  37. Section 5.1 Summary – pages 111-120 Water pollution • Detergents, heavy metals, and industrial chemicals in runoff can cause death in aquatic organisms. • Abandoned drift nets in oceans have been known to entangle and kill dolphins, whales, and other sea life.

  38. Section 5.1 Summary – pages 111-120 Land pollution • Trash, or solid waste, is made up of the cans, bottles, paper, plastic, metals, dirt, and spoiled food that people throw away every day.

  39. Section 5.1 Summary – pages 111-120 Land pollution • Recycling Click image to view movie.

  40. Section 5.1 Summary – pages 111-120 Land pollution • The average American produces about 1.8 kg of solid waste daily. • That’s a total of about 657 kg of waste per person per year. • Although some of it might decompose quickly, most trash becomes part of the billions of tons of solid waste that are buried in landfills.

  41. Section 5.1 Summary – pages 111-120 Land pollution • The use of pesticides and other chemicals can also lead to habitat degradation.

  42. Section 5.1 Summary – pages 111-120 Exotic species • People sometimes introduce a new species into an ecosystem, either intentionally or unintentionally. • These species can cause problems for the native species. Kudzu

  43. Section 5.1 Summary – pages 111-120 Exotic species • When exotic species are introduced, these species can grow at an exponential rate due to the fact that they are not immediately as vulnerable to local competitors or predators as are the established native species.

  44. Section 1 Check Question 1 The term that refers to the variety of species in a specific area is _________. A. ecology B. conservation biology C. biodiversity D. endangered species

  45. Section 1 Check The answer is C. The simplest measure of biodiversity is the number of different species that live in a certain area.

  46. Section 1 Check Question 2 Describe the possible effect on a biological community of removing one species.

  47. Section 1 Check Because living things are interdependent, removing a single species from a community can remove a food source or otherwise break symbiotic relationships causing remaining organisms to suffer. This decreases the stability of the ecosystem.

  48. Section 1 Check Question 3 When the population of a species begins to significantly decline in numbers, it is __________. A. threatened B. extinct C. fragmented D. diverse

  49. Section 1 Check The answer is A. When the population of a species is declining and likely to become endangered, it is said to be a threatened species. Results of Species Search* Current Range Scientific Name Group Listing status Common Name Mammals T Africa African elephant Loxodonta africana *U.S. Fish & Wildlife Service Threatened and Endangered Species System (TESS) Through the Fish and Wildlife Service, information is available to the public on all species threatened or endangered T, under Listing Status, refers to threatened. An E would indicate endangered.

  50. 5.2 Section Objectives – page 121 Section Objectives • Describe strategies used in conservation biology. • Relate success in protecting an endangered species to the methods used to protect it.