1. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh Edition Solomon Berg Martin Chapter 55 Humans in the Environment

2. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Biological diversity Variety of organism considered at three levels –Genetic diversity –Species diversity –Ecosystem diversity Decreasing worldwide

3. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Extinct species All members of the species are dead Endangered species In imminent danger of extinction Threatened species Population is quite small, but extinction is less imminent

4. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment An extinct species

5. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Four causes of declining biological diversity Most significantly, habitat loss and fragmentation In addition, pollution, introduction of invasive species, pest and predator control, and commercial activity

6. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Percentage of imperiled U.S. species that are threatened by various human activities

7. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Conservation biology Study of how humans affect organism Development of ways to protect biological diversity

8. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Habitat destruction

9. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Biodiversity hotspots

10. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment In situ conservation Efforts to preserve biological diversity in the wild Ex situ conservation Efforts to preserve biological diversity in human-controlled settings

11. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Endangered Species Act (ESA) Authorizes the U.S. Fish and Wildlife Service to protect bio- diversity domestically and abroad CITES International organization to protect species from illegal international wildlife trade

12. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Illegal commercial harvesting

13. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Organisms listed as endangered or threatened in the U.S., 2003

14. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Forests provide many ecosystem services Watershed protection Soil erosion prevention Climate moderation Protection from flooding Wildlife habitat Greatest problem is deforestation

15. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Deforestation

16. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Greenhouse gases Carbon dioxide Methane Surface ozone Nitrous oxide Chlorofluorocarbons Causes greenhouse effect and global warming and enhanced greenhouse effect

17. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Mean annual global temperature,1960 to 2002

18. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Surface Ozone Ozone (O 3 ) is a form of oxygen Human-made pollutant in lower atmosphere Occurs naturally in the stratosphere

19. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Ozone destruction in the stratosphere Amount of ozone in the stratosphere is declining (ozone depletion) Large areas of ozone thinning over Antarctica and the Arctic Excessive exposure to UV radiation linked to human disease, i.e., skin cancer

20. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Increase in greenhouse gases, preindustrial to present

21. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Enhanced greenhouse effect

22. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment UV radiation and the ozone layer

23. Copyright © 2005 Brooks/Cole — Thomson Learning Biology, Seventh EditionCHAPTER 55 Humans in the Environment Ozone thinning