Chapter 6

1. Chapter 6 Humans in the Biosphere Created by C. Ippolito Jan 2004

2. Chapter 6 Section 1A Changing Landscape What types of human activities affect the biosphere? Created by C. Ippolito Jan 2004

3. Objectives • Describe human activities that can affect the biosphere. Created by C. Ippolito Jan 2004

4. Human Activities • Hunting and Gathering • Agriculture • Industry • Urban Development Created by C. Ippolito Jan 2004

5. Hunting and Gathering • Subsistence Hunting • Non demanding • Use only what is needed • Over Hunting • Reduces populations Created by C. Ippolito Jan 2004

6. Agriculture • Farming • Dependable food supply • Domestication of Animals • Overgrazing • Soil erosion • Water supply • Modern Technique • Irrigation • Machinery Created by C. Ippolito Jan 2004

7. Green Revolution • Increase food supply to help feed poor • New strains of crops • Larger yields • Less nutrients • Less water • Monoculture • Plant fields with one strain • positive - greater yields • negative - more susceptible to pests Created by C. Ippolito Jan 2004

8. Industrial Growth and Urban Development • Machines & Factories • Large scale agriculture • Better food supply • More products – less effort • Mobility • Suburban sprawl • Industrialization • Higher energy requirements • Higher waste production • Air Damage • Water Damage • Soil Damage Created by C. Ippolito Jan 2004

9. Chapter 6 Section 2Renewable and Nonrenewable Resources How are environmental resources classified? What effects do human activities have on natural resources? Created by C. Ippolito Jan 2004

10. Objectives • Explain how environmental resources are classified. • Describe how human activities affect land, air, and water resources. • Identify the characteristics of sustainable use. Created by C. Ippolito Jan 2004

11. Tragedy of the Commons • Natural resources are available to everyone to use. • No one is responsible to preserve resources • Natural resources will eventually be destroyed. Created by C. Ippolito Jan 2004

12. Types of Resources • Renewable • Can regenerate, so it is replaceable • Trees – lumber • Water • Soil • Nonrenewable • Cannot be regenerated by natural processes • Fossil fuels – coal, natural gas, oil • Mineral ores – iron, aluminum Created by C. Ippolito Jan 2004

13. Sustainable Use • Way to use natural resources with out depleting them. • Human use with out harm Created by C. Ippolito Jan 2004

14. Land Resources • Soil is needed for crops • Soil erosion • Caused by plowing • Desertification • Caused by farming, overgrazing, natural cycles • Sustainable practices • Contour plowing – across slopes • Leave crop roots in soil Created by C. Ippolito Jan 2004

15. Forest Resources • Deforestation • Soil erosion • Old Growth Forests • Nonrenewable – never been cut • Sustainable Use • Forest Management • Cut old trees • Breed faster growing trees Created by C. Ippolito Jan 2004

16. Ocean Resources • Overfishing • Harvested faster than can grow • Cod, halibut, salmon, herring, king crab • Sustainable Use • Close fisheries • Not possible in international waters • Aquaculture • Can cause pollution Created by C. Ippolito Jan 2004

17. Air Resources • Emissions – industry, transportation • Smog – health issues • Particulate matter – • Acid rain – damage water resources • Corrective Measures • Auto emission control • Smokestack scrubbers • Clean Air Legislation Created by C. Ippolito Jan 2004

18. Water Resources • Water Pollution • Runoff – fertilizers, pesticides • Sewage – microorganisms cause disease • Sustainable Use • Maintain natural wet lands • Water conservation Created by C. Ippolito Jan 2004

19. Chapter 6 Section 3Biodiversity What is the value of biodiversity? What are the current threats to biodiversity? What is the goal of conservation biology? Created by C. Ippolito Jan 2004

20. Objectives • Define biodiversity and explain its value. • Identify current threats to biodiversity. • Describe the goal of conservation biology. Created by C. Ippolito Jan 2004

21. Value of Biodiversity • Provides food, industrial products, medicines – some yet to be found • Biodiversity • different species in biosphere • Ecological Diversity • different habitats, communities, and processes • Genetic Diversity • different genetic information within species Created by C. Ippolito Jan 2004

22. Threats to Biodiversity • Human activities • Habitat reduction • Farming • Urban development • Species Extinction • Hunting – poaching – animal part trafficking • Habitat destruction – fragmentation - • Toxins in food web – biological magnification • Introduction of foreign species Created by C. Ippolito Jan 2004

23. Pollution • DDT – insecticide • Raptor endangerment • Weakened egg shells • Biological Magnification • Poison concentrated in food web Created by C. Ippolito Jan 2004

24. Invasive Species • Foreign species introduced by man • Rapid reproduction • No natural predators • Loosestrife plants • Zebra mussels • Mediterranean fruit fly • Kudzu vine • Gypsy moth Created by C. Ippolito Jan 2004

25. Conservation • Management of natural resources • Protect habitat • Wildlife Preserves • National Parks • Protect wildlife • Endangered Species Act • Protect ecosystems Created by C. Ippolito Jan 2004

26. Chapter 6 Section 4Charting a Course for the Future What are two types of global change of concern to biologists? Created by C. Ippolito Jan 2004

27. Objectives • Describe two types of global change of concern to biologists Created by C. Ippolito Jan 2004

28. Ozone Depletion • Ozone Layer • O3 gas • Absorbs UV light • Mutagen – changes DNA • CFC’s catalyze O3 breakdown • Aerosols • Refrigerants • AC, refrigerators, freezers Created by C. Ippolito Jan 2004

29. Global Warming • Increase in the average temperature over past century • +0.5°C in last 120 years • Last 20 years rate increasing • Greenhouse Effect • CO2 in atmosphere Created by C. Ippolito Jan 2004