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Humans in the Biosphere

Humans in the Biosphere. Chapter 6. Changing Landscape. Activities affect environment Relationship between resources and sustainable use. Effect of Human Activity. Living on Island Earth We affect environment when: Obtain food Eliminate waste products Build places to live

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Humans in the Biosphere

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  1. Humans in the Biosphere Chapter 6

  2. Changing Landscape Activities affect environment Relationship between resources and sustainable use

  3. Effect of Human Activity • Living on Island Earth • We affect environment when: • Obtain food • Eliminate waste products • Build places to live • Humans impact regional and global environments: • Agriculture • Development • Industry Which impact natural resources such as soil, water and the atmosphere.

  4. Effect of Human Activity Agriculture • Dependable supply of food that can be stored for future use • Monoculture-clearing large areas of land to plant a single highly productive crop annually (soybean) • Efficient sowing , tending, and harvesting of crops • Providing food for nearly 7 billion people-impacts natural resources • Fertilizer production and Farm machinery-consume large amounts of fossil fuels.

  5. e.g.-Canola Oil Soybean

  6. Effects of Human Activity • Development • Dense human communities produce lots of wastes. • Not disposed correctly they affect air, water and soil. • Consumes farmland • Habitat fragmentation

  7. Effects of Human Activity • Industrial Growth • Conveniences utilize a great deal of energy to produce and power • Energy comes from burning fossil fuels such as coal, oil and natural gas (emits greenhouse gases-90 % of US emissions) • Past-dumped waste directly into air, water and soil

  8. Sustainable development • Goods-things that can be bought and sold and have value in terms of dollars and cents. • Services-processes or actions that produce goods. • Ecologically-these are goods and services produced by ecosystems that benefit the human economy.

  9. What type of goods and service?

  10. Ecosystem Goods and Services • Many natural and free of charge • Breathable air • Drinkable water • In environment cant provide-society must spend money to produce • E.g. many places drinkable water is free; source polluted or damages and water quality falls-must pay for water treatment to be safe.

  11. Renewable and Nonrenewable Resources Renewable Nonrenewable Natural processes cannot replenish these goods within a reasonable amount of time. E.g. fossil fuels (formed from buried organic material over millions of years) ; when depleted they are gone. • Can be produced or replaced by healthy ecosystem. • E.g. southern white pine that can grow back when an old tree dies or is cut down.

  12. Sustainable Resource Use • Conscious Way to use resources • Provides for human needs while preserving the ecosystem that produce natural resources • No harm to soil, water or climate • Flexible enough to survive environmental stresses (droughts, floods, heat waves, etc.) • Human economic systems-more than just enable people to survive-must help situation.

  13. Using Resources Wisely

  14. Soil Resources • Important objects that rely on soil • Grain in cereal • Wood in home • Pages of textbook • Healthly soil supports agriculture and forestry.

  15. Topsoil- mineral- and nutrient- rich portions of soil • GOOD • absorbs and retains moisture • allows draining • rich organic matter and nutrients • Renewable Resource • Properly managed • Healthy soil can take centuries to forms but be lost quickely

  16. 1930s drought • Badly eroded once-fertile soil of Great Plains • Thousands lost jobs and homes • Became a desert w/ dry soil- aka “dust bowl” • Cause-conversion of prairie land to cropland in way that left soil vulnerable to erosion (wearing away).

  17. Soil Erosion • Removal of soil by water or wind • Worse- land plowed and left barren b/w plantings. • No roots to hold soil-easily washed away • Badly eroded-organic materials and minerals that make soil fertile are carried away.

  18. Desertification • Dry climates-farming, overgrazing, seasonal drought and climate change can turn farmland to desert. • Great Plains is an example • 40% of Earth’s land is considered at risk

  19. Desertification Risk

  20. Deforestation • Loss of forest • Forests value • Wood • Hold soil in place • Protect quality of water • Absorb CO2 • Moderate local temperature

  21. Deforestation • ½ of world’s old-growth forests (never been cut) lost • Temperate areas-forest can regrow after cutting; centuries for succession • Tropics-forest DO NOT grow back after logging • Old-Growth forest usually considered non-renewable.

  22. Deforestation can: • Leads to severe erosion • Change local soils and microclimates in a way prevent regrowth of trees • E.g Tropical Rain Forest- • Soil is thin and decomposition quick b/c of high heat and humidity. • Soil ok for few years • Then becomes wasteland; harsh conditions prevent regrowth

  23. Soil use and sustainability • Minimize erosion through careful management of both agricultural and forestry • Leaving stems and roots can help • Crop rotation-planting different crops at different seasons or in different years (erosion and nutrient loss) • Altering shape (e.g. planting fields across, instead of down and slope; reduce water runoff and erosion.

  24. Freshwater Resources • Goods and services-drinking water, industry, transportation, energy and waste disposal. • Fresh water is renewable resource; some is not • Ogallala Aquifer- spans 8 states (South Dakota to Texas); more than a million years to collect; not replenished by rainfall; expected to run dry in 20-40 years. • 3% Earth’s water is fresh water- most locked in ice at poles

  25. Water Pollution • Pollutant-harmful material that can enter biosphere. • Point source- pollution enter water supply from single source (e.g. factory or oil spill) • Nonpoint source- pollutant enters from many smaller sources (e.g. grease and oil washed off streets; chemicals released by factories and autos) • Primary sources-industrial and agriculture chemicals; residential sewage; and nonpoint sources

  26. Industrial and Agricultural Chemicals Industrial Chemicals Agricultural Chemicals Pesticides and insecticides Runoff-enter water supply DDT-pesticide; dangerous, controls against pest and disease carrying mosquitoes; threatened fish-eating birds-females laid fragile eggs; lowered numbers Biomagnification • PCBs-Chemical used in industry until 1970s; large-scale contamination events; banned. • Can be difficult, if not impossible to eliminate • Others-Cadmium, lead, mercury and zinc

  27. Biological Magnification Pollutant concentrations increase as they move up the trophic levels.

  28. DDT (dichlorodiphenyltrichloroethane)

  29. Residential Sewage • Household waste-becomes sewage • Not poisonous-contains lots of nitrogen and phosphorus • Reasonable amounts-process and absorbed healthy ecosystem • Large amounts-blooms of algae and bacteria rob water of oxygen. • Dead zones-oxygen poor areas- fresh or salt water • Sewage carry microorganism that can spread disease.

  30. Water Quality and Sustainability • Protect natural systems involved in water cycle. • Watershed-land whose groundwater, streams, and rivers drain into same place (lake or river) • Sewage treatment can lower bacteria and prevent dead zones • Integrated Pest Management (IPM) instead of pesticides-biological control

  31. Water Quality and Sustainability • Use of less-poisonous sprays • Crop rotation • Water conservation • drip irrigation

  32. Atmospheric Resources Common resource whose quality has a direct effect on health *Provides Oxygen we breathe

  33. Ozone Form of oxygen-O3 Natural; Upper atmosphere Absorbs harmful UV radiation from sunlight; protecting skin from cancer

  34. Atmospheric Services • Greenhouse Gases- (CO2, Methane and water vapor) regulate global temperatures • W/out Earth would be 30°C cooler • Never “Used Up” • Human activities can have lasting impact

  35. Air Pollution • Air quality reduced-respiratory illnesses are made worse and tend to increase. • Globally-climate patterns may be impacted

  36. Cause of Air Pollution • Industrial processes • Burning fossil fuels

  37. Forms of Air Pollution • Smog • Acid Rain • Greenhouse Gases • Particulates

  38. Smog • Gray-brown haze formed by chemical reactions among pollutants released into the air by industrial processes and automobile exhaust.

  39. Smog • Products • Ozone-High in atmosphere protective; ground level, threatens health, especially those with respiratory conditions. • 2008 summer Olympics in Beijing

  40. Acid Rain • Rain containing nitric and sulfuric acids • Cause-burning fossil fuel releases nitrogen and sulfur compounds; combine with water vapors and from acids. • Effects • kills plants • Damages leaves • Changes chemistry of the soil and surface water • Dissolve and release mercury and other toxic elements from soil (enter other parts of biosphere)

  41. Greenhouse Gases • Burning fossil fuels and forest-release carbon into atmosphere as CO2 • Agriculture-raising cattle to farming rice releases methane and other green house gasses. • Contribute to global warming and climate change.

  42. Particulates • Visible, microscopic particles from certain industrial processes and certain diesel engines. • Ash, dust, soot, smoke aerosols • Enter nose and mouth-to lungsand cause serious health problems.

  43. Air Quality and Sustainability • Difficult to improve • Doesn’t stay in one place • Doesn’t “belong” to anyone • Improvements • Automobile emissions standards • Clean-air regulations • Phasing out of lead gas; now banned in US

  44. Complete: Analyzing Data, page 164.

  45. Biodiversity Total of all the genetically based variation in all organisms in the biosphere Variety of organisms

  46. Types of Biodiversity • Ecosystem Diversity-Variety of habitats, communities and ecological processes in the biosphere. • Species Diversity- The number of different species in the biosphere or in a particular area. • 1.8 species identified and named • 30 million more to be discovered • Genetic Diversity-Sum total of all different forms of genetic information carried by a particular species, or all organisms on Earth.

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