1. Biosphere Sum total of the places in which organisms live
Includes portions of the hydrosphere, lithosphere, and atmosphere

2. Factors that Affect Distribution
Geologic history
Topography
Climate
Species interactions

3. Climate Average weather condition in a region Affected by:
amount of incoming solar radiation
prevailing winds
elevation

4. Warming the Atmosphere
Solar energy warms the atmosphere and sets global air circulation patterns in motion
Figure 48.3
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5. Rotation and Wind Direction
Earth rotates faster under the air at the equator than it does at the poles
Deflection east and west
Figure 48.2
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6. Seasonal Variation
Northern end of Earth’s axis tilts toward sun in June and away in December
Difference in tilt causes differences in sunlight intensity and day length
The greater the distance from the equator, the more pronounced the seasonal changes

7. Fig. 48-4, p.869 cold cool temperature warm temperature tropical
(equator)
warm temperature
cool temperature
cold
March
231/2º
June
December
September
Fig. 48-4, p.869

8. Fig. 48-5a, p.869

9. Fig. 48-5b, p.869

10. Pollutants
Substances with which an ecosystem has had no prior evolutionary experience
No adaptive mechanisms are in place to deal with them

11. Air Pollutants Carbon oxides Sulfur oxides Nitrogen oxides
Volatile organic compounds
Photochemical oxidants
Suspended particles

12. Fig. 48-9, p.871

13. Thermal Inversion
Weather pattern in which a layer of cool, dense air is trapped beneath a layer of warm air
cool air
warm inversion air
cool air
Figure 48-7 
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14. Acid Deposition Affects much of eastern North America
Caused by the release of sulfur and nitrogen oxides
Coal-burning power plants and motor vehicles are major sources

15. Fig. 48-8, p.871

16. Ozone Layer
Region 17 to 27 kilometers above sea level in the stratosphere
Molecules of ozone absorb most layers of ultraviolet light
Protects living organisms from excess exposure to UV light

17. Ozone Thinning
In early spring and summer ozone layer over Antarctica thins
Seasonal loss of ozone is at highest level ever recorded
South
America
Antarctica
Figure 48-6 
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18. Effect of Ozone Thinning
Increased amount of UV radiation reaches Earth’s surface
UV damages DNA and negatively affects human health
UV also affects plants, lowers primary productivity

19. Protecting the Ozone Layer
CFC production has been halted in developed countries, will be phased out in developing countries
Methyl bromide will be phased out
Even with bans it will take more than 50 years for ozone levels to recover

20. Soil Characteristics Amount of humus pH Degree of aeration
Ability to hold or drain water
Mineral content

21. Soil Profiles Layer structure of soil
Soil characteristics determine what plants will grow and how well
Rainforest
Desert
Grassland
Figure 48.13
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22. Deforestation Removal of all trees from large tracts of land
38 million acres logged each year
Wood is used for fuel, lumber
Land is cleared for grazing or crops

23. Effects of Deforestation
Increased leaching and soil erosion
Increased flooding and sedimentation of downstream rivers
Regional precipitation declines
Possible amplification of the greenhouse effect

24. Desertification
Conversion of large tracts of grassland to desertlike conditions
Conversions of cropland that result in more than 10 percent decline in productivity

25. Fig , p.884

26. Ongoing Desertification
Sahel region of Africa is undergoing rapid desertification
Causes are overgrazing, overfarming, and prolonged drought
One solution may be to substitute native herbivores for imported cattle

27. Eutrophication Enrichment of a body of water with nutrients
Can occur naturally over long time span
Can be triggered by pollutants

28. Streams Begin as springs or seeps Carry nutrients downstream
Solute concentrations influenced by streambed composition and human activities

29. Fig c, p.888

30. Fig d, p.888

31. Water Pollutants Sewage Animal wastes Fertilizers Pesticides
Industrial chemicals
Radioactive material
Excess heat (thermal pollution)

32. Wastewater Treatment Primary treatment Secondary treatment
Use of screens and settling tanks
Addition of chlorine to kill pathogens
Secondary treatment
Microbes break down organic matter
Tertiary treatment removes additional toxic substances; rarely used

33. Fig , p.889

34. Cholera Connection
Cholera outbreaks correlate with rises in sea temperature
Copepod population increases when phytoplankton increase in warming seas
Copepod host of Vibrio cholerae
harbors dormant stage