1. 1 Review What causes soul erosion
1 Review What causes soul erosion? Why is soil erosion a problem Apply Concepts What are 3 ways in which the agricultural and forestry industries can improve the sustainability of soil 2 Review How is fresh water both a renewable and a limited resource Explain why are some pollutants more harmful to organisms at higher trophic levels Propose a Solution Pick one source of water pollution and describe a way in which we can reduce its effect.

2. Ch 6 Humans in the Biosphere
6.2 Using Resources Wisely

3. Soil Resources Topsoil Mineral and nutrient-rich portion of soil
Absorbs and retains moisture
Rich in organic matter and nutrients
Allows water to drain
Low in salts.

4. Soil Resources Can be a renewable resource if it is managed properly
Can be damaged or lost if it is mismanaged
1930’s “Dust bowl.”

5. Soil Erosion Removal of soil by water or wind
Occurs fasters without plants
Also removes organic materials
Humans cause by over use of land and logging.

6. Desertification
Process of farmland or other productive biome into desert
Change due to overgrazing, over farming, or drought
40 percent of Earth’s land is at risk.

7. Deforestation Loss of forests
Hold soil in place, protect the quality of fresh water supplies, absorb carbon dioxide, and help moderate local climate
Forests can regrow after cutting, but it takes centuries for succession to produce mature, old- growth forests
Old growth considered non renewable.

8. Soil Use and Sustainability
Leaving stems and roots of the previous year’s crop in the soil
Crop rotation
Contour plowing
Plant crops across and not down slopes
Terracing
Shaping the land to create level “steps”
Selective harvest of trees.

9. Freshwater Resources Can be either renewable or non renewable
Only 3 percent of Earth’s water is fresh water and most of that is locked in ice at the poles.

10. Water Pollution Pollutant Point source pollution
Harmful material that can enter the biosphere
Point source pollution
Enter water supplies from a single source
Think an actual pipe
Non point source pollution
Enter water supplies from many smaller sources.

11. Water Pollution May enter both surface water and underground water
Primary sources are industrial and agricultural chemicals, residential sewage, and nonpoint sources.

12. Biological Magnification
When a pollutant, such as DDT, mercury, or a PCB, is picked up by an organism and is not broken down or eliminated from its body.

13. Biological Magnification
Primary producers pick up a pollutant from the environment
Herbivores eat those producers and concentrate and store the compound
Carnivores eat the herbivores and concentrate and store the compound
Concentrations may reach 10 million times their original concentration.

14. Residential Sewage Contains lots of nitrogen and phosphorus
Can stimulate blooms of bacteria and algae that rob water of oxygen
Oxygen-poor areas called “dead zones” can appear
Also contains microorganisms.

15. Water Quality and Sustainability
Protect wetlands
Sewage treatment
Pollution control
Careful agricultural practices
Water conservation.

16. Atmospheric Resources
Oxygen
Ozone
Greenhouse gases.

17. Air Pollution Smog Acid rain
Chemical reactions in industrial processes and automobile exhaust
Acid rain
Nitrogen and sulfur compounds combine with water to form nitric and sulfuric acid
From burning fossil fuels.

18. Air Pollution Greenhouse gases Particulates
Burning fossil fuels and forests releases stored carbon
Agriculture releases methane
Particulates
Microscopic particles of ash and dust released by certain industrial processes and certain kinds of diesel engines.

19. Air Quality and Sustainability
Emission standards and clean-air regulations.

20. Each year, the U. S. EPA estimates emissions from a variety of sources
Each year, the U.S. EPA estimates emissions from a variety of sources. Look at the graph on pg 137.
Interpret Data Describe the overall trend in emissions since Is this what you would expect given the trends in energy consumption and automobile travel- Explain?
Interpret Data How does the graph differ from one that shows absolute values for emissions? Describe that graph/
Infer What do you think has contributed to the trends you see in this graph? Why would the EPA be particularly interested in this data?