1. OBJECTIVE 14
Trace biogeochemical cycles through the environment, including water, carbon, oxygen, and nitrogen
Relating natural disasters, climate changes, nonnative species, and human activity to the dynamic equilibrium of ecosystems
Describing the process of ecological succession

2. Biogeochemical Cycles

3. The Water Cycle CONDENSATION PRECIPITATION:
Water vapor in the atmosphere condenses to form clouds.
PRECIPITATION:
Water falls to the Earth’s surface in the form of precipitation (rain or snow).
EVAPORATION and TRANSPIRATION:
Remaining water is heated by the sun and reenters the atmosphere by evaporation….OR
Some seeps into the soil becoming part of groundwater. Water is taken up by the roots of plants, passes through the plants, and reenters the atmosphere by transpiration (evaporation from leaves).

4. The Water Cycle

5. The Water Cycle

6. The Carbon Cycle Carbon gas is in the atmosphere. PHOTOSYNTHESIS:
Carbon dioxide in the air or dissolved in water if used in by plants, algae, or bacteria in photosynthesis and then release oxygen back into the atmosphere.
RESPIRATION, COMBUSTION, OR EROSION
Respiration: All living organisms use take in oxygen for respiration and release carbon dioxide back into the atmosphere.
Combustion: Carbon returns to the atmosphere through combustion or burning of wood or fossil fuels.
Erosion: As limestone erodes, the carbon becomes available to other organisms.

7. The Carbon Cycle

8. The Oxygen Cycle Oxygen is in the atmosphere.
Respiration: ALL living things take in oxygen from the atmosphere and release carbon dioxide.
Photosynthesis: Plants take in carbon dioxide and release oxygen back into the atmosphere.

9. The Oxygen Cycle

10. The Nitrogen Cycle
N2 (nitrogen gas) makes up about 78 percent of the atmosphere.
Nitrogen fixation: Nitrogen-fixing bacteria that live in the soil take nitrogen from the atmosphere and change it to a form that organisms can use (ammonia or NH3).
Ammonification: Bacteria produce ammonia from decaying matter.
Nitrification: Nitrate is produced from ammonia by the nitrogen-fixing bacteria.
Assimilation: Plants absorb nitrogen and use it to form organic compounds.
Denitrification: Nitrate is converted to nitrogen gas and release back into the atmosphere.
Organisms eat the plants, and the get rid of the nitrogen in the form of waste. The nitrogen returns to the soil.

11. The Nitrogen Cycle

12. Ecosystem Equilibrium

13. Natural disasters
Hurricanes, Tornadoes, Fires, Landslides, Floods, Droughts, etc.
Can wipe out entire populations within an ecosystem
Can sometimes move entire populations to a new location

14. Climate changes
Organisms must adapt to new climates or migrate to a new location to survive

15. Nonnative species Interrupting the food chain Habitat degradation
Diseases

16. Human activity Human-induced environmental changes Acid Rain
Caused by coal-burning power plants (sulfur combines with water vapor in the atmosphere to produce sulfuric acid)
Dying lakes and damaged forests due to pH acidity in the environment
Ozone Hole
Allows more ultraviolet radiation to read Earth’s surface causing an increase in human diseases such as skin cancer, cataracts, and cancer of the retina
Major cause: CFCs (chlorofluorocarbon chemicals) found in coolants in refrigerators and air conditioners, aerosol propellants in spray cans, plastic-foam cups and containers; use is now limited

17. Human activity Human-induced environmental changes Global Warming
Large increase in carbon dioxide in the Earth’s atmosphere related to burning of fossil fuels that has accompanied forest clearing and urban industrialization
Caused by the greenhouse effect – chemical bonds in the carbon dioxide molecules absorb solar energy as heat radiates from the Earth trapping the heat
Chemical Pollution
Industrial and Agricultural

18. Human activity Human-induced environmental changes Loss of Resources
Extinction of species
Destruction of habitats
Loss of Topsoil
Turning over to eliminate weeds
Allowing animals to overgraze ranges and pastures
Poor land management
Ground-water pollution and depletion
Wasted on watering lawns, washing cars, leaky and inefficient faucets and toilets
Polluted by irresponsible disposal of chemical wastes

19. Human activity Human-induced environmental changes
Human Population Growth

20. Ecological Succession