1. Chapter 18 Section 4 Ecosystem Recycling

2. Interview…  Interview 2 of your peers using the following question:  How could the local drinking water become polluted or contaminated?  Human or Animal waste  Pesticides  Toxic run-off from manufacturing plants

3. The Water Cycle  Where can water be found?  Lakes, rivers, streams, oceans, vapor, in the ground.  When you open a new bottle of water do you think it is brand new water?  The movement of water between these reservoirs is known as the water cycle.

4. The Water Cycle  Made up of 3 Processes…  1. Evaporation- adds water as vapor to the atmosphere  How does this happen?

5. The Water Cycle  2. Transpiration- the process when water evaporates from the leaves of plants in terrestrial ecosystems.

6. The Water Cycle  3. Precipitation- the process by which water leaves the atmosphere and abiotic factors play a role.

9. Time for Questions…  What is the main power source behind the water cycle?  What does the water cycle have to do with the weather?

10. Carbon Cycle  Photosynthesis- plants and other autotrophs use carbon dioxide, solar energy, and water to make carbohydrates.

11. Carbon Cycle  Cellular Respiration- processes that takes place in the cells and tissues during which energy is released and carbon dioxide is produced.  Organisms use the oxygen released to help breakdown carbohydrates.

12. Carbon Cycle  Decomposition- decomposers release carbon dioxide back into the atmosphere when they break down organic material.

13. Questions Time…  How might the removal of vegetation affect oxygen levels in the atmosphere?

14. Nitrogen Cycle  The way nitrogen flows through the ecosystem.  Where can nitrogen be found?  Nitrogen Gas- 78% of the atmosphere  Plants can only use nitrogen in the form of nitrate.  Nitrogen Fixation- process of converting nitrogen gas into nitrate.  Nitrogen Fixing Bacteria- convert nitrogen gas into usable form.  Live in the soil  Inside swellings on the roots of plants: beans, peas  Plant provide Carbohydrates and the bacteria provide the usable nitrogen.  Example: Farmers plant legumes

15. Nitrogen Cycle  Decomposers- break down dead plants and animals that contain nitrogen.  Dung and Urine also contain nitrogen that are decomposed, releasing Carbon Dioxide back into the atmosphere.

16. Time for Questions…  Identify the role of bacteria in the Nitrogen Cycle and tell their role.  What are the mutual benefits in the association between nitrogen-fixing bacteria and the plants they inhabit.

17. Water Trivia Game  Only 3% of Earth’s water is fresh water. 97% of the water on Earth is salt water.  The water found at the Earth’s surface in lakes, rivers, streams, ponds, and swamps makes up only 0.3% of the world’s fresh water.  68.7% of the fresh water on Earth is trapped in glaciers.  30% of fresh water is in the ground.  More than 25% of bottled water comes from a municipal water supply, the same place that tap water comes from.  A ten meter rise in sea levels due to melting glaciers would flood 25% of the population of the United States.  There is more fresh water in the atmosphere than in all of the rivers on the planet combined.  If all of the water vapor in the Earth’s atmosphere fell at once, distributed evenly, it would only cover the earth with about an inch of water.  Approximately 400 billion gallons of water are used in the United States per day.  It takes six and a half years for the average American residence to use the amount of water required to fill an Olympic-sized swimming pool (660,000 gallons).  American residents use about 100 gallons of water per day.  Americans use more water each day by flushing the toilet than they do by showering or any other activity.[ii]