1. The Cycling of Materials

2. Cycling of Materials Materials in ecosystem are constantly reused
Carbon cycle
Nitrogen cycle
Phosphorus cycle
Sulfur Cycle

3. Carbon Cycle
Carbon cycle is a process by which carbon is cycled between the atmosphere, land, water, and organisms

4. Carbon Cycle
Photosynthesis = plants convert carbon dioxide into carbohydrates

5. Carbon Cycle
Cellular Respiration = carbon is converted back into carbon dioxide

6. Carbon Cycle
Organisms store carbon which may be released into the soil or air after an organism dies. These deposits can turn into coal, oil and natural gas

7. Carbon Cycle Carbon sink = the ocean
The ocean absorbs over a billion tons of carbon dioxide each year
Carbon Sinks = limestone is one of the larges carbon reservoirs on Earth

8. Carbon Cycle
When we burn fossil fuels, we release carbon into the atmosphere as carbon dioxide

9. Nitrogen Cycle Nitrogen makes up 78% of the gases in the atmosphere
Organisms cannot use atmospheric nitrogen, it must be altered before organisms can use it
Only nitrogen-fixing bacteria can do this.
They are a crucial part of the nitrogen cycle

10. Nitrogen Cycle
Nitrogen cycle: a process in which nitrogen is cycled between the atmosphere, bacteria and other organisms

11. Nitrogen Cycle
Bacteria take nitrogen gas from the air and transform it into molecules that living things can use

12. Nitrogen Cycle
Decomposers break down wastes and return nitrogen to the soil

13. Phosphorus Cycle
Phosphorus cycle: is the movement of phosphorus from the environment to organisms and then back to the environment

14. Phosphorus Cycle
Is incredible slow and does not normally include the atmosphere because phosphorus rarely occurs as a gas

15. Phosphorus Cycle
Erosion occurs and phosphorus enters soil and water

16. Phosphorus Cycle
Plants absorb phosphates in the soil through their roots

17. Phosphorus Cycle
Phosphorus is added to the soil and water by excreted waste from organisms and from when they die and decompose

18. Sulfur is important for the functioning of proteins and enzymes in plants, and in animals that depend upon plants for sulfur. Plants absorb sulfur when it is dissolved in water. Animals consume these plants, so that they take up enough sulfur to maintain their health
Sulfur Cycle

19. Fertilizers Fertilizers contain nitrogen and phosphate.
If excessive amounts are used, the fertilizer can enter terrestrial and aquatic ecosystems nearby
Can cause algal blooms
Algal blooms can deplete the oxygen in the aquatic ecosystem

20. Acid Rain
When we burn fuel, nitric oxide is released in the atmosphere which affects the nitrogen cycle
Nitric oxide can combine with oxygen and water vapor to form nitric acid which contributes to acid precipitation