1. Matter on Earth is limited, so the matter is used over and over again.
Cycles in Nature
Matter on Earth is limited, so the matter is used over and over again.

2. The Water Cycle (a.k.a. The Hydrologic Cycle)
The movement of water between the oceans, atmosphere, and living things.
Evaporation= the sun’s heat causes water to change from a liquid to a gas
Condensation= Water vapor cools and returns to the liquid state
Precipitation = Water that falls from the atmosphere to the land as rain, snow, sleet, or hail

3. Run off = Precipitation that falls on land and flows into streams, rivers, lakes, etc.
Groundwater = Precipitation that seeps into the ground and is stored in spaces between or within rocks.
Transpiration = The process in which plants release water through their leaves.

5. The Carbon Cycle
The exchange of carbon between the environment and living things.
Photosynthesis is the basis of the carbon cycle.
Plants need carbon dioxide
Humans need the oxygen and the food that the plants make

6. Decomposition = the breaking down of substances into simpler molecules
Decomposition = the breaking down of substances into simpler molecules. Carbon is released into the environment this way. Combustion = the burning of a substance to release carbon back into the environment.

8. The Nitrogen Cycle
The movement of nitrogen between the environment and living things.
78% of the atmosphere is nitrogen gas, but most organisms cannot use this gas directly.
Bacteria in the soil change nitrogen gas into forms that plants can use. This process is called Nitrogen Fixation.
Other organisms eat the plants and get the nitrogen they need this way.

10. Ecological Succession = the replacement of one type of community by another at a single place over a period of time --ex. Yellowstone National Park after a fire (page 36 figure 1)(pic on r 2yrs after wild fire)

11. Primary Succession
Primary Succession = The changes that occur in an area where no ecosystem had existed.
- No soil, just bare rock to begin with.
Organisms live and die on the rock and the rock is transformed slowly into soil.
Most primary succession begins with lichens.
Pioneer Species = the first organisms to live in an area where other organisms had not previously lived.
They start the process of succession!
(page 37 figure 2)

12. Secondary Succession
Secondary Succession = the changes that occur after a disturbance in an ecosystem. -Natural disasters -Figure 3 page 38 As succession proceeds, more species may become established. Biodiversity = The variety of species that are present in an area.