1. Ecology
E 2.2 Cycles in Nature

2. Cycles in Nature
The amount of water, carbon, nitrogen, oxygen and other materials for life are fixed within the Earth’s biosphere.
Evaporation – liquid water changes into water vapor
This occurs from lakes, rivers, plants, exhaling, and animal wastes.

4. Cycles in Nature Condensation – water vapor forms tiny droplets
Water Cycle – model that shows the movement of water from the surface to the atmosphere and back

7. Cycles in Nature
Nitrogen Cycle – transfer of the nitrogen from the atmosphere, to the soil, to living organisms, an back to the atmosphere
Nitrogen Fixation – bacteria in the soil forms nitrogen compounds that plants need
Most fertilizers contain nitrogen compounds.

9. Cycles in Nature
Carbon Cycle – model that shows the movement of carbon
Carbon dioxide is released into the atmosphere.
Carbon dioxide is taken into plants and supplies the carbon that it needs.
Photosynthesis uses carbon to make sugar and respiration uses sugar to make carbon dioxide.

11. Cycles in Nature Water cycle Evaporation Condensation Nitrogen cycle
Nitrogen fixation
Carbon cycle