10/8/14

Objective: What are the biogeochemical cycles?

Do Now:

Cycles

• Biogeochemical cycles: the cycles of materials between living things and the environment– Nitrogen, carbon,

and water

Water Cycle

• Evaporation: liquid turns into a gas • Transpiration: evaporation from leaves of plants• Condensation: gas turns into a liquid in clouds• Precipitation: water in clouds falls to ground

Carbon Cycle

• Process that add carbon dioxide into the atmosphere:– Decomposition– Respiration (breathing)– Burning of fossil fuels

• Processes that take carbon dioxide out of the atmosphere:– Photosynthesis (by plants)

The Nitrogen Cycle

• 78 % of the gases in the atmosphere, but plants can’t use it directly. What must nitrogen be converted into?- Nitrates or Ammonia What converts Nitrogen? Where are these organisms found?• Nitrogen-fixing bacteria: convert atmospheric nitrogen into a form plants

can use– Can be found on roots of legumes

If plants absorb nitrates from the soil, how do animals get their nitrogen?- Eating plants or other animals