1. Warm- up 3/17: What is a trophic level? How much energy is transferred between trophic levels? Where does the lost energy go? Biogeochemical Cycling In The Ecosystem pp. 371-374

2. DEFINITIONS Ecosystem: an environment where the living (biotic) and non-living (abiotic) things affect one another Biogeochemical process: circulation of substances through living organisms and the environment

3. WATER CYCLE

4. Evaporation: water vapor enters the atmosphere Transpiration: evaporation of water through the leaves of plants Precipitation: water vapor that leaves the atmosphere

5. CARBON CYCLE

6. Photosynthesis: converting light energy into organic compounds Cellular respiration: breaking down organic compounds to release energy Combustion: burning of fossil fuels for energy releases CO 2 CO 2 from atmosphere to macromolecules Carbon from Macromolecules to CO 2 into atmosphere Carbon from old Macromolecules to CO 2 into atmosphere

7. NITROGEN CYCLE

8. nitrogen fixation: bacteria convert nitrogen gas to usable form (ammonia) ammonification: decomposers break down proteins/nucleic acids to NH 3 (ammonia) nitrification: bacteria convert NH 3 to nitrates/nitrites (i.e. like fertilizers) assimilation: plants take up nitrates/nitrites to make amino acids denitrification: bacteria return nitrogen to atmosphere

9. Homework Friday: Biome Week One Due Quiz: Friday Due Monday: Read P 371- 374 P 374 #1-5

10. ENERGY TRANSFER Trophic Level: position in a series of energy transfers

11. FOOD CHAIN Single pathway that traces the transfer of energy

12. Large Carnivore 3˚ Consumer (tertiary) Killer Whale Small Carnivore 2˚Consumer (secondary) Ex: Sea Otter Herbivore 1˚ Consumer (primary) Ex: Sea Urchin Producer Ex: Kelp

13. FOOD WEB Interconnected food chains Arrows show transfer of ENERGY