1. Energy in an Ecosystem For your warm-up, answer these… Where is energy in an ecosystem? Where does it come from initially? Where does it go to / end up? What form is it in? You have 3 minutes – tick – tock – tick – tock

2. Organisms cannot exist without matter & energy All living things are made of water. All living things are made of the same matter as non-living things (carbon, hydrogen, nitrogen, phosphorus). All living things use energy (cell theory).

3. Biotic and abiotic factors are interdependent Living factors depend on non-living factors as a source of nutrients. Non-living factors depend on living factors to cycle matter.

4. Energy is transferred not recycled!

5. Energy Transfer = Food Chain SUN AUTOTROPHS HERBIVORES CARNIVORES

6. Trophic Level # of energy transfers from sun to organism (i.e. each step in a food chain)

7. TROPHIC LEVELS IN A CHAIN 1 st trophic level is the producer 2 nd trophic level is the primary consumer or herbivore 3 rd level is the secondary consumer or carnivore 4 th level is the tertiary consumer or carnivore feeding on other carnivores.

8. FOOD WEB a network of connected food chains

9. Energy Flow is Inefficient Energy stored as fat (~17%) E lost as HEAT (~48%) Organic Wastes (~35%)

10. So…10% Law Only 10% of energy from previous trophic level is available to next level as food or biomass.

11. Pyramid of Energy PYRAMID OF ENERGY

12. BIOMASS amount of energy converted to mass of living tissue that can be used by the next trophic level.

13. PYRAMID OF NUMBERS

14. CYCLE

15. Matter is cycled! Molecules are simply rearranged as they are made and broken down.

16. Water Cycle Precipitation/Condensation Absorption (roots, groundwater/soil, plant leaves) Transpiration (through stomata in plant leaves). Evaporation (heat)

18. Carbon Cycle CO 2 absorbed by plants Carbohydrate made (glucose) Death and decomposition Fossil fuels (combustion) releases C into atmosphere.

20. Nitrogen Cycle Assimilation - N from atmosphere is gained by soil through nitrogen fixation by bacteria. Ammonification (from excretory wastes). Denitrification converts NH 3 back to N 2.