1. ENERGY TRANSFER pp

2. In an ecosystem energy flows:
Sun  autotrophs  heterotrophs
producers consumer

3. PRODUCERS
Can make their own food through photosynthesis or chemosynthesis
Productivity: energy made by producers (after biological processes) available to consumers

4. gross primary productivity: rate at which producers capture energy in organic compounds
biomass: the amount of organic material produced
net primary productivity: the rate at which biomass accumulates (after some is used)

5. CONSUMERS get energy by eating other organisms
- herbivores: eat producers
- carnivores: eat other consumers
- omnivores: eat producers and consumers
- detritivores: feed on “garbage”
- decomposers: breakdown big molecules to
smaller molecules and recycle materials

6. ENERGY TRANSFER
trophic level: position in a series of energy transfers

7. Only 10% of the total energy is passed onto the next trophic level
1. lost to biological processes
2. lost as heat
3. not enough at level above to support
below

8. FOOD CHAIN single pathway that traces of energy transfer
Producer  herbivore  small  large
carnivore carnivore
Producer 1˚ consumer ˚ ˚

9. FOOD WEB
interrelated food chains
SEA OTTER
SEA STARS
SEA URCHINS
KELP

10. KEYSTONE SPECIES most dominant species in the community
Dictates community structure
Demonstrated by removal of keystone species from community
EX. sea stars in tidepools