1. Feb 5, 2010
How is predation different from parasitism?

2. Q: Let’s turn our focus to ecosystems
Q: Let’s turn our focus to ecosystems. What are some interactions of ecosystems?
Habitat: where organisms live
Niche: an organism’s role in the ecosystem (shelter, food, reproduction)

3. Q: How does energy flow in an ecosystem?
It always starts with the SUN. (most energy available)

4. Q: How does energy flow in an ecosystem?
Autotroph: makes their own food using sunlight (PLANTS) or chemicals (some bacteria), also called PRODUCERS
“Auto” = self
“troph” = feed

5. Q: How does energy flow in an ecosystem?
Heterotroph: eats other stuff
“hetero” = different/other
“troph” = feed
Can be called consumers

6. Q: How does energy flow in an ecosystem?
Herbivores: eat only plants
Carnivores: eat other heterotrophs (animals)
Omnivores: eat plants and animals
Detritivores: eat dead matter and return nutrients to soil
Decomposers: secrete chemical to break down matter and absorb nutrients, return nutrients to soil

7. Plankton
Microscopic World
Daphnia

8. Q: How can we show energy flow in an ecosystem?
Energy is “lost” as we move through an ecosystem (HEAT!)
Food chains
Simplified version
Use arrows to show flow of energy

10. Q: How can we show energy flow in an ecosystem?
Food Webs
Many food chains put together
Use arrows to show flow of energy
***Trophic Level: each step of a food chain/web/pyramid***

11. Q: How can we show energy flow in an ecosystem?
Ecological Pyramids
Pyramid of Energy: represents energy available at each trophic level

12. Q: How can we show energy flow in an ecosystem?
90% of energy is lost each time you move a step
If you start with 100 J of energy in producers:
primary consumers will get 10 J
secondary consumers will get 1 J
tertiary consumers will get 0.1 J.

13. Q: How can we show energy flow in an ecosystem?
Pyramid of Biomass: each level represents amount of biomass consumed by next trophic level
Biomass: total mass of living matter at each trophic level

15. Q: How can we show energy flow in an ecosystem?
Pyramid of Numbers: each level represents number of organisms consumed by the next trophic level