Feb 5, 2010 How is predation different from parasitism?

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)

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

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

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

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

Plankton Microscopic World Daphnia

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

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***

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

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.

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

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