The document discusses key concepts about energy flow within ecosystems, including food chains, food webs, and energy pyramids. It defines producers as organisms at the first trophic level that convert sunlight into chemical energy through photosynthesis. Consumers are organisms at higher trophic levels that get energy by eating other organisms, including herbivores, omnivores, and carnivores. Decomposers break down dead organic matter and cycle nutrients. Food chains show a single path of energy transfer, while food webs illustrate the many interconnected food chains in an ecosystem. Energy pyramids demonstrate that the amount of available energy decreases at each trophic level as heat is lost during energy transfers between organisms.

1. Biology I: Energy Flow Through an Ecosystem (part 2) Food Chains, Food Webs, Energy Pyramids

2. Agenda – Tues. Oct. 4, 2011 Warm-Up Lesson Wrap-Up (Identifying food chains) Wrap-Up (Identifying producers, consumers, decomposers) Homework Worksheet

3. Today’s Objectives I will explore energy flow within an ecosystem. I will define: ecosystem, herbivores, omnivores, carnivores, food chain, food web, energy pyramid. I will trace food chains within a food web. I will classify organisms as: producers, consumers, or decomposers.

4. Warm-Up What do decomposers do? If you ate chicken that previously ate grass, what type of consumer would you be? Where does energy flow ultimately begin?

5. What is an Ecosystem? An Ecosystem is all of the living organisms and non-living environment found in a particular place

6. What is an Ecosystem? Example: a pond or aquatic ecosystem Living Things: fish, turtles, algae, insects, bacteria Non-Living Things: physical and chemical properties of the pond like the amount of oxygen in the pond and its pH

7. Trophic Level Each feeding level in an ecosystem Each level of a food chain or food web First Trophic Level: made up of only producers

8. Trophic Level Second Trophic Level: made up of primary consumers Herbivores: primary consumers that mainly eat plants Examples: rabbits and grasshoppers

9. Trophic Level Third Trophic Level: made up of secondary and tertiary consumers Omnivores: consumers that eat both plants and animals Examples: humans and squirrels

10. Trophic Level Carnivores: consumers that mainly eat other animals Examples: lions and sharks

11. Food Chain The flow of energy from the sun to producers to primary consumers then to higher order consumers can be shown in a food chain .

12. Food Chain Shows only one path for the flow of energy in an ecosystem.

13. Food Web Ecosystems have many different types of food chains. A food web shows how many different types of food chains are connected. Food webs show the feeding relationships in an ecosystem.

14. Example Food Web

15. Energy Pyramid Energy Pyramids show the energy loss between trophic levels in an ecosystem. The flow of energy: radiant energy (sunlight) chemical energy (stored in plants) kinetic energy and heat loss (created as consumers feed on each other)

16. Energy Pyramid The amount of available energy decreases up the energy pyramid.

17. Energy Pyramid Most of the “lost” energy is released as heat into the environment. Each trophic level contains fewer organisms. Why does this make sense?

18. How Many Chains are in this web? copyright cmassengale

19. Identify the Producers, Consumers, and Decomposers