Principles of Ecology

1. Principles of Ecology Chapter 2.2: Flow of Energy in Ecosystems

2. Student Performance Standards • SB4. Students will assess the dependence of all organisms on one another and the flow of energy and matter within their ecosystems. • A. Investigate the relationships among organisms, populations, communities, ecosystems, and biomes. • B. Explain the flow of matter and energy through ecosystems by: • Arranging components of a food chain according to energy flow. • Comparing the quantity of energy in the steps of an energy pyramid. • Explaining the need for cycling of major nutrients (C, O, H, N, P). • C. Relate plant adaptations, including tropisms, to the ability to survive stressful environmental conditions.

3. Essential Question • How does energy flow through an ecosystem?

4. Ecosystems are Open Systems! • Ecosystems are not isolated from each other. • They do not have clear boundaries. • Things move from one ecosystem to another. • Example: A green turtle that lives off the shores of Miami, Florida swims 90 miles to an island off the coast of Cuba to lay her eggs every summer. She travels from one ecosystem to another.

6. Chapter 2, Section 2: Flow of Energy in Ecosystems • Organisms cannot survive without a constant source of energy. • You are a living organism. You get your energy from the foods you eat. • Many of the foods you eat come from plants. • Where do plants get their energy?

7. Life Depends on the Sun • Plants use sunlight to make sugar molecules in a process called photosynthesis: Sunlight + carbon dioxide + water = sugar molecules (called carbohydrates), and oxygen gas

8. Flour Production Wheat Products: Pizza Dough Pretzels Breads Pasta Cookies Cakes

9. Photosynthesis Equation: carbohydrate 6CO2 6H2O Solar energy C6H12O6 6O2

10. The Flow of Energy from Plants to Animals:

11. When animals eat a plant……. • Some of the energy is transferred from the plant to the animal. • Organisms use this energy to move, grow, and reproduce.

12. From Producers to Consumers • A producer is an organism that makes its own food. • Also called autotrophs – use sunlight to make and store their own food. • Ex: Plants, bacteria, algae • In places where sunlight is unavailable, some bacteria use hydrogen sulfide and carbon dioxide to make organic molecules as food.

13. From Producers to Consumers • A consumer is an organism that gets its energy from eating other organisms. • Also called heterotrophs. • Name the producer. • Name the consumer.

14. 4 Types of Consumers: • Herbivores – eat only producers. • Carnivores – eat other consumers. • Omnivores – eat both plants and animals.

15. 4. Detritivores (decomposers) – eat fragments of dead matter; help break down dead organisms. Ex: centipedes, woodlice, earthworms, bacteria, and molds

16. Models of Energy Flow • Ecologists often use models to show the flow of energy through an ecosystem. • Food Chains • Food Webs • Ecological Pyramids

17. A Food Chain is…… • Energy is transferred from one organism to the next as each organism eats another:

18. Food Chain

19. Food Web • Energy flow in an entire ecosystem. • A food web shows many possible feeding relationships in an ecosystem:

21. Ecological Pyramids • An ecological pyramid is a diagram that can show the relative amounts of energy, biomass, or numbers of organisms at each trophic level in an ecosystem. • Energy Pyramid • Biomass Pyramid • Pyramid of Numbers

22. Energy Pyramids Times Times Times Times

23. Ecological Pyramid

24. Trophic Levels • Each step through which energy is transferred is called a trophic level: • Primary • Secondary • Tertiary • Quaternary • Each time energy is transferred from one organism to another, some of the energy is lost as heat and less energy is available to organisms at the next level.

25. Rule of Ten • Ecological Pyramid – only 10% of energy transfers up each trophic level

26. How Energy Loss Affects an Ecosystem: • The decreased amount of energy at each trophic level affects the organization of an ecosystem. • Because so much energy is lost at each level, there are fewer organisms at the higher trophic levels.

27. Chemical Equation for Cellular Respiration: Cellular Respiration: Carbohydrates + oxygen = carbon dioxide + water + energy C6H12O6 6O2 6CO2 6H2O energy

28. Biomass Pyramid • Biomass – the total mass of living matter at each trophic level. • In a pyramid of biomass, each level represents the amount of biomass consumed by the level above it.

29. Pyramid of Numbers

30. Biomagnification • Increase in concentration of a toxic substance as it moves up the food chain. • Contaminants, such as mercury, concentrate in the fat of organisms permanently. • As bigger animals eat smaller animals, contamination in the food is added to the level already in their body. • Bioaccumulation is a problem in the north because of higher concentrations of toxic pollution.

31. Ticket out the Door • Draw a food web that includes: • 4 Producers • 3 Primary Consumers • 2 Secondary Consumers • 1 Tertiary Consumer • Make sure to draw arrows in correct direction • From what’s being eaten to the eater • Make sure to label each organism with what trophic level they are (P, 1°, 2°, 3°)