1. Some Terms and Definitions • Ecosystems: A grouping of plants, animals, and microbes occupying an explicit unit of space and interacting with each other and their environment. • Ecotone: Transitional region between different ecosystems.

2. Ecosystems: A Description • Biotic communities: grouping or assemblage of plants, animals, and microbes. • Species: different kinds of plants, animals, and microbes in the community. • Populations: number of individuals that make up the interbreeding, reproducing group. • Associations: how a biotic community fits into the landscape.

3. Ecotones on Land • Shares many of the species and characteristics of both ecosystems • May also include unique conditions that support distinctive plant and animal species

4. Terrestrial-to-Aquatic-System Ecotone • Shares many of the species and characteristics of both ecosystems • May also include unique conditions that support distinctive plant and animal species

6. The Structure of Ecosystems • Trophic categories • Trophic relationships: food chains, food webs, trophic levels. • Nonfeeding relationships: symbiosis • Abiotic factors

7. Autotrophs = Producers = Self feeders

9. Consumers = Heterotrophs • Primary consumers = herbivores = rabbit: eat plant material • Secondary consumers = carnivores = predators = coyotes: prey are herbivores and other animals.

10. Parasites = predator = either plant or animal: prey are plants or animals. Consumers = Heterotrophs

11. Detritus Food Web

12. Trophic Categories

13. Third-order Consumer Secondary Consumer Primary Consumer Producer Trophic Relationships: Food Chain

14. Match Organisms with Trophic Level(s)

15. Match Trophic Categories with Trophic Level(s)

16. Trophic Relationships Among Producers and Consumers

17. Food Webs = Food Chain Interrelationships

18. Third-order Consumer 1Kcal - 10x Secondary Consumer 10 Kcal - 10x Primary Consumer 100 Kcal - 100x Trophic Level Energy Flow 10,000 Kcal Producer

19. Biomass Pyramid

20. 5 4 3 2 1 Trophic Levels: Pyramid of Biomass Which level is occupied by: producers? primary consumers? secondary consumers? third-order consumers?

21. 5 4 3 2 1 Trophic Levels: Pyramid of Energy Which level is occupied by: producers? primary consumers? secondary consumers? third-order consumers?

22. Nutrient Cycles and Energy Flow

23. HW Questions(answer these 5 questions in a Word doc and bring the word doc to next class (do not submit or email it)! • Q1. How are “ecotone” and “environmental gradient” similar or different? Explain your answer. • Q2. Answer the questions presented in Slide 20 and Slide 21 of this PPT • Q3. What is the difference between the biotic community and the abiotic environmental factors of an ecosystem? • See next slide for more questions • (always refer to your Pearson IB textbook p. 14-20 while answering)

24. HW questions (Contd) • Q4. Define and compare the terms species, population, association, and ecosystem. • Q6. Compared with an ecosystem, what are an ecotone, landscape, biome, and biosphere? • Q7. Identify and describe the biotic and the abiotic components of the ecosystem such as the Gulshan Lake that is a part of your community. • Q8. Name and describe the roles of the three main trophic categories that make up the biotic structure of every ecosystem. Give examples of organisms from each category.