1. Chapter 2 Principles of Ecology

2. I. Organisms and their environments Main Idea: The interactions of biotic & abiotic factors in a community or ecosystem form a tight web

3. A. What is Ecology? 1. The scientific study of interactions among organisms and their environment. *Ecology comes from the greek word oikos meaning house and ology-to study*

4. 2. Reveals interdependence 3. Scientist who study it = Ecologist

5. B. Aspects of Ecological Study

6. 1. -the portion of earth that supports life -scientist study the diversity of organisms & factors that effect them

7. 2. Abiotic Factors a. air currents b. temperature c. moisture d. light e. soil f. rainfall g. available nutrients

8. 3. Biotic Factors a. plants b. animals c. bacteria d. fungi e. protists

9. C. Levels of Organization 1. Ecologist study interactions among organisms at several different levels. Know list on page 36

10. 2. Levels include: a. Organism- one individual living thing

11. b. Population- group of one species that interbreed and live in the same place.

12. c. Biological Community- collection of interacting populations that occupy the same geographic area

13. d. Ecosystems- interactions among populations in a community and the physical surroundings. Mobile, AL

14. D. Organisms in Ecosystems

15. 1. Habitat-place an organism lives.

16. 2.Niche-role and position a species has in its environment.

17. 3. Living Relationships a. Symbiosis- Living together

18. b. Symbiotic relationships include: (1) Commensalism-one species benefits and the other species is unaffected.

19. (2) Mutualism- both species benefit. Termites and intestinal flagellates: Sea anemone and the clown fish

20. (3)Parasitism- one organism derives benefit at the expense of another.

21. II. Flow of energy in an Ecosystem

22. Main Idea: Autotrophs capture energy, making it available for all members of a food web

23. A. How organisms obtain energy 1. Autotrophs-make their own nutrients from an energy source.

24. 2. Heterotrophs- cannot make their own energy-they must feed on other organisms.

25. 3. Heterotrophs include: a. herbivores-plant eaters

26. b. carnivores-kill and eat meat

27. c.Scavengers-eat already dead animals (don’t kill)

28. d. Omnivores- eat meat and plants

29. e.Decomposers- breakdown complex molecules. (detrivores)

30. B.Models of Energy Flow

31. 1. Food Chain a. Shows how matter and energy move through an ecosystem. b. Simple-shows one possible route. c. Algae fish heron d. Consist of 3-5 steps.

33. 2. Trophic Levels a. Trophic levels = feeding step b. Feeding = energy transfer

34. 3. Food Webs A model representing the many interconnected food chains and pathways in which energy can flow.

36. 4. Ecological Pyramids a. Energy Pyramid- shows how energy flows through an ecosystem.

38. b. Numbers pyramid * number of individuals at each level decreases b/c there is less energy to support them

39. c. Biomass Pyramid Expresses weight of living material at each trophic level

40. III. Cycles in the Biosphere Biogeochemical Cycles- exchange of matter through the biosphere

41. - Matter, in the form of nutrients moves through the organisms at each trophic level. - Matter cannot be replenished by sunlight. - Matter must be constantly recycled.

42. -Nutrient Cycles include:

43. A. Water Cycle

44. B. Carbon/Oxygen Cycle

45. c.Nitrogen Cycle

47. d. Phosphorus Cycle