April 30, 2009

1. April 30, 2009 • What are the levels of organization? • Where does all energy come from?

2. Ecology

3. What is ecology? • Ecology is the study of the interactions of living organisms with one another and with their physical environment (soil, water, climate…) • ECO = • LOGY = house the study of

4. Biosphere • The biosphere contains the combined portions of the planet in which all of life exists, including land, water and atmosphere.

5. Ecologists ask questions about events and organisms that are in the biosphere to understand the relationships within the biosphere.

6. Levels of Organization

7. SPECIES • A group of organisms so similar to one another that they can breed and produce fertile offspring

8. POPULATION • A group of individuals that belong to the same species and live in the same area

9. COMMUNITY • An assemblage of different populations that live together in a defined area

10. ECOSYSTEM • A collection of all the organisms that live in a particular place, together with their physical environment

11. BIOME • A group of ecosystems that have the same climate and dominant communities

12. LEVELS OF ORGANIZATION Species Population Community Ecosystem Biome Biosphere

13. What is the highest level of organization? The entire biosphere

14. ECOLOGICAL METHODS Three basic approaches to conduct ecological research: • Observing • Experimenting • Modeling

15. ECOLOGICAL METHODS Why might an ecologist set up an artificial environment in a laboratory? To imitate and manipulate conditions that organisms may encounter in the natural world.

16. ECOLOGICAL METHODS Many ecological phenomena are difficult to study because they may occur over very long periods of time, or they occur on such large spatial scales (and are too big to study)…

17. ECOLOGICAL METHODS Scientists make models to gain an insight into complex phenomena

18. Energy Flow

19. ENERGY FLOW • Every organism needs… …ENERGY!!!

20. ENERGY FLOW • What are autotrophs? • Organisms that capture energy from the sun or chemicals to produce their own food.

21. ENERGY FLOW • What is a producer? • Organisms that first capture energy (Autotrophs) • FIRST TROPHIC LEVEL

22. ENERGY FLOW • During photosynthesis, autotrophs use light energy to power chemical reactions that convert CO2 and water into oxygen and high energy sugars (glucose).

23. PRODUCERS LAND: Plants UPPER LAYERS OF OCEAN: Algae TIDAL FLATS/SALT MARSHES: Photosynthetic bacteria / cyanobacteria

24. CHEMOSYNTHESIS • Chemosynthesis is the process by which organisms use CHEMICAL energy to PRODUCE carbohydrates. • Making food without sunlight!

25. CHEMOSYNTHESIS • What organisms carry out chemosynthesis? • BACTERIA • Where do they live?

26. CHEMOSYNTHESIS • Where do these bacteria live? • Remote places—volcanic vents on deep ocean floor, hot springs in Yellowstone Park

27. CHEMOSYNTHESIS • Where do these bacteria live? • Common places—tidal marshes along the coast

28. ENERGY FLOW • If AUTOTROPHS are called PRODUCERS, because they make their own food, what are HETEROTROPHS called?

29. CONSUMERS • Organisms that consume plants or other organisms to obtain energy. • All organisms that are NOT producers!!! (Heterotrophs) • Three categories • Primary • Secondary • Tertiary

30. PRIMARY CONSUMERS • Herbivores • Eat plants or other primary producers • Examples • Cows • Horses • Rabbits • Some Insects • SECOND TROPHIC LEVEL

31. SECONDARY CONSUMERS • Carnivores • Animals that eat animals • Examples: tigers, wolves, snakes • Omnivores • Animals that are herbivores and carnivores • Examples: bears, humans • THIRD TROPHIC LEVEL

32. TERTIARY CONSUMERS • Carnivores that consume other carnivores • Known as “top carnivores” • Example: • A hawk that eats a snake • A lion that eats a hyena • FOURTH TROPHIC LEVEL

33. DETRITOVORES • Feed on plant and animal remains and other dead matter • Examples: mites, earthworms, snails, crabs

34. DECOMPOSERS • Break down and absorb nutrients from dead organisms • They cause decay • Decomposition of bodies and wastes releases nutrients back into the environment to be recycled by other organisms. • Examples: bacteria, fungi

35. SCAVENGERS • Do not kill their food—they search for a source of food that is already dead • “Clean-up” the ecosystem • Examples: buzzards

36. FEEDING RELATIONSHIPS • Energy flows through an ecosystem in ONE direction: Sun (or inorganic chemicals) Autotrophs/Producers Heterotrophs/Consumers

37. FOOD CHAIN • A food chain is a series of steps in which organisms transfer energy by eating or being eaten. • It is how energy moves through an ecosystem!

38. FOOD WEB • A food web is a network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem.

39. FOOD CHAIN vs. FOOD WEB • A food web will link together all of the food chains in a particular ecosystem…

40. A terrestrial food chain A marine food chain

43. TROPHIC LEVELS • A trophic level is a step in a food chain or food web. • Different organisms are on different levels depending on their source of energy. • Where does energy come from? SUN

44. TROPHIC LEVELS

45. TROPHIC LEVELS • A consumer in a food chain depends on the trophic level below it for energy.

46. Ecological Pyramids

47. ECOLOGICAL PYRAMIDS • An ecological pyramid is a diagram that show the relative amounts of energy or matter contained within each trophic level of a food chain or food web.

48. ECOLOGICAL PYRAMIDS • Only part of the energy stored in a trophic level is passed on to the next because organisms use much of the energy they con

49. ENERGY PYRAMID • All energy originates from the sun (or inorganic chemicals). • Sunlight (radiant energy) is converted to digestible energy by plants during photosynthesis.

50. ENERGY PYRAMID • When the plants are eaten, the energy is transferred to animals to sustain life. • Energy is transferred up the food chain.