1. Ecology Introduction Chapter 18

2. Ecology

3. Biological levels of organization

4. Sponge Bob Ecology? Organism Population Community Ecosystem

5. "It is an obvious truth, which has been taken notice of by many writers, that population must always be kept down to the level of the means of subsistence; but no writer that the Author recollects has inquired particularly into the means by which this level is effected..." -- Thomas Malthus, 1798

6. Interdependence All living organisms interact with other living organisms

7. Parts of an Ecosystem Biotic factors – Living things that affect the organisms Abiotic factors – Non-living things that affect the organisms Biotic and abiotic factors are interdependent

8. The Niche A niche is a way of life Includes all aspects of lifestyle – Range of tolerable conditions – Means of acquiring resources – Number of offspring – Interactions with environment – Time of day of activity – And on and on and on and …..

9. Changing Environments Tolerance curve – Set of boundaries that organisms require for survival

10. Acclimation Tolerance curves can be affected – Acclimation – Homeostasis

11. Surviving Outside the Tolerance Zone Escape – Migration – Hibernation

12. Niche differences Specialists – Have very narrow niches and tend to specialize on utilizing a resource other organisms are unable to use.

13. Niche differences Generalists – Have broad niches and can tolerate a wide range of conditions

14. Energy Transfer

15. Producers Photosynthesis Chemosynthesis

16. Measuring productivity Biomass – Mass of organic material produced in an ecosystem Gross primary productivity (GPP) – Rate at which producers capture solar energy and produce organic material Net primary productivity (NPP) – Rate at which biomass accumulates – Kcal/m 2 /yr = GPP– rate of respiration in producers

17. Net Primary Productivity

18. Consumers Herbivores- eat producers Carnivores- eat consumers Omnivores- eat producers and consumers Detritivores- eat dead stuff or excrement – Decomposers- break down complex organic material

19. Energy Flow Trophic levels – Indicates the number of energy transfers Only 10% of the energy in one level is available to the next Tertiary consumers Secondary consumers Primary consumers Producers

20. Food Webs Interweaving diagram of food chains

21. fox owl stoat rabbit rat beetle

22. Energy and Nutrient Flow Patterns

23. Consumers Decomposers Inorganic Nutrients Producers Energy and Nutrient Flow Energy Nutrients

24. Consumers Decomposers Inorganic Nutrients Producers Energy and Nutrient Flow Energy Nutrients

25. Energy does not cycle 95% 90%

26. Energy Flow: Food Chains

27. Energy Flow: Food webs

28. Matter Does Cycle Most important – Water – Carbon – Nitrogen – Phosphorous – Sulfur

29. Water Cycle

31. Biogeochemical Cycles: Nitrogen