Ecology Introduction

1. Ecology Introduction Chapter 18

2. Ecology • the study of the interdependence of living organisms • the interdisciplinary scientific study of the distributions, abundance and relations of organisms and their interactions with the environment

3. Biological levels of organization

4. Sponge Bob Ecology? Ecosystem Organism Population Community

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/m2/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

20. Food Webs • Interweaving diagram of food chains

21. owl stoat fox rat rabbit beetle

22. Energy and Nutrient Flow Patterns

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

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

25. Energy does not cycle 90% 90% 95%

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