Table of Contents

1. Introduction to Ecology Chapter 18 Table of Contents Section 1 Introduction to Ecology Section 2 Ecology of Organisms Section 3 Energy Transfer Section 4 Ecosystem Recycling

2. Section 1 Introduction to Ecology Chapter 18 Objectives • Identifya key theme in ecology. • Describean example showing the effects of interdependence upon organisms in their environment. • Identifythe importance of models to ecology. • Statethe five different levels of organization at which ecology can be studied.

3. Section 1 Introduction to Ecology Chapter 18 Interdependence: A Key Theme in Ecology • Organisms and Their Environments • Species interact with both other species and their nonliving environment. • Interdependence is a theme in ecology—one change can affect all species in an ecosystem.

4. Section 1 Introduction to Ecology Chapter 18 Ecological Models • Ecological models help to explain the environment.

5. Section 1 Introduction to Ecology Chapter 18 Making an Ecosystem Model

6. Section 1 Introduction to Ecology Chapter 18 Levels of Organization • Ecologists recognize a hierarchy of organization in the environment: biosphere, ecosystem, community, population, and organism.

7. Section 1 Introduction to Ecology Chapter 18 Levels of Organization

8. Section 1 Introduction to Ecology Chapter 18 Levels of Organization, continued • The Biosphere • The broadest, most inclusive level of organization is thebiosphere,the volume of Earth and its atmosphere that supports life.

9. Section 1 Introduction to Ecology Chapter 18 Levels of Organization, continued • Ecosystems • The biosphere is composed of smaller units called ecosystems. • An ecosystemincludes all of the organisms and the nonliving environment found in a particular place.

10. Section 1 Introduction to Ecology Chapter 18 Ecosystem

11. Section 1 Introduction to Ecology Chapter 18 Levels of Organization, continued • Communities, Populations, and Organisms • Acommunityis all the interacting organisms living in an area. • Below the community level of organization is thepopulationlevel,where the focus is on the individual organisms of a single species.

12. Section 1 Introduction to Ecology Chapter 18 Community

13. Section 2 Ecology of Organisms Chapter 18 Objectives • Compareabiotic factors with biotic factors, and list two examples of each. • Describetwo mechanisms that allow organisms to survive in a changing environment. • Explainthe concept of the niche.

14. Section 2 Ecology of Organisms Chapter 18 Ecosystem Components • Biotic and Abiotic Factors • Bothbiotic, or living, factors andabiotic, or nonliving, factors influence organisms. Examples of abiotic factors are climate, sunlight, and pH.

15. Section 2 Ecology of Organisms Chapter 18 Organisms in a Changing Environment • Acclimation • Some organisms can adjust their tolerance to abiotic factors through the process ofacclimation.

16. Section 2 Ecology of Organisms Chapter 18 Organisms in a Changing Environment, continued • Control of Internal Conditions • Conformers are organisms that do not regulate their internal conditions; they change as their external environment changes. • Regulators use energy to control some of their internal conditions.

17. Section 2 Ecology of Organisms Chapter 18 Organisms in a Changing Environment, continued • Escape from Unsuitable Conditions • Some species survive unfavorable environmental conditions by becoming dormant or by migrating.

18. Section 2 Ecology of Organisms Chapter 18 The Niche • A nicheis a way of life, or a role in an ecosystem.

19. Section 2 Ecology Of Organisms Chapter 18 Earthworm Niche

20. Section 3 Energy Transfer Chapter 18 Objectives • Summarizethe role of producers in an ecosystem. • Identifyseveral kinds of consumers in an ecosystem. • Explainthe important role of decomposers in an ecosystem. • Comparethe concept of a food chain with that of a food web. • Explainwhy ecosystems usually contain only a few trophic levels.

21. Section 3 Energy Transfer Chapter 18 Producers • Most producersare photosynthetic and make carbohydrates by using energy from the sun.

22. Section 3 Energy Transfer Chapter 18 Producers, continued • Measuring Productivity • Gross primary productivityis the rate at which producers in an ecosystem capture the energy of sunlight by producing organic compounds. • The rate at which biomass accumulates is callednet primary productivity.

23. Section 3 Energy Transfer Chapter 18 Consumers • Consumersobtain energy by eating other organisms and include herbivores, omnivores, carnivores, detritivores, and decomposers.

24. Section 3 Energy Transfer Chapter 18 Energy Flow • Food Chains and Food Webs • A single pathway of energy transfer is afood chain. • A network showing all paths of energy transfer is a food web.

25. Section 3 Energy Transfer Chapter 18 Food Chains and Food Webs

26. Section 3 Energy Transfer Chapter 18 Food Chain in an Antarctic Ecosystem

27. Food Web in an Antarctic Ecosystem Section 3 Energy Transfer Chapter 18

28. Section 3 Energy Transfer Chapter 18 Energy Flow, continued • Energy Transfer • Ecosystems contain only a few trophic levels because there is a low rate of energy transfer between each level. • http://www.deltacollege.edu/emp/jdebow/energytransfer.html

29. Section 3 Energy Transfer Chapter 18 Energy Transfer Through Trophic Levels

30. Section 3 Energy Transfer Chapter 18 Energy Pyramid

31. Section 4 Ecosystem Recycling Chapter 18 Objectives • Listfour major biogeochemical cycles. • Summarizethree important processes in the water cycle. • Outlinethe major steps in the carbon cycle. • Describethe role of decomposers in the nitrogen cycle. • Summarizethe major steps of the phosphorus cycle.

32. Section 4 Ecosystem Recycling Chapter 18 The Water Cycle • Key processes in thewatercycleare evaporation, transpiration, and precipitation.

33. Section 4 Ecosystem Recycling Chapter 18 Water Cycle

34. Section 4 Ecosystem Recycling Chapter 18 The Carbon Cycle • Photosynthesis and cellular respiration are the two main steps in thecarbon cycle.

35. Section 4 Ecosystem Recycling Chapter 18 Carbon Cycle

36. Section 4 Ecosystem Recycling Chapter 18 Nitrogen Cycle • Nitrogen-fixing bacteriaare important in thenitrogen cyclebecause they change nitrogen gas into a usable form of nitrogen for plants.

37. Section 4 Ecosystem Recycling Chapter 18 Nitrogen Cycle

38. Section 4 Ecosystem Recycling Chapter 18 Phosphorus Cycle • In thephosphorus cycle,phosphorus moves from phosphate deposited in rock, to the soil, to living organisms, and finally to the ocean.