Chapter 4-1 & 4-2

1. Chapter 4-1 & 4-2 Ecosystems: What Are They and How Do They Work?

2. QUESTION OF THE DAY • What would be an example of a parasite? • Ticks feeding on a deer • Startlings displacing bluebirds from nesting sites • Bees consuming nectar and carrying pollen from one flower to another • Moss growing on a tree trunk

3. THE NATURE OF ECOLOGY • Ecology is a study of connections in nature. • How organisms interact with one another (biotic) and with their nonliving (abiotic) environment. Figure 3-2

4. Organisms and Species • Organisms, the different forms of life on earth, can be classified into different species based on certain characteristics. Figure 3-3

5. Populations, Communities, and Ecosystems • Members of a species interact in groups called populations. • Populations of different species living and interacting in an area form a community. • A community interacting with its physical environment of matter and energy is an ecosystem.

6. Populations • A population is a group of interacting individuals of the same species occupying a specific area. • The space an individual or population normally occupies is its habitat. Figure 3-4

7. Populations • Genetic diversity • In most natural populations individuals vary slightly in their genetic makeup. Figure 3-5

8. Visualizing an Ecosystem biosphere ecosystem community population organism

9. THE EARTH’S LIFE SUPPORT SYSTEMS • The biosphere consists of several physical layers that contain: • Air • Water • Soil • Minerals • Life Figure 3-6

10. The Earth’s Components • Atmosphere • Membrane of air around the planet. • Stratosphere • Lower portion contains ozone to filter out most of the sun’s harmful UV radiation. • Hydrosphere • All the earth’s water: liquid, ice, water vapor • Lithosphere • The earth’s crust and upper mantle.

11. The Biosphere • Biosphere: the space where organisms live and interact. It includes • Most of the Hydrosphere • Parts of the lower atmosphere • Parts of the upper lithosphere http://serc.carleton.edu/eslabs/climate/index.html

12. What Sustains Life on Earth? 1. Solar energy 2. The cycling of matter 3. Gravity sustain the earth’s life. Figure 3-7

13. The Effect of Solar Energy on the Earth • Solar energy flowing through the biosphere 1. Warms the atmosphere 2. Evaporates and recycles water 3. Generates winds and 4. Supports plant growth. Figure 3-8

14. Ecosystem inputs biosphere constant inputof energy energy flowsthrough nutrients cycle Don’t forgetthe laws of Physics! Matter cannot be created ordestroyed nutrients can only cycle inputs • energy • nutrients

15. Decompositionconnects all trophic levels Generalized Nutrient cycling consumers consumers producers consumers decomposers decomposers nutrientsENTER FOOD CHAIN= made availableto producers nutrientsmade availableto producers return toabioticreservoir abioticreservoir abioticreservoir geologicprocesses geologicprocesses

16. Summary 1. What do ecologists study? Interactions among organisms, populations, communities, ecosystems, and the biosphere. 2. How does a population differ from a community? Example 3. What is an ecosystem? A community of different species interacting with each other and with their nonliving environment of matter and energy. All of the earth’s diverse ecosystems comprise the biosphere. 4. What are the interconnected spherical layers make up the earth’s life-support system? 5. How does solar energy sustain life?

17. Chapter 4-3 EcosystemsComponents

18. QUESTION OF THE DAY All forms of water make up the • lithosphere • atmosphere • hydrosphere • tranosphere • biosphere

19. ECOSYSTEM COMPONENTS • Life exists on land systems called • Biomes Ex. deserts, forests, and grasslands • Aquatic life zones in freshwater and ocean. Ex. coral reefs, coastal estuaries, deep ocean

20. ECOSYSTEM COMPONENTS • Major biomes found along the 39th parallel across the United States • What causes the differences? Figure 3-9

21. Components of Ecosystems • Abiotic: non-living living components Ex. • Biotic: living components. Ex. Figure 3-10

22. Factors That Limit Population Growth • Availability of matter and energy resources can limit the number of organisms in a population. Ex. Figure 3-11

23. Factors That Limit Population Growth • The physical conditions of the environment can limit the distribution of a species. • i.e. Figure 3-12

24. Major Biological Components • Autotrophs(self-feeders): make their own food from compounds in the environment • Consumers (heterotrophs): feed on other organisms or their remains. • Natural ecosystems produce little waste or no waste. In nature, waste becomes food.

25. Producers: Basic Source of All Food • Most producers capture sunlight to produce carbohydrates by photosynthesis: • Chemosynthesis: Some organisms such as deep ocean bacteria draw energy from hydrothermal vents and produce carbohydrates from hydrogen sulfide (H2S) gas .

26. Photosynthesis: A Closer Look • Chlorophyll molecules in the chloroplasts of plant cells absorb solar energy. • This initiates a complex series of chemical reactions in which carbon dioxide and water are converted to sugars and oxygen. Figure 3-A

27. Consumers • Consumers (heterotrophs) get their food by eating or breaking down all or parts of other organisms or their remains. • Herbivores • Primary consumers that eat producers • Carnivores • Secondary consumers eat primary consumers • Third and higher level consumers: carnivores that eat carnivores. • Omnivores • Feed on both plant and animals.

28. Role of Decomposers and Detritivores • Detritivores: Insects or other scavengers that feed on wastes or dead bodies. • They leave some parts and their feces that are converted to energy by the decomposers. • Improve the nutritional value and the texture of the soil • Millipedes, earthworms and slugs feed on dead plants and animals • Decomposers: • Recycle nutrients in ecosystems. • Help in the process of decay by converting what is left by the detritivores • Bacteria and fungi Figure 3-13

29. Decomposers and Detrivores Figure 3-13

30. Aerobic and Anaerobic Respiration: Getting Energy for Survival • Organisms break down carbohydrates and other organic compounds in their cells to obtain the energy they need • This is usually done through aerobic respiration. • The opposite of photosynthesis

31. Aerobic and Anaerobic Respiration: Getting Energy for Survival • Anaerobic respiration or fermentation: • Some decomposers get energy by breaking down glucose (or other organic compounds) in the absence of oxygen. • The end products vary based on the chemical reaction: • Methane gas • Ethyl alcohol • Acetic acid • Hydrogen sulfide

32. Two Secrets of Survival: Energy Flow and Matter Recycle • An ecosystem survives by a combination of • Energy flow and • Matter recycling Figure 3-14

33. BIODIVERSITY • Functional diversity: biological & chemical processes necessary for life • Genetic Diversity: variety of genetic material within a species or population • Species Diversity: the number of species present in different habitats. • Ecological Diversity: the variety of terrestrial & aquatic ecosystems in an area or on the earth. Figure 3-15

34. BIODIVERSITY Figure 3-15

35. Biodiversity Loss and Species Extinction: Remember HIPPO • H for habitat destruction and degradation • I for invasive species • P for pollution • P for human population growth • O for overexploitation

36. Why Should We Care About Biodiversity? • Biodiversity provides us with: • Natural Resources (food water, wood, energy, and medicines) • Natural Services (air and water purification, soil fertility, waste disposal, pest control) • Aesthetic pleasure

37. Solutions • Goals, strategies and tactics for protecting biodiversity. • Species approach • Ecosystem Approach Figure 3-16

38. SUMMARY 1. Why do limiting factors affect species’ range? 2. What are the two major biological components of ecosystems? 3. How are the roles of decomposers and detritivores related? 4. What are the four kinds of biodiversity? 5. What are the causes of biodiversity loss and species extinction?

39. Chapter 4-4 & 4-5 Energy Flow in Ecosystems & Primary Productivity Energy Flow

40. ENERGY FLOW IN ECOSYSTEMS • Food chains and webs show how eaters, the eaten, and the decomposed are connected to one another in an ecosystem. Figure 3-17

41. Food Webs • Trophic levels are interconnected within a more complicated food web. • What is the purpose of a food web? Figure 3-18

42. Energy Flow in an Ecosystem: Losing Energy in Food Chains and Webs • In accordance with the 2nd law of thermodynamics, there is a decrease in the amount of energy available to each succeeding organism in a food chain or web.

43. Energy Flow in an Ecosystem: Losing Energy in Food Chains and Webs • Ecological efficiency: percentage of • useable energy transferred as biomass from one trophic level to the next. • % energy transferred: • Where does the majority of energy go? • How does this effect the # of organisms found in each trophic level? Figure 3-19

44. Productivity of Producers: The Rate Is Crucial • Gross primary production (GPP) • Rate at which an ecosystem’s producers convert solar energy into chemical energy as biomass. • Which areas have the greatest GPP? Figure 3-20

45. Net Primary Production (NPP) • NPP = GPP – R • Rate at which producers use photosynthesis to store energy minus the rate at which they use some of this energy through respiration (R). Figure 3-21

46. What are nature’s three most productive and three least productive systems? Figure 3-22

47. Chapter 4-4 /4-5 Summary 1. Food Chains: 2. Food Webs 3. 1st Law of Thermodynamics 4. 2nd Law of Thermodynamics 5. Efficiency of Energy Flow 6. Pyramid of Energy 7. Pyramid of Biomass 8. Gross Primary Productivity 9. Net Primary Productivity

48. Chapter 4-7 Matter Cycling in Ecosystems Matter & Energy Transfer

49. MATTER CYCLING IN ECOSYSTEMS • Nutrient Cycles: Global Recycling • Global Cycles recycle nutrients through the earth’s air, land, water, and living organisms. • Nutrients are the elements and compounds that organisms need to live, grow, and reproduce. • Biogeochemical cycles move these substances through air, water, soil, rock and living organisms.

50. Background on Biogeochemical cycles • Earth system has four parts • Atmosphere • Hydrosphere • Lithosphere • Biosphere • Biogeochemical cycles: The chemical interactions (cycles) that exist between the atmosphere, hydrosphere, lithosphere, and biosphere. • Abiotic (physio-chemical) and biotic processes drive these cycles