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Chapter 3

Chapter 3. Ecosystems: What Are They and How Do They Work?. Core Case Study: Have You Thanked the Insects Today?. Many plant species depend on insects for pollination and plant reproduction. Insects can control other pest insects by eating them. They also mix up the soil. Figure 3-1.

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Chapter 3

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  1. Chapter 3 Ecosystems: What Are They and How Do They Work?

  2. Core Case Study: Have You Thanked the Insects Today? • Many plant species depend on insects for pollination and plant reproduction. • Insects can control other pest insects by eating them. • They also mix up the soil Figure 3-1

  3. Core Case Study: Have You Thanked the Insects Today? • …if all insects disappeared, humanity probably could not last more than a few months [E.O. Wilson, Biodiversity expert]. • Insect’s role in nature is part of the larger biological community in which they live. why are honeybees dis.flv honeybees part 2.flv

  4. THE NATURE OF ECOLOGY • Ecology is • How organisms interact with one another and with their nonliving environment. Figure 3-2

  5. So, really intricate and amazing interrelationships occur between plants and animals.

  6. Well, as mentioned earlier, plants rely on insects, birds, and rodents for pollination Fynbos biome

  7. And, of course birds and animals need plants……what what

  8. Biosphere!!!!!!!

  9. Re-wind: from this diagram I would like you to remember the differences between good and bad ozone, and the greenhouse vs. the ozone layer

  10. What Happens to Solar Energy Reaching the Earth? Solar energy • Warms and lights up the troposphere • Drives the cycling of matter • Evaporates water and drives weather and climate • 1% generates winds • Green plants/algae use less than .1% in photosynthesis Figure 3-8

  11. What are the abiotic factors in this diagram? Sun Oxygen (O2) Producer Carbon dioxide (CO2) Secondary consumer (fox) Primary consumer (rabbit) Precipitation Producers Falling leaves and twigs Soil decomposers Soluble mineral nutrients Water Fig. 3-10, p. 57

  12. Factors That Limit Population Growth • Availability of matter and energy resources can limit the number of organisms in a population. • Examples of limiting factors: (temperature, sunlight, nutrients, dissolved oxygen, salinity…etc) Figure 3-11

  13. Lower limit of tolerance Upper limit of tolerance No organisms Few organisms Few organisms No organisms Abundance of organisms Population size Zone of intolerance Zone of intolerance Zone of physiological stress Zone of physiological stress Optimum range Low Temperature High Fig. 3-11, p. 58

  14. Producers: Basic Source of All Food • Most producers capture sunlight to produce carbohydrates by photosynthesis: • KNOW THE FORMULA

  15. Write the chemical equations for photosynthesis and respiration. Explain how these two processes are intertwined; include the terms oxygen, carbon dioxide, light reaction, dark reaction, chloroplasts, mitochondria, photosynthesis, respiration, glucose, water, sunlight, ATP, plants, animals. Good luck!!

  16. 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.

  17. 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.(2-40% range) Figure 3-19

  18. 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. Figure 3-20

  19. Gross primary productivity (grams of carbon per square meter) Fig. 3-20, p. 66

  20. 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

  21. Sun Photosynthesis Energy lost and unavailable to consumers Respiration Gross primary production Net primary production (energy available to consumers) Growth and reproduction Fig. 3-21, p. 66

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

  23. Chemosynthesis: • Some organisms such as deep ocean bacteria draw energy from hydrothermal vents and produce carbohydrates from hydrogen sulfide (H2S) gas .

  24. Consumers: Eating and Recycling to Survive • 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.

  25. Decomposers and Detrivores Burying Beetles Video -- National Geographic • Decomposers: Recycle nutrients in ecosystems. • Detrivores: Insects or other scavengers that feed on wastes or dead bodies. Generally scavengers are considered to be larger animals and detrivores are insects. Figure 3-13

  26. Detrivores Decomposers Termite and carpenter ant work Carpenter ant galleries Bark beetle engraving Long-horned beetle holes Dry rot fungus Wood reduced to powder Mushroom Time progression Powder broken down by decomposers into plant nutrients in soil Fig. 3-13, p. 61

  27. 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

  28. 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

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

  30. 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

  31. Why???????

  32. But what’s wrong with corn?” you might ask. In a sense, nothing. In its whole form, corn is a cheap, filling source of starch and vitamins, and its obvious versatility makes it an important culinary staple. As it has been, for thousands of years. But only the tiniest fraction of our corn supply ends up boiled and buttered, or even converted to cornmeal. Given current farm bills and modern commodity agriculture, large-scale corn producers receive government subsidies—to the tune of 4 billion dollars a year—making the crop ludicrously (and, in a sense, artificially) cheap. That creates the incentive to sell, sell, sell, in every possible form. And since we can only eat so much corn on the cob, that means conjuring all sorts of corn-based derivatives. So we end up with corn processed beyond recognition, into forms that eliminate virtually all of its nutritional content.

  33. Of course then we also have URBAN DEVELOPMENT

  34. Why Should We Care About Biodiversity? The health of a species reflects the health of an ecosystem which reflects of the health of the biosphere which is where humans live. “We are all connected”

  35. Some species are so critical to the functioning of an Ecosystem that they are called KEYSTONE SPECIES 1800’s sea otters hunted for fur Sea otters eat sea urchins, so with no predators, they began to multiply Fish begin to decline because Kelp are the breeding grounds for fish, this affected fishermen's catches. Sea urchins eat kelp, which then began to disappear California Sea Otter Tax Check-Off - Defenders of Wildlife

  36. Food Webs • Trophic levels are interconnected within a more complicated food web. Figure 3-18

  37. Animation: Prairie Food Web PLAY ANIMATION

  38. Which of the following ecosystems has the highest average net primary productivity? a. agricultural land b. open ocean c. temperate forest d. swamps and marshes e. lakes and streams Which of the following ecosystems has the lowest level of kilocalories per square meter per year? a. open ocean b. tropical rain forest c. agricultural land d. lakes and streams e. temperate forest

  39. Ecosystem egg • 1. What does the light reaction in photosynthesis produce? • 2. Which law of thermodynamics accounts for the 10% rule? • 3. Which terrestrial ecosystem has the highest GPP? • 4. which aquatic ecosystem has the highest GPP?

  40. Ecosystem egg continued • 5. which aquatic ecosystem has the lowest GPP? • 6. which terrestrial ecosystem has the lowest GPP? • 7. Primary productivity would be greatest at which line of latitude? • 8. Primary productivity would be greatest in which ocean realm of the Arctic ocean

  41. Eco egg continued • 9. What % of sunlight reaching the earth is actually used by plants for the process of photosynthesis? • 10. What is likely the biggest threat to biodiversity on this planet? • 11. Good ozone can be found where? • 12. Bad ozone is caused by what? • 13. Good ozone does what for the planet?

  42. Eco egg continued • 14. Which greenhouse gas is a product of anaerobic respiration? • 15. Aside from habitat destruction, what is the other main cause of loss of biodiversity on the planet? • 16. The phenomenon causing global warming occurs in which layer of the atmosphere? • 17. What do humans do that is messing up or breaking down the ozone layer?

  43. Eco egg cont • 18. Give one example of an abiotic factor and one example of a biotic factor in an ecosystem. • 19. What is the Edge effect and how does is influence biodiversity? • 20. What is the formula for NPP? • 21. What is an example of a keystone species • 22. give the formula for cellular respiration

  44. Eco egg continued • 23. Please give an example of an aquatic tertiary consumer? (2 pts) • 24. What’s the difference between a detrivore and a scavenger and a decomposer (3pts) • 25. what is the MOST limiting factor in the Arctic Ocean? (1pt) • 26. what is the ultimate source of energy for life on earth? (1 pt) • 27. Name a primary consumer (1 pt)

  45. Eco egg cont • 28 What is a likely result of lack of genetic diversity in a food crop like corn? (2pts) • 29. What is the process called in which organisms make food from hydrogen sulfide gas coming from hydrothermal vents? (2 pts) • 30. What is the approximate efficiency of energy transfer going from one trophic level to the next? (2pts)

  46. Last question…..not on the test but worth a buncha points • Describe in detail the “corn controversy” relate it to the concepts covered in this class. (5 pts)

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