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. Fig. 3-10, p. 57 Sun Oxygen (O 2 ) Carbon dioxide (CO 2 ) Secondary consumer (fox) Soil decomposers Primary consumer (rabbit) Precipitation Falling leaves and twigs Producer Producers Water What are the abiotic factors in this diagram?

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

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

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

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

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 (H 2 S) 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 –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 Burying Beetles Video -- National Geographic

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

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

32. Why???????

33. 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.

34. Of course then we also have URBAN DEVELOPMENT

35. 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”

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

37. Flower power. Rosy periwinkle has given rise to drugs used to treat childhood leukemia and Hodgkin's disease.

38. Spider find. A compound in the venom of black widow spiders found in the Negev Desert in Israel may hold promise for treating strokes

39. It had to be yew. The drug Taxol, made from the bark of the Pacific yew, helps fight breast and ovarian cancers.

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

41. Animation: Prairie Food Web PLAY ANIMATION

42. 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

43. 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?

44. 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

45. 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?

46. 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?

47. 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

48. 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)

49. 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)

50. 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)

51. SOIL: A RENEWABLE RESOURCE Soil is a slowly renewed resource that provides most of the nutrients needed for plant growth and also helps purify water. –Soil formation begins when bedrock is broken down by physical, chemical and biological processes called weathering. Mature soils, or soils that have developed over a long time are arranged in a series of horizontal layers called soil horizons.

52. SOIL: A RENEWABLE RESOURCE Figure 3-23

54. Fig. 3-23, p. 68 Fern Mature soil Honey fungus Root system Oak tree Bacteria Lords and ladies Fungus Actinomycetes Nematode Pseudoscorpion Mite Regolith Young soil Immature soil Bedrock Rock fragments Moss and lichen Organic debris builds up Grasses and small shrubs Mole Dog violet Wood sorrel Earthworm Millipede O horizon Leaf litter A horizon Topsoil B horizon Subsoil C horizon Parent material Springtail Red Earth Mite

55. Animation: Soil Profile PLAY ANIMATION

56. Layers in Mature Soils Infiltration: the downward movement of water through soil. Leaching: dissolving of minerals and organic matter in upper layers carrying them to lower layers. The soil type determines the degree of infiltration and leaching.

57. Soil Profiles of the Principal Terrestrial Soil Types Figure 3-24

58. Fig. 3-24a, p. 69 Mosaic of closely packed pebbles, boulders Weak humus- mineral mixture Dry, brown to reddish-brown with variable accumulations of clay, calcium and carbonate, and soluble salts Alkaline, dark, and rich in humus Clay, calcium compounds Desert Soil (hot, dry climate) Grassland Soil (semiarid climate)

59. Fig. 3-24b, p. 69 Tropical Rain Forest Soil (humid, tropical climate) Acidic light-colored humus Iron and aluminum compounds mixed with clay

60. Fig. 3-24b, p. 69 Deciduous Forest Soil (humid, mild climate) Forest litter leaf mold Humus-mineral mixture Light, grayish- brown, silt loam Dark brown firm clay

61. Fig. 3-24b, p. 69 Coniferous Forest Soil (humid, cold climate) Light-colored and acidic Acid litter and humus Humus and iron and aluminum compounds

62. Leaf mold, a humus-mineral mixture, and silty loam are indicative of a.coniferous forest soil. b.deciduous forest soil. c.tropical forest soil. d.grassland soil. e.desert soil. Soil comprised of litter and humus, and is acidic due to the accumulation of needles a.desert soil b.grassland soil c.tropical rainforest soil d.coniferous forest soil e.deciduous forest soil

63. Soils found in mid-latitude grasslands would be most accurately described as having a.a high acid content with little organic matter b.a deep layer of humus and decayed plant material c.a layer of permafrost right below the O-horizon d. a high content of iron oxides and very little moisture e.a small amount of nutrients but an abundant decomposer food web

64. Some Soil Properties Soils vary in the size of the particles they contain, the amount of space between these particles, and how rapidly water flows through them. Figure 3-25 http://techalive.mtu.edu/meec/module06/Porosity.htm

65. Fig. 3-25, p. 70 0.05–2 mm diameter High permeabilityLow permeability Water Clay less than 0.002 mm Diameter Silt 0.002–0.05 mm diameter Sand

66. The porosity of a soil is defined to be the volume of the pores as a percentage of the total volume of soil. Sandy soils have porosities ranging from 30 to 40 percent, compared with 40 to 60 percent for clays. Porosity provides a measure of the amount of water that each soil can retain. Clay soils have a higher porosity and can hold more water. (smaller pores, but more of them)

67. More on soils If a soil is acidic, that can be a problem, because when the pH is low, this causes the release or “freeing up” of aluminum ions. Then the soil tends to want to uptake aluminum rather than the nutrients needed So to recap, acidic soil releases aluminum and this can burn the plants leaves and kill the plant

68. Give a brief description of what pH is…………show chart from booklet here. How can this problem be solved?????????????

69. Eutrophication!!!!!! Happens when excess nitrogen or phosphorus from fertilizers or animal manure runs off into water ways Causes the excess growth of algae The algae eventually dies and decomposes The decomposing bacteria take dissolved oxygen out of the water Aquatic life (like fishies) dies off (a perfect example of this is the Salton Sea or the Gulf of Mexico)

71. Legumes as nitrogen fixers Legumes (soybeans, alfalfa, clover) have specialized bacteria on their root nodules that “fix” nitrogen from the air and put it into the soil So, they work perfectly as “cover crops” to renew soil nitrogen on plots of land that are “resting” in between plantings

73. 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.

74. The Water Cycle Figure 3-26

75. Animation: Hydrologic Cycle PLAY ANIMATION

76. Water’ Unique Properties There are strong forces of attraction between molecules of water. Water exists as a liquid over a wide temperature range. Liquid water changes temperature slowly. It takes a large amount of energy for water to evaporate. Liquid water can dissolve a variety of compounds. Water expands when it freezes.

77. Effects of Human Activities on Water Cycle We alter the water cycle by: –Withdrawing large amounts of freshwater. –Clearing vegetation and eroding soils. –Polluting surface and underground water. –Contributing to climate change.

78. The Carbon Cycle: Part of Nature’s Thermostat Figure 3-27 http://www.epa.gov/climatechange/kids/carbon_cycle_version2.html

79. Fig. 3-27, pp. 72-73

80. Animation: Carbon Cycle PLAY ANIMATION

81. Effects of Human Activities on Carbon Cycle We alter the carbon cycle by adding excess CO 2 to the atmosphere through: –Burning fossil fuels. –Clearing vegetation faster than it is replaced. Figure 3-28

82. Fig. 3-28, p. 74 CO 2 emissions from fossil fuels (billion metric tons of carbon equivalent) Year Low projection High projection

83. The Nitrogen Cycle: Bacteria in Action Figure 3-29

84. Fig. 3-29, p. 75 Gaseous nitrogen (N 2 ) in atmosphere Ammonia, ammonium in soil Nitrogen-rich wastes, remains in soil Nitrate in soil Loss by leaching Loss by leaching Nitrite in soil Nitrification Ammonification Uptake by autotrophs Excretion, death, decomposition Loss by denitrification Food webs on land Fertilizers Nitrogen fixation

85. Animation: Nitrogen Cycle PLAY ANIMATION

86. Effects of Human Activities on the Nitrogen Cycle We alter the nitrogen cycle by: –Adding gases that contribute to acid rain. –Adding nitrous oxide to the atmosphere through farming practices which can warm the atmosphere and deplete ozone. –Contaminating ground water from nitrate ions in inorganic fertilizers. –Releasing nitrogen into the troposphere through deforestation.

87. Effects of Human Activities on the Nitrogen Cycle Human activities such as production of fertilizers now fix more nitrogen than all natural sources combined. Figure 3-30

88. Fig. 3-30, p. 76 Nitrogen fixation by natural processes Global nitrogen (N) fixation (trillion grams) Year

89. The Phosphorous Cycle Figure 3-31

90. Fig. 3-31, p. 77 Dissolved in Ocean Water Marine Sediments Rocks uplifting over geologic time settling out weathering sedimentation Land Food Webs Dissolved in Soil Water, Lakes, Rivers death, decomposition uptake by autotrophs agriculture leaching, runoff uptake by autotrophs excretion death, decomposition miningFertilizer weathering Guano Marine Food Webs

91. Animation: Phosphorous Cycle PLAY ANIMATION

92. Effects of Human Activities on the Phosphorous Cycle We remove large amounts of phosphate from the earth to make fertilizer. We reduce phosphorous in tropical soils by clearing forests. We add excess phosphates to aquatic systems from runoff of animal wastes and fertilizers.

93. The Sulfur Cycle Figure 3-32

94. Fig. 3-32, p. 78 Hydrogen sulfide Sulfur Sulfate salts Decaying matter Animals Plants Ocean Industries Volcano Hydrogen sulfide Oxygen Dimethyl sulfide Ammonium sulfate Ammonia Acidic fog and precipitation Sulfuric acid Water Sulfur trioxide Sulfur dioxide Metallic sulfide deposits

95. Animation: Sulfur Cycle PLAY ANIMATION

96. Effects of Human Activities on the Sulfur Cycle We add sulfur dioxide to the atmosphere by: –Burning coal and oil –Refining sulfur containing petroleum. –Convert sulfur-containing metallic ores into free metals such as copper, lead, and zinc releasing sulfur dioxide into the environment. http://teachers.sduhsd.k12.ca.us/bbodas/biogeochemical cycleactivity 2007.pdf