APES Potluck Party Review

1. APES Potluck Party Review 2012

3. Producers: Basic Source of All Food • Most producers capture sunlight to produce carbohydrates by photosynthesis:

4. 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

5. Producers: Basic Source of All Food • Chemosynthesis: • Some organisms such as deep ocean bacteria draw energy from hydrothermal vents and produce carbohydrates from hydrogen sulfide (H2S) gas .

6. 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

7. 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

8. 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

9. 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

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

11. 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.

12. 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

13. 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.

14. 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.

15. 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.

16. The Carbon Cycle:Part of Nature’s Thermostat Figure 3-27

17. Effects of Human Activities on Carbon Cycle • We alter the carbon cycle by adding excess CO2 to the atmosphere through: • Burning fossil fuels. • Clearing vegetation faster than it is replaced. Figure 3-28

19. 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.

20. The Phosphorous Cycle Figure 3-31

21. 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.

22. The Sulfur Cycle Figure 3-32

23. 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.

24. The Gaia Hypothesis: Is the Earth Alive? • Some have proposed that the earth’s various forms of life control or at least influence its chemical cycles and other earth-sustaining processes. • The strong Gaia hypothesis: life controls the earth’s life-sustaining processes. • The weak Gaia hypothesis: life influences the earth’s life-sustaining processes.

25. Geographic Information Systems (GIS) • A GIS organizes, stores, and analyzes complex data collected over broad geographic areas. • Allows the simultaneous overlay of many layers of data. Figure 3-33

26. Core Case StudyBlowing in the Wind: A Story of Connections • Wind connects most life on earth. • Keeps tropics from being unbearably hot. • Prevents rest of world from freezing. Figure 5-1

27. Earth’s Current Climate Zones Figure 5-2

28. Solar Energy and Global Air Circulation: Distributing Heat • Global air circulation is affected by the uneven heating of the earth’s surface by solar energy, seasonal changes in temperature and precipitation. Figure 5-3

29. Coriolis Effect • Global air circulation is affected by the rotation of the earth on its axis. Figure 5-4

30. Convection Currents • Global air circulation is affected by the properties of air water, and land. Figure 5-5

31. HIGH PRESSURE LOW PRESSURE Heat releasedradiates to space Condensation and precipitation Cool, dry air Rises, expands, cools Falls, is compressed, warms Warm, dry air Hot, wet air Flows toward low pressure, picks up moisture and heat HIGH PRESSURE LOW PRESSURE Moist surface warmed by sun Fig. 5-5, p. 103

32. Convection Cells • Heat and moisture are distributed over the earth’s surface by vertical currents, which form six giant convection cells at different latitudes. Figure 5-6

33. Cell 3 North Cold, dry air falls Moist air rises — rain Polar cap Cell 2 North Arctic tundra Evergreen coniferous forest 60° Cool, dry air falls Temperate deciduous forest and grassland 30° Desert Cell 1 North Tropical deciduous forest Moist air rises, cools, and releases Moisture as rain Tropical rain forest 0° Equator Tropical deciduous forest 30° Desert Cell 1 South Temperate deciduous forest and grassland Cool, dry air falls 60° Cell 2 South Polar cap Cold, dry air falls Moist air rises — rain Cell 3 South Fig. 5-6, p. 103

34. Ocean Currents: Distributing Heat and Nutrients • Ocean currents influence climate by distributing heat from place to place and mixing and distributing nutrients. Figure 5-7

35. Topography and Local Climate:Land Matters • Interactions between land and oceans and disruptions of airflows by mountains and cities affect local climates. Figure 5-8

36. Tropic of Cancer Equator High mountains Polar ice Polar grassland (arctic tundra) Tropic of Capricorn Temperate grassland Tropical grassland (savanna) Chaparral Coniferous forest Temperate deciduous forest Tropical forest Desert Fig. 5-9, p. 106

37. Cold Polar Tundra Subpolar Temperate Coniferous forest Decreasing temperature Desert Deciduous Forest Grassland Tropical Chaparral Hot Desert Savanna Wet Rain forest Dry Tropical seasonal forest Scrubland Decreasing precipitation Fig. 5-10, p. 107

38. Elevation Mountain ice and snow Tundra (herbs, lichens, mosses) Coniferous Forest Latitude Deciduous Forest Tropical Forest Tundra (herbs, lichens, mosses) Polar ice and snow Deciduous Forest Coniferous Forest Tropical Forest Fig. 5-11, p. 108

39. HUMAN IMPACTS ON TERRESTRIAL BIOMES • Human activities have damaged or disturbed more than half of the world’s terrestrial ecosystems. • Humans have had a number of specific harmful effects on the world’s deserts, grasslands, forests, and mountains.

41. RISKS AND HAZARDS • Risk is a measure of the likelihood that you will suffer harm from a hazard. • We can suffer from: • Biological hazards: from more than 1,400 pathogens. • Chemical hazards: in air, water, soil, and food. • Physical hazards: such as fire, earthquake, volcanic eruption… • Cultural hazards: such as smoking, poor diet, unsafe sex, drugs, unsafe working conditions, and poverty.

42. BIOLOGICAL HAZARDS: DISEASE IN DEVELOPED AND DEVELOPING COUNTRIES • Diseases not caused by living organisms cannot spread from one person to another (nontransmissible disease), while those caused by living organisms such as bacteria and viruses can spread from person to person (transmissible or infectious)

43. Ecological Medicine and Infectious Diseases • Mostly because of human activities, infectious diseases are moving at increasing rates from one animal species to another (including humans). • Ecological (or conservation) medicine is devoted to tracking down these connections between wildlife and humans to determine ways to slow and prevent disease spread.

44. CHEMICAL HAZARDS • A toxic chemical can cause temporary or permanent harm or death. • Mutagens are chemicals or forms of radiation that cause or increase the frequency of mutations in DNA. • Teratogens are chemicals that cause harm or birth defects to a fetus or embryo. • Carcinogens are chemicals or types of radiation that can cause or promote cancer.

45. CHEMICAL HAZARDS • A hazardous chemical can harm humans or other animals because it: • Is flammable • Is explosive • An irritant • Interferes with oxygen uptake • Induce allergic reactions.

46. Effects of Chemicals on the Immune, Nervous, and Endocrine Systems • Long-term exposure to some chemicals at low doses may disrupt the body’s: • Immune system: specialized cells and tissues that protect the body against disease and harmful substances. • Nervous system: brain, spinal cord, and peripheral nerves. • Endocrine system: complex network of glands that release minute amounts of hormones into the bloodstream.

47. Case Study: A Black Day in Bhopal, India • The world’s worst industrial accident occurred in 1984 at a pesticide plant in Bhopal, India. • An explosion at Union Carbide pesticide plant in an underground storage tank released a large quantity of highly toxic methyl isocyanate (MIC) gas. • 15,000-22,000 people died • Indian officials claim that simple upgrades could have prevented the tragedy.

48. TOXICOLOGY: ASSESSING CHEMICAL HAZARDS • Factors determining the harm caused by exposure to a chemical include: • The amount of exposure (dose). • The frequency of exposure. • The person who is exposed. • The effectiveness of the body’s detoxification systems. • One’s genetic makeup.

49. TOXICOLOGY: ASSESSING CHEMICAL HAZARDS • Children are more susceptible to the effects of toxic substances because: • Children breathe more air, drink more water, and eat more food per unit of body weight than adults. • They are exposed to toxins when they put their fingers or other objects in their mouths. • Children usually have less well-developed immune systems and detoxification processes than adults.

50. TOXICOLOGY: ASSESSING CHEMICAL HAZARDS • Some scientists and health officials say that preliminary but not conclusive evidence that a chemical causes significant harm should spur preventive action (precautionary principle). • Manufacturers contend that wide-spread application of the precautionary principle would make it too expensive to introduce new chemicals and technologies.