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Chapter 5

Chapter 5. Climate and Terrestrial Biodiversity. Chapter Overview Questions. What factors the earth’s climate? How does climate determine where the earth’s major biome’s are found? What are the major types of desert biomes? What are the major types of grassland biomes?.

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Chapter 5

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  1. Chapter 5 Climate and Terrestrial Biodiversity

  2. Chapter Overview Questions • What factors the earth’s climate? • How does climate determine where the earth’s major biome’s are found? • What are the major types of desert biomes? • What are the major types of grassland biomes?

  3. Chapter Overview Questions (cont’d) • What are the major types of forest and mountain biomes? • How have human activities affected the world’s desert, grassland, forest, and mountain biomes?

  4. Updates Online The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles. • InfoTrac: Of Chicks and Frogs. Steven Pinker. Forbes, August 14, 2006 v178 i3 p40. • InfoTrac: Nice Rats, Nasty Rats: Maybe It's All In the Genes. Nicholas Wade. The New York Times, July 25, 2006 pF1(L). • InfoTrac: Ancient shrub unlocks a clue to Darwin's 'abominable mystery.’ The Christian Science Monitor, May 18, 2006 p02. • The Jane Goodall Institute • Natural History Museum: Ancient Birds

  5. 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

  6. Wind: Case Study • Wind blows Sahara desert nutrients to Bahamas and Brazil. • Wind blows iron from Gobi Desert to Pacific Ocean which nourishes the phytoplankton • SUVs destroy sand crust and wind blows increased amounts of sediment • Wind transports viruses, molds, bacteria and fungi

  7. CLIMATE: A BRIEF INTRODUCTION • Weather is a local area’s short-termphysical conditions such as temperature and precipitation. • Climate is a region’s average weather conditions over a long time. • Latitude and elevation help determine climate.

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

  9. Solar Energy and Global Air Circulation: Distributing Heat • FOUR FACTORS that determine global air patterns

  10. 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

  11. Winter (northern hemisphere tilts away from sun) Spring (sun aims directly at equator) 23.5 ° Solar radiation Summer (northern hemisphere tilts toward sun) Fall (sun aims directly at equator) Fig. 5-3, p. 102

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

  13. Cold deserts Westerlies Forests Northeast trades Hot deserts Forests Equator Southeast trades Hot deserts Forests Westerlies Cold deserts Fig. 5-4, p. 102

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

  15. 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

  16. 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

  17. 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

  18. 4 Factors affecting Global Air Circulation • Uneven heating of the Earth’s surface • “Denser” light shines on equator • Seasonal changes in temperature and precipitation • Rotation of the Earth on its axis • Equator spins faster than poles creating Coriolis effect • Properties of air, water and land • Cyclical convection cells created

  19. 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

  20. (a) Rays of sunlight penetrate the lower atmosphere and warm the earth's surface. (b) The earth's surface absorbs much of the incoming solar radiation and degrades it to longer-wavelength infrared (IR) radiation, which rises into the lower atmosphere. Some of this IR radiation escapes into space as heat, and some is absorbed by molecules of greenhouse gases and emitted as even longer-wavelength IR radiation, which warms the lower atmosphere. (c) As concentrations of greenhouse gases rise, their molecules absorb and emit more infrared radiation, which adds more heat to the lower atmosphere. Fig. 5-7, p. 104

  21. Ocean Currents: Distributing Heat and Nutrients • Global warming: • Considerable scientific evidence and climate models indicate that large inputs of greenhouse gases from anthropogenic activities into the troposphere can enhance the natural greenhouse effect and change the earth’s climate in your lifetime.

  22. ATMOSPHERE GASES AND CLIMATE • Greenhouse gases allows visible light and UV to pass through, but absorbs some of the returning Infrared light and returns it at a longer wavelength

  23. GREENHOUSE GASES • Water vapor: H2O • Carbon Dioxide: CO2 • Methane: CH4 • Nitrous oxide: N2O

  24. GREENHOUSE GASES • Could result in: • change in precipitation patterns • shift in cropland • rise in sea levels • change in areas where some plants and animals live

  25. 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

  26. A RAIN SHADOW IS FORMED Prevailing winds pick up moisture from an ocean. On the windward side of a mountain range, air rises, cools, and releases moisture. On the leeward side of the mountain range, air descends, warms, and Releases little moisture. Dry habitats Moist habitats Fig. 5-8, p. 105

  27. Heat and Water • Heat is absorbed and released more slowly by water than by land • This means coastal areas and large lakes have weather moderated by the water.

  28. BIOMES: CLIMATE AND LIFE ON LAND • Different climates lead to different communities of organisms, especially vegetation. • Biomes – large terrestrial regions characterized by similar climate, soil, plants, and animals. • Each biome contains many ecosystems whose communities have adapted to differences in climate, soil, and other environmental factors.

  29. BIOMES: CLIMATE AND LIFE ON LAND Figure 5-9

  30. 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

  31. Climate change is part of history • Change caused by solar output, volcanic eruptions, and continents moving. • 5,000 years ago part of Saharan Desert was fertile • 15,000 years ago arid Western US was rainy and contained many lakes • Evidence that we are changing climate in 50-100 years

  32. BIOMES: CLIMATE AND LIFE ON LAND • Biome type is determined by precipitation, temperature and soil type Figure 5-10

  33. 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

  34. Tropical = hot • Temperate = moderate • Polar = cold

  35. Biomes • Biomes are not uniform • Contain a mosaic of patches with somewhat different biological communities with similarities unique to the biome

  36. BIOMES: CLIMATE AND LIFE ON LAND • Parallel changes occur in vegetation type occur when we travel from the equator to the poles or from lowlands to mountaintops. Figure 5-11

  37. 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

  38. DESERT BIOMES • Deserts are areas where evaporation exceeds precipitation. • Deserts have little precipitation and little vegetation. • Where are they found? • Found in tropical, temperate and polar regions. • Desert plants have adaptations that help them stay cool and get enough water.

  39. DESERT BIOMES • Variations in annual temperature (red) and precipitation (blue) in tropical, temperate and cold deserts. Figure 5-12

  40. Deserts • Cover about 30% of the earth’s land surface • Found mainly in tropical and subtropical regions • Largest Deserts found in the interiors of continents, far from moist sea air • Or form in Rain Shadows

  41. Deserts not Desserts • Sun bakes ground in day • At night, heat radiates quickly from rocks to atmosphere • Without moisture in the soil, the heat is not stored • This allows you to bake in the day, and freeze during the nights

  42. Hot and Dry most of the year. Example: Sahara and Namib Tropical Desert Freezing point Mean monthly temperature (C) Mean monthly precipitation (mm) Month Fig. 5-12a, p. 109

  43. Day temps high in summer and low in winter. Example: Mojave desert Temperate Desert Freezing point Mean monthly temperature (C) Mean monthly precipitation (mm) Month Fig. 5-12b, p. 109

  44. Cold Deserts: Cold winters, warm summers, sparse vegetation Polar Desert Freezing point Mean monthly precipitation (mm) Mean monthly temperature (°C) Month Example: Gobi Desert in China Fig. 5-12c, p. 109

  45. DESERT BIOMES • The flora and fauna in desert ecosystems adapt to their environment through their behavior and physiology. Figure 5-13

  46. Red-tailed hawk Gambel'sQuail Yucca Agave Jack rabbit Collared lizard Prickly pear cactus Roadrunner Darkling Beetle Bacteria Diamondback rattlesnake Fungi Kangaroo rat Primary to secondary consumer Secondary to higher-level consumer Producer to primary consumer All producers and consumers to decomposers Fig. 5-13, p. 110

  47. Deserts • Evergreen plants conserve water by having wax coated leaves that reduce water loss • Wildflowers and grasses store much of their biomass in seeds that remain inactive until they receive enough water to germinate

  48. Deserts • Most animals are small • They hide in cool burrows or rocky crevices by day and come out at night or early morning • Others are dormant during extreme heat • Insects and reptiles have thick outer coverings to minimize water loss • Their wastes are dry or concentrated urine

  49. Deserts are Fragile • Soils take a long time to heal • Low diversity • Slow nutrient cycling • Slow plant growth • Tank tracks are still visible in the Mojave desert from 1940s

  50. GRASSLANDS AND CHAPARRAL BIOMES • Variations in annual temperature (red) and precipitation (blue). Figure 5-14

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