Topic 1 world ecosystems


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Topic 1 world ecosystems

  1. 1. Topic 1 World ecosystems
  2. 2. Index <ul><li>Natural environment. </li></ul><ul><li>Green house effect </li></ul><ul><li>Human effects on ecosystem cycles. </li></ul>
  3. 3. Natural environment <ul><li>An ecosystem is a community of trees, plants, animals and insects living in a particular environment. </li></ul><ul><li>All living things are linked and depend on the land, water and air. </li></ul>
  4. 4. What is an ECOSYSTEM? <ul><li>An ecosystem is a group of living things plus the non-living things they need. </li></ul><ul><li>The parts of an ecosystem are linked together. </li></ul><ul><li>For example: in a woodland ecosystem, rain is an input which makes the trees grow. Evaporation is an output. </li></ul><ul><li>Copy the diagram and add examples to each box. </li></ul>
  5. 5. <ul><li>Human action also affects. </li></ul>
  6. 6. At what SCALE do ecosystems operate? <ul><li>There are many different ecosystems in the world. </li></ul><ul><li>Some are small-scale , such as a pond. </li></ul><ul><li>Others are large-scale and cover vast areas, such as a rainforest. </li></ul>
  7. 7. FOOD CHAINS <ul><li>Living things in the ecosystem are linked together by the flows of energy and matter as things eat each other. </li></ul><ul><li>These links can be shown as food chains </li></ul>
  8. 8. FOOD CHAINS This shows a food chain in the sea. Removing one animal from this would seriously harm the system. HOW?
  9. 9. FOOD WEBS This shows a food web in a woodland area. What would happen if the RABBITS were removed from the ecosystem?
  10. 10. Sections <ul><li>Abiotic </li></ul><ul><li>Biotic </li></ul>
  11. 11. World ecosystems 8 types
  12. 12. Lets go to the rainforest and find out what its like, the types of vegetation & its soil 1.Tropical rainforest
  13. 13. Location
  14. 14. Equatorial Ecosystem Hot all year Wet all year High annual rainfall over 2000mm Wide biodiversity Plants love the heat & humidity Trees are evergreen Trees have thin barks – no need for protection against the cold
  15. 15. Characteristics of vegetation in the rainforest Tall straight trunks no side branches Aerial roots of epiphytes absorb moisture from the air Shallow spreading root system Buttress roots Thick, waxy surface of leaves protects against hot sun, heavy rain, and strong winds
  16. 16. Rainforest Floor Dark Forest Floor
  17. 17. FACTS <ul><ul><li>The Amazon Rainforest has been described as the &quot;Lungs of our Planet&quot; because it provides the essential environmental world service of continuously recycling carbon dioxide into oxygen. More than 20 percent of the world oxygen is produced in the Amazon Rainforest. </li></ul></ul><ul><ul><li>One and one-half acres of rainforest are lost every second with tragic consequences for both developing and industrial countries. </li></ul></ul>
  18. 18. A Discontinuous Canopy of tree Crowns of the Tallest trees 40 – 50m ( Emergent) B 25 – 40m Continuous layer of Main canopy C 10 -25m Discontinuous under Canopy of D Layer of shrubs & Young trees E Herb layer with Ferns 6m+ high 5 10 15 20 25 30 35 40 45
  19. 19. Rainforest Floor Dark Forest Floor
  20. 20. Human impact on Tropical Rainforest <ul><li>Before clearance </li></ul><ul><li>Rain intercepted </li></ul><ul><li>Organic matter decays quickly </li></ul><ul><li>Nutrients released </li></ul><ul><li>Nutrients taken up by the trees </li></ul><ul><li>After Clearance </li></ul><ul><li>All rain reaches the surface </li></ul><ul><li>No trees left to supply nutrients </li></ul><ul><li>Nutrients already in the soil are washed out </li></ul><ul><li>Increased surface runoff </li></ul><ul><li>Increased soil deposited into the rivers </li></ul>
  21. 21. Solutions?
  22. 22. Management <ul><li>Making a survey of the area’s resources before using them </li></ul><ul><li>Selecting only a few trees per hectare </li></ul><ul><li>Cutting down only fully grown trees </li></ul><ul><li>Replanting those cut down </li></ul><ul><li>Checking the work is done according to the plans </li></ul>
  23. 23. 2.Tropical Grassland
  24. 24. <ul><li>Resistant trees </li></ul><ul><li>Waxy leaves and thorns=espinas </li></ul>
  25. 25. 3.Desert <ul><li>Drought resistant plants, such as cacti, with very long roots to reach water supplies deep underground. </li></ul>
  26. 26. Desert Savanna Equatorial Rainforest Savanna Desert Sahel
  27. 27. Baobab Acacia
  28. 28. Almost uninhabited <ul><li>Nomads </li></ul><ul><ul><li>Tuaregs in Sahara </li></ul></ul><ul><ul><li>Mongols in Gobi </li></ul></ul>
  29. 29. Some towns have developed in deserts around the oil and natural gas industries
  30. 30. Dubai
  31. 31. Dubai Airport
  32. 32. Las Vegas in Mojave Desert
  33. 35. 4.Mediterranean <ul><li>Evergreen woodland, such as cork and pine, thorny shrubs. </li></ul>
  34. 36. Holm oaks = Encina
  35. 37. Pine trees
  36. 38. Shrubs = bush
  37. 39. Lavender
  38. 40. 5.Temperate grassland <ul><li>Grasses up to 2 metres tall, some trees such as willow=sauce </li></ul>
  39. 41. Prairies of tall grass
  40. 42. Landscapes of low grass = Steppes
  41. 43. Willow
  42. 44. 6. Decidous forest or woodland <ul><li>Trees which shed their leaves in winter, such as oak and ash, shrubs and short grasses. </li></ul>
  43. 45. Deciduous forests (Bosques de hoja caduca) Ash Haya Oak roble Beech Fresno
  44. 46. 7.Coniferous forest <ul><li>Dense evergreen trees, such as fir=abeto, pine. </li></ul>
  45. 47. Coniferous trees <ul><li>Fir ( Abeto) </li></ul><ul><li>Pine (Pino) </li></ul>
  46. 48. 8.Tundra <ul><li>Short plans, such as moors, heather and lichen. </li></ul><ul><li>Some stunted trees </li></ul>
  47. 49. Tundra landscapes <ul><li>Moss (musgo) </li></ul><ul><li>Lichens (líquenes) </li></ul><ul><li>Small trees </li></ul>
  48. 50. Animals <ul><li>Reindeer </li></ul><ul><li>Foxes </li></ul><ul><li>Wolves </li></ul>
  49. 51. Small groups of Sami and Inuits
  50. 52. How are ecosystem affected by human action? <ul><li>Almost all ecosystems around the world have been affected by human activity. </li></ul><ul><li>In some areas little remains of the orginal ecosystem. </li></ul><ul><li>Today large areas of untouched tropical rainforest are under threat from deforestation. </li></ul>
  51. 53. <ul><li>The greenhouse effect is a natural phenomenon that controls the balance of heat within the Earth's atmosphere. </li></ul>What is the “greenhouse effect”?
  52. 54. <ul><li>It is the process whereby the natural layer of gases in our atmosphere trap a small percentage of the sun's radiation reflected from the earth's surface. Without the greenhouse effect, the average surface temperature would be about -18 degrees Celsius. </li></ul>
  53. 55. Greenhouse effect
  54. 56. <ul><li>Global warming is caused by the increases in the amount of carbon dioxide and other gases being released into the atmosphere by the burning of fossil fuels. These gases add to the natural greenhouse effect are causing global temperatures to rise. </li></ul>
  55. 57. What problems are caused by global warming ?
  56. 58. Sea levels will rise due to the melting of the ice caps.
  57. 59. Consequences <ul><li>Sea temperatures will rise </li></ul>
  58. 60. Ice caps and glaciers will start to melt
  59. 61. Low-lying areas will be flooded
  60. 62. Violent storms, and extreme hot weather
  61. 63. Deserts will spread
  62. 64. Vegetation and climatic belts will move
  63. 65. Increasement in insect pests
  64. 66. Tropical diseases may spread
  65. 67. Global warming is thought to be due to the greenhouse effect. Climate changing gases
  66. 69. Kyoto Protocol-1997 <ul><li>In 1997, the Kyoto Protocol brought agreement between countries that greenhouse gases should be reduced. So far, many European countries, including Britain, have admitted difficulty in achieving the target. </li></ul><ul><li> </li></ul>
  67. 70. Activity: the Kyoto Protocol <ul><li>http:// = oJAbATJCugs&feature = player_embedded#t =184 </li></ul><ul><li>Watch it and answer the questions. </li></ul>
  68. 71. Human effects on ecosystem cycles: floods and deforestation Floods and deforestation
  69. 72. Activities that alter the natural landscape The development of agriculture The construction of towns and cities The concentration of industries and other economic activities
  70. 73. Serious disturbances-Intervention of human societies <ul><li>Erosion and desertification </li></ul><ul><li>Deforestation </li></ul><ul><li>Pollution </li></ul>
  71. 75. Why do some floods have disastrous consequences?
  72. 77. <ul><li>The flood plain is the area around the river that is likely to flood. The more people there are living and working on the flood plain, the more damage a flood will do. </li></ul>
  74. 79. MEDC flood example-Lynmouth 1952 <ul><li>Very heavy rain for 2 weeks before flood. </li></ul><ul><li>Another heavy storm on 15 August . </li></ul><ul><li>Lynmouth is situated by a confluence, increasing chance of flooding </li></ul><ul><li>Small bridges on the river trapped boulders and trees. </li></ul>
  75. 80. Effects <ul><li>34 people died </li></ul><ul><li>90 buildings destroyed </li></ul><ul><li>1000 people homeless </li></ul><ul><li>150 cars/boats destroyed. </li></ul>
  76. 81. Floods - Bangladesh, 1998 (LEDC) <ul><li>80% of Bangladesh on flood plain </li></ul><ul><li>Strong winds lead to storm. </li></ul><ul><li>Rivers flood in summer due to monsoon rain. </li></ul><ul><li>Deforestation in Nepal . </li></ul><ul><li>River Ganges used for irrigation upstream – less silt in downstream to build up the floodplain </li></ul><ul><li>Rising population –slope collapse </li></ul>
  77. 82. Effects <ul><li>1040 people died </li></ul><ul><li>Over half the country flooded </li></ul><ul><li>23 million homeless </li></ul><ul><li>130 million cattle drowned </li></ul><ul><li>Crops ruined </li></ul><ul><li>Drinking water polluted </li></ul><ul><li>Communities destroyed </li></ul>
  78. 83.
  79. 84. Deforestation What can we do to stop it?
  80. 86. Deforestation in Brazil-5 reasons <ul><li>1. Trees are logged and exported to MEDCs. </li></ul><ul><li>LEDCs don't plan for the future because they are more concerned with making money today. </li></ul>
  81. 87. <ul><li>2. The population is increasing and the government wants to build settlements and roads in the tropical rainforest. </li></ul><ul><li>Trees have to be cut down to make space. </li></ul>
  82. 88. <ul><li>3. The forest is cleared to set up cattle ranches which quickly make the land useless. </li></ul>
  83. 89. <ul><li>4. Mineral extraction helps Brazil pay foreign debts — In Brazil is the world's largest iron reserve. </li></ul><ul><li>Forest is removed to make way for roads and mines. </li></ul>
  84. 90. <ul><li>5. Hydro-electric power (HEP) development has meant that large areas of land have been flooded. </li></ul>
  85. 91. 5 reasons
  86. 92.