people and the biosphere

• biome


  large scale ecosystem
• ecosystem


  community of living organisms interacting with non-living
• abiotic & biotic


  non-living & living
• tropical rainforest


  hot and wet all year, no seasons

  at least 75 inches rain

  between 21 and 32 degrees as close to equator
• tropical rainforest (animals)


  monkeys, snakes, leopards, frogs
• temperature/deciduous forest

  not extreme temperature, between -28 and 32 degrees

  four seasons, about same length

  half way between equator and poles
• temperate/deciduous forest (plants)


  plants - coniferous, broad leaved and mixed trees

  long growing season and fertile soil
• temperate/deciduous forest (animals)


  deer, hawks, foxes, squirrels, rabbits
• taiga


  coldest forest biome (-51 degrees)

  dry only 12-12 inches rain annually

  winter can last 9 months
• taiga (plants)


  conifers - grow in cone shape so snow slides off, good for holding in water

  thin layer of soil, short growing season
• taiga (animals)


  lynx, wolverines, wolves, moose, hare, deer
• desert


  hot in day (38+ degrees) cold at night (below 0 degrees)

  can be dust storms

  major desert = Sahara
• desert (plants)


  not many but cacti, grass, shrubs, short trees
• desert (animals)


  (nocturnal) meerkats, camels, reptiles
• savanna/grassland


  warm all year round

  6 month wet season 15-25 inches

  dry season winter, wildfires in January
• savanna/grassland (plants)


  Bermuda grass - long roots to survive fires and grazing
• savanna/grassland (animals)


  gazelles, buffalos, black mamba, lions, cheetahs
• tundra


  coldest biome (-27 degrees), long summer, short winter

  lack of rain, 10 inches or less

  permofrost
• tundra (animals)


  arctic hare, arctic fox, ermine change coat to white in summer

  snowy owl, musk oxen,
• global factors


  temperature (over 5 degrees needed for plant growth)

  sunshine hours (affect photosynthesis and therefore plant growth)

  precipitation (plants cant grow in dry seasons)
• local factors


  altitude, soil, geology, drainage
• cattle ranching


  rainforest cut down and grass grown to use for cattle feed

  cattle decrease fertility of soil

  removing trees = removing carbon sinks
• commercial / cash crops


  crops grown for money and put into products

  destruction of wildlife/habitats
• rainforest services


  atmospheric composition - carbon sinks

  regulating hydrological cycle

  nutrient cycling
• reasons for higher demand for resources

  population growth

  rising affluence

  urbanisation

  industrialisation
• consumption theories - Boserup


  optimistic, when in need we invent a fix

  'necessity is the mother of invention'

  technological inventions - GM crops, fertilisers, machinery
• Malthus


  pessimistic, population increases geometrically whereas food production increases arithmetically - too many people for food

  positive checks - war, starvation, famine

  preventative checks - one child policies, later marriage