Ecosystems

• Ecosystem

  A community of plants and animals that interact with eachother and their physical environment
• Biotic


  Living
• Abiotic


  Non-living
• Where is Epping Forest

  South-east england, just north-east of london and south of Stanstead airport, north of london city airport. The M25 and M11 run through it
• Desiduos trees


  Drop leaves in autumn and grow them back in spring
• What causes CHANGE in an ecosystem

  • Extreme weather and droughts - destroys trees e.g.(1976-1977 England experienced drought and during a storm in 1987 15 million trees fell)
  • Deforestation - People chop down trees for space or to use the wood
  • Disease - If trees get diseased they must be chopped down and burnt
• How did introducing cows to Epping Forest restore the ecosystem

  • Grazing allowed more flowers to flourish than mowing would
  • Allows more opportunity for oak trees to reastablish in Epping Forest
  • Low growing species thrive where the thatch of dead grass stems is regularly removed and hooves create bare ground
  • Oak increases species which consume it
• Rainforest

  • Close to the Equator
  • Experiences high rainfall due to low pressure at equator
  • Ideal conditions for plants to grow
  • Only cover 6% of earth's land surface yet over 50% of earth's plants and animals live here
  • 25% of all medicines come from rainforest plants
• Desert

  • Roughly 30 N and S of equator
  • Covers 20% of earth's land surface
  • Hot deserts in sub-tropical high pressure belts - sinking air stops clouds from forming resulting in high day temperatures and low night temperatures
  • Low rainfall
  • Plants and animals must be well adapted to survive here
• Corniferous forest

  • Roughly 50 - 60 N of equator
  • Corniferous trees are cone-bearing
  • Evergreens retain their leaves to maximise photosynthesis
  • Better suited to cold environments
• Grassland

  • Roughly 30 - 40 N and S of equator
  • Inland away from coasts
  • Hot summers, cold winters
  • Grasses can tolerate these conditions and the land is mainly used for grazing animals
• Desiduous forest

  • Roughly 50 - 60 N of equator
  • Shed their leaves in winter to retain moisture
• Savanna

  • Roughly 15 - 30 N and S of equator
  • Tropical climate characterised by distinct wet and dry seasons
  • Violent thunderstorms during wet season
  • Large herds of animals graze on these grasslands like lions and leapords
• Tundra

  • From the Arctic circle to about 60 - 70 N (e.g. Canada, northern europe)
  • Low lying plants which are adapted to retaining heat and moisture in the cold windy and dry conditions
  • Animals like reindeer are adapted to survive here
  • Ecosystem is vunerable to oil exploitation and tourism
  • Not found in large amounts in the southern hemisphere due to lack of land at these latitudes
• What factors affect the loaction of biomes

  • Latitude
  • Altitude
  • Mountain ranges
  • Ocean currents
  • Global atmospheric circulation
• Difference between soil in rainforest and cold environments

  • Both low in nutrients but cold environment soil has more
  • Rainforest covered in leaf litter, Cold environment covered in permafrost
  • Rainforest has tall trees whilst cold environments have short plants