The Living World

• What is an ecosystem?


  a system in which organisms interact with each other and their environment
• What is interdependence in a rainforest?

  Where plants and animals depend on each other for survival
• What is an abiotic factor?

  non-living factors of an ecosystem

  EG: air, water, temperature
• What is a biotic factor


  living factors of an ecosystem

  EG: plants, animals, insects
• Producers use sunlight energy to produce food

  EG: Plants
• Consumers get their energy from eating other organisms
• Decomposers get their energy by breaking down dead material
• ~An example of a small scale ecosystem is Epping Forest

  MANAGEMENT:

  ~Visitors pick fruit and berries which help disperse seeds

  ~Trees are cut down for new growth for timber

  COMPONENTS AND INTERRELATIONSHIPS:

  ~Spring: flowering plants(bluebells) store nutrients to be eaten by consumers later

  ~Summer: broad tree leaves grow quickly to maximise photosynthesis

  ~Autumn: Trees shed leaves to conserve energy due to sunlight hours decreasing

  ~Winter: Bacteria decompose the leaf litter, releasing nutrients into the soil
• What is a biome?


  A large geographical area of distinctive plant and animal groups which are adapted to that particular environment.
• Characteristics of rainforests:

  >contain more animal species than any other ecosystem

  >people have adapted to love in rainforest, they make a living by hunting, fishing and farming

  >Plants are evergreen to take advantage of the continual growing season

  >Soil is not very fertile as heavy rain washes away the nutrients, however there are surface nutrients from decayed leaf fall
• What is desertification?


  The degradation of land, making the soil drier and less fertile
• Process of desertification

  1. Vegetation dies or is removed
  2. the exposed soil is easily removed by wind or water as there are no roots holding it together
  3. Nutrients in the soil are lost, making it unproductive.
• Causes of desertification:
• Climate change:

  • Rainfall is reduced in areas that are already dry, leading to less water available for plant growth
• Temperature:

  • Global temperatures are increasing, causing more water to evaporate from the land
• Removal of fuel wood for cooking:

  • Removing trees for fuel leaves the soil exposed
• Overgrazing:

  • Too many cattle eat plants faster than they can regrow
• Overcultivation:

  • Plants are continuously planted in the same area, depleting all nutrients and making it impossible to grow plants in those areas
• What are strategies to reduce the risk of desertification?

  >Water management: using drip irrigation instead of surface to prevent soil being eroded by water

  >Soil management: letting soil recover their nutrients by leaving areas to rest

  >Tree planting: stabilise roots