Trophic Levels (Triple)

• Trophic Levels 

  • Trophic levels describe the position of an organism in a food chain, web or pyramid 
  • Trophic levels can be represented by numbers, starting at level 1 with plants and algae. Further trophic levels are numbered subsequently according to how far the organism is along the food chain
• • Trophic level 1 - Producers. plants and algae - produce their own organic nutrients and biomass using energy from sunlight
  • Trophic level 2 - primary consumers , herbivores - feed on producers (plants and algae)
  • Trophic level 3 - secondary consumers, predators - feed on primary consumers
  • Trophic level 4 - tertiary consumers, predators - feed on secondary consumers
  • Trophic level 5 - quaternary consumers, predators - feed on tertiary consumers

  
• • Energy flows from the Sun to the first trophic level (producers) in the form of light Producers convert the light into energy
  • This occurs during photosynthesis, when producers convert carbon dioxide & water into glucose & oxygen
  • This chemical energy is then transferred to primary consumers as they consume producers
  • The chemical energy is then transferred from one consumer to another as they eat one another
  • Apex predators are at the top of the food chain – they have no predators. The chemical energy stored within apex predators are passed on to decomposers when they die & are decomposed
• The Importance of Decomposers

  • The two main groups of decomposers are bacteria and fungi
  • Decomposers carry out a very important function in ecosystems – they break down dead plant and animal material
  • They do this by:
  • Secreting digestive enzymes onto the surface of the dead organism
  • These enzymes break down the dead matter into small soluble food molecules
  • These molecules are then absorbed by the decomposers
  • This process of decomposition also helps to release organic nutrients back into the environment (eg. the soil) which are essential for the growth of plants (producers)