Trophic level:The position that an organism occupies in a food chain, or a group of organisms in a community that occupy the same position in food chains.
It is possible to classify the way organisms obtain energy into two categories.
Producers or Autotrophs: These manufacture their own food from simple inorganic substances (plants). Consumers or Heterotrophs: Feed on autotrophs or other heterotrophs to obtain energy (herbivores, carnivores, omnivores, detrivores and decomposers)
But within the consumers their is a feeding hierarchy of feeding
The first trophic level, the autotrophs supports the energy requirements of all the other trophic levels above.
Plants capture the suns energy and convert it to glucose, herbivores eat plants and carnivores eat herbivores – different feeding levels (Greek for food is trophe)
Trophic level 1 – producer
Trophic level 2 – herbivore (primary consumers)
Trophic level 3 – carnivore (secondary consumers)
Trophic level 4 – carnivore (tertiary consumer)