Download Feeding Levels

Feeding Levels
214-1 Describe and apply
classification systems and
nomenclature with respect to
trophic levels in ecosystems
• How can we compare food chains in
different ecosystems? In order to do this
we must think of ecosystems as being
made up of several feeding levels, or
trophic levels.
• Producers (plants) make up the first
trophic level. Primary consumers feed at
the second trophic level (herbivores).
Secondary consumers feed at the third
trophic level (carnivores). Many
organisms eat a variety of foods and may
consume organisms from more than one
trophic level.
• Most of the energy that enters each
trophic level is used by the organisms at
that level just to stay alive (to move,
breathe, run, etc.). The amount of energy
that is transferred from one trophic level to
the next varies from 5-20%.
• Many organisms do not get eaten until
they die. Consumers known as
scavengers feed on the bodies of larger
dead animals (e.g. vultures, eagles). The
bodies of smaller dead animals, dead
plant matter and animal dung are food for
detritivores. Detritivores also include
decomposers such as bacteria and fungi.