Download Food Webs, and Energy

Food Webs and
Energy Pyramids
Trophic Levels
The trophic level of an organism is the position it
holds on the food chain or web.
Food Web
Energy moves from one organism to the next in a one-way
direction.
•Overlapping food chains.
•More accurate in showing energy connections in an
ecosystem.
Food Web
Pg.486
Identify:
•Producers
•Primary consumers
•Secondary consumers
•Tertiary consumers
Energy Pyramid
The pyramid
represents energy.
More energy is
available at the
base of the
pyramid than at its
top.
Energy is lost each
time one organism
eats another.
Energy Pyramid
Organisms use 90%
of energy they
bring in for survival
and
store 10% of
energy in their
tissues
When a consumer
eats an organism it
gets the left over
10% of stored
energy.
Yellowstone Wolves
Without wolves in the
ecosystem the Elk became
overpopulated. There was not
enough grass for all species.
Wolves kill old, injured and
diseased elk.
The reintroduction of the
wolf returned balance to the
Yellowstone ecosystem.