Energy in Ecosystems
MRS.REESE
Energy
 All organisms need energy to live. Organisms use
FOOD as their source of energy.
 THE SUN IS THE DRIVING FORCE FOR
CREATING OR ATTAINING THE FOOD THE
ORGANISMS NEED.
AUTOTROPHS
 AUTOTROPHS: Organisms (such as plants) that
make their own food using the sun’s energy, carbon
dioxide, and water. This is also known as
photosynthesis.
 “Auto” means self and “troph” means feeder.
 Another name for an autotroph is a PRODUCER.
HETETROPH
 HETEROTROPH: Organisms that CANNOT make
their own food.
 “Hetero” means other
 A heterotroph’s energy still comes from the sun but
in an indirect way. Heterotrophs eat autotrophs
directly or other heterotrophs who eat autotrophs.
 Another name for a heterotroph is a CONSUMER.
Herbivore (Consumer)
 Consumers include herbivores, omnivores,
carnivores, and decomposers.
 Herbivores eat only plants.
(Example are grasshoppers, mice, rabbits, deer,
beavers, moose, cows, sheep, goats and groundhogs)
Omnivores (Consumer)
 Omnivores eat both plants and animals.
Examples of omnivores are:
 Bears --They eat insects, fish, moose, elk, deer, sheep as
well as honey, grass, and sedges.
 Turtles -- They eat snails, crayfish, crickets, earthworms,
but also lettuce, small plants, and algae.
 Monkeys -- They eat frogs and lizards as well as fruits,
flowers, and leaves.
 Squirrels -- They eat insects, moths, bird eggs and
nestling birds and also seeds, fruits, acorns, and nuts.
Carnivores and Decomposers (Consumers)
 Carnivores eat only animals.
(Examples of carnivores are foxes, frogs, snakes,
hawks, and spiders.)
 Decomposers break down waste and remains of
dead animals.
Food Chain
 Energy flows from producers to consumers to
decomposers in every ecosystem. This is called the
food chain. In simpler terms, a food chain is
simply "who eats what".
 THERE ARE MULTIPLE FOOD CHAINS IN EVERY
ECOSYTEM AND THESE FOOD CHAINS TEND TO
OVERLAP.
 A food web can be used to illustrate the interactions
between multiple food chains.
Levels of Consumers
 Those that feed directly from producers, i.e. organisms
that eat plant or plant products are called primary
consumers (hervibore).
 Organisms that feed on primary consumers are called
secondary consumers (omnivores and
carnivores).
 Those who feed on secondary consumers are tertiary
consumers (omnivores).
 Some organisms, like a squirrel are at different levels.
When the squirrel eats acorns or fruits (which are plant
product), it is a primary consumer; however, when it eats
insects or nestling birds, is it is a tertiary consumer.
Food Chain Example 1
Food Chain Example 2
EcoKids
 http://www.ecokidsonline.com/pub/eco_info/topics
/frogs/chain_reaction/index.cfm