Eco Energy Flow

Energy flow in an ecosystem

• Energy for almost all life on Earth
starts with the sun (solar energy).

• Producers (autotrophs) convert the
sun’s energy into chemical energy
(glucose).

• Consumers (heterotrophs) eat other
organisms since they can’t make their
own food.

• Decomposers recycle nutrients of
dead organisms back into the
ecosystem to be reused.

• Direction of the arrows show how
energy is transferred (flows) from one
organism to another.

Different types of consumers

•Herbivores (primary
consumers) only eat producers
(example: plants)

•Carnivores are animals that
most eat other animals.

•Omnivores are animals that
eat a variety of foods
(producers, animals, fungi)

Food Chain

•A food chain shows one
path of how energy flows
through an ecosystem.

Producer

Primary Consumer

Secondary
Consumer

Tertiary
Consumer

Food Web

•A food web shows
many paths of how
energy can flow
through an ecosystem.

•The stability of the
entire food web
depends upon the
producers.

Let’s practice!

•Which organisms would be
considered the top
predators?

•Name two organisms that
consume the silverside fish?

•Name two organisms
consumed by the
menhaden?

•Name two organisms that
would be affected if bull
minnows were
over-harvested from the
Delaware Bay?

SOL Practice

SOL Practice!

Energy flow and Trophic Levels

• Trophic level – each step in the food chain or web

Energy Pyramid

• Energy pyramid – shows
how much of sun’s energy is
available at each trophic level.

• Of all the energy available
(100%) in an ecosystem, only
10% is passed from one
trophic level to the next.

• The other 90% is used by the
organisms for energy or lost
as heat energy.

Biomass Pyramid

• Biomass pyramid-
illustrates the mass of
producers needed to
support primary consumers,
the mass of primary
consumers needed to
support secondary
consumers, and so on up
the pyramid.

• Where is most of the
biomass according to this
diagram? Producer level