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.

Multiple Choice

If there is 1000 Kcal available at the producers level, how much energy is available in the primary consumers level?

• 100 Kcal

• 10 Kcal

• 1 Kcal

• 1000 Kcal

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

Multiple Choice

A primary consumer

• makes its own food

• eats other animals

• is a carnivore

• consumes the producer

Multiple Choice

A producer

• Eats grass

• Makes its own food

• Does not need food(energy)

• Is a primary consumer

Multiple Choice

A secondary consumer

• Only eats meat

• Only eats plants

• makes its own food

• eats the primary consumer

Word Cloud

A primary consumer can only get 10% of what producers make, but, what determines how much energy producers like a trees can actually make?

Multiple Choice

The efficiency of energy transfer from a lower trophic level to the next highest level is roughly

• 1%
• 10%
• 100%
• 1000%

Multiple Choice

Following up on our previous work cloud; in which ecosystem do you think PRIMARY CONSUMERS would have the most energy?

• In the Arizona desert.

• In the Alaskan Tundra.

• In a Virginia Forest.

• The middle of the Atlantic Ocean.