SEV1b Energy Transfer in Ecosystems

Energy Transfer in Ecosystems

​SEV1. Obtain, evaluate, and communicate information to investigate the flow of energy and cycling of matter within an ecosystem.

b. Develop and use a model based on the Laws of Thermodynamics to predict energy transfers

throughout an ecosystem (food chains, food webs, and trophic levels).

Ecosystems Require Energy

Ecosystems require constant inputs of
energy from sunlight or chemicals.

Plants use energy and inorganic
molecules to make food. They are producers.

Animals take in food by eating plants or other living things. They are consumers.

Decomposers, worms and mushrooms, break down dead organisms and other organic wastes and release inorganic molecules back to the environment.

Multiple Choice

What are the organisms that break down dead stuff?

• Producers
• Consumers
• Decomposers
• Organisms

Multiple Choice

What is the role of a producer?

• Use sunlight to make food
• Gain energy from eating other organisms
• Keep other species from overpopulating
• Breaking down dead stuff 

First Law of
Thermodynamics

Also called the Law of
Conservation of Energy

Energy in an isolated
system can be
transformed but can’t be
created or destroyed.

Multiple Choice

A community of living and nonliving things in their natural environment makes up a 

• food web
• ecosystem
• food chain

The Second Law of
Thermodynamics

This explains entropy. It states that as
energy is transferred or transformed,
entropy occurs.

Most energy that is taken in (sunlight
or food) is used by the organism and
isn’t available to anything that eats it.

BTW this also explains why motors
aren’t 100% efficient.

Multiple Choice

Identify the producer in the image.

• Grass

• Grasshopper

• Frog

• Snake

• Eagle

Multiple Choice

Identify the organism that receives the most energy.

• Grass

• Grasshopper

• Shrew

• Owl

Multiple Choice

Energy Transfer supports the concepts of the Law of Conservation of Energy which states.

• Energy is created at the sun and then passed on to other organisms

• Energy cannot be created but it can be used up

• Energy cannot be created or destroyed it can only change forms

• Plants create the energy that we all use.

In ecology, we relate this transfer of energy by showing food chains

or food webs to illustrate that flow of energy.

At each level, some of the energy transfers from the previous level,

and some is transferred to the environment.

Food Chain

There is a straight line from the
producer to the first consumer and
then to the second consumer.

There is one choice for each
consumer to eat.

Since it is so simple you can’t tell
what would actually happen if one
organism was removed.

Multiple Choice

What is missing from this food chain?
Grass > Grasshopper > Bird > Snake

• Producer
• Primary Consumer
• Secondary Consumer
• Decomposer

Arrows

The arrows show the
direction that energy flows.

It is very important to make
sure they are pointing in the
correct direction.

Arrows point from what is
eaten to what is doing the
eating.

Multiple Choice

In a food web, arrows point at:

• who gets energy.
• who gets eaten.

Food Web

Organisms eat and are eaten by multiple organisms.

A food web more closely shows
what happens in an ecosystem.

An extensive food web is very
stable if something happens to
one organism.

Multiple Choice

If the grasshopper were to be removed completely from the food web, what organism would be most effected?

• The squirrel
• The shrew
• The deer
• The rabbit

Multiple Choice

What is this called?

• Food Web
• Food Chain
• Abiotic Factors

Hotspot

Select all of the organisms in the food chain from Phytoplankton to Tundra Swans

​Since environmental science studies the relationships between organisms and their environment, we can also label with the organism's niche as well as their name.

Hotspot

Select any animal that is just a carnivore

Multiple Choice

Which of the following is a herbivore?

• cricket
• frog
• hawk
• shrew

Match

Match the Vore with it's definition

• Carnivore

• Herbivore

• Omnivore

• Detrivore

• Insectivore

Eats other animals or meat

Eats only plants

Eats both plants and animals

Only eats dead things, helps decompose

Eats only insects

• Eats other animals or meat

• Eats only plants

• Eats both plants and animals

• Only eats dead things, helps decompose

• Eats only insects

Multiple Select

Which answers describe a producer (select all correct answers)

• Plant

• Autotroph

• Start food webs & chains as well as trophic pyramids

• Heterotrophs

Multiple Select

Which answers describe a consumer (select all correct answers)

• Heterotroph

• Autotroph

• Eats other organisms

• Carnivore, Herbivore, Omnivore

Match

Match the following - some answers fit for others but all answers should work like a puzzle.

• Producer

• Plant

• Autotroph

• Consumer

• Heterotroph

Plant

Autotroph

Makes its own energy

Eats other Organisms

Consumer

• Plant

• Autotroph

• Makes its own energy

• Eats other Organisms

• Consumer

Trophic levels show the different jobs that organisms have, their niche.

Multiple Choice

The overlapping of food chains results in a ________.

• woven chain
• braided chain
• food web
• food nest

Energy Movement

We have looked at ways
to show the movement of
energy in ecosystems.

Now we will look at
energy pyramids and
trophic levels.

Trophic Levels

Trophic levels describe what
organisms eat. The lowest are
simple plants that get energy
from sunlight to apex predators
at the top of the food chain.

Trophic Pyramid

A trophic pyramid can place multiple organisms in a food web on each level. This is based on what position they have in the food web.
There are rarely more than 4 levels in a trophic pyramid.

Reorder

Reorder the following

• Sun

• Producer

• Primary Consumer

• Secondary Consumer

• Tertiary Consumer

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Draw

In the ecological pyramid circle every word that applies, or describes each trophic level.

Ecosystem Energy Flow

For most of life the energy flow starts with the sun. Only 1% of
the energy entering the biome is captured. Only 10% of this
energy is passed on, the rest is converted to heat as it is used.

Labelling

A food pyramid is shown to represent the transfer of energy in a food chain. Label the amount of energy available to each trophic level if producers have 10,000 kJ of energy.

Drag labels to their correct position on the image

9 kJ

100 kJ

1 kJ

1,000 kJ

100,000 kJ

9000 kJ

10 kJ

900 kJ

Lesson Summary

➢

Thermodynamics deals with the
transfer of energy from one place to
another and from one form to
another.

➢

In ecology, we relate this transfer of
energy by showing food chains or
food webs to illustrate that flow of
energy which we label these food
chains with the organism's niche as
well as their name.

➢

At each level, some of the energy
transfers from the previous level,
and some is transferred to the
environment.