Energy Flow
EQ: How does energy flow
through living systems?
Interactions and Interdependence


Ecology: the
interaction
between
animals and
the
environment
The earth can
be divided into
different levels
of
organization
Producers



Defined as something
that produces or converts
energy from the sun into
energy that animals can
use
Another term for these
organisms is autotrophs
These organisms perform
photosynthesis and are
the basis for the food
chains
Photosynthesis

The process by
which plants
convert the sun’s
energy to sugar
with the help of
carbon dioxide
 The bi-product of
this process is
oxygen
Consumers

An organism that
consumes (eats)
energy produced
by plants or other
animals
 Another term for
these organisms is
heterotrophs
Different Types of Consumers
 Herbivores:
eat only plants
 Carnivores: eat only meat
 Omnivores: eat both plants and meat
 Detritivores: feed on the remains of other
organisms
 Decomposers: break down dead material
Food Chains
 Show
the flow of energy between
organisms
 Only one possible prey item shown at
each level
 Simplest way to show interactions
Example of a Food Chain
Phytoplankton
Zooplankton
Angel Fish
Sea Turtle
Food Web
 Shows
the flow of energy between all
members of an ecosystem
 Shows complex interactions
 Allows one to see what would happen if
one species is removed
Food Web
Food Pyramid
 Each
organism on the food chain is placed
into a different trophic level
 The organism with the most energy is
placed on the bottom and the organism
that receives the least energy is placed on
top
 Shows the loss of energy as you go up the
food chain from plants to top predators
Ecological Pyramids
Pyramid of Numbers
Shows the relative
number of individual
organisms at each
trophic level.
Biomass Pyramid
Represents the amount of
living organic matter at each
trophic level. Typically, the
greatest biomass is at the
base of the pyramid.
Energy Pyramid
Shows the relative amount of
energy available at each trophic
level. Organisms use about 10
percent of this energy for
life processes. The rest is lost
as heat.
Food Pyramid
Food Pyramid Layers
 The
bottom level of a food pyramid are the
primary producers

The plants and algae that perform
photosynthesis to convert the suns energy to
chemical energy
 The
second level are the primary
consumers


These are the organisms that eat the
producers
These organisms are called herbivores
Food Pyramid Layers

The next level contains the secondary
consumers



These are the organisms that eat the primary
consumers
These animals are considered carnivores if there diet
is strictly other animals or omnivores if they also
include plants in their diet
The top level is the tertiary consumers


These animals eat the secondary consumers
Usually the top predators in an ecosystem
Example of a Food Pyramid
Tertiary
Consumer
Secondary
Consumer
Primary
Consumer
Producer
Sea Turtle
Angel Fish
Zooplankton
Phytoplankton
Energy Transfer
 Only
10 percent of the energy is
transferred between levels



This is because an animal needs to expend
energy in order to capture and eat its prey
If it is taking too much energy to capture the
prey than the animal will abandon the hunt
(cheetah and gazelle)
If there was 1000kg of energy at the producer
level than the top predator would only get 1 kg
Energy transfer
1 kg
Of energy
10 kg
Of energy
100 kg
Of energy
1000 kg
Of energy
Sea Turtle
Angel
Fish
Zooplankton
Phytoplankton
Explains why a sea
Turtle must eat so much
To survive