Energy Flow
Through an
Ecosystem
Food Chains, Food Webs,
Energy Pyramids
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What does the arrow represent?
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The
fusion of
two
hydroge
n atoms
to form
helium
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Food Chains
Producer
AKA:
Autotroph
Primary
Consumer
Herbivore
or
omnivore
Secondary
Consumer
Omnivore,
carnivore,
or detrivore
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Tertiary
Consumer
carnivore,
detrivore,
decomposer
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What does the arrow represent?
Where does that energy come from?
Now draw your food chain in the form of a pyramid?
Why do we draw the flow of energy in a pyramid?
What happens when the energy as it moves up the
food chain?
Why do you think this energy is lost?
This is called the 10% rule
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Ecological
Pyramid
A model that shows
the energy flow
through an
ecosystem.
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Ecosystem Productivity
•
Gross primary productivity vs. Net primary productivity
(GPP- energy used for respiration)
• Producers typically only capture 1% of available
•
solar energy. What is the energy they capture
called? GPP or NPP?
What is the energy left after respiration called?
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Let’s look at the numbers
60% of the
original energy
from the sun is
used for cellular
respiration
40% is used for
growth and
development
And
Passed on if
eaten This
energy is called
ECOLOGICAL
EFFICIENCY
1% of the
Sun Energy
is captured
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Ecological Pyramids of Energy
•
•
45,000 Kcal are available by the producers in a
pond ecosystem. How many Kcal are available to
the alligator, a quaternary consumer?
Hypothetically speaking, 2,000,000 Kcal are
available from the sun to be transformed by the
plants. How many Kcal are actually transformed
by the plants?
What factors could/would effect NPP?
Which of the following biomes would you assume to
have the highest NPP?
A.Tundra
B.desert
C.Savanna
D.Tropical rain forest
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The other pyramids…
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Ecological Pyramids of
Numbers
The figures represent number of
individuals counted at each trophic level.
What do you notice about this pyramid
of numbers?
Note: There's only one oak tree, but lots of caterpillars indicated by the shape of the pyramid
Pyramid of
Numbers
This pyramid
represents the
same data. It does
NOT show the total
number of
organisms though.
What am I?
Pyramid of
Numbers
This pyramid
represents the
same data. It does
NOT show the total
number of
organisms though.
This is a pyramid
of BIOMASS!!
What am I?
Ecological Pyramids of Biomass
The total dry weight of organisms in a particular
trophic level is referenced as biomass.
BIOMASS
=
# of organisms
x
the weight of an
average individual
Ecological Pyramids of Biomass
• Ecologists estimate that there are 2500 ants in the
•
average ant pile. If each ant weights .2 grams,
what is the biomass of the ants in the ant pile?
Another ecologist determined that there are on
average 5 hawks in every one acre in Southlake.
The mass of a single hawk is about 650 grams.
What is the biomass of the hawk in that acre?
Identify the Producers, Consumers, &
Decomposers:
Count the
Food
Chains!
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