Energy Flow
Through the Ecosystem
Energy and matter
The Earth has internal (chemical) and
external (solar) energy.
That energy is used to move matter
through the Earth’s systems.
Energy changes the physical and
chemical properties of matter.
Sustaining Life on Earth
Requires Energy and Matter
One-way flow
of Energy
Sun
Chemicals
Cycling
of Matter
Energy in Living Systems
Living systems use
energy
Energy used for
growth, reproduction
and metabolism
No organism can create
energy
Can store it, but not
create it
http://ecology.com/wp-content/uploads/2011/09/sun.jpg
Ecosystem energy flow
Energy enters an ecosystem in 2 ways:
Energy is “fixed” (stored in tissues) by
organisms and moves through food webs.
Heat energy is transferred (air, water, soil
convection) and warms life on Earth.
Sunlight is primary source of
energy for most life on Earth
Exception: Chemicals used in deep sea vents
Primary Producers
http://people.westminstercollege.edu/faculty/tharrison/emigration/2_diatoms.gif
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Le
af_1_web.jpg/300px-Leaf_1_web.jpg
Primary producers
capture sunlight or
chemicals and
convert it into
useable energy.
These organisms
are called
“autotrophs.”
Primary Producers
http://people.westminstercollege.edu/faculty/tharrison/emigration/2_diatoms.gif
Primary producers use
solar or chemical
energy to make
complex organic
compounds out of
inorganic materials.
Primary producers
store energy.
Used for their own
energy needs
Also used by organisms
that consume them
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Le
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Primary Producers
http://people.westminstercollege.edu/faculty/tharrison/emigration/2_diatoms.gif
Primary producers include
plants, algae and certain
bacteria.
Use either
Photosynthesis: use
solar energy to make
carbohydrates; release
oxygen
Phytoplankton (aquatic
autotrophs) account for
50% of the oxygen
produced
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f4/Le
af_1_web.jpg/300px-Leaf_1_web.jpg
Chemosynthesis: use
chemical energy to make
carbohydrates
Consumers = heterotrophs
http://video.ecb.org/badger/download/vlc/images/VLC124_Consumers.jpg
Consumers
(heterotrophs) rely
on other organisms
for energy and
nutrients.
Different types of
consumers are
classified by the
way they get
energy.
Types of Consumers:
Carnivores
http://producersconsumers.wikispaces.com/file/view/lionDD.jpg/37331363/lionDD.jpg
Carnivores kill and
eat other animals.
The process of
obtaining meat
requires energy but
meat is generally
high in energy and
nutrients and is
easy to digest.
Types of Consumers:
Herbivores
Herbivores obtain
energy from plants:
roots, leaves,
stems, seeds or
fruits.
Examples include
koalas, cows,
rabbits and deer.
http://www.eoearth.org/files/199301_199400/199323/koaladiet2.jpg
Types of Consumers:
Omnivores
http://www.saburchill.com/images02/010805012.jpg
Omnivores eat a
variety of foods
including both
plants and animals.
Example: Bears eat
other animals but
also eat berries and
other plant
products.
What about the human diet?
Humans who are vegans
(plant products only) can
be considered
_______________.
What about vegetarians who
eat milk products?
___________________
http://3.bp.blogspot.com/_gfZRLG7ChzA/TQVxb_hRoMI/AAAAAAAAAHk/62yyPSZjuIk/s160
0/omnivore.jpg
Humans who eat meat and
fat only can be considered
____________.
Humans who eat meat,
vegetables and fruit can be
considered
________________.
Types of Consumers:
Scavengers
Scavengers eat
animals that have
been killed by other
animals or have
died of other
causes.
Vultures are
scavengers.
http://1.bp.blogspot.com/lbViVUxHu10/TiWOpgNdKNI/AAAAAAAAABk/QT7Hyi8tTFU/s400/vulture.jpg
Types of Consumers:
Detritivores
http://www.theanimalfiles.com/images/detritivore.jpg
Earthworms are detritivores.
Detritivores help
decompose organic
matter by
consuming detritus:
dead animal and
plant parts and
organic wastes.
Commonly digest
decomposers that
live on or in detritus
Types of Consumers:
Decomposers
http://www.scienceiscool.info/pseudomonas_bacteria.jpg
Decomposers
chemically break down
organic matter and use
it for energy.
Release inorganic
compounds into soil
Decomposers include
bacteria and fungi.
Mushrooms are types of
fungi.
http://www.geography4kids.com/files/art/land_chain4_240.jpg
Decomposers and detritivores
Energy Flow in an
Ecosystem: Food Chains and
Food Webs
Energy flows through
an ecosystem in one
direction -- from
producers to various
levels of consumers.
Producers and
consumers are linked
through feeding
relationships.
http://www.sleepingdogstudios.com/Network/Biology/foodweb_2.gif
Energy Flows Through
“Trophic Levels”
Each step of a food
web or food chain is
called a trophic
level.
Energy flows up
from one trophic
level to the next.
http://belizesharks.org/wpcontent/uploads/2012/02/trophiclevels.jpg
Trophic Levels
First Trophic Level
Producers (plants)
Second Trophic Level
Primary consumers
(herbivores)
Feed directly on
producers
Third Trophic Level
Secondary consumer
(carnivores)
Feed on Primary
Consumers
Fourth Trophic Level
Tertiary consumer
Feed on other
carnivores
Food Chains
http://gis.bcsd5.org/Inspiration/Food%20Chain.jpg
Food chains are the
series of steps
through which
organisms transfer
energy by eating or
being eaten.
Can be short or long
Food Webs
Food Web = more
complicated network of
feeding interactions
Include interconnected
food chains
Removal of one
organism affects all
other members of the
web.
Remember: Decomposers and detritivores play an
important role by releasing organic nutrients that can
be used by the primary producers.
Identify three food chains
within this food web.
http://silverfalls.k12.or.us/staff/Read_Shari/mysite/foodweb1.jpg
Note: Energy flows in the direction
of the arrow.
Which is shortest?
______________
______________
Which is longest?
______________
______________
Describe the
possible effects
of a grasshopper
extinction.
______________
______________
______________
Ecological Pyramids
Diagrams used to show the relative
amounts of energy or matter in each
trophic level of a food chain or food
web.
Three types:
Pyramids of Energy
Pyramids of Biomass
Pyramids of Numbers
Pyramid of Energy
Shows the relative
amount of energy
available at each
trophic level of a
food chain or food
web
Pyramid of Energy: 10% Rule
As energy is
transferred up to the
next trophic level,
90% of the energy
is lost.
Only 10% of the
energy within one
trophic level is
transferred to the
next level.
Pyramid of Energy: 10% Rule
Example: A bird (1st
consumer) eats plant
seeds (primary
producer).
Only 10% of the energy
in the grass will be
stored in the tissues of
the bird.
How much of the
energy from the grass
will be stored in the
tissues of the hawk that
eats the bird?
___________________
Pyramid of Biomass
http://images.tutorvista.com/content/ecosystem/biomass-upright-pyramid.jpeg
The total dry mass of
organisms in a trophic
level is its “biomass”.
A pyramid of biomass
shows the relative
amount of organic
matter at each level.
Most at primary
producer level; least at
the top trophic level
What does this say about the amount of primary producer
biomass required to support tertiary consumers?
Pyramid of Numbers
http://images.tutorvista.com/content/ecosystem/upright-pyramid-of-numbersgrassland-pond.jpeg
Shows the relative
number of individual
organisms at each
trophic level
Generally follows
the same pattern as
the pyramid of
biomass