Download energy flow

Chapter 3: The
Biosphere
Section 3-2: Energy
Flow
Interest Grabber
Section 3-2
Pass It Along
• Energy flows in one direction through an
ecosystem, from the sun or inorganic
compounds to producers (organisms that can
make their own food) through various levels to
consumers (organisms that rely on other
organisms for food).
• Your body gets the energy and materials it
needs for growth and repair from the foods
you eat.
The need for energy…
• Energy is needed to drive life
processes
• Example: Ants can lift many times
their mass - energy is needed!
• You need energy to wake up!
• Ecosystems need energy to sustain
life.
Sunlight is the main
energy source for life
on Earth.
A. Producers
What were examples of
producers associated with
the food web game?
A.1:Energy From the Sun
• Photosynthesis:
Plants harvesting
energy from the
sun
• Convert CO2 &
H2O into
Carbohydrates &
water (Ch 8)
Photosynthetic Organisms
• Land
– Plants are the
primary
photosynthetic
organisms
• Water
– Algae or
phytoplankton are
the main
photosynthetic
organisms
– Some
photosynthetic
bacteria as well
Photosynthetic Bacteria
• Photosynthetic
bacteria like these
are found in tidal
flats and salt
marshes
• They are called
cynobacteria and
contribute to the
oxygen on the
earth
A-2:Life Without Light:
Chemosynthesis
• Chemosynthetic
bacteria such as
these use sulfur
in hydrogen
sulfide to
produce energy
rich
carbohydrates
Chemosynthetic Bacteria
• These bacteria
live in remote
places on the
earth
• Yellowstone
National Park’s
hot springs is one
such place
• Tidal marshes are
another
Comparison of
Photosynthesis &
Chemosynthesis
B. Consumers
Heterotrophs:
Obtaining energy from
producers
Heterotrophs
• Organisms
that rely on
other
organisms for
energy needs
• Also called
consumers
What were the
heterotrophs associated
the food web game?
Types of Heterotrophs
• 1.
• 2.
• 3.
• 4.
Herbivores
Carnivores
Detritivores
Decomposers
1. Herbivores
• Eat plant
material
• Examples?
2. Carnivores
• Organisms that
eat animals
• Examples?
3. Omnivores
• Organisms
that eat both
plants and
animals
• Examples?
4. Detritivores
• Organisms that
feed on plant &
animal remains
• They eat dead
matter - detritus!
• Examples?
C. Feeding
Relationships
Movement of
energy through
an ecosystem
Energy Flow
• Food - be it plant
or animal food contains energy
• Some food
contains more
energy than
others
• Energy flows in
one direction in
an ecosystem
Energy Flow
Energy flow…..!
C-1:Food
Chains
• Energy is passed
along in an
ecosystem
through food
chains
• Food chain is a
series of steps in
which organisms
pass energy in
the form of food
Aquatic Food Chains
• Algae/phytoplankton are the basis for the
aquatic systems.
Pollution: Disruption in
Aquatic Food Chains
Biomagnification
C-2: Food Webs
• Complex feeding
relationships
• Feeding
relationships can
be quite
confusing!
• This is a Great
Lakes food web!
C-3: Trophic Levels
• Each step in a food
chain is called a
trophic level
• Produces make up the
first level
• Consumers make up
the 2nd, 3rd etc
• Each consumer
depends on the trophic
level below
D. Ecological
Pyramids
Representing Energy
or the amount of
Matter or Numbers in
an Ecosystem
3 Types of Pyramids
Section 3-2
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.
Ecological Pyramids
Biomass Pyramid
Represents the amount of
living organic matter at each
trophic level. Typically, the
greatest biomass is at the
base of the pyramid.
Pyramid of Numbers
Shows the relative
number of individual
organisms at each
trophic level.
D-1: Energy Pyramid
• Energy is passed
between trophic
levels
• Organisms use the
energy for life
functions
• Some of the energy
is released as heat
• 10% is passed on to
each successive
trophic level
D-2: Biomass Pyramid
• Represents the amount of biomass at
each trophic level
• Expressed in grams / unit area
Biomass Pyramid Enlarged
Notice the
change in
grams @
each
successive
stage
• Represents
the number
of each
organism at
each trophic
level
• May be the
same or
different than
an energy of
biomass
pyramid
D-3: Pyramid of
Numbers