2. Energy Flow
• Energy in an ecosystem originally
comes from the sun
• Energy flows through Ecosystems
from producers to consumers
– Producers (make food)
– Consumers (use food by eating
producers or other consumers)
copyright cmassengale 2
3. Producers
• Sunlight is the main
source of energy
for most life on
earth.
• Producers contain
chlorophyll & can
use energy directly
from the sun
copyright cmassengale 3
4. Autotrophs
• An Autotroph is any organism
that can produce its own food
supply!
• Autotrophs are also called
Producers
• Plants, algae, some protists, &
some bacteria are examples
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5. Niche of a Producer
• Captures energy and transforms
it into organic, stored energy for
the use of living organisms.
• May be photoautotrophs using
light energy (e.g. plants)
• May be chemoautotrophs using
chemical energy (e.g.
cyanobacteria)
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6. Photoautotroph
Producer That Captures Energy
from the sun by:
– Photosynthesis
• Adds Oxygen to the
atmosphere
• Removes Carbon Dioxide from
the Atmosphere
Algae
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7. Habitat of Photoautotrophs
• On Land
– Plants
• In The Sea
– Algae
• Tidal Flats & Salt Marshes
– Cyanobacteria
copyright cmassengale 7
8. Chemoautotrophs
• Capture energy from
the bonds of inorganic
molecules such as
Hydrogen Sulfide
• Process is called
Chemosynthesis
• Often occurs in deep
Called a Black
sea vents or gut of smoker (thermal
animals copyright cmassengale
vent) 8
10. Consumers
Heterotrophs eat other
organisms to obtain
energy. (e.g. animals)
• Herbivores
– Eat Only Plants
• Carnivores
– Eat Only Other Animals
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11. Consumers
Heterotrophs eat other organisms
to obtain energy.
• Omnivores (Humans)
– Eat Plants & Animals
• Detritivores (Scavengers)
– Feed On Dead Plant & Animal
Remains (buzzards)
• Decomposers
– Fungi & Bacteriacmassengale
copyright 11
12. Feeding Relationships
Energy flows
through an
ecosystem in
one direction
from producers
to various
levels of
consumers copyright cmassengale 12
13. Feeding Relationships
• Food Chain
– Simple Energy path through an
ecosystem
• Food Web
– More realistic path through an
ecosystem made of many food
chains
copyright cmassengale 13
14. Food Chain
3rd
1 order
st 2nd Order Order
Consumer consumer 4th Order
Consumer
Consumer
Producer (trapped
sunlight & stored food) copyright cmassengale 14
15. Name the Producer, Consumers
& Decomposers in this food
chain:
copyright cmassengale 15
18. Trophic Levels
Each Level In A Food Chain or Food
Web is a Trophic Level.
• Producers
– Always The First Trophic Level
– How Energy Enters The System
• Herbivores
– Second Trophic Level
copyright cmassengale 19
19. Trophic Levels
• Carnivores/Omnivores
– Make Up The Remaining
Trophic Levels
Each level depends on the
one below it for energy.
copyright cmassengale 20
20. Ecological Pyramids
Graphic Representations Of The
Relative Amounts of Energy or
Matter At Each Trophic Level
May be:
Energy Pyramid
Biomass Pyramid
Pyramid of Numbers
copyright cmassengale 21
