Energy Flow in an Ecosystem

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Energy Flow in an Ecosystem
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Energy Flow in an Ecosystem

• Energy flows through an ecosystem as one organism
  eats another. The way in which energy flows can
  determine how many species can live in an
  ecosystem.
• Each step in the transfer of energy through an
  ecosystem is called a
• trophic level
• In an ecosystem, energy flows from the sun to
  producers to consumers to decomposers

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Energy Flow in an Ecosystem

• Autotrophs organisms that manufacture their own
  nutrients using stored energy or energy from the
  sun
• Examples?
• Heterotrophs cannot make their own food, they
  feed on autotrophs or other heterotrophs
• Examples?

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Energy Flow in an Ecosystem

• The sun is the ultimate source of energy for all
  organisms
• Producers change light energy into energy they
  can use to grow.
• Plants and other photosynthetic organisms
• Consumers eat other organisms instead of
  producing their own food
• Decomposers are organisms that break down the
  remains of organisms
• Fungi, bacteria, some insects

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Types of Consumers

• Herbivores feed on plants
• Rabbits, grasshoppers, squirrels, etc
• Carnivores feed on other animals
• Lions, snakes, wolves, etc
• Scavengers feed on dead animals
• Vultures, crows, etc
• Decomposers break down and absorb nutrients
  from dead organisms
• Fungi, bacteria, some insects

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Trophic Levels in an Ecosystem
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Energy Flow in an Ecosystem

• Food Chains
• In an ecosystem, energy flows from one trophic
  level to the next, forming a food chain
• Simple way to show flow of energy from one
  trophic level to the next
• Arrows point in the direction of energy flow

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Energy Flow in an Ecosystem

• Food Webs
• Energy does not follow a simple pattern!
• Many organisms eat more than one kind of food
• A group of interconnected food chains form a food
  web

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Energy Flow in an Ecosystem

• Energy is stored at each level of a food web and
  moves throughout trophic levels as organisms feed
  on each other. But not all of it is used some
  of it dissipates as heat back into the
  environment and does not move on to the next
  trophic level.

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Energy Flow in an Ecosystem

• Rule of 10
• Also called The 10 Rule
• Only TEN PERCENT of the energy available in a
  trophic level will move on to the next!
• The other NINETY percent is changed into heat
  energy!

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Energy Flow in an Ecosystem

• Energy Pyramid
• Triangular diagram that shows an ecosystems loss
  of energy as it moves through a food chain
• Each layer represents one trophic level
• Producers are always at the base. They have the
  MOST energy!
• Consumers make up higher levels