FEEDING

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FEEDING in Ecosystems
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Types of Feeders
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PRODUCERS

• aka autotrophs
• make their own food from inorganic molecules and
  energy

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CONSUMERS

• kinds of heterotrophs
• organisms that cannot make their own food

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CONSUMERS

• HERBIVORES
• aka primary consumers
• organisms that eat only plants
• vegetarians

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CONSUMERS

• CARNIVORES
• aka secondary or tertiary consumers
• organisms that eat herbivores
• and other carnivores
• meat eaters

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CONSUMERS

• OMNIVORES
• aka primary, secondary
• or tertiary consumers
• organisms that eats producers
• and other consumers

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CONSUMERS

• SCAVENGERS
• aka 1, 2, or 3 level consumers
• organisms that eats dead organisms
• usually does not hunt
• may eat plants or animals
• small aquatic ones often known as detritivores
  (i.e. crabs)

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DECOMPOSERS

• kinds of heterotrophs
• bacteria and fungi that consume the bodies of
  dead organism and other organic wastes

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Trophic Levels
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A TROPHIC LEVEL is a layer in the
structure of feeding relationships in an
ecosystem.
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TROPHIC LEVELS
producers 1st trophic level consumers
2nd trophic level consumers 3rd trophic
level consumers etc trophic level
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TROPHIC LEVELS
Autotrophs are the sole point of entry for new
energy into the ecosystem.
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Food Chains and Food Webs
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A FOOD CHAIN is a series of energy (food)
transfers between the trophic levels of an
ecosystem
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Food chains start with producers.
producer
primary consumer
secondary consumer
tertiary consumer
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A FOOD WEB is a network of food chains
representing the feeding relationships among the
organisms in a more complex system
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Food webs include all the food chains in an
ecosystem
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DIVERSITY STABILITY Some ecologists think that
an ecosystem with high diversity and a more
complex food web is more stable. WHY?
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Biological Magnification
The increasing concentration of a pollutant in
organisms at higher trophic levels in a food web.
i.e. DDT
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Energy in the Ecosystem
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Energy enters an ecosystem when producers use
sunlight to make organic matter through
photosynthesis.
energy
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Consumers take in this energy when they eat
producers or other consumers.
energy
energy
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Most of the energy that enters through organisms
in a trophic level does not become biomass. WHY
NOT?
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Biomass
The total amount of organic matter present in a
trophic level
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10 law
only about 10 of the energy entering one trophic
level forms biomass in the next trophic level.