Chapter 17 Ecosystems

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Chapter 17 - Ecosystems

• High School Biology Class

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What is Ecology?

• Greek Word Roots
• eco come from oikos which means house
• logy means study of

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What is Ecology?

• Ecology study of the interactions of living
  organisms with one another and with their
  physical environment.

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Ecology Terms

• Habitat a place where a particular population
  of a species live.
• Community - the groups of many different species
  that live together in a particular habitat.

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Ecology Terms

• Ecological system or ecosystem consists of a
  community and its habitat.

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Ecosystem Terms

• Biotic Factors all of the living organisms that
  belong in a habitat.
• Examples
• a) animals
• b) plants
• c) fungi
• d) protists
• e) bacteria

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Ecosystem Terms

• Abiotic Factors all of the physical
  (non-living) aspects that belong in a habitat.
• Examples
• a) soil (mineral), water, wind (air)
• b) energy such as light or sound
• c) climate, weather, temperature

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Ecosystem Terms

• Biodiversity a measure of the number of species
  living in a certain ecosystem.
• The Tropical Rainforest is the most diverse
  ecosystem.

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Ecosystem Terms

• Niche an ecological role that an organism
  fulfills in an ecosystem.
• All members of an ecosystem are interdependent.

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Ecosystems Change Over Time

• When a new habitat is created (fire, earthquake,
  logging, etc) the change is somewhat regular
• Primary Succession pioneer species such as
  small plants first appear and fill niches.
• Secondary Succession current species and new
  species compete for the niches.

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Energy Flow in Ecosystems

• A) The primary source of energy is the sun.
• B) Producers are organisms that capture light
  energy and convert it into chemical energy.
• C) Consumers are organisms that consume producers
  or other consumers for energy.
• D) Decomposers are organisms that consume
  producers, consumers, and other decomposers for
  energy once they have died.

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Energy Flow in Ecosystems

• Producers - organisms that make energy-storing
  molecules, such as glucose, from light or
  chemical energy.
• They are the first and the most important link in
  an ecosystem, they are sometimes called
• Autotrophs - produce food for themselves.
• Examples some bacteria, few protists, and all of
  the green plants

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Energy Flow in Ecosystems

• Consumers - organisms that consume plants or
  other producer organisms in order to obtain
  energy.
• They are the second and less important links in
  an ecosystem, they are sometimes called
• Heterotrophs rely on other organisms for food.
• Examples some bacteria, most protists, some
  fungi, all plants not green, and all animals

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Consumer Types

• 1) Herbivore feed directly on green plants.
• Examples deer, cattle, zooplankton, turtles
• 2) Carnivore feed on other animals.
• Examples lions, hawks, fish, frogs
• 3) Omnivore feed on plants and animals.
• Examples bears, raccoons, crayfish, humans

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Energy Flow in Ecosystems

• Decomposers organisms that consume organic
  wastes and dead bodies of other organisms.
• They are the last and much needed link in an
  ecosystem, they are sometimes called
• Heterotrophs rely on other organisms for food.
• Examples some bacteria, few protists, and some
  fungi

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Energy Flow in Ecosystems

• Every living organism requires energy.
• Trophic Level - shows how energy gets transferred
  from organism to organism.
• Sun ? Producer ? Consumer ? Decomposer

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Energy Flow in Ecosystems

• Food Chain the path of energy through the
  various trophic levels of an ecosystem.

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Food Chains

• 1st level
• Producers - make their own food.
• 2nd level
• Herbivores - eat primary producers.
• 3rd level
• Carnivores - eat herbivores.
• Omnivores - eat both herbivores and carnivores.
• 4th level
• Decomposers - eat all dead organisms.

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Energy Flow in Ecosystems

• Food Web all of the interconnected groups of
  organisms that make up many food chains.

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Ecosystem Energy

• The energy that is stored at each trophic level
  is about 1/10 that of the level below it.
• By showing the declining amounts of energy in
  each of the trophic levels an ecological pyramid
  can be formed.

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Few ecosystem can contain more than five trophic
levels.
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Any Questions?

• You have brains in your head.
• You have feet in your shoes.
• You can steer yourself any direction you choose.
• Your own your own.
• And you know what you know.
• And you are the guy
• Wholl decide where you go.
• -Theodor Geisel (Dr. Seuss)