Chapter 192 Ecology of Organisms

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Chapter 19-2 Ecology of Organisms
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Objectives

• Contrast abiotic factors with biotic factors, and
  list two examples of each
• Explain the importance of tolerance curves
• Describe adaptations that allow organisms to
  avoid unfavorable conditions
• Explain the concept of the niche
• Contrast the fundamental with the realized niche

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Biotic Abiotic

• Habitat where an organism lives
• Biotic living components of the environment
• Abiotic Nonliving factors
• How many of these can you name?
• These are interdependent factors

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Abiotic factors

• Temperature
• Humidity
• pH
• Salinity
• Oxygen Concentration
• Sunlight
• Nitrogen
• Precipitation
• Slope of terrain
• Pressure

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Response to a changing environment

• There is a wide range of environments to survive
  in
• Each organism adapts to a specific range
• You can determine this range by measuring
  activity over different increment
• Tolerance curve graph of performance versus an
  environmental variable

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Horsepower curve for an Engine

• What a graph like this points out is that any
  engine has a peak horsepower - an rpm value at
  which the power available from the engine is at
  its maximum.

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Acclimation

• Adjusting tolerance curve
• If you spend a few weeks at a higher elevation
  your body begins to produce more red blood cells
• EPO doping is artificially simulating this by
  injecting your own blood into you
• Blood doping
• Train high and play low?

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Control internal conditions

• Environments
• Change!
• Conformers change their
• internal environment with the external
• A lizard in the desert
• Regulators use energy to control and maintain a
  constant internal environment
• Some fish conform to temperature, but regulate
  salt concentration

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Escape from Unsuitable Conditions

• Dormancy Hibernate or go into Torpor
• Migration Too cold? just walk south

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Niches

• Niche an organisms position in the ecosystem
• Has biotic abiotic aspects
• Resource acquisition, allocation, method of
  reproduction
• Fundamental niche everywhere it can potentially
  live
• Realized niche where it does live
• Limited by competition

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Niche Differences

• Generalists Broad niches
• Cockroach
• Humans
• Specialists Narrow niches
• Koala
• Humming bird

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Theres only one earth