Chapter 3 Ecosystem Ecology

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Chapter 3Ecosystem Ecology
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Ecology

• Ecology
• eco house logy study of
• The study of interactions among and between
  organisms in their abiotic environment
• Broadest field in biology
• Biotic- living environment
• Includes all organisms
• Abiotic- non living or physical environment
• Includes living space, sunlight, soil,
  precipitation, etc.

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Energy

• The ability or capacity to do work
• Chemical, radiant, thermal, mechanical, nuclear,
  electrical
• Energy exists as
• Potential energy (stored energy)
• Kinetic energy (energy of motion)

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Thermodynamics

• Study of energy and its transformations
• System- the object being studied

• Closed System does not exchange energy
  with surroundings (rare in nature)
• Open System exchanges energy with surroundings

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Laws of Thermodynamics

• First Law of Thermodynamics
• Energy cannot be created or destroyed it can
  change from one form to another
• Ex organisms cannot create energy they need to
  survive- they must capture it from another source
• Focus is on quantity
• Second Law of Thermodynamics
• When energy is converted from one form to
  another, some of it is degraded to heat
• Heat is highly entropic (disorganized)
• Focus is on quality

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Photosynthesis

• Biological process by which energy from the sun
  (radiant energy) is transformed into chemical
  energy of sugar molecules
• Energy captured by plants via photosynthesis is
  transferred to the organisms that eat the plants

6 CO2 12 H2O radiant energy
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Cellular Respiration

• The process where the chemical energy captured in
  photosynthesis is released within cells of plants
  and animals
• This energy is then used for biological work
• Creating new cells, reproduction, movement, etc.

C6H12O6 6 O2 6 H2O
6 CO2 12 H2O energy
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Energy Flow

• Passage of energy in a one-way direction through
  an ecosystem
• Producers
• Primary consumers
• Secondary consumers
• Decomposers

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Food Chains- The Path of Energy Flow

• Energy from food passes from one organism to
  another
• Each link is called a trophic level

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Food webs represent interlocking food chains that
connect all organisms in an ecosystem