Cedar Bog Lake System Description

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Cedar Bog Lake System Description

• Lake in Minnesota which almost disappeared due to
  sediment growth
• One of the first environmental simulations (other
  than weather forecasting) as reported in
  Williams, R.B. (1971) Computer Simulation of
  Energy Flow in Cedar Bog Lake, Minnesota Based on
  the Classical Studies of Lindeman, Systems
  Analysis and Simulation in Ecology, B.C. Patten,
  Ed. Academic Press

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Lindemans Studies

• Done in 1930s introduced trophic dynamic
  concepts into biology (In trophic systems energy
  is lost as it moves to higher animals)
• Never published (concepts not accepted by
  biologists in those days) preserved by his
  post-doctoral advisor and finally published in
  1942
• Now considered a classic in biodiversity studies
• Measured mass and changes in mass converted to
  energy over time

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View of Lake(fed by and drains to a creek 9
square miles study area)
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Typical Sedimentation
Natural infill of a lake with sediment in the
nature reserve at Stackpole, Pembs
From http//www.nationaltrust.org.uk/environment/h
tml/nat_con/papers/dredging01_04.htm
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Cedar Bog Lake System
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Variables

• All variables are scaled into the energy content
  of various lake contents and solar input (trophic
  dynamic approach in biology)
• xp energy in plants
• xh energy in herbivores
• xc energy in carnivores
• xo energy in lake bed organic sediment
• xe energy lost to environment (respiration and
  migration)
• xs solar energy supply impinging on lake
  surface

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EquationsIn units of calories/centimeters2
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Initial Conditions

• Prior simulations started with no sediment and
  used the following initial conditions
• Xp(0) .83
• Xh(0) .003
• Xc(0) .0001
• Xo(0) 0
• Xe(0) 0
• See 532-10-CedarBogLake.ppt, CedarBogLake.gps,
  CedarBogLakeResults.xls