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Energy and Ecosystems

  • An ecosystem is all organisms and non-living components in one area (biotic and abiotic components).
  • The first law of thermodynamics states that energy cannot be created or destroyed; it can only be changed from one form to another.
  • Gross Primary Productivity (GPP) is the total amount of light energy converted to chemical energy.
  • Net Primary Productivity (NPP) is the GPP minus the energy required for respiration (R).
  • The law of conservation of mass dictates that mass cannot be created or destroyed, therefore chemicals important to living organisms cycle between parts of the ecosystem. These cycles are known as biogeochemical cycles.
  • The four most significant biogeochemical cycles for living organisms are: the water cycle, the carbon cycle, the nitrogen cycle and the phosphorous cycle.
  • Burning fossil fuels removes carbon from the reservoirs and relocates the carbon to the atmosphere in the form of CO2.
  • Increases in CO2 levels resulting from fossil fuel consumption have contributed the increase in average global temperatures through the greenhouse effect.

Energy and Ecosystems

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AP Biology Intro