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Production and Consumption

Description:

In any natural ecosystem there is a daily production and consumption of organic matter or oxygen. The proportion of production and consumption is different at night and in the daytime.

Examples:

  • Photosynthesis and respiration in the forest
  • A self-sufficient economic system with the time sessions or years
    		•  Diagram

    Variables:

    TN = total available nutrients
    N = storage of nutrients
    J = sunlight
    K, K1, K2, K3 = increasing and decreasing factors
    Q = storage of biomass

    Equations:

    JR = J/(1 + K*N)
    N = TN - K3*Q
    DQ = K1*JR*N - K2*Q

    Simulation:

    The graph shows the changes of J (red), Q (blue) and N (green) over a time period of 3 days.
    Source code: Daypr.java

    "What if" Experiments:

  • How would the growth of the forest be different if acid rain reduced the total available nutrients?
  • If this pond was a pond with algae and small fish, what would the changes be if you started with a larger consumer fish?
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