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Net Production


In an ecological system we have producers and consumers. Production is proportional to the incoming resources which are varied through four seasons and then repeated the next year. Consumption is proportional to the product storage. The balance between gross production and consumption is called net production.


  • Ponds, lakes, rivers, oceans, fields, forests etc.
  • Economic production such as the products of an industry
  • Diagram


    S = Energy source
    P = Gross production
    C = Consumption
    Q = Storage
    K1, K2 = production and consumption factors


    P = K1*S
    C = K2*Q
    DQ = P - C
    S = 200'000, 350'000, 450'000, 350'000 (varies with the 4 seasons)


    The graph shows the changes of S, P, P-C and Q over 8 years.
    Source code:

    "What if" Experiments:

  • What is the effect of increasing the rate of consumption?
  • What is the effect of increasing the rate of production?
  • What kind of graphs will result if the product storage starts off at a higher value than the steady state in the initial simulation? (Enter Q=1'000'000)