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Openaq Pulse Saltmrsh Prairie Fire Lagoon Climax Species Specarea

Pulse and Recycle

Description:

This pulse model is a production-consumption model with recycling feedback. It is more realistic for producer-consumer systems than the prey-predator model. Recycling of outputs of consumation are used by production. The total materials (TM) conserved in the system include those available for production (M), those incorporated in the producers (F1*Q) and those in the consumers (F2*C).

Examples:

  • Grassland with grasshoppers that have a slow consumption mode and a frenzied consumption mode.
  • "Slash and burn" shifting agriculture in the Amazonas.
  • Geological history of the world (fossil fuels).
    		•  Diagram

    Variables:

    M = materials available for production
    Q = materials stored in the producers
    C = materials stored in the consumers
    K1...K4 = factors of interaction

    Equations:

    M = TM - F1*Q - F2*C
    DQ = K1*E*M - K2*Q - K3*C*C*Q
    DC = K2*Q + K3*Q*C*C - K4*C

    Simulation:

    The graph shows the changes of Q (blue) and C (pink) over a time period.
    Source code: Pulse.java

    "What if" Experiments:

    Think about a shifting agriculture farm in the rain forest:

  • If fertilizer were added to the farm, what would that do to the pulsing of the system?
  • Experiment with the factors K2 and K4 and try to explain what they stand for.
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