Understanding the EcoBase and EcoPath variables and the reconstruction of the food web

[Mateusz Iskrzyński]

The current User's Guide and related documents do not present a transparent description of how to reconstruct the whole food web based on EcoBase / Ecopath parameters. Is there any good explanation of how the network and its flows are built? At best with equations and diagrams?

• The flows around primary producers are not specified. The consumption, respiration and flows across the ecosystem boundary can neither be found in Ecobase tables nor even in the Ecopath model. How are they estimated (by Ecopath/Ecosim) so that the whole network can be simulated?
  

 

• Where does the egestion fit in the parameters? Eq.2 of "2.1 Mortality for a prey is consumption for a predator" of the current user guide does not offer a place for it- we can assume that part would go to detritus and not only be exported across the system boundary (http://sources.ecopath.org/trac/Ecopath/wiki/EwEugMortalityForaPreyIsConsumptionForaPredator#a2.1Mortalityforapreyisconsumptionforapredator):
  

• Equation 10 contradicts Equation 3 (http://sources.ecopath.org/trac/Ecopath/wiki/EwEugMortalityForaPreyIsConsumptionForaPredator#a2.1Mortalityforapreyisconsumptionforapredator) - Equation 3 suggests a donor-control assumption about consumption flows, whereas Equation 10 a mixed control;

[Mateusz Iskrzyński]

My first attempt at summing the translation up is attached. I refer to the Matlab implementation of Ecobase which seems to be at odds with EwE6 User Guide.