Changes between Version 1 and Version 2 of EwEugEditMultiStanzaGroups


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Timestamp:
2010-02-05 15:13:37 (9 years ago)
Author:
varunr
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Added page and images.

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  • EwEugEditMultiStanzaGroups

    v1 v2  
    11== 6.3 Edit multi-stanza groups == 
    2 Multi-stanza groups are defined using the [[Edit groups.htm|Edit groups]] form, accessible from the ''Ecopath menu'' on the ''Menu bar''. Multi-stanza groups represent life history stages or stanzas for species that have complex trophic ontogeny. Mortality rates (''M0'', predation, fishing) and diet composition are assumed to be similar for individuals within each stanza (e.g., larvae having high mortality and feeding on zooplankton, juveniles having lower mortality and feeding on benthic insects, adults having still lower mortality and feeding on fish). For Ecosim and Ecospace it is advised to split top predators into multi-stanza groups as this makes their dynamics more realistic, provides insights on stock-recruitment relationships, and allows consideration of stanza-specific habitat use. See the introductory material on [[Representation of multi stanza.htm|multi-stanza groups]] and [[Using Ecosim to study compensation.htm|Using Ecosim to study compensation in recruitment relationships]] (Chapters 2 and 3 of the EwE6 User Guide) for more information on how these groups are modelled in Ecopath, Ecosim and Ecospace. 
     2Multi-stanza groups are defined using the [wiki:EwEugEditGroups Edit groups] form, accessible from the ''Ecopath menu'' on the ''Menu bar''. Multi-stanza groups represent life history stages or stanzas for species that have complex trophic ontogeny. Mortality rates (''M0'', predation, fishing) and diet composition are assumed to be similar for individuals within each stanza (e.g., larvae having high mortality and feeding on zooplankton, juveniles having lower mortality and feeding on benthic insects, adults having still lower mortality and feeding on fish). For Ecosim and Ecospace it is advised to split top predators into multi-stanza groups as this makes their dynamics more realistic, provides insights on stock-recruitment relationships, and allows consideration of stanza-specific habitat use. See the introductory material on [wiki:EwEugRepresentationOfMultiStanza multi-stanza groups] and [wiki:EwEugUsingEcosimToStudyCompensation Using Ecosim to study compensation in recruitment relationships] (Chapters 2 and 3 of the EwE6 User Guide) for more information on how these groups are modelled in Ecopath, Ecosim and Ecospace. 
    33 
    44Once you have defined a multi-stanza group(s) you must go to the ''Edit multi-stanza groups'' form to set the parameters needed to calculate the biomass and numbers in each age category. To open the ''Edit multi-stanza groups'' form, choose the ''Edit multi-stanza groups...'' option on the'' Ecopath menu''. Features of the ''Edit multi-stanza groups'' form are shown in Figure 6.1. 
     
    2626'''Relative biomass accumulation rate (BA/B)''' 
    2727 
    28 The ''BA/B'' term represents effect on the numbers at age of the population growth rate (e.g. the cohort born one year ago should be smaller by the factor ../Resources/Images/0800001E.png than the cohort born “''a''” years ago (see [[Representation of multi stanza.htm|Multi-stanza groups]]). See [[Other production.htm|Other production]] for notes about estimating the relative biomass accumulation rate. 
     28The ''BA/B'' term represents effect on the numbers at age of the population growth rate (e.g. the cohort born one year ago should be smaller by the factor [[Image(wiki:EwEugImages:0800001E.png)]] than the cohort born “''a''” years ago (see [wiki:EwEugRepresentationOfMultiStanza Multi-stanza groups]). See [wiki:EwEugOtherProduction Other production] for notes about estimating the relative biomass accumulation rate. 
    2929 
    3030'''Weight at maturity/W_infinity''' 
     
    3434'''Forcing function number for hatchery stocking''' 
    3535 
    36 Multi-stanza populations can be designated as hatchery populations (see [[Hatchery populations in Ecosim.htm|Hatchery populations in Ecosim]]), and hatchery production can be varied over time in Ecosim using time forcing functions. To turn off natural reproduction select the hatchery forcing function from the pull-down menu in the ''Forcing function number for hatchery stocking'' box. 
     36Multi-stanza populations can be designated as hatchery populations (see [wiki:EwEugHatcheryPopulationsInEcosim Hatchery populations in Ecosim]), and hatchery production can be varied over time in Ecosim using time forcing functions. To turn off natural reproduction select the hatchery forcing function from the pull-down menu in the ''Forcing function number for hatchery stocking'' box. 
    3737 
    38 Note, you must already have a forcing time series loaded in Ecosim (see [[Time series.htm|Time series]] and [[Forcing function.htm|Forcing function]]). Note that forcing functions to represent historical changes in stocking rates can be entered via the same csv files as used to set up historical fishing and model fitting scenarios. Enter stocking rates as values relative to the stocking rate of 1.0 assumed for the Ecopath base year. 
     38Note, you must already have a forcing time series loaded in Ecosim (see [wiki:EwEugTimeSeries Time series] and [wiki:EwEugForcingFunction Forcing function]). Note that forcing functions to represent historical changes in stocking rates can be entered via the same csv files as used to set up historical fishing and model fitting scenarios. Enter stocking rates as values relative to the stocking rate of 1.0 assumed for the Ecopath base year. 
    3939 
    4040At each simulation time step, the base recruitment for the population (calculated from Ecopath input parameters) will be multiplied by the current time value for the designated forcing function.