# Changes between Version 6 and Version 7 of EwEugMortalityForaPreyIsConsumptionForaPredator

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Timestamp:
2010-11-18 02:10:38 (9 years ago)
Comment:

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• ## EwEugMortalityForaPreyIsConsumptionForaPredator

 v6 Eq. 2.2 can be re-expressed as ''''' '''[[Image(08000002.png)]] Eq. 3''' This system of simultaneous linear equations can be re-expressed ../Resources/Images/08000008.png^''''''^''' Eq. 6'''^''''''^ '''[[Image(08000008.png)]] Eq. 6''' with ''n'' being equal to the number of equations, and ''m'' to the number of unknowns. where ''EE,,i,,'' is called the 'ecotrophic efficiency' of (''i''), and can be described as the proportion of the production that is utilized in the system. The production term describing predation mortality, ''M2'', serves to link predators and prey as, ../Resources/Images/0800000B.png^''''''^''' Eq. 10'''^''''''^ '''[[Image(0800000B.png)]] Eq. 10''''' where the summation is over all (''n'') predator groups (''j'') feeding on group (''i''), ''Q,,j,,'' is the total consumption rate for group (''j''), and ''DCji'' is the fraction of predator (''j'')'s diet contributed by prey (''i''). ''Qj'' is calculated as the product of ''Bj'', the biomass of group (''j'') and ''Qj / Bj'', the consumption/biomass ratio for group (''j''). while ''P,,i,,/B,,i,,'' and ''Q,,i,,/B,,i,,''are attempted solved by inverting the same equation. The'' P/B'' ratio is then estimated (if possible) from ../Resources/Images/0800000C.png^''''''^''' Eq. 12'''^''''''^ '''[[Image(0800000C.png)]] Eq. 12''''' This expression can be solved if both the catch, biomass and ecotrophic efficiency of group ''i'', and the biomasses and consumption rates of all predators on group i are known (including group ''i'' if a zero order cycle, i.e., 'cannibalism' exists). The catch, net migration and biomass accumulation rates are required input, and hence always known; The ''EE'' is estimated from ../Resources/Images/0800000D.png'''Eq. 13''' '''[[Image(0800000D.png)]] Eq. 13''''' where the predation mortality ''M2'' is estimated from Eq. 2.2.10.