Changes between Version 1 and Version 2 of EwEugKeyIndices
- Timestamp:
- 2010-11-23 01:22:01 (13 years ago)
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EwEugKeyIndices
v1 v2 2 2 '''Biomass accumulation''' 3 3 4 Ecopath is not necessarily a steady-state model. If the biomass for a group is known, e.g., at the beginning of the year and at the beginning of the next year, the biomass accumulation (''BA'') can be calculated as the difference between these biomasses. ''BA'' is a production term that can be entered for all living groups (default is 0), but is calculated for detritus groups (see [ [Detritus fate.htm|Detritus fate]]). ''BA'' is a flow term, with a rate unit of, e.g., t / km² / year. The default value for ''BA'' is zero indicating no biomass accumulation. A negative value signifies biomass depletion (biomass decreased during period modelled).4 Ecopath is not necessarily a steady-state model. If the biomass for a group is known, e.g., at the beginning of the year and at the beginning of the next year, the biomass accumulation (''BA'') can be calculated as the difference between these biomasses. ''BA'' is a production term that can be entered for all living groups (default is 0), but is calculated for detritus groups (see [EwEugDetritusFate Detritus fate]). ''BA'' is a flow term, with a rate unit of, e.g., t / km² / year. The default value for ''BA'' is zero indicating no biomass accumulation. A negative value signifies biomass depletion (biomass decreased during period modelled). 5 5 6 6 '''Biomass accumulation rate''' … … 19 19 '''Flow to detritus''' 20 20 21 For each group, the flow to the detritus consists of what is egested (the non-assimilated food) and those elements of the group, which die of old age, diseases, etc., (i.e., of sources of ‘other mortality’, expressed by 1 - ''EE''). The flow to the detritus, expressed, e.g., in t·km-2·year-1, should be positive for all groups.21 For each group, the flow to the detritus consists of what is egested (the non-assimilated food) and those elements of the group, which die of old age, diseases, etc., (i.e., of sources of 'other mortality', expressed by 1 - ''EE''). The flow to the detritus, expressed, e.g., in t·km-2·year-1, should be positive for all groups. 22 22 23 23 === === … … 42 42 '''Omnivory index''' 43 43 44 The ‘omnivory index’was introduced in 1987 (Pauly et al., 1993a) in the initial version of the Ecopath II software. This index (''OI'') is calculated as the variance of the trophic level of a consumer's prey groups. Thus44 The 'omnivory index' was introduced in 1987 (Pauly et al., 1993a) in the initial version of the Ecopath II software. This index (''OI'') is calculated as the variance of the trophic level of a consumer's prey groups. Thus 45 45 46 46 [[Image(wiki:EwEugImages:08000057.png)]] '''Eq. 22'''