Population & Energetic Parameters for Mass-Balanced Approaches

All species-specific parameter values are entered and saved in the spreadsheet “EmpiricalValues-Species.xls” available in the “Community database” folder of our EBM Predators working group on the NCEAS portal (#). Definitions and units for each column are available by clicking on the corresponding in the database itself.

All taxonomic group level relationships (e.g. allometric relationships) are entered and save in the spreadsheet “EmpiricalRelationships-Groups.xls” also found in the database folder.

Each person entering data should start their own EndNote library for keeping track of their collected citations.

When you upload your files to the database folder, make sure that you rename your filename so that it's not the same as the file already in the folder! For example, append your name and date to the filename (EmpricalRelationships-Groups-MN-March11.xls).

Please periodically upload your EndNote library and Excel file to the NCEAS portal (“Mass-Balance-Models” folder) so that others can cross-check references to see if they can find information for their own webs.

1) Parameter Documentation

Every value entered should have a corresponding reference saved in an EndNote file, which should be coded and pedigreed. A reference identifier code must be included in the “Call Number” space of each EndNote citation. Codes correspond to the respective system analyzed and person responsible:

Tim Tinker & Estes lab 1-999

Mark & Ute 1000-1999

Tim Wootton 2000-2999

Mark Novak 3000-3999

If PDF's of the reference are available, please save PDF with the respective code name, for example 999.pdf. These can be uploaded to the folder “ReferencePDFs” in the “Mass-Balance-Models” folder.

Pedigree of values entered in the EndNote record under “Label” should follow this classification:

If you have to use an allometric equation for an value estimate save equation, its species specific inputs (intercept, slope etc.) and reference for this equation on an system specific worksheet.

If you don't use EndNote, save your coded references on a system specific worksheet and create an extra column to add the pedigree value.

2) Parameters values required

Only models constructed using an energy related currency (e.g. t km² year^-1) can be run under Ecopath (www.ecopath.org) or EcoNetwrk.

Diet Composition

Diet should be expressed as the fraction each prey contributes to the overall diet (on a weight, energy, volume or guesstimate basis). The “Guesstimate” basis should follow the hierarchy that is present in the database:

Diet Fraction of Species B in Diet of Species A

Almost completely 95%

Dominant 80%

Mostly 50-60%

Fairly common 50%

Frequent 20-50%

Occasional 5-20%

Rare 5%

3) Parameter relationships

Parameter values for which we cannot find species-specific information will be inferred using higher taxon-level relationships.

Note: Not all parameters are required to run either the Ecopath or the Netwrk program, helpful links to calculate parameters needed (like production related values), can be found at:

http://www.awi-bremerhaven.de/Benthic/Ecosystem/FoodWeb/Handbook/main.html