Manually set respiration = 0?

[Tormey Reimer]

Hi everyone,

I'm new to the group and new to EwE, and I'm trying to do something that's a little bit outside the scope of the software.

Essentially, I'm using a nutrient (nitrogen) as a currency rather than biomass. I have already built and balanced the Ecopath model and it looks great. I was hoping to use my nitrogen-Ecopath model in Ecosim, but I realise that Ecosim doesn't work when the program is working in nutrients. Therefore, I'm looking for workarounds. 

My understanding is that the major difference in the software when working in nutrients is that R = 0, and unassimilated consumption (U) is now calculated as U = Q - P instead of defaulting to 20%.

I'm wondering if I can "trick" the program into allowing Ecosim in nutrients by selecting "biomass" in the Model Parameters screen, manually setting R = 0, and manually setting the  U for each group taken from my balanced nutrient model. In the 2005 version of Ecopath with Ecosim: a User’s Guide, section 4.7.6 "Alternative input", page 30, it details exactly how to set total R, R/B or R/Q in some previous version of EwE, but I don't think this version exists on www.ecopath.org any more.

Does anyone know if the "Alternative Input" routine can still be accessed in the available EwE software? Or if there's another way to acheive what I want?