Ecologia Aplicada
05/03/2012
This week we will model a part of the standard DEB model.
1. Consider the standard DEB model part that include reserve and structure –
respectively 𝐸/𝑀𝐸 and 𝑉/𝑀𝑉 ). The model can be schematized in units of energy
(and volume) or in units of mass:
a. Write the equations needed to implement the model, for both of the approaches.
b. Explain succinctly why we need to compute both state variables reserve and
structure when we want only to see the results of structure.
c. Explain in what conditions and why we don’t need to compute the state
variables maturity and reproduction buffer (in other words the (1 − 𝜅) 𝑝̇ 𝐶 branch
of the model) when we want only to see the results of structure.
2. Compute the simplified model for Solea solea with the state variables 𝐸 and 𝑉,
using the following parameters
[𝐸𝐺 ] = 5868 J/cm3 𝑣̇ = 0.00364 cm/d 𝜅 = 0.99
{𝑝̇𝐴𝑚 } = 151.76 J/d.cm2 [𝑝̇ 𝑀 ] = 7.809 J/d.cm3
and the following initial conditions
𝑡𝑏 = 20 d 𝐸𝑏 = 20 J 𝑉𝑏 = 2 cm3
Assume that there is no food limitation.
Present in graphs the evolution of the following state variables and fluxes vs time:
in one window: a. Reserve; b. Structure; c. Reserve density
in another window: d. Assimilation flux; e. Assimilation and somatic maintenance
fluxes; f. ; g. Mobilization flux, Somatic plus growth fluxes and growth flux.
Discuss the results of graph g, explaining the areas formed by the different lines
in the graph.
This work is to be delivered by Monday, march 12th.