General Overview


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This report is the result of the use of the python package bgc_md, as means to translate published models to a common language. The underlying yaml file was created by Verónika Ceballos-Núñez (Orcid ID: 0000-0002-0046-1160) on 29/3/2016.

About the model

The model depicted in this document considers carbon allocation with a process based approach. It was originally described by Thomas & Williams (2014).

Space Scale

global

state_variables
Name Description
\(C_{leaf}\) Carbon in foliage
\(C_{wood}\) Carbon in wood
\(C_{root}\) Carbon in roots
\(C_{labile}\) Labile carbon
\(C_{bud}\) Bud carbon
\(C_{labileRa}\) Maintenance respiration pool
photosynthetic_parameters
Name Description Expression Unit
\(GPP\) Photosynthesis; based on ACM model (see article for description) - \(gC\cdot day^{-1}\)
respiration_fluxes
Name Description Unit
\(Ra_{growth}\) Growth respiration that occurs when tissue is allocated; a constant fraction of carbon allocated to tissue \(gC\cdot m^{-2}\cdot day^{-1}\)
\(Ra_{excess}\) Respiration that occurs when labile C exceeds a maximum labile C store; used for N fixation \(gC\cdot m^{-2}\cdot day^{-1}\)
\(Ra_{main}\) Respiration of living tissues; a function of N content and temperature \(gC\cdot m^{-2}\cdot day^{-1}\)
allocation_fluxes
Name Description Unit
\(a_{budC2leaf}\) Allocation from bud C pool to leaf C \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{woodC}\) Allocation from labile C to wood C \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{rootC}\) Allocation from labile C to root C \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{budC2Ramain}\) Allocation of bud C pool to maintenance respiration pool when maintain respiration pool reaches zero; represents forgoing future leaf C to prevent carbon starvation. \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{budC}\) Allocation of labile C to bud C; a fraction of the potential maximum leaf C \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{Ramain}\) Allocation of labile C to future maintenance respiration; helps prevent carbon starvation during periods of negative NPP \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{labileRamain}\) Allocation of labile C to respiration of living tissues \(gC\cdot m^{-2}\cdot day^{-1}\)
turnover_fluxes
Name Description Expression Unit
\(\tau_{leaf}\) Turnover of leaf (C and N) - \(day^{-1}\)
\(\tau_{wood}\) Turnover of wood (C and N) - \(day^{-1}\)
\(\tau_{root}\) Turnover of root (C and N) - \(day^{-1}\)
\(t_{leafC}\) Turnover of leaf C to litter C; constant over year in humid tropics; seasonal otherwise \(t_{leafC}=C_{leaf}\cdot\tau_{leaf}\) \(gC\cdot m^{-2}\cdot day^{-1}\)
\(t_{woodC}\) Turnover of wood C to CWDC pool; occurs throughout year \(t_{woodC}=C_{wood}\cdot\tau_{wood}\) \(gC\cdot m^{-2}\cdot day^{-1}\)
\(t_{rootC}\) Turnover of root C to litter C; occurs throughout year \(t_{rootC}=C_{root}\cdot\tau_{root}\) \(gC\cdot m^{-2}\cdot day^{-1}\)
components
Name Description Expression
\(x\) vector of states (C\(_{i}\)) for vegetation \(x=\left[\begin{matrix}C_{labile}\\C_{bud}\\C_{leaf}\\C_{wood}\\C_{root}\\C_{labileRa}\end{matrix}\right]\)
\(u\) scalar function of photosynthetic inputs \(u=GPP\)
\(b\) vector of partitioning coefficients of photosynthetically fixed carbon \(b=\left[\begin{matrix}1\\0\\0\\0\\0\\0\end{matrix}\right]\)
\(A_{x}\) matrix of cycling rates \(A_{x}=\left[\begin{matrix}\frac{- Ra_{excess} - Ra_{growth} - a_{budC} - a_{labileRamain} - a_{rootC} - a_{woodC}}{C_{labile}} & 0 & 0 & 0 & 0 & 0\\\frac{a_{budC}}{C_{labile}} &\frac{- a_{budC2Ramain} - a_{budC2leaf}}{C_{bud}} & 0 & 0 & 0 & 0\\0 &\frac{a_{budC2leaf}}{C_{bud}} & -\tau_{leaf} & 0 & 0 & 0\\\frac{a_{woodC}}{C_{labile}} & 0 & 0 & -\tau_{wood} & 0 & 0\\\frac{a_{rootC}}{C_{labile}} & 0 & 0 & 0 & -\tau_{root} & 0\\\frac{a_{labileRamain}}{C_{labile}} &\frac{a_{budC2Ramain}}{C_{bud}} & 0 & 0 & 0 & -\frac{Ra_{main}}{C_{labileRa}}\end{matrix}\right]\)
\(f_{v}\) the righthandside of the ode \(f_{v}=u b + A_{x} x\)

Pool model representation


Figure 1
Figure 1: Pool model representation

Input fluxes

\(C_{labile}: GPP\)

Output fluxes

\(C_{labile}: Ra_{excess} + Ra_{growth}\)
\(C_{leaf}: C_{leaf}\cdot\tau_{leaf}\)
\(C_{wood}: C_{wood}\cdot\tau_{wood}\)
\(C_{root}: C_{root}\cdot\tau_{root}\)
\(C_{labileRa}: Ra_{main}\)

Internal fluxes

\(C_{labile} \rightarrow C_{bud}: a_{budC}\)
\(C_{labile} \rightarrow C_{wood}: a_{woodC}\)
\(C_{labile} \rightarrow C_{root}: a_{rootC}\)
\(C_{labile} \rightarrow C_{labileRa}: a_{labileRamain}\)
\(C_{bud} \rightarrow C_{leaf}: a_{budC2leaf}\)
\(C_{bud} \rightarrow C_{labileRa}: a_{budC2Ramain}\)

Steady state formulas

\(C_labile = C_{labile}\)

\(C_bud = C_{bud}\)

\(C_leaf = \frac{a_{budC2leaf}}{\tau_{leaf}}\)

\(C_wood = \frac{a_{woodC}}{\tau_{wood}}\)

\(C_root = \frac{a_{rootC}}{\tau_{root}}\)

\(C_labileRa = C_{labileRa}\)

References

Thomas, R. Q., & Williams, M. (2014). A model using marginal efficiency of investment to analyze carbon and nitrogen interactions in terrestrial ecosystems (ACONITE version 1). Geoscientific Model Development, 7(5), 2015–2037. http://doi.org/10.5194/gmd-7-2015-2014