General Overview

This report is the result of the use of the Python 3.4 package Sympy (for symbolic mathematics), as means to translate published models to a common language. It was created by Verónika Ceballos-Núñez (Orcid ID: 0000-0002-0046-1160) on 29/3/2016, and was last modified on lm.

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).

Abstract

National Science Foundation Awards AGS-1020767 and EF-1048481

Space Scale

global

State Variables

The following table contains the available information regarding this section:

Information on State Variables
Name Description
\(C_{leaf}\) Carbon in foliage
\(C_{wood}\) Carbon in wood
\(C_{root}\) Carbon in roots
\(C_{labile}\) -
\(C_{bud}\) -
\(C_{labileRa}\) -
\(N_{leaf}\) -
\(N_{wood}\) -
\(N_{root}\) -
\(N_{labile}\) -
\(N_{bud}\) -

Photosynthetic Parameters

The following table contains the available information regarding this section:

Information on Photosynthetic Parameters
Name Description Type Units
\(GPP\) Photosynthesis; based on ACM model (see article for description) variable \(gC\cdot day^{-1}\)

Allocation Fluxes

The following table contains the available information regarding this section:

Information on Allocation Fluxes
Name Description Type Units
\(a_{budC2leaf}\) Allocation from bud C pool to leaf C variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{woodC}\) Allocation from labile C to wood C variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{rootC}\) Allocation from labile C to root C variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{budC2Ramain}\) Allocation of bud C pool to maintenance respiration pool when maintain respiration pool reaches zero; represents forgoing future leaf C to prevent carbon starvation. variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{budC}\) Allocation of labile C to bud C; a fraction of the potential maximum leaf C variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{Ramain}\) Allocation of labile C to future maintenance respiration; helps prevent carbon starvation during periods of negative NPP variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(a_{budN2leaf}\) Allocation from bud N pool to leaf C (???); bud N is set in previous year variable \(gN\cdot m^{-2}\cdot day^{-1}\)
\(a_{budN2Ramain}\) When bud C is used for maintenance respiration (a\(_budC2Ramain\) > 0), bud N is returned to the labile N pool variable \(gN\cdot m^{-2}\cdot day^{-1}\)
\(a_{budN}\) Allocation of labile N to bud N; in seasonal environments it occurs in year prior to being displayed as leaf N variable \(gN\cdot m^{-2}\cdot day^{-1}\)
\(a_{woodN}\) Allocation from labile N to wood N variable \(gN\cdot m^{-2}\cdot day^{-1}\)
\(a_{rootN}\) Allocation from labile N to root N (???) variable \(gN\cdot m^{-2}\cdot day^{-1}\)
\(a_{labileRamain}\) Allocation of labile C to respiration of living tissues variable \(gC\cdot m^{-2}\cdot day^{-1}\)

Nitrogen Uptake And Fixation

The following table contains the available information regarding this section:

Information on Nitrogen Uptake And Fixation
Name Description doi Type Units
\(U_{NH4}\) Uptake of NH\(_4^+\) from mineral soil NH\(_4^+\) \(\frac{10.1007}{BF_{00015315}}\) variable \(gN\cdot m^{-2}\cdot day^{-1}\)
\(U_{NO3}\) Uptake of NO\(_3^-\) from mineral soil NO\(_3^-\) \(\frac{10.1007}{BF_{00015315}}\) variable \(gN\cdot m^{-2}\cdot day^{-1}\)
\(U_{Nfix}\) Fixation of N from N\(_2\); function of Ra\(_excess\) flux, temperature, N demand, and C cost - variable \(gN\cdot m^{-2}\cdot day^{-1}\)

Turnover Fluxes

The following table contains the available information regarding this section:

Information on Turnover Fluxes
Name Description Expressions Type Units
\(\tau_{wood}\) Turnover of wood (C and N) - parameter \(day^{-1}\)
\(\tau_{root}\) Turnover of root (C and N) - parameter \(day^{-1}\)
\(t_{leafC}\) Turnover of leaf C to litter C; constant over year in humid tropics; seasonal otherwise - variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(t_{woodC}\) Turnover of wood C to CWDC pool; occurs throughout year \(t_{woodC}=C_{wood}\,\tau_{wood}\) variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(t_{rootC}\) Turnover of root C to litter C; occurs throughout year \(t_{rootC}=C_{root}\,\tau_{root}\) variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(t_{retransN}\) Reabsorption of N from leaves to labile N - - \(gN\cdot m^{-2}\cdot day^{-1}\)
\(t_{leafN}\) Turnover of leaf N to litter N; constant over year in humid tropics; seasonal otherwise - variable \(gN\cdot m^{-2}\cdot day^{-1}\)
\(t_{woodN}\) Turnover of wood N to CWDN pool; occurs throughout year \(t_{woodN}=N_{wood}\,\tau_{wood}\) variable \(gN\cdot m^{-2}\cdot day^{-1}\)
\(t_{rootN}\) Turnover of root N to litter N; occurs throughout year \(t_{rootN}=N_{root}\,\tau_{root}\) variable \(gN\cdot m^{-2}\cdot day^{-1}\)

Respiration Fluxes

The following table contains the available information regarding this section:

Information on Respiration Fluxes
Name Description Type Units
\(Ra_{growth}\) Growth respiration that occurs when tissue is allocated; a constant fraction of carbon allocated to tissue variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(Ra_{excess}\) Respiration that occurs when labile C exceeds a maximum labile C store; used for N fixation variable \(gC\cdot m^{-2}\cdot day^{-1}\)
\(Ra_{main}\) Respiration of living tissues; a function of N content and temperature variable \(gC\cdot m^{-2}\cdot day^{-1}\)

Components

The following table contains the available information regarding this section:

Information on Components
Name Description Expressions
\(x\) vector of states (C\(_i\)) for vegetation \(x=\left[\begin{matrix}C_{leaf}\\C_{wood}\\C_{root}\\C_{labile}\\C_{bud}\\C_{labileRa}\\N_{leaf}\\N_{wood}\\N_{root}\\N_{labile}\\N_{bud}\end{matrix}\right]\)
\(I\) vector of fluxes into pool (C\(_i\)) \(I=\left[\begin{matrix}a_{budC2leaf}\\a_{woodC}\\a_{rootC}\\GPP\\a_{budC}\\a_{budC2Ramain} + a_{labileRamain}\\a_{budN2leaf}\\a_{woodN}\\a_{rootN}\\U_{NH4} + U_{NO3} + U_{Nfix} + a_{budN2Ramain} + t_{retransN}\\a_{budN2leaf}\end{matrix}\right]\)
\(O\) vector of fluxes out of pool (C\(_i\)) \(O=\left[\begin{matrix}- t_{leafC}\\- t_{woodC}\\- t_{rootC}\\- a_{budC} - a_{rootC} - a_{woodC}\\- a_{budC2leaf}\\0\\- t_{leafN} - t_{retransN}\\- t_{woodN}\\- t_{rootN}\\- a_{budN} - a_{rootN} - a_{woodN}\\0\end{matrix}\right]\)
\(R\) vector of respiration fluxes of pool (C\(_i\)) \(R=\left[\begin{matrix}0\\0\\0\\- Ra_{excess} - Ra_{growth} - a_{labileRamain}\\- a_{budC2Ramain}\\- Ra_{main}\\0\\0\\0\\0\\- a_{budN2Ramain}\end{matrix}\right]\)
\(f_{v}\) the righthandside of the ode \(f_{v}=I+O+R\)

The right hand side of the ODE

\(\left[\begin{matrix}a_{budC2leaf} - t_{leafC}\\- C_{wood}\cdot\tau_{wood} + a_{woodC}\\- C_{root}\cdot\tau_{root} + a_{rootC}\\GPP - Ra_{excess} - Ra_{growth} - a_{budC} - a_{labileRamain} - a_{rootC} - a_{woodC}\\a_{budC} - a_{budC2Ramain} - a_{budC2leaf}\\- Ra_{main} + a_{budC2Ramain} + a_{labileRamain}\\a_{budN2leaf} - t_{leafN} - t_{retransN}\\- N_{wood}\cdot\tau_{wood} + a_{woodN}\\- N_{root}\cdot\tau_{root} + a_{rootN}\\U_{NH4} + U_{NO3} + U_{Nfix} - a_{budN} + a_{budN2Ramain} - a_{rootN} - a_{woodN} + t_{retransN}\\- a_{budN2Ramain} + a_{budN2leaf}\end{matrix}\right]\)

The Jacobian (derivative of the ODE w.r.t. state variables)

\(\left[\begin{array}{ccccccccccc}0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0\\0 & -\tau_{wood} & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0\\0 & 0 & -\tau_{root} & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0\\0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0\\0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0\\0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0\\0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0\\0 & 0 & 0 & 0 & 0 & 0 & 0 & -\tau_{wood} & 0 & 0 & 0\\0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & -\tau_{root} & 0 & 0\\0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0\\0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0 & 0\end{array}\right]\)

Steady state formulas

\(C_{leaf} = C_{leaf}\)
\(C_{wood} = \frac{a_{woodC}}{\tau_{wood}}\)
\(C_{root} = \frac{a_{rootC}}{\tau_{root}}\)
\(C_{labile} = C_{labile}\)
\(C_{bud} = C_{bud}\)
\(C_{labileRa} = C_{labileRa}\)
\(N_{leaf} = N_{leaf}\)
\(N_{wood} = \frac{a_{woodN}}{\tau_{wood}}\)
\(N_{root} = \frac{a_{rootN}}{\tau_{root}}\)
\(N_{labile} = N_{labile}\)
\(N_{bud} = N_{bud}\)

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