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 29/7/2015.

About the model

The model depicted in this document considers carbon allocation with a process based approach. It was originally described by King (1993).

Space Scale

forest

Available parameter values

Information on given parameter sets
Abbreviation Source
Chosen based on the performance of Pinus radiata at Puruki, New Zeland King (1993)
state_variables
Name Description Unit
\(F\) Foliage dry mass \(kgC\cdot m^{-2}\)
\(R\) Fine roots dry mass \(kgC\cdot m^{-2}\)
\(W\) Woody tissue dry mass \(kgC\cdot m^{-2}\)
photosynthetic_parameters
Name Description Expression Unit
\(k\) Radiation extinction coefficient of canopy - -
\(\Phi_{0}\) Incident PAR - \(MJ\cdot m\cdot ^{-2}\cdot year^{-1}\)
\(\omega\) Specific leaf area - \(m\cdot ^2\cdot kg^{-1}\)
\(\Phi\) Annual photosynthetically active radiation (PAR) intercepted by the canopy \(\Phi=\Phi_{0}\cdot\left(1 - e^{- F\cdot k\cdot\omega}\right)\) \(MJ\cdot m\cdot ^{-2}\cdot year^{-1}\)
\(\epsilon\) Light utilization coefficient - \(kg\cdot MJ^{-1}\)
\(G\) Rate of biomass production per unit ground area \(G=\Phi\cdot\epsilon\) \(kg\cdot m^{-2}\cdot year^{-1}\)
allocation_coefficients
Name Description Expression
\(\eta_{f}\) Fraction of biomass production partitioned to leaves -
\(\eta_{r}\) Fraction of biomass production partitioned to roots -
\(\eta_{w}\) Fraction of biomass production partitioned to wood \(\eta_{w}=-\eta_{f} -\eta_{r} + 1\)
cycling_rates
Name Description Unit
\(\gamma_{f}\) Senescence rate per unit foliage biomass \(kg^{-1}\)
\(\gamma_{r}\) Senescence rate per unit fine roots biomass \(kg^{-1}\)
components
Name Description Expression
\(x\) vector of states for vegetation \(x=\left[\begin{matrix}F\\R\\W\end{matrix}\right]\)
\(u\) scalar function of photosynthetic inputs \(u=G\)
\(b\) vector of partitioning coefficients of photosynthetically fixed carbon \(b=\left[\begin{matrix}\eta_{f}\\\eta_{r}\\\eta_{w}\end{matrix}\right]\)
\(A\) matrix of turnover (cycling) rates \(A=\left[\begin{matrix}-\gamma_{f} & 0 & 0\\0 & -\gamma_{r} & 0\\0 & 0 & 0\end{matrix}\right]\)
\(f_{v}\) the righthandside of the ode \(f_{v}=u b + A x\)

Pool model representation


Figure 1
Figure 1: Pool model representation

Input fluxes

\(F: \Phi_{0}\cdot\epsilon\cdot\eta_{f}\cdot\left(1 - e^{- F\cdot k\cdot\omega}\right)\)
\(R: \Phi_{0}\cdot\epsilon\cdot\eta_{r}\cdot\left(1 - e^{- F\cdot k\cdot\omega}\right)\)
\(W: \Phi_{0}\cdot\epsilon\cdot\left(1 - e^{- F\cdot k\cdot\omega}\right)\cdot\left(-\eta_{f} -\eta_{r} + 1\right)\)

Output fluxes

\(F: F\cdot\gamma_{f}\)
\(R: R\cdot\gamma_{r}\)

Steady state formulas

\(F = 0\)

\(R = 0\)

\(W = W\)

References

King, D. A. (1993). A model analysis of the influence of root and foliage allocation on forest production and competition between trees. Tree Physiology, 12(2), 119–135. http://doi.org/10.1093/treephys/12.2.119