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 .

About the model

The model depicted in this document considers carbon allocation with a process based approach. It was originally described by Haverd et al. (2016).

state_variables
Name Description Unit
\(C_{L}\) Leaf biomass \(molC\cdot m^{-2}\)
\(C_{R}\) Fine roots biomass \(molC\cdot m^{-2}\)
\(C_{stem}\) Trunk and coarse roots \(molC\cdot m^{-2}\)
partitioning_parameters
Name Description
\(\alpha_{L}\) carbon allocation coefficient, Heaviside step function that depends on C_L and C_R
\(\alpha_{R}\) carbon allocation coefficient, Heaviside step function that depends on C_L and C_R
\(\alpha_{stem}\) carbon allocation coefficient, Heaviside step function that depends on C_L and C_R
release_rates
Name Description Unit
\(k_{L}\) First-order rate constant \(day^{-1}\)
\(k_{R}\) First-order rate constant \(day^{-1}\)
\(m_{stem}\) Stem biomass turnover \(molC\cdot m^{-2}\cdot day^{-1}\)
components
Name Description Expression
\(x\) vector of states for vegetation \(x=\left[\begin{matrix}C_{L}\\C_{R}\\C_{stem}\end{matrix}\right]\)
\(u\) scalar function of photosynthetic inputs \(u=F_{Cgrowth}\)
\(\beta\) vector of partitioning coefficients of photosynthetically fixed carbon \(\beta=\left[\begin{matrix}\alpha_{L}\\\alpha_{R}\\\alpha_{stem}\end{matrix}\right]\)
\(B\) matrix of cycling rates \(B=\left[\begin{matrix}- k_{L} -\frac{m_{stem}}{C_{stem}} & 0 & 0\\0 & - k_{R} -\frac{m_{stem}}{C_{stem}} & 0\\0 & 0 & - m_{stem}\end{matrix}\right]\)
\(f_{v}\) the righthandside of the ode \(f_{v}=u\beta + B x\)

Pool model representation


Figure 1
Figure 1: Pool model representation

Input fluxes

\(C_{L}: F_{Cgrowth}\cdot\alpha_{L}\)
\(C_{R}: F_{Cgrowth}\cdot\alpha_{R}\)
\(C_{stem}: F_{Cgrowth}\cdot\alpha_{stem}\)

Output fluxes

\(C_{L}: \frac{C_{L}\cdot\left(C_{stem}\cdot k_{L} + m_{stem}\right)}{C_{stem}}\)
\(C_{R}: \frac{C_{R}\cdot\left(C_{stem}\cdot k_{R} + m_{stem}\right)}{C_{stem}}\)
\(C_{stem}: C_{stem}\cdot m_{stem}\)

Steady state formulas

\(C_L = \frac{F_{Cgrowth}^{2}\cdot\alpha_{L}\cdot\alpha_{stem}}{F_{Cgrowth}\cdot\alpha_{stem}\cdot k_{L} + m_{stem}^{2}}\)

\(C_R = \frac{F_{Cgrowth}^{2}\cdot\alpha_{R}\cdot\alpha_{stem}}{F_{Cgrowth}\cdot\alpha_{stem}\cdot k_{R} + m_{stem}^{2}}\)

\(C_stem = \frac{F_{Cgrowth}\cdot\alpha_{stem}}{m_{stem}}\)

References

Haverd, V., Smith, B., Raupach, M., Briggs, P., Nieradzik, L., Beringer, J., … Cleverly, J. (2016). Coupling carbon allocation with leaf and root phenology predicts treegrass partitioning along a savanna rainfall gradient. Biogeosciences, 13(3), 761–779. http://doi.org/10.5194/bg-13-761-2016