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 21/1/2016.

About the model

The model depicted in this document considers carbon allocation with a process based approach. It was originally described by Arora & Boer (2005).

Space Scale

global

Available parameter values

Information on given parameter sets
Abbreviation Description Source
Original dataset of the publication Eastern US and Germany, cold broadleaf deciduous Arora & Boer (2005)
state_variables
Name Description Unit
\(C_{L}\) Amount of carbon for the leaf \(kgC\cdot m^{-2}\)
\(C_{S}\) Amount of carbon for the stem \(kgC\cdot m^{-2}\)
\(C_{R}\) Amount of carbon for the root \(kgC\cdot m^{-2}\)
photosynthetic_parameters
Name Description Expression
\(G\) Carbon gain via photosynthesis (Gross Primary Productivity, GPP) -
\(N\) Net primary Productivity (NPP) \(N=G - R_{gL} - R_{gR} - R_{gS} - R_{mL} - R_{mR} - R_{mS}\)
\(LAI\) Leaf Area Index -
\(k_{n}\) PFT-dependent light extinction coefficient -
\(L\) Light availability (scalar index between 0 and 1) \(L=e^{- LAI\cdot k_{n}}\)
water_availability
Name Description Expression
\(\theta_{i}\) Volumetric soil moisture content -
\(\theta_{field}\) Field capacity -
\(\theta_{wilt}\) Wilting point -
\(W_{i}\) Availability of water in soil layer i. Weighted by the fraction of roots present in each soil layer \(W_{i}=\max\left(0,\min\left(1,\frac{\theta_{i} -\theta_{wilt}}{\theta_{field} -\theta_{wilt}}\right)\right)\)
\(W\) Averaged soil water availability index -
respiration_fluxes
Name Description Unit
\(t\) time step \(year\)
\(R_{gL}\) Growth respiration flux for the leaves -
\(R_{mL}\) Maintenance respiration flux for the leaves -
\(R_{gS}\) Growth respiration flux for the stem -
\(R_{mS}\) Maintenance respiration flux for the stem -
\(R_{gR}\) Growth respiration flux for the root -
\(R_{mR}\) Maintenance respiration flux for the root -
\(R_{hD}\) Heterotrophic respiration from litter (debris) -
\(R_{hH}\) Heterotrophic respiration from soil carbon (humus) -
allocation_fractions
Name Description Expression
\(\epsilon_{L}\) PFT-dependent parameter for leaf -
\(\epsilon_{S}\) PFT-dependent parameter for stem -
\(\epsilon_{R}\) PFT-dependent parameter for root \(\epsilon_{R}=-\epsilon_{L} -\epsilon_{S} + 1\)
\(\omega\) PFT-dependent parameter -
\(a_{S}\) Stem allocation fraction \(a_{S}=\frac{\epsilon_{S} +\omega\cdot\left(1 - L\right)}{\omega\cdot\left(- L - W + 2\right) + 1}\)
\(a_{R}\) Root allocation fration \(a_{R}=\frac{\epsilon_{R} +\omega\cdot\left(1 - W\right)}{\omega\cdot\left(- L - W + 2\right) + 1}\)
\(a_{L}\) Leaf allocation fraction \(a_{L}=- a_{R} - a_{S} + 1\)
allocation_coefficients
Name Description Expression
\(A_{S}\) Amount of carbon allocated to the stem \(A_{S}=\begin{cases} G\cdot a_{S} &\text{for}\: N < 0\\N\cdot a_{S} + R_{gS} + R_{mS} &\text{for}\: N > 0\end{cases}\)
\(A_{R}\) Amount of carbon allocated to the root \(A_{R}=\begin{cases} G\cdot a_{R} &\text{for}\: N < 0\\N\cdot a_{R} + R_{gR} + R_{mR} &\text{otherwise}\end{cases}\)
temperature
Name Description Unit
\(T_{air}\) Temperature of the air \(°C\)
\(T_{cold}\) Cold temperature threshold for a PFT below which leaf loss begins to occur \(°C\)
\(b_{T}\) Parameter that describes sensitivity of leaf loss to temp. below the T\(_{cold}\) -
\(\beta_{T}\) Temperature measure (varies between 0 and 1) -
litter_fluxes
Name Description Expression
\(D_{L}\) Litter loss from the leaves \(D_{L}=C_{L}\cdot\left(\gamma_{N} +\gamma_{T} +\gamma_{W}\right)\)
\(D_{S}\) Litter loss from the stem \(D_{S}=C_{S}\cdot\gamma_{S}\)
\(D_{R}\) Litter loss from the root \(D_{R}=C_{R}\cdot\gamma_{R}\)
components
Name Description Expression
\(x\) vector of states for vegetation \(x=\left[\begin{matrix}C_{L}\\C_{S}\\C_{R}\end{matrix}\right]\)
\(u\) Vector of functions of photosynthetic inputs \(u=\left[\begin{matrix}G - R_{mL}\\a_{S}\\a_{R}\end{matrix}\right]\)
\(A\) matrix of cycling rates \(A=\left[\begin{matrix}-\gamma_{N} -\gamma_{T} -\gamma_{W} & 0 & 0\\0 & - R_{gS} - R_{mS} -\gamma_{S} & 0\\0 & 0 & - R_{gR} - R_{mR} -\gamma_{R}\end{matrix}\right]\)
\(f_{v}\) the righthandside of the ode \(f_{v}=A x + u\)

Pool model representation


Figure 1
Figure 1: Pool model representation

Input fluxes

\(C_{L}: G - R_{mL}\)
\(C_{S}: \frac{\epsilon_{S} +\omega\cdot\left(1 - e^{- LAI\cdot k_{n}}\right)}{\omega\cdot\left(- W + 2 - e^{- LAI\cdot k_{n}}\right) + 1}\)
\(C_{R}: \frac{-\epsilon_{L} -\epsilon_{S} +\omega\cdot\left(1 - W\right) + 1}{\omega\cdot\left(- W + 2 - e^{- LAI\cdot k_{n}}\right) + 1}\)

Output fluxes

\(C_{L}: C_{L}\cdot\left(\gamma_{N} +\gamma_{Tmax}\cdot\left(1 -\beta_{T}\right)^{b_{T}} +\gamma_{W}\right)\)
\(C_{S}: C_{S}\cdot\left(R_{gS} + R_{mS} +\gamma_{S}\right)\)
\(C_{R}: C_{R}\cdot\left(R_{gR} + R_{mR} +\gamma_{R}\right)\)

Steady state formulas

\(C_L = \frac{G - R_{mL}}{\gamma_{N} +\gamma_{Tmax}\cdot\left(1 -\beta_{T}\right)^{b_{T}} +\gamma_{W}}\)

\(C_S = \frac{-\epsilon_{S}\cdot e^{LAI\cdot k_{n}} -\omega\cdot e^{LAI\cdot k_{n}} +\omega}{R_{gS}\cdot W\cdot\omega\cdot e^{LAI\cdot k_{n}} - 2\cdot R_{gS}\cdot\omega\cdot e^{LAI\cdot k_{n}} + R_{gS}\cdot\omega - R_{gS}\cdot e^{LAI\cdot k_{n}} + R_{mS}\cdot W\cdot\omega\cdot e^{LAI\cdot k_{n}} - 2\cdot R_{mS}\cdot\omega\cdot e^{LAI\cdot k_{n}} + R_{mS}\cdot\omega - R_{mS}\cdot e^{LAI\cdot k_{n}} + W\cdot\gamma_{S}\cdot\omega\cdot e^{LAI\cdot k_{n}} - 2\cdot\gamma_{S}\cdot\omega\cdot e^{LAI\cdot k_{n}} +\gamma_{S}\cdot\omega -\gamma_{S}\cdot e^{LAI\cdot k_{n}}}\)

\(C_R = \frac{\left(W\cdot\omega +\epsilon_{L} +\epsilon_{S} -\omega - 1\right)\cdot e^{LAI\cdot k_{n}}}{R_{gR}\cdot W\cdot\omega\cdot e^{LAI\cdot k_{n}} - 2\cdot R_{gR}\cdot\omega\cdot e^{LAI\cdot k_{n}} + R_{gR}\cdot\omega - R_{gR}\cdot e^{LAI\cdot k_{n}} + R_{mR}\cdot W\cdot\omega\cdot e^{LAI\cdot k_{n}} - 2\cdot R_{mR}\cdot\omega\cdot e^{LAI\cdot k_{n}} + R_{mR}\cdot\omega - R_{mR}\cdot e^{LAI\cdot k_{n}} + W\cdot\gamma_{R}\cdot\omega\cdot e^{LAI\cdot k_{n}} - 2\cdot\gamma_{R}\cdot\omega\cdot e^{LAI\cdot k_{n}} +\gamma_{R}\cdot\omega -\gamma_{R}\cdot e^{LAI\cdot k_{n}}}\)

References

Arora, V. K., & Boer, G. J. (2005). A parameterization of leaf phenology for the terrestrial ecosystem component of climate models. Global Change Biology, 11(1), 39–59. http://doi.org/10.1111/j.1365-2486.2004.00890.x