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 14/3/2016.

About the model

The model depicted in this document considers carbon allocation with a process based approach. It was originally described by Wang, Law, & Pak (2010).

Space Scale

global

Available parameter values

Information on given parameter sets
Abbreviation Source
Evergreen needle leaf forest Wang et al. (2010)
Evergreen broadleaf forest @Wang2010Biogeosciences
Deciduous needle leaf forest Wang et al. (2010)
Deciduous broadleaf forest @Wang2010Biogeosciences
Mixed forest Wang et al. (2010)
Shrub land (open and close shrubland) Wang et al. (2010)
Woddy savannah Wang et al. (2010)
Savannah Wang et al. (2010)
Grassland Wang et al. (2010)
Crop land (cropland mosaic was aggregated into this term) Wang et al. (2010)
Barren or sparse vegetation Wang et al. (2010)
state_variables
Name Description
\(C_{leaf}\) Plant (carbon) pool Leaf
\(C_{root}\) Plant (carbon) pool Root
\(C_{wood}\) Plant (carbon) pool Wood
photosynthetic_parameters
Name Description Expression Unit
\(\Delta_{t}\) Time step of model integration - \(d\)
\(N_{min}\) Amount of mineral N in soil - \(gN\cdot m^{-2}\)
\(P_{lab}\) Amount of labile P in soil - \(gP\cdot m^{-2}\)
\(F_{nupmin}\) Minimum amount of N uptake required to sustain a given NPP - -
\(F_{pupmin}\) Minimum amount of P uptake required to sustain a given NPP - -
\(x_{nup}\) Nitrogen uptake limitation on NPP \(x_{nup}=\min\left(1,\frac{N_{min}}{\Delta_{t}\cdot F_{nupmin}}\right)\) -
\(x_{pup}\) Phosphorus uptake limitation on NPP \(x_{pup}=\min\left(1,\frac{P_{lab}}{\Delta_{t}\cdot F_{pupmin}}\right)\) -
\(x_{npup}\) Nutrient uptake limiting factor \(x_{npup}=\min\left(x_{nup}, x_{pup}\right)\) -
\(n_{leaf}\) N:C ratio of leaf biomass - \(gN/gC\)
\(p_{leaf}\) P:C ratio of leaf biomass - \(gP/gC\)
\(k_{n}\) Empirical constant - \(gN\cdot (gC)^{-1}\)
\(k_{p}\) Empirical constant - \(gP\cdot (gC)^{-1}\)
\(x_{nleaf}\) \(x_{nleaf}=\frac{n_{leaf}}{k_{n} + n_{leaf}}\) -
\(x_{pleaf}\) \(x_{pleaf}=\frac{p_{leaf}}{k_{p} + p_{leaf}}\) -
\(x_{npleaf}\) Nutrient concentration limiting factor \(x_{npleaf}=\min\left(x_{nleaf}, x_{pleaf}\right)\) -
\(F_{cmax}\) Nutrient unlimited NPP - \(gC\cdot m^{-2}\cdot d^{-1}\)
\(F_{c}\) Net Primary Productivity (flux) \(F_{c}=F_{cmax}\cdot x_{npleaf}\cdot x_{npup}\) \(gC\cdot m^{-2}\cdot d^{-1}\)
allocation_coefficients
Name Description
\(a_{leaf}\) Fraction of NPP allocated to plant pool Leaf
\(a_{root}\) Fraction of NPP allocated to plant pool Root
\(a_{wood}\) Fraction of NPP allocated to plant pool Wood
components
Name Description Expression Unit
\(x\) vector of states for vegetation \(x=\left[\begin{matrix}C_{leaf}\\C_{root}\\C_{wood}\end{matrix}\right]\) -
\(u\) scalar function of photosynthetic inputs \(u=F_{c}\) -
\(b\) vector of partitioning coefficients of photosynthetically fixed carbon \(b=\left[\begin{matrix}a_{leaf}\\a_{root}\\a_{wood}\end{matrix}\right]\) -
\(A\) matrix of turnover (cycling) rates \(A=\left[\begin{matrix}-\mu_{leaf} & 0 & 0\\0 & -\mu_{root} & 0\\0 & 0 & -\mu_{wood}\end{matrix}\right]\) -
\(f_{v}\) the righthandside of the ode \(f_{v}=u b + A x\) \(gC\cdot m^{-2}\cdot d^{-1}\)

Pool model representation


Figure 1
Figure 1: Pool model representation

Input fluxes

\(C_{leaf}: F_{cmax}\cdot a_{leaf}\cdot\min\left(\frac{n_{leaf}}{k_{n} + n_{leaf}},\frac{p_{leaf}}{k_{p} + p_{leaf}}\right)\cdot\min\left(1,\frac{N_{min}}{\Delta_{t}\cdot F_{nupmin}},\frac{P_{lab}}{\Delta_{t}\cdot F_{pupmin}}\right)\)
\(C_{root}: F_{cmax}\cdot a_{root}\cdot\min\left(\frac{n_{leaf}}{k_{n} + n_{leaf}},\frac{p_{leaf}}{k_{p} + p_{leaf}}\right)\cdot\min\left(1,\frac{N_{min}}{\Delta_{t}\cdot F_{nupmin}},\frac{P_{lab}}{\Delta_{t}\cdot F_{pupmin}}\right)\)
\(C_{wood}: F_{cmax}\cdot a_{wood}\cdot\min\left(\frac{n_{leaf}}{k_{n} + n_{leaf}},\frac{p_{leaf}}{k_{p} + p_{leaf}}\right)\cdot\min\left(1,\frac{N_{min}}{\Delta_{t}\cdot F_{nupmin}},\frac{P_{lab}}{\Delta_{t}\cdot F_{pupmin}}\right)\)

Output fluxes

\(C_{leaf}: C_{leaf}\cdot\mu_{leaf}\)
\(C_{root}: C_{root}\cdot\mu_{root}\)
\(C_{wood}: C_{wood}\cdot\mu_{wood}\)

Steady state formulas

\(C_leaf = \frac{F_{cmax}\cdot a_{leaf}\cdot\min\left(\frac{n_{leaf}}{k_{n} + n_{leaf}},\frac{p_{leaf}}{k_{p} + p_{leaf}}\right)\cdot\min\left(1,\frac{N_{min}}{\Delta_{t}\cdot F_{nupmin}},\frac{P_{lab}}{\Delta_{t}\cdot F_{pupmin}}\right)}{\mu_{leaf}}\)

\(C_root = \frac{F_{cmax}\cdot a_{root}\cdot\min\left(\frac{n_{leaf}}{k_{n} + n_{leaf}},\frac{p_{leaf}}{k_{p} + p_{leaf}}\right)\cdot\min\left(1,\frac{N_{min}}{\Delta_{t}\cdot F_{nupmin}},\frac{P_{lab}}{\Delta_{t}\cdot F_{pupmin}}\right)}{\mu_{root}}\)

\(C_wood = \frac{F_{cmax}\cdot a_{wood}\cdot\min\left(\frac{n_{leaf}}{k_{n} + n_{leaf}},\frac{p_{leaf}}{k_{p} + p_{leaf}}\right)\cdot\min\left(1,\frac{N_{min}}{\Delta_{t}\cdot F_{nupmin}},\frac{P_{lab}}{\Delta_{t}\cdot F_{pupmin}}\right)}{\mu_{wood}}\)

References

Wang, Y. P., Law, R. M., & Pak, B. (2010). A global model of carbon, nitrogen and phosphorus cycles for the terrestrial biosphere. Biogeosciences, 7(7), 2261–2282. http://doi.org/10.5194/bg-7-2261-2010