General Overview


Logo

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 24/3/2016, 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 Luo, Weng, & Yang (n.d.).

Abstract

Ecosystem ecology is a subdiscipline of ecology that focuses on exchange of energy and materials between organisms and the environment. The materials that are commonly studied in ecosystem ecology include water, carbon, nitrogen, phosphorus, and other elements that organisms use as nutrients. The source of energy for most ecosystems is solar radiation. In this entry, material cy-cling and energy exchange are generally described before the carbon cycle is used as an example to illustrate our quantitative and theoretical understanding of ecosystem ecology.

Space Scale

global

Available parameter values

Information on given parameter sets
Abbreviation Description
Original parameters of the publication Parameter value of GPP corresponds to an annual average

Available initial values

Information on given sets of initial values
Abbreviation Description
Original initial values of the publication original dataset of the publication. Parameter value of GPP corresponds to an annual average

State Variables

The following table contains the available information regarding this section:

Information on State Variables
Name Description Values

Original initial values of the publication
\(C_{f}\) Carbon in foliage \(250\)
\(C_{r}\) Carbon in roots \(192\)
\(C_{w}\) Carbon in woody tissue \(4145\)

Photosynthetic Parameters

The following table contains the available information regarding this section:

Information on Photosynthetic Parameters
Name Description Expressions Type Units Values

Original parameters of the publication
\(GPP\) Photosynthetic rate (Carbon input) at time t - variable \(gC\cdot day^{-1}\) \(3370\)
\(T\) Temperature - variable - -
\(Q_{10}\) Temperature quotient that describes a change in decomposition rate for evey 10°C difference in temperature - parameter - -
\(W\) Volumetric soil moisture - variable - -
\(f_{W}\) Function of W \(f_{W}=\operatorname{Min}\left(0.5\,W, 1\right)\) variable - -
\(f_{T}\) Function of T \(f_{T}=Q_{10}^{\frac{T-10}{10}}\) variable - -
\(\epsilon_{t}\) Environmental scalar \(\epsilon_{t}=f_{W}\,f_{T}\) variable \(km^2\) -

Allocation Coefficients

The following table contains the available information regarding this section:

Information on Allocation Coefficients
Name Description Type Values

Original parameters of the publication
\(\eta_{f}\) Fixed partitioning ratio (fraction) of available carbon allocated to foliage parameter \(0.14\)
\(\eta_{r}\) Fixed partitioning ratio (fraction) of available carbon allocated to roots parameter \(0.26\)
\(\eta_{w}\) Fixed partitioning ratio (fraction) of available carbon allocated to wood parameter \(0.14\)

Cycling Rates

The following table contains the available information regarding this section:

Information on Cycling Rates
Name Description Entry Author Orcid Type Values

Original parameters of the publication
\(\gamma_{f}\) Foliage turnover rate 0000-0002-0046-1160 parameter \(0.00258\)
\(\gamma_{r}\) Roots turnover rate 0000-0002-0046-1160 parameter \(0.00239\)
\(\gamma_{w}\) Wood turnover rate 0000-0002-0046-1160 parameter \(5.86\cdot 10^{-5}\)

Components

The following table contains the available information regarding this section:

Information on Components
Name Description Expressions
\(x\) vector of states for vegetation \(x=\left[\begin{matrix}C_{f}\\C_{w}\\C_{r}\end{matrix}\right]\)
\(u\) scalar function of photosynthetic inputs \(u=GPP\,\epsilon_{t}\)
\(b\) vector of partitioning coefficients of photosynthetically fixed carbon \(b=\left[\begin{matrix}\eta_{f}\\\eta_{w}\\\eta_{r}\end{matrix}\right]\)
\(A\) matrix of turnover (cycling) rates \(A=\left[\begin{matrix}-\gamma_{f} & 0 & 0\\0 & -\gamma_{w} & 0\\0 & 0 & -\gamma_{r}\end{matrix}\right]\)
\(f_{v}\) the righthandside of the ode \(f_{v}=u\,b+A\,x\)

Pool model representation

Flux description

Figure 1
Figure 1: Pool model representation

Input fluxes

\(C_{f}: GPP\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\eta_{f}\cdot\min\left(1, 0.5\cdot W\right)\)
\(C_{r}: GPP\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\eta_{w}\cdot\min\left(1, 0.5\cdot W\right)\)
\(C_{w}: GPP\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\eta_{r}\cdot\min\left(1, 0.5\cdot W\right)\)

Output fluxes

\(C_{f}: C_{f}\cdot\gamma_{f}\)
\(C_{r}: C_{w}\cdot\gamma_{w}\)
\(C_{w}: C_{r}\cdot\gamma_{r}\)

The right hand side of the ODE

\(\left[\begin{matrix}- C_{f}\cdot\gamma_{f} + GPP\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\eta_{f}\cdot\min\left(1, 0.5\cdot W\right)\\- C_{w}\cdot\gamma_{w} + GPP\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\eta_{w}\cdot\min\left(1, 0.5\cdot W\right)\\- C_{r}\cdot\gamma_{r} + GPP\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\eta_{r}\cdot\min\left(1, 0.5\cdot W\right)\end{matrix}\right]\)

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

\(\left[\begin{matrix}-\gamma_{f} & 0 & 0\\0 & -\gamma_{w} & 0\\0 & 0 & -\gamma_{r}\end{matrix}\right]\)

Steady state formulas

\(C_{f} = \frac{GPP}{\gamma_{f}}\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\eta_{f}\cdot\min\left(1.0, 0.5\cdot W\right)\)
\(C_{w} = \frac{GPP}{\gamma_{w}}\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\eta_{w}\cdot\min\left(1.0, 0.5\cdot W\right)\)
\(C_{r} = \frac{GPP}{\gamma_{r}}\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\eta_{r}\cdot\min\left(1.0, 0.5\cdot W\right)\)

Steady states (potentially incomplete), according jacobian eigenvalues, damping ratio

Parameter set: Original parameters of the publication

\(C_f: 182868.217054264\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\min\left(1.0, 0.5\cdot W\right)\), \(C_w: 8051194.53924915\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\min\left(1.0, 0.5\cdot W\right)\), \(C_r: 366610.878661088\cdot Q_{10}^{\frac{T}{10} - 1}\cdot\min\left(1.0, 0.5\cdot W\right)\)

\(\lambda_{1}: -0.002\)
\(\lambda_{2}: -0.000\)
\(\lambda_{3}: -0.003\)

References

Luo, Y., Weng, E., & Yang, Y. (n.d.). Ecosystem ecology. In A. Hastings & L. Gross (Eds.), Encyclopedia of theoretical ecology (pp. 219–229). Berkeley: University of California Press.