Skip to contents

Carbon Exchange Parameters

Ecosystem CO2 Flux Partitioning (EC flux partitioning) methods are used to estimate how the total carbon flux between an ecosystem and the atmosphere is divided among different processes, such as photosynthesis (carbon uptake) and respiration (carbon release). These methods are important for understanding the carbon balance of ecosystems.

Flux partitioning methods can use a light response curve (LRC). We can use daytime NEE (NEEday) from tower sites to fit LRCs and nighttime NEE (NEEnight) to estimate ecosystem respiration with temperature response curves (TRC) at night.

Here are some common methods for partitioning carbon fluxes:

Function_Name Equation Data Needed
LRC_PARMS_01 NEEday=a1⋅PAR⋅axa1⋅PAR+ax−rNEE_{\text{day}} = \frac{a_1 \cdot \text{PAR} \cdot a_x}{a_1 \cdot \text{PAR} + a_x} - r NEE; PAR
LRC_PARMS_02 NEEday=a1⋅PAR+ax−(a1⋅PAR+ax)2−4⋅PAR⋅a1⋅ax2⋅Θ−rNEE_{\text{day}} = \frac{a_1 \cdot \text{PAR} + a_{\text{x}} - \sqrt{(a_1 \cdot \text{PAR} + a_{\text{x}})^2 - 4 \cdot \text{PAR} \cdot a_1 \cdot a_{\text{x}}}}{2 \cdot \Theta} - r NEE; PAR
LRC_PARMS_03 NEEday=ax(1−exp(−a1⋅PARax))−rNEE_{\text{day}} = a_x \left( 1 - \exp \left( -\frac{a_1 \cdot \text{PAR}}{a_{\text{x}}} \right) \right) - r NEE; PAR
LRC_PARMS_04 NEEday=a1(1−B⋅PAR1+Y⋅PAR)⋅PAR−rNEE_{\text{day}} = a_1 \left( \frac{1 - B \cdot \text{PAR}}{1 + Y \cdot \text{PAR}} \right) \cdot \text{PAR} - r NEE; PAR
LRC_PARMS_05 NEEday=−a1⋅exp(−B⋅PAR)−Y⋅exp(Z⋅PAR)NEE_{\text{day}} = -a_1 \cdot \exp(-B \cdot \text{PAR}) - Y \cdot \exp(Z \cdot \text{PAR}) NEE; PAR
LRC_PARMS_06 NEEday=ax(1−exp(a1⋅(PAR−Icomp)))NEE_{\text{day}} = a_x \left( 1 - \exp \left( a_1 \cdot \left( \text{PAR} - I_{\text{comp}} \right) \right) \right) NEE; PAR
LRC_PARMS_07 NEEday=a1⋅PAR⋅βa1⋅PAR+βNEE_{\text{day}} = \frac{a_1 \cdot \text{PAR} \cdot \beta}{a_1 \cdot \text{PAR} + \beta} NEE; PAR; VPD
TRC_PARMS_01 NEEnight=rb⋅exp(E0((1Tref−T0)−(1Tair−T0)))NEE_{\text{night}} = r_b \cdot \exp \left( E_0 \left( \left( \frac{1}{T_{\text{ref}} - T_0} \right) - \left( \frac{1}{T_{\text{air}} - T_0} \right) \right) \right) NEE; T
TRC_PARMS_02 NEEnight=r0⋅exp(α⋅T+β⋅T2)NEE_{\text{night}} = r_0 \cdot \exp \left( \alpha \cdot T + \beta \cdot T^2 \right) NEE; T
TRC_PARMS_03 NEEnight=a(T−Topt)2+ERmaxNEE_{\text{night}} = a \left( T - T_{\text{opt}} \right)^2 + E_{\text{Rmax}} NEE; T
TRC_PARMS_04 NEEnight=Rref⋅Q10⋅exp(T−Tref10)NEE_{\text{night}} = R_{\text{ref}} \cdot Q_{10} \cdot \exp \left( \frac{T - T_{\text{ref}}}{10} \right) NEE; T
TRC_PARMS_05 NEEnight=a*exp(b*T)NEE_{\text{night}} = a * \exp \left(b*T\right) NEE; ?
TRC_PARMS_06 NEEnight=Rref⋅exp(EaR(1Tref−1T))NEE_{\text{night}} = R_{\text{ref}} \cdot \exp \left( \frac{E_a}{R} \left( \frac{1}{T_{\text{ref}}} - \frac{1}{T} \right) \right) NEE; T

Installation

You can install the development version of CarbonExchangeParameters from GitHub with:

# install.packages("pak")
pak::pak("Malone-Disturbance-Ecology-Lab/CarbonExchangeParameters")