f.modified.arrhenius: Temperature dependence of Jmax and Vcmax

In TESTgroup-BNL/LeafGasExchange: A package containing functions for fitting photosynthetic response curves, simulat leaf and canopy photosynthesis

Temperature dependence of Jmax and Vcmax

Description

The temperature dependence of the photosynthetic parameters Vcmax, the maximum catalytic rate of the enzyme Rubisco, and Jmax, the maximum electron transport rate is modeled by a modified Arrhenius equation. It is modified to account for decreases in each parameter at high temperatures.

Usage

f.modified.arrhenius(PRef, Ha, Hd, s, Tleaf, TRef = 298.16, R = 8.314)

Arguments

PRef	Value of the parameter, here Vcmax or Jmax, at the reference temperature in micromol.m-2.s-1.
Ha	Energy of activation in J.mol-1.
Hd	Energy of desactivation in J.mol-1.
s	Entropy term in J.mol-1.K-1.
Tleaf	Temperature of the leaf in Kelvin.
TRef	Reference temperature in Kelvin, usually 25 + 273.16 K.
R	Ideal gas constant.

Value

Value of the parameter Jmax or Vcmax at a given temperature

References

Leuning, R. (2002), Temperature dependence of two parameters in a photosynthesis model. Plant, Cell & Environment, 25: 1205-1210. doi:10.1046/j.1365-3040.2002.00898.x.

Examples

plot(x=seq(25,35,0.1),y=f.modified.arrhenius(PRef=50,Ha=73637,Hd=149252,s=486,Tleaf=seq(273.15+25,273.15+35,0.1)),xlab='Temperature degree C',ylab='Vcmax')

TESTgroup-BNL/LeafGasExchange documentation built on May 17, 2024, 8:11 p.m.