c4_temperature_param_vc {PhotoGEA}R Documentation

C4 temperature response parameters from von Caemmerer

Description

Temperature response parameters describing the temperature response of important C4 photosynthetic parameters, intended to be passed to the calculate_temperature_response function.

Usage

c4_temperature_param_vc

Format

List with 10 named elements that each represent a variable whose temperature-dependent value can be calculated using either an Arrhenius or Gaussian equation:

The J_norm parameter is calculated using a Gaussian function and hence its corresponding list element is itself a list with 4 named elements:

Each of the remaining elements is a list with 4 named elements:

Source

Some of these parameters (Vcmax, Vpmax, RL, gmc, and J) are normalized to their values at 25 degrees C. These variables include _norm in their names to indicate this.

The remaining parameters (Kc, Ko, Kp, gamma_star, and ao) are not normalized because they are assumed to not vary significantly between species.

Here, the Arrhenius scaling factors (c; dimensionless) and activation energy values (Ea; kJ / mol) are obtained from von Caemmerer (2021). In that publication, the overall scaling for each parameter is specified by its value at 25 degrees C; the scaling factors are determined from this information as described in the documentation for calculate_temperature_response_arrhenius.

The Gaussian parameters (t_opt and sigma) for J_norm are also obtained from von Caemmerer (2021), assuming that J and Jmax follow the same temperature response. The value of optimum_rate is chosen such that J_norm is equal to 1 at a temperature of 25 degrees C.

References:


[Package PhotoGEA version 1.3.3 Index]