J: Rate of electron transport (umol/m^2/s)

Calculate the rate of electron transport as a function of photosynthetic photon flux density (PPFD).

Usage

J(pars, unitless = FALSE)

Arguments

pars: Concatenated parameters (leaf_par, enviro_par, and constants)
unitless: Logical. Should units be set? The function is faster when FALSE, but input must be in correct units or else results will be incorrect without any warning.

Value

Value in $\mu$mol/ (m^2 s) of class units

Details

$J$ as a function of PPFD is the solution to the quadratic expression:

$$0 = \theta_J J ^ 2 - J (J_\mathrm{max} + \phi_J PPFD) + J_\mathrm{max} \phi_J PPFD$$

Symbol	R	Description	Units	Default
$J_\mathrm{max}$	`J_max`	potential electron transport (T_leaf)	$\mu$mol CO2 / (m$^2$ s)	calculated
$\phi_J$	`phi_J`	initial slope of the response of J to PPFD	none	0.331
PPFD	`PPFD`	photosynthetic photon flux density	$\mu$mol quanta / (m^2 s)	1500
$\theta_J$	`theta_J`	curvature factor for light-response curve	none	0.825

Examples


library(magrittr)
library(photosynthesis)

bake_par = make_bakepar()
constants = make_constants(use_tealeaves = FALSE)
enviro_par = make_enviropar(use_tealeaves = FALSE)
leaf_par = make_leafpar(use_tealeaves = FALSE)
enviro_par$T_air = leaf_par$T_leaf
leaf_par %<>% bake(enviro_par, bake_par, constants)

pars = c(leaf_par, enviro_par, constants)
J(pars, FALSE)
#> 181.6577 [umol/m^2/s]