A_supply: CO2 supply and demand function (mol / m^2 s)

A_supplyR Documentation

CO2 supply and demand function (mol / m^2 s)


This function is not intended to be called by users directly.


A_supply(C_chl, pars, unitless = FALSE, use_legacy_version = FALSE)

A_demand(C_chl, pars, unitless = FALSE)



Chloroplastic CO2 concentration in Pa of class units


Concatenated parameters (leaf_par, enviro_par, and constants)


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.


Logical. Should legacy model (<2.1.0) be used? See NEWS for further information. Default is FALSE.


Supply function:

A = g_\mathrm{tc} (C_\mathrm{air} - C_\mathrm{chl})

Demand function:

A = (1 - \Gamma* / C_\mathrm{chl}) \mathrm{min}(W_\mathrm{carbox}, W_\mathrm{regen}, W_\mathrm{tpu}) - R_\mathrm{d}

Symbol R Description Units Default
A A photosynthetic rate \mumol CO2 / (m^2 s) calculated
g_\mathrm{tc} g_tc total conductance to CO2 \mumol CO2 / (m^2 s Pa) calculated
C_\mathrm{air} C_air atmospheric CO2 concentration Pa 41
C_\mathrm{chl} C_chl chloroplastic CO2 concentration Pa calculated
R_\mathrm{d} R_d nonphotorespiratory CO2 release \mumol CO2 / (m^2 s) 2
\Gamma* gamma_star chloroplastic CO2 compensation point Pa 3.743


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


bake_par = make_bakepar()
constants = make_constants(use_tealeaves = FALSE)
enviro_par = make_enviropar(use_tealeaves = FALSE)
leaf_par = make_leafpar(use_tealeaves = FALSE)
leaf_par = bake(leaf_par, enviro_par, bake_par, constants)
# Or bake with piping (need library(magrittr))
# leaf_par %<>% bake(enviro_par, bake_par, constants)
enviro_par$T_air = leaf_par$T_leaf

pars = c(leaf_par, enviro_par, constants)
C_chl = set_units(350, umol/mol)

A_supply(C_chl, pars)

A_demand(C_chl, pars)

photosynthesis documentation built on Aug. 15, 2023, 9:08 a.m.