Farquhar-von Caemmerer-Berry (FvCB) C3 photosynthesis model
Farquhar-von Caemmerer-Berry (FvCB) C3 photosynthesis model
Rubisco-limited assimilation rate
RuBP regeneration-limited assimilation rate
TPU-limited assimilation rate
FvCB(C_chl, pars, unitless = FALSE) W_carbox(C_chl, pars, unitless = FALSE) W_regen(C_chl, pars, unitless = FALSE) W_tpu(C_chl, pars, unitless = FALSE)
C_chl |
Chloroplastic CO2 concentration in Pa of class |
pars |
Concatenated parameters ( |
unitless |
Logical. Should |
Equations following Buckley and Diaz-Espejo (2015):
Rubisco-limited assimilation rate:
W_carbox = V_cmax C_chl / (C_chl + K_m)
where:
K_m = K_c (1 + O / K_o)
RuBP regeneration-limited assimilation rate:
W_regen = J C_chl / (4 C_chl + 8 Γ*)
where J is a function of PPFD, obtained by solving the equation:
0 = θ_J J ^ 2 - J (J_max + φ_J PPFD) + J_max φ_J PPFD
TPU-limited assimilation rate:
W_tpu = 3 V_tpu C_chl / (C_chl - Γ*)
| Symbol | R | Description | Units | Default |
| C_chl | C_chl |
chloroplastic CO2 concentration | Pa | input |
| Γ* | gamma_star |
chloroplastic CO2 compensation point (T_leaf) | Pa | calculated |
| J_max | J_max |
potential electron transport (T_leaf) | μmol CO2 / (m^2 s) | calculated |
| K_C | K_C |
Michaelis constant for carboxylation (T_leaf) | μmol / mol | calculated |
| K_O | K_O |
Michaelis constant for oxygenation (T_leaf) | μmol / mol | calculated |
| O | O |
atmospheric O2 concentration | kPa | 21.27565 |
| φ_J | phi_J |
initial slope of the response of J to PPFD | none | 0.331 |
| PPFD | PPFD |
photosynthetic photon flux density | umol quanta / (m^2 s) | 1500 |
| R_d | R_d |
nonphotorespiratory CO2 release (T_leaf) | μmol CO2 / (m^2 s) | calculated |
| θ_J | theta_J |
curvature factor for light-response curve | none | 0.825 |
| V_c,max | V_cmax |
maximum rate of carboxylation (T_leaf) | μmol CO2 / (m^2 s) | calculated |
| V_tpu | V_tpu |
rate of triose phosphate utilization (T_leaf) | μmol CO2 / (m^2 s) | calculated |
A list of four values with units umol CO2 / (m^2 s) of class units:
- W_carbox: Rubisco-limited assimilation rate
- W_regen: RuBP regeneration-limited assimilation rate
- W_tpu: TPU-limited assimilation rate
- A: minimum of W_carbox, W_regen, and W_tpu
Buckley TN and Diaz-Espejo A. 2015. Partitioning changes in photosynthetic rate into contributions from different variables. Plant, Cell & Environment 38: 1200-11.
Farquhar GD, Caemmerer S, Berry JA. 1980. A biochemical model of photosynthetic CO2 assimilation in leaves of C3 species. Planta 149: 78–90.
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, bake_par, constants) pars <- c(leaf_par, enviro_par, constants) C_chl <- set_units(24.28, "Pa") FvCB(C_chl, pars)
Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.