Photosynthesis model |
α
|
0.201
|
µmol CO2 µmol photon−1
|
Photochemical efficiency or initial quantum yield |
Γ* |
– |
Pa |
Compensation point for CO2 in the absence of mitochondrial respiration |
A
|
– |
µmol CO2 m−2 s−1
|
Net photosynthetic rate |
Ac
|
– |
µmol CO2 m−2 s−1
|
RUBISCO-limited photosynthetic rate |
Aj
|
– |
µmol CO2 m−2 s−1
|
Electron transport rate-limited photosynthetic rate |
Ap
|
– |
µmol CO2 m−2 s−1
|
Triose phosphate utilization-limited photosynthetic rate |
c |
– |
– |
Scaling constant |
Ca
|
– |
Pa |
Ambient CO2 partial pressure |
Ci
|
– |
Pa |
Intercellular CO2 partial pressure |
ΔHa
|
– |
kJ mol−1
|
Enthalpy of activation |
ΔHd
|
2002
|
kJ mol−1
|
Enthalpy of deactivation |
Kc
|
– |
Pa |
Michaelis–Menten constant of RUBISCO for CO2
|
Ko
|
– |
kPa |
Michaelis–Menten constant of RUBISCO for O2
|
J
|
– |
µmol electron m−2 s−1
|
Electron transport rate |
Jmax
|
– |
µmol m−2 s−1
|
Maximum electron transport rate |
Na
|
– |
g m−2
|
Area based N content |
Namin
|
– |
g m−2
|
Minimum value of Na at which P25 → 0 |
O
|
21 |
kPa |
Oxygen partial pressure |
P25
|
– |
µmol m−2 s−1
|
Value of Vcmax, Jmax, TPU or Rd at 25 °C |
PPFD |
– |
µmol m−2 s−1
|
Photosynthetic photon flux density |
R
|
0.00831 |
kJ mol−1 K−1
|
Universal gas constant for perfect gases |
Rd
|
– |
µmol m−2 s−1
|
Mitochondrial respiration in light |
ΔS
|
0.6352
|
kJ mol−1
|
Entropy term |
SNa
|
– |
µmol g−1 s−1
|
Slope of the relationship between Na and Vcmax, Jmax, TPU or Rd
|
Tleaf
|
– |
°C |
Leaf temperature in degrees Celsius |
Tk
|
– |
Kelvin degrees |
Leaf temperature in Kelvin |
TPU |
– |
µmol m−2 s−1
|
Triose phosphate utilization rate |
Vc
|
– |
µmol m−2 s−1
|
Carboxylation rate |
Vo
|
– |
µmol m−2 s−1
|
Oxygenation rate |
Vcmax
|
– |
µmol m−2 s−1
|
Maximum rate of RUBISCO carboxylation |
Stomatal conductance model |
Cs
|
– |
Pa |
CO2 partial pressure at the leaf surface |
gb
|
2.3573
|
mol m−2 s−1
|
Boundary layer conductance |
gs
|
– |
mmol m−2 s−1
|
Stomatal conductance |
go
|
0.020 |
mmol m−2 s−1
|
Residual stomatal conductance when A → 0 |
VPD |
– |
kPa |
Water VPD |
Do
|
2.86 |
kPa |
Empirical factor assessing stomata sensitivity to VPD |
a1
|
12.5 |
– |
Empirical stomatal conductance factor |