Table 2 Nomenclature (model variables and parameters used in this document)
From: SurEau: a mechanistic model of plant water relations under extreme drought
Plant | C | Capacitance (specific to apoplasm) | mmol MPa−1 |
ℇ | Modulus of elasticity | MPa | |
π0 | Osmotic potential at full turgor (specific to symplasm) | MPa | |
P50 | Water potential causing 50% cavitation in the xylem | MPa | |
Slope | Slope of the curve at P50 | % MPa−1 | |
k | Specific conductivity (is defined between compartments) | mmol.MPa−1m2s−1 | |
K | Conductance (k times the surface exchange area) | mmol.MPa−1s−1 | |
LAI | Leaf area index | m2 m−2 | |
Area | Developed area of the organ considered | m2 | |
E | Transpiration rate | mmol.m2.s−1 | |
gcanopy | Canopy conductance | mmol.m2.s−1 | |
gcrown | Crown conductance | mmol.m2.s−1 | |
gbound0 | Reference leaf boundary layer conductance | mmol.m2.s−1 | |
gbound | Leaf boundary layer conductance | mmol.m2.s−1 | |
gstom | Stomatal conductance | mmol.m2.s−1 | |
gstom-max | Maximal stomatal conductance | mmol.m2.s−1 | |
gstom300 | Stomatal conductance at a reference [CO2] of 300 ppm | mmol.m2.s−1 | |
gstom_PAR | Stomatal response to PAR | - | |
δ | Shape parameter of the gs(PAR) relationship | - | |
Toptim | Temperature at maximal conductance | °C | |
Tsens | Stomatal conductance sensitivity to temperature | - | |
γ | Factor for the regulation of gStom by turgor loss | - | |
Tpref | Reference turgor pressure for the onset of gStom regulation | MPa | |
frac | Fraction coefficient to compute of Tpref based on tlp | - | |
Pgs12 | Water potential causing 12% stomatal closure | MPa | |
Pgs88 | Water potential causing 88% stomatal closure | MPa | |
gcuti | Cuticular conductance | mmol.m2.s−1 | |
gcuti20 | Cuticular conductance at the reference temperature | mmol.m2.s−1 | |
Tphase | Temperature for phase transition of gcuti | °C | |
Q10a | Q10 values for gcuti = f(T) below Tphase | - | |
Q10b | Q10 values for gcuti = f(T) above Tphase | - | |
Torgan | Organ temperature | °C | |
Fluid | Water fluidity (temperature dependent) | - | |
OT | Osmotic potential dependence to temperature | - | |
ST | Surface tension (temperature dependent) | - | |
Rs | Relative water deficit of the symplasm | - | |
Prefill | Threshold apoplasmic water potential for xylem refilling | MPa | |
Soil | REW | Relative extractable water | - |
gsoil | Soil conductance to water vapor | mmol.m−2.s−1 | |
θs | Soil water content at saturation | - | |
θfc | Soil water content at field capacity | - | |
θr | Soil residual water content | - | |
ksat | Soil hydraulic conductivity at saturation | ||
α | In verse of the pressure air entry (Van-Genuchten model) | MPa−1 | |
n | Pore size distribution index (Van-Genuchten equation) | ||
l | Shape parameter (Van-Genuchten equation) | ||
Lv | Root length per unit soil volume | m.m−3 | |
La | Root length per unit soil area | m.m−2 | |
r | Root radius | m | |
Ksoil | Soil hydraulic conductance | ||
ρ | Parameter accentuating the isolation of the root system | ||
KR.interf | Soil-root interface hydraulic conductance | ||
Ambiant | T | Temperature | °C |
PAR | Photosynthetic active radiation | μmol.m−2.s−1 | |
esat | Saturation vapor pressure | kPa | |
e | Actual vapor pressure | kPa | |
VPD | Vapor pressure deficit | kPa | |
Wind | Wind speed | m.s−1 | |
RH | Air relative humidity | % | |
Patm | Atmospheric pressure | kPa | |
Ca | Air CO2 concentration | ppm |