Table 4.

Inputs for using measured terahertz spectroscopy peak field ratio (PFR) to predict leaf water status variables, water mass per area ($\widehat{\text{WMA}}$), relative water content ($\widehat{\text{RWC}}$), and leaf water potential ($\widehat{{\mathrm{\Psi }}_{\text{leaf}}}$). Predictions were made for each individual leaf during dehydration ($\widehat{{\text{WMA}}_{\text{leaf}}}$, $\widehat{{\text{RWC}}_{\text{leaf}}}$ and $\widehat{{\mathrm{\Psi }}_{\text{leaf,leaf}}}$, left column), based on the relationship of water mass per area (WMA) to ln(PFR) for each dehydrating leaf, and from individual leaf values for saturated water mass per leaf area (SWMA) and species‐level mean pressure–volume curve (PV) parameters. Predictions were also tested using species‐level relationships of WMA to ln(PFR) ($\widehat{{\text{WMA}}_{\text{species}}}$, $\widehat{{\text{RWC}}_{\text{species}}},$ and $\widehat{{\mathrm{\Psi }}_{\text{leaf,species}}}$, middle column) and all‐species‐level relationships of WMA to ln(PFR) ($\widehat{{\text{WMA}}_{\text{all}}}$, $\widehat{{\text{RWC}}_{\text{all}}},$ and $\widehat{{\mathrm{\Psi }}_{\text{leaf,all}}}$, right column), using species‐level mean values for SWMA and PV parameters

	Individual leaf level prediction	Species‐level prediction	All‐species‐level prediction
$\widehat{\text{WMA}}$	$\widehat{{\text{WMA}}_{\text{leaf}}}$, from WMA ~ ln (PFR) relationship for each leaf	$\widehat{{\text{WMA}}_{\text{species}}}$, from WMA ~ ln (PFR) relationship for all leaves of given species	$\widehat{{\text{WMA}}_{\text{all}}}$, from WMA ~ ln (PFR) relationship for all leaves of all species
$\widehat{\text{RWC}}$	$\widehat{{\text{RWC}}_{\text{leaf}}}$, from $\widehat{{\text{WMA}}_{\text{leaf}}}$ and SWMA of each leaf	$\widehat{{\text{RWC}}_{\text{species}}}$, from $\widehat{{\text{WMA}}_{\text{species}}}$ and species‐level mean SWMA	$\widehat{{\text{RWC}}_{\text{all}}}$, from $\widehat{{\text{WMA}}_{\text{all}}}$ and species‐level mean SWMA
$\widehat{{\mathrm{\Psi }}_{\text{leaf}}}$	$\widehat{{\mathrm{\Psi }}_{\text{leaf,leaf}}},$ from $\widehat{{\text{RWC}}_{\text{leaf}}}$ and species‐level mean P‐V parameters	$\widehat{{\mathrm{\Psi }}_{\text{leaf,species}}},$ from $\widehat{{\text{RWC}}_{\text{species}}}$ and species‐level mean P‐V parameters	$\widehat{{\mathrm{\Psi }}_{\text{leaf,all}}},$ from $\widehat{{\text{RWC}}_{\text{all}}}$ and species‐level mean P‐V parameters