Leaf energy balance model
To determine whether there were provenance-level differences in how leaf
thermal traits covaried, we modelled Tleaf using a leaf
energy balance equation implemented using the FindTleaf function in the
‘plantecophys’ package in R (Duursma, 2015). The leaf trait inputs used
were individual plant-averages of leaf width (m) measured at the canopy
top, along with stomatal conductance (µmol m2s-1) and leaf inclination angle (°) measured atc. 2.5 m height. Microclimate inputs were set to their average
conditions during the measurement campaign, with wind speed set to 2.3 m
s-1, Tair to 28.0 °C, and VPD to 1.7
kPa. While PPFD averaged 1545 µmol m2s-1 during the campaign, we modified this value to
account for variation in the interception of incoming radiation with the
measured mean leaf inclination angle of each plant using the
‘insolation’ package in R (Corripio, 2021).