2.3. Minimum leaf conductance (g min)

Minimum leaf conductance (Kerstiens, ¹⁹⁹⁶) was measured as described in Pearcy and Zimmermann (²⁰⁰⁰). One leaf per individual was cut before dawn when stomata were assumed to be still closed. The cut petiole was immediately sealed with melted candle wax, and the leaf area was scanned using a flatbed scanner, followed by analysis using Pixstat (Schleppi, ²⁰²¹). The leaves were stuck to a lab tape run between two lab stands, standing in a small dark climate chamber with stable T (26°C) and humidity (60%) and the ventilation on. Every 15–20 min, the leaves were taken from the climate chamber and weighed in a dark room using a fine‐precision scale (Mettler‐Toledo). This procedure was repeated eight times. g _min (mmol m⁻² s⁻¹) was calculated as cuticular transpiration per mole fraction VPD, assuming the leaf internal air to be fully saturated (Pearcy & Zimmermann, ²⁰⁰⁰).