Figure 6.

A, Transpiration rate. B, Leaf to air VPD. C, The ¹⁸O isotopic composition of δ_t and at the δ_e calculated from the Craig-Gordon model (Eq. 18), measured from late afternoon (phase IV) and throughout the dark period (phase I) and into the light (phase II) with data (±SEM) for three replicate leaves from plants of K. daigremontiana that had been maintained in a controlled-environment chamber on a reverse light/dark cycle. The source water used for irrigation of plants had an isotopic composition of δ¹⁸O_VSMOW = −5.5‰.