Figure 5.

Δ¹³C measured in association with gas exchange from late afternoon (phase IV) and throughout the dark period (phase I) and into the light period (phase II), with data (white circles, ±SEM) for three replicate leaves from plants of K. daigremontiana maintained in a controlled-environment chamber on a reverse light/dark cycle. Predicted Δ¹³C for the dark period (phase I) determined from the model developed in this article (see “Theory” section for details); dashed line is modeled Δ¹³C including correction for the draw down from substomatal cavity to cytoplasm calculated with g_i = 0.044 mol m⁻² s⁻¹ bar⁻¹ with Equation 8 and 14 b₄ = 6.27‰ at a leaf temperature of 20°C; continuous line is modeled Δ¹³C using infinite g_i (effectively using p_i/p_a) to parameterize the model.