Fig. 2.

Scatterplot of Δ¹³C versus δ¹⁸O and residuals of the regression analysis between δ¹⁸O and Δ¹³C versus integrated net photosynthetic rate over the whole period of the experiment (A_w). Solid symbols represent well-watered conditions (WW), while open symbols represent the water deficit level (WD). Triangles represent eCO₂ (elevated [CO₂]) while circles represent aCO₂ (ambient [CO₂]) Regression lines are shown only when significant and they are fitted for either WD (dashed line) or WW (solid line) with pooled data from both growth [CO₂] levels.