Table 5.

Correlations between measured variables of both well-watered and water-limited plants and leaf water enrichment (Δ ¹⁸ O _LW ), bulk leaf enrichment (Δ ¹⁸ O _BL ), and δ ¹³ C _BL for S. viridis and δ¹³C_BLfor S. italica

The source water used to calculate Δ¹⁸O_LW and Δ¹⁸O_BL is listed in the header of each column. Significant correlations (r) are in bold, and the level of significance is given. Levels of significance are *P<0.05, **P<0.01, ***P<0.001. Other factors also were analysed and are given in Supplementary Tables S5 and S6. Correlations between Δ¹⁸O_LW and Δ¹⁸O_BL were only calculated where the same source water was used to calculate both

Parameter	S. viridis							S. italica
	Δ18OLW			Δ18OBL			δ13CBL	δ13CBL
	Irrigation water	Soil	Root crown	Irrigation water	Soil	Root crown
g s	−0.75***	−0.57**	—0.71***	−0.50**	—0.26	−0.29	0.65***	0.77***
E	−0.66***	−0.46*	—0.61***	−0.41*	—0.22	−0.26	0.59***	0.77***
A net	−0.77***	—0.73***	—0.76***	−0.33	—0.06	−0.17	0.56**	0.56**
Fresh aboveground biomass	−0.47*	−0.44*	−0.36	−0.45*	—0.22	−0.19	0.87***	0.77***
Dry aboveground biomass	−0.26	−0.21	−0.15	−0.32	—0.13	−0.09	0.74***	0.76***
Total water transpired	−0.28	−0.23	−0.17	−0.33	—0.14	−0.10	0.85***	0.77***
Leaf water per area (l m−2)	−0.57**	−0.66**	—0.59**	−0.33	—0.32	−0.33	0.33	−0.02
TEplant	0.30	0.25	0.17	0.42*	0.29	0.18	—0.87***	— 0.39*
TEinstantaneous	−0.05	−0.04	−0.16	0.26	0.36	0.16	—0.55**	—0.72***
TEintrinsic	0.64***	0.64***	0.56**	0.56**	0.35	0.35	—0.81***	—0.81***
δ13CBL	−0.60***	−0.54**	—0.50**	−0.59***	—0.36	−0.35
Δ18OBL	0.63***	0.31	0.45*