Table 6.

Pearson correlation coefficients between different physiological parameters of M. alba (n = 60).

	gs	C i	Tr	WUE	C p	R	Z
P N	0.888 **	0.685 **	0.850 **	−0.319 *	0.380 **	−0.425 **	−0.192
gs		0.834 **	0.820 **	−0.413 **	0.546 **	−0.532 **	−0.236
C i			0.573 **	−0.280 *	0.480 **	−0.482 **	−0.088
Tr				−0.709 **	0.544 **	−0.464 **	−0.311 *
WUE					−0.585 **	0.395 **	0.410 **
C p						−0.892 **	−0.545 **
R							0.600 **

Note: ** Correlation is significant at the 0.01 level. Two-tailed significance was used. * Correlation is significant at the 0.05 level. Two-tailed significance was used. P_N: the net photosynthetic rate. g_s: the stomatal conductance. C_i: the intercellular CO₂ concentration. Tr: the transpiration rate. WUE: the water use efficiency. C_p: the physiological capacitance. R: the physiological resistance. Z: the physiological impedance.