Table 2. Summary of correlation analysis between physiological and morphological characteristics with RNO_{2 leaf}, RSO_{2 leaf} at the species and individual tree levels.

		NO₂		SO₂
		R²	P	R²	P
Chl a		0.328	0.083	0.034	< 0.605
Chl b		0.671	0.003^**	0.229	< 0.161
Chl a+b		0.61	0.007^**	0.112	< 0.342
Carotenoid		0.575	0.01^*	0.035	< 0.6
SLA		0.385	0.055	0.456	< 0.001^***
ML_leaf	Broad	0.211	0.036^*	0.437	< 0.001^**
ML_leaf	Needle	0.489	0.035^*	0.872	< 0.001^***

The significance level represented by the abbreviations. *, P < 0.05; **, P < 0.01; ***, P < 0.001.