Table 2. Correlation coefficients (r ² values) for the GLM with the log(-O₃ uptake) and log(isoprene Fc) as dependent variables, and [O₃], short-wave incoming radiation, (Rg) and air temperature (Air _t) as independent variables.

Model outcome	Variable	r2
log(-O3 uptake)	Airt + Rg + [O3]	0.28
	Airt + Rg	0.16
	Difference by [O3]	0.12*
	[O3]	0.24
log (isoprene Fc)	Airt + Rg + [O3]	0.55
	Airt + Rg	0.54
	Difference by [O3]	0.01*
	[O3]	0.21

^*Partial r² gained by including [O3] in the model.