Supplementary Materials

Table 1S GLM analysis to assess the significance of the effects of drought stress treatment (H2O), ozone (O3) and their interaction (H2O*O3) on growth parameters at the end of the experiment, in plants subjected to repeated measurements during the season (set 2). Significance levels are reported for p<0.05; p<0.01 and p<0.001. Ns = not significant.

O3 / H2O / O3*H2O
Height (H), cm / ns / <0.001 / ns
Diameter (D), mm / ns / <0.1 / ns
Stem biomass, DW, g / ns / <0.001 / ns
Leaves biomass, DW, g / <0.05 / <0.01 / ns
Roots biomass, DW, g / <0.001 / <0.001 / <0.05
Leaf Mass per Area (LMA), mg cm-2 / <0.01 / ns / ns

Table 2S GLM analysis to assess the significance of the effects of drought stress treatment (H2O), ozone (O3) and their interaction (H2O*O3) on growth parameters on the different assessment dates. Significance levels are reported for p<0.05; p<0.01 and p<0.001. ns = not significant.

H2O / O3 / H2O*O3
Net Photosynthesis / 10-Jun / ns / ns / ns
24-Jun / <0.001 / ns / ns
08-Jul / <0.001 / ns / ns
22-Jul / <0.001 / ns / ns
05-Aug / <0.001 / <0.05 / ns
Height (H) / 10-Jun / ns / ns / ns
24-Jun / <0.05 / ns / ns
08-Jul / <0.001 / ns / ns
22-Jul / <0.001 / ns / ns
05-Aug / <0.001 / ns / ns
Diameter (D) / 10-Jun / ns / ns / ns
24-Jun / ns / ns / ns
08-Jul / <0.01 / ns / ns
22-Jul / <0.05 / ns / ns
05-Aug / <0.05 / ns / ns
Stem biomass,DW, g / 10-Jun / ns / ns / ns
24-Jun / <0.05 / ns / ns
08-Jul / <0.001 / ns / ns
22-Jul / <0.001 / ns / ns
05-Aug / <0.001 / ns / ns
Root/Shoot ratio / 10-Jun / _ / _ / _
24-Jun / ns / ns / ns
08-Jul / ns / ns / ns
22-Jul / <0.05 / ns / ns
05-Aug / ns / <0.05 / ns
Leaves/Stem H / 10-Jun / ns / ns / ns
24-Jun / ns / ns / ns
08-Jul / <0.05 / ns / ns
22-Jul / ns / <0.05 / <0.05
05-Aug / <0.05 / ns / ns

Table 3S GLM analysis to assess the significance of the effects of drought stress treatment (H2O), ozone (O3) and their interaction (H2O*O3) on stable isotopes ratios on the different assessment dates. Significance levels are reported for p<0.05; p<0.01 and p<0.001. ns = not significant.

H2O / O3 / H2O*O3
δ13C Stem / 10-Jun / ns / ns / ns
24-Jun / ns / ns / ns
08-Jul / ns / ns / ns
22-Jul / <0.001 / ns / ns
05-Aug / 0 / <0.05 / ns
δ13C Roots / 10-Jun / ns / ns / ns
24-Jun / <0.05 / ns / <0.001
08-Jul / <0.001 / ns / ns
22-Jul / <0.001 / ns / ns
05-Aug / <0.001 / <0.05 / ns
δ13C Leaves / 10-Jun / ns / ns / ns
24-Jun / <0.01 / ns / ns
08-Jul / <0.001 / ns / ns
22-Jul / <0.001 / ns / ns
05-Aug / <0.001 / ns / ns
δ18O Stem / 10-Jun / ns / ns / ns
24-Jun / ns / ns / ns
08-Jul / ns / ns / ns
22-Jul / <0.01 / ns / ns
05-Aug / ns / ns / ns
δ18O Roots / 10-Jun / ns / ns / ns
24-Jun / ns / ns / ns
08-Jul / ns / ns / ns
22-Jul / <0.01 / ns / ns
05-Aug / ns / ns / ns
δ18O Leaves / 10-Jun / ns / ns / ns
24-Jun / ns / ns / ns
08-Jul / <0.05 / ns / ns
22-Jul / <0.05 / ns / ns
05-Aug / <0.01 / ns / ns

Table 4S Significance of differences related to ozone stress (NF vs CF chambers) on each date for the parameters considered. The T-test for groups of independent samples was applied. Significance levels are reported for p<0.05; p<0.01 and p<0.001. ns = not significant.

10-Jun / 24-Jun / 08-Jul / 22-Jul / 05-Aug
Net Photosynthesis / W / ns / ns / ns / ns / ns
D / ns / ns / ns / ns / ns
Height (H) / W / ns / ns / ns / ns / ns
D / ns / ns / ns / ns / ns
Diameter (D) / W / ns / ns / ns / ns / ns
D / ns / ns / ns / ns / ns
Stem biomass,DW, g / W / ns / ns / ns / ns / ns
D / ns / ns / ns / ns / ns
Root/Shoot ratio / W / ns / ns / ns / ns / >0.01
D / ns / ns / ns / ns / ns
Leaves/Stem H / W / ns / ns / ns / >0.05 / ns
D / ns / ns / ns / ns / ns
δ13C Stem / W / ns / ns / ns / ns / ns
D / ns / ns / ns / ns / ns
δ13C Roots / W / ns / ns / ns / ns / ns
D / ns / ns / ns / ns / ns
δ13C Leaves / W / ns / ns / ns / ns / ns
D / ns / ns / ns / ns / ns
δ18O Stem / W / ns / ns / ns / ns / ns
D / ns / ns / ns / ns / ns
δ18O Roots / W / ns / ns / ns / ns / ns
D / ns / ns / ns / ns / ns
δ18O Leaves / W / ns / ns / ns / ns / ns
D / ns / ns / ns / ns / ns