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Table III

Statistical significance of the P values (ANOVA) for the single and interactive effects of population, drought and enhanced UV-B radiation on different physiological parameters.

Parameter Population Drought UV-B Population × drought Population × UV-B Drought × UV-B Population × drought × UV-B
WUEi 0.000*** 0.000*** 0.000*** 0.002** 0.112ns 0.000*** 0.001***
WUE T 0.000*** 0.000*** 0.000*** 0.000*** 0.064ns 0.000*** 0.507ns
δ13C 0.209ns 0.000*** 0.000*** 0.456ns 0.062ns 0.000*** 0.092ns
ABA 0.047* 0.000*** 0.000*** 0.003** 0.255ns 0.002** 0.015*
Soluble protein 0.071ns 0.001*** 0.001*** 0.242ns 0.358ns 0.006** 0.757ns
UV-absorbing 0.000*** 0.000*** 0.000*** 0.028* 0.037* 0.000*** 0.000***
compounds
C content
 Leaves 0.689ns 0.000*** 0.001*** 0.001*** 0.066ns 0.683ns 0.659ns
 Stems 0.047* 0.031* 0.070ns 0.025* 0.017* 0.445ns 0.376ns
 Roots 0.000*** 0.280ns 0.024* 0.010** 0.117ns 0.579ns 0.019*
N content
 Leaves 0.000*** 0.009** 0.006** 0.002** 0.017* 0.000*** 0.976ns
 Stems 0.000*** 0.000*** 0.000*** 0.000*** 0.014* 0.001*** 0.000***
 Roots 0.000*** 0.000*** 0.015* 0.100ns 0.567ns 0.378ns 0.513ns
C/N ratio
 Leaves 0.000*** 0.000*** 0.000*** 0.000*** 0.002** 0.000*** 0.417ns
 Stems 0.000*** 0.000*** 0.000*** 0.000*** 0.945ns 0.000*** 0.000***
 Roots 0.000*** 0.000*** 0.009** 0.000** 0.078ns 0.163ns 0.039*
ns

not significant;

*

P < 0.05;

**

P < 0.01;

***

P < 0.001.

WUEi = intrinsic water use efficiency; WUET = transpiration efficiency; δ13C = stable isotope composition.