Table 3. Parameters derived from the PN/Ci response curves performed at the end of the experimental period and the chemical and structural leaf traits.
F. ornus | p | ||||||
Parameters | C | N | O3 | O3N | N | O3 | O3N |
PNmax | 25.64 ± 4.40 | 32.23 ± 4.24 | 22.73 ± 0.19 | 22.14 ± 3.65 | 0.015 | 0.01 | 0.09 |
Vcmax | 0.078 ± 0.01 | 0.067 ± 0.01 | 0.051 ± 0.00 | 0.057 ± 0.01 | 0.742 | 0.03 | 0.23 |
Jmax | 106.6 ± 18.44 | 136.5 ± 13.93 | 98.32 ± 6.26 | 91.58 ± 15.58 | 0.012 | 0.01 | 0.04 |
Γ | 48.67 ± 3.68 | 56.2 ± 18.02 | 70.65 ± 23.13 | 52.20 ± 1.68 | 0.555 | 0.34 | 0.18 |
PNUE | 1.9 ± 0.64 | 1.55 ± 0.28 | 1.40 ± 0.44 | 2.19 ± 1.07 | 0.59 | 0.86 | 0.19 |
NL | 1.71 ± 0.09 | 2.14 ± 0.45 | 1.26 ± 0.1 | 1.56 ± 0.32 | 0.058 | 0.01 | 0.71 |
CL | 44.73 ± 0.27 | 45.31 ± 0.6 | 44.25 ± 0.45 | 44.66 ± 0.42 | 0.094 | 0.06 | 0.76 |
CL/NL | 26.15 ± 1.21 | 21.7 ± 3.97 | 35.21 ± 2.75 | 29.49 ± 6.66 | 0.067 | 0.01 | 0.8 |
LMA | 0.013 ± 0.001 | 0.013 ± 0.001 | 0.011 ± 0.001 | 0.012±0.001 | 0.081 | 0.003 | 0.539 |
Q. ilex | p | ||||||
C | N | O3 | O3N | N | O3 | O3N | |
PNmax | 24.73 ± 3.91 | 29.9 ± 1.50 | 23.54 ± 5.41 | 28.67 ± 3.10 | 0.003 | 0.370 | 0.989 |
Vcmax | 0.076 ± 0.01 | 0.086 ± 0.009 | 0.074 ± 0.014 | 0.10 ± 0.017 | 0.059 | 0.498 | 0.368 |
Jmax | 105.9 ± 12.72 | 125.8 ± 4.19 | 102.3 ± 0.99 | 129.7 ± 8.64 | 0.000 | 0.982 | 0.438 |
Γ | 67.69 ± 1.67 | 60.06 ± 13.14 | 67.11 ± 1.92 | 74.36 ± 12.98 | 0.972 | 0.238 | 0.204 |
PNUE | 3.44 ± 0.97 | 3.00 ± 0.94 | 1.84 ± 0.13 | 2.2 ± 0.54 | 0.925 | 0.021 | 0.372 |
NL | 1.26 ± 0.14 | 1.44 ± 0.35 | 1.14 ± 0.07 | 1.36 ± 0.23 | 0.158 | 0.479 | 0.888 |
CL | 44.43 ± 0.48 | 45.24 ± 0.37 | 45.28 ± 0.21 | 45.55 ± 0.35 | 0.036 | 0.026 | 0.243 |
CL/NL | 35.6 3± 4.03 | 32.57 ± 7.51 | 39.79 ± 2.36 | 34.01 ± 5.45 | 0.178 | 0.378 | 0.663 |
LMA | 0.014 ± 0.001 | 0.013 ± 0.001 | 0.015 ± 0.001 | 0.012 ± 0.001 | 0.000 | 0.98 | 0.01 |
PNmax, (μmol m-2 s-1) = maximum rate of net photosynthesis; Vcmax, (mol m-2 s-1) = in vivo apparent Rubisco activity; Jmax, (μmol m-2 s-1) = maximum rate of electron transport; Γ, (ppm) = CO2 compensation point; PNUE, photosynthetic nitrogen use efficiency (μmol mol-1 s-1); NL, nitrogen at leaf level (%); CL, carbon concentration at leaf level (%); CL/NL, ratio between carbon and nitrogen at leaf level; Leaf Mass Area (LMA, g cm-2). Data are shown as the mean ± standard deviation (n = 5) for each treatment. On the right panel, results of two-way ANOVA for each parameter are shown. Significant p-value (p < 0.05) are marked in bold; quasi ‘significant’ values (0.1 > p > 0.05) are underlined.