Overview of the history of ozone exposure and the experimental designs.

<p>Starting from a four-year exposure of a weed community under three ozone selection treatments (0, 90 and 120 ppb) [8]; the subsequent sowing of the soil seed bank samples, coming from each ozone selection treatment replication, in nine plots; the <i>Germination </i><i>experiments</i> (Seed germination and Seed dormancy experiments) carried out with <i>S. arvensis</i> seeds harvested from the plots; and the <i>Soil </i><i>seed </i><i>bank </i><i>experiment</i> developed with seeds harvested from plants exposed to ambient and added ozone (control and added ozone treatment respectively; maternal ozone treatments).</p

Germination (%) of <i>Spergula</i><i>arvensis</i> seeds for each ozone selection treatment, pre-treatment and incubation temperature.

<p>White, grey and black bars represent germination of seeds (n = 3, ± SE) for 0, 90 and 120 ppb ozone selection treatment, respectively, after 22 days of exposure to pre-treatments: storage at 10 °C and dry condition (control) (A), storage at 5 °C and 75% RH followed by scarification (B), and storage at 25 °C and 75% followed by scarification (C); and then incubated at 10, 15 and 15/25 °C. Above each plot, <i>P-values</i> indicate the effects of Incubation Temperature (Temp.), Ozone selection treatment (Ozone) and the interaction (Temp. xOzone) within each Pre-treatment.</p

Germination (%) of <i>Spergula</i><i>arvensis</i> seeds for each ozone selection treatment

<p><b>, storage condition and incubation temperature</b>. White, grey and black bars represent germination of seeds (n = 3, ± SE) for 0, 90 and 120 ppb ozone selection treatment, respectively, after being exposed for 22 days to storage conditions combining two temperatures (panels A, B and C: 5 °C, and panels D, E and F: 25 °C) and three relative humidity regimes (panels A and D: 5% RH; panels B and E: 75% RH; panels C and F: 11 days at 75% and 11 days at 5% RH) and incubation temperatures (10, 15 and 15/25 °C). Above each plot, <i>P-values</i> indicate the effects of Incubation Temperature (Temp.), Ozone selection treatment (Ozone) and the interaction (Temp. xOzone) within each storage condition.</p

Community structure of the experimental plots during ozone exposure at 0, 90 and 120 ppb and after transplanting under common ecological conditions.

<p>Community structure of the experimental plots during ozone exposure at 0, 90 and 120 ppb and after transplanting under common ecological conditions.</p

Means and statistics from analysis of variance of species richness (<i>S</i>), species diversity (Shannon-Weaver index, H´) and species evenness (<i>H</i>´/log_e (<i>S</i>)) for arthropod communities established from different historic exposure regimens.

<p>Means and statistics from analysis of variance of species richness (<i>S</i>), species diversity (Shannon-Weaver index, H´) and species evenness (<i>H</i>´/log_e (<i>S</i>)) for arthropod communities established from different historic exposure regimens.</p

Mean seedling density in 1 m² plots established from plant communities. selected under different episodic concentrations of tropospheric ozone (0, 90 and 120 ppb).

<p>Mean seedling density in 1 m² plots established from plant communities. selected under different episodic concentrations of tropospheric ozone (0, 90 and 120 ppb).</p

Relative abundance of <i>Spergula arvensis</i>, <i>Calandrinia ciliata</i> and other species in plant communities selected under different episodic concentrations of tropospheric ozone.

<p>Ozone concentrations in the open top chambers during long-term exposure were 0 ppb (white bars), 90 ppb (grey bars) and 120 ppb (dark bars). Data represents species abundances during the first (a) and second (b) year of experiment after original soil seed bank was transplanted to a common natural field environment. Relative abundance for each plant species was calculated as the summed abundances of each plant species for a particular year/total number of seedlings recorded in the plot (n = 3). Error bars represent standard error. Year a ANOVA <i>P</i> _species < 0.01, <i>P</i>_ozone 0.016, <i>P</i>_{species x ozone} 0.034; year b ANOVA <i>P</i> _species < 0.01, <i>P</i>_ozone 0.024, <i>P</i>_{species x ozone} 0.042</p