Micrometeorological determination of time-integrated stomatal ozone fluxes over wheat: a case study in Northern Italy

摘要: Abstract Ozone deposition fluxes have been measured over a wheat field in Northern Italy May–June 2001 with the eddy-correlation method order to evaluate amount of ozone taken up by plants during whole grain filling period, from anthesis harvest. uptake is due its penetration through stomata; for this reason stomatal were determined, using analogy water vapour (Penman–Monteith approach), which are easily measured. The total dose was obtained integrating time. observational results showed that decrease time, following maturation and senescence plants. On average, flux found be 50–60% flux, but fraction decreased senescence, emphasizing importance non-stomatal pathways. approach consisting on evaluating then compared currently used procedure based evaluation exposure index AOT40, uses concentrations. Important differences between these two methods highlighted. integration appears more suitable physiological than use index.