Our analysis of trends in ozone uptake into vegetation has just been published in Elementa: Science of the Anthropocene. The paper, led by Allison Ronan, used the SynFlux dataset, developed in the group by Jason Ducker. Despite the reductions in ozone air pollution across large parts of the United States and Europe, we found no consistent reductions in the amount of ozone that plants are taking up. Since the ozone uptake is directly related to damages, including lost crop yield, this work means that plants are not yet seeing the benefits of improved air quality. The reason for the disconnect is that the stomatal pores on leaf surfaces adapt to changing weather and climate and these stomatal changes have a bigger impact on the ozone uptake than the trends in ozone in the surrounding atmosphere.
Trends (2005–2014) in O3 metrics relevant to plant injury at SynFlux sites in Europe. POD is the phytotoxic ozone dose, representing the uptake of ozone into plant leaves. Other metrics quantify the concentration of ozone in ambient air. All metrics are calculated for June–September daytime. Arrows show linear trends and colors indicate significance of the trend (p value). From Ronan et al. (2020).
Ronan, A. C., Ducker, J.A., Schnell, J.L., Holmes, C.D. (2020) Have improvements in ozone air quality reduced ozone uptake into plants? Elementa Sci. Anthro. 8, 2, https://doi.org/10.1525/elementa.399 [pdf]