Conclusions and implications for conservation of crop pollinators and pollination.
Increased air pollution can affect plant and animal physiology in multiple ways (Van Dingenen et al. 2009; Mills et al.2013; Emberson 2020). In Europe, the biggest problem today is the increased concentrations of tropospheric ozone due to its harmful effects on health and ecosystems (Ilić & Maksimović 2021). Air pollution does not constitute a single problem, but presents an array of threats and opportunities to plants and animals (Dudley & Stolton 2021). Plants are more sensitive to ozone than animals, but air pollution, by modifying the physiology and biochemistry of plants, has a decisive influence on the interactions of plants and insects (Ilić & Maksimović 2021). Thereby, changes in plant communities can propagate throughout the food webs to affect other organisms (Lovett et al.2009; Dudley & Stolton 2021; Ilić & Maksimović 2021).
While we were not able to detect effects of oxide nitrates, our results highlight potential negative effects of ozone on crop pollinators and changes in the contribution of pollinators to crop production, while also affecting the sensitivity of pollinators to pesticide exposure. Indeed, different air pollutants (such as ozone and NOx) can act at different spatio-temporal scales and interact with other natural and anthropogenic factors that also alter ecosystem functioning (Dudley & Stolton 2021).
Even if more detailed studies are required and further evidence from other regions and crops is needed, our findings suggest management plans involving changes in pesticide use, should take into account the ongoing increase in air pollution, and specifically of the predicted increased concentration of tropospheric ozone in the near future (Van Dingenenet al. 2009; Avnery et al. 2011b; Archibald et al.2020). Our results also highlight that negative impacts of ozone pollution on pollinators and pollination exist, and should be considered when developing transport, manufacturing and renewable energy policies in favor of the protection of air quality and the conservation of biodiversity and associated ecosystem services.