Impacts of air pollution and climate change on floral VOC signals

This project aims to assess the threat to pollinating and foraging insects as a consequence of altered floral Volatile Organic Compound (VOC) signalling in response to air pollution and climate change. Insects pollinate over 80% of flowering plants and a reduction in the distance of detectable floral scents in air pollution conditions may be adding to the stresses that are contributing to declines in pollinator numbers. We need to know by how much floral VOC emissions are reduced by air pollution and to what extent the emitted floral VOC signal is subsequently degraded by air pollution. We need to identify the locations where the largest risks of air pollution to floral VOC signals occur.

Our project integrates floral VOC emission and degradation in response to air pollution by bringing together the unique and complementing expertise of partners in the UK and USA. We will have a series of exchange visits to share skills and expertise. We will measure floral VOC emissions in response to ozone (O3) pollution in order to calculate the reduction in signal strength and the modification of the integrity of the signal. We will develop and apply numerical models to determine the reaction of floral VOCs with the air pollutants ozone and nitrate radical in order to quantify floral VOC signal degradation in polluted areas. Models will also consider the future influences of regional environmental changes in response to climate change. We will combine existing data of pollutant concentrations and grassland distribution in the UK and USA in order to identify the locations of largest risk to pollinating and foraging insects. Finally, we will develop a conceptual model that will improve our understanding of the contribution of air pollution and climate change to floral VOC signalling and the corresponding reduction in the distance of detectable floral scents by insects. This collaborative project will identify key knowledge gaps and develop strategies to address these beyond the lifetime of this grant.

This project will provide data and information on a novel topic of the threat to pollinating and foraging insects as a consequence of altered floral VOC signalling in response to air pollution and climate change. Insects pollinate over 80% of flowering plants but pollinators are declining in numbers globally. We will measure floral VOC emissions in response to ozone pollution in order to calculate the reduction in signal strength and the modification of the integrity of the signal. We will develop and apply numerical models to determine the reaction of floral VOCs with the air pollutants ozone and nitrate radical in order to quantify floral VOC signal degradation in polluted areas. Models will also consider the future influences of regional environmental changes in response to climate change. We will combine existing data of pollutant concentrations and grassland distribution in the UK and USA in order to identify the locations of largest risk to pollinating and foraging insects. Finally, we will develop a conceptual model that will improve our understanding of the contribution of air pollution and climate change to floral VOC signalling and the corresponding reduction in the distance of detectable floral scents by insects.

Outputs from this project will provide scientists, environmental regulators and policy makers with invaluable insight of the role of air pollution and climate change in influencing floral VOC signals and the consequences for insect pollinators. Knowledge transfer to these groups will be achieved by a combination of peer-reviewed publications, targeted factsheets, and presentations at conferences and meetings, in addition to incorporation of key results in appropriate twitter feeds and CEH and University webpages. In particular, project partners will also make use of their existing contacts with national and international (e.g. UNECE Convention on Long-range Transboundary Air Pollution) policy makers to discuss the challenges for future policies to mitigate any adverse impacts of air pollution and climate change on pollinators and the services they provide.