Characterising volatile organic compound emission changes in native black poplar under elevated carbon-dioxide (CO2), elevated ozone (O3) and herbivory

Plants communicate information about their status, intra- and inter- plant, and with other ecosystem members, through the release of volatile organic compounds (VOCs). The effects of rising CO₂ in conjunction with ozone (O₃) on plant VOC emissions is not yet fully understood, but research suggests that some herbivore-induced VOCs are degraded by O₃, potentially reducing their signalling function. Furthermore, elevated CO₂ has been shown to attenuate induced VOC responses to herbivory in Brassica oleracea. 

We are using two tri-trophic model systems; black poplar [Populus nigra betulifolia], winter moth [Operophtera brumata] and a tachinid fly parasitoid of winter moth, Cyzenis albicans; and oil seed rape [Brassica napus], diamond back moth [Plutella xylostella] (DBM), and a parasitoid of DBM, braconid wasp, Cotesia plutella. Additionally, we are working within two ground-breaking facilities; the Birmingham Institute of Forest Research (BIFoR)’s free-air carbon enrichment (FACE) experiment, and University of Reading’s free-air diesel and ozone enrichment experiment. We will also collect some data from lab-based experiments.

Our project seeks to characterise the volatile organic compound (VOC) profiles emitted for both plants under herbivory, examine how these VOC profiles differ under combined elevated CO₂ and O₃, and explore whether changes to VOC profiles impact key ecological relationships, e.g, the ability of plants to signal to herbivore enemies.