Ozone degrades floral scent and reduces pollinator attraction to flowers.
In this work we analyzed the degradation of floral scent volatiles from Brassica nigra by reaction with ozone along a distance gradient and the consequences for pollinator attraction. For this purpose we used a reaction system comprising three reaction tubes in which we conducted measurements of floral volatiles using a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) and GC-MS. We also tested the effects of floral scent degradation on the responses of the generalist pollinator Bombus terrestris. The chemical analyses revealed that supplementing air with ozone led to an increasing reduction in the concentrations of floral volatiles in air with distance from the volatile source. The results revealed different reactivities with ozone for different floral scent constituents, which emphasized that ozone exposure not only degrades floral scents, but also changes the ratios of compounds in a scent blend. Behavioural tests revealed that floral scent was reduced in its attractiveness to pollinators after it had been exposed to 120 ppb O3 over a 4.5 m distance. The combined results of chemical analyses and behavioural responses of pollinators strongly suggest that high ozone concentrations have significant negative impacts on pollination by reducing the distance over which floral olfactory signals can be detected by pollinators.
CSIC, Global Ecology Unit CREAF-CSIC-UAB, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.|CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.
Gerard
G
Farré-Armengol
CSIC, Global Ecology Unit CREAF-CSIC-UAB, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.|CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.
Josep
J
Peñuelas
Department of Environmental Science, University of Eastern Finland, PO Box 1627, FIN-70211, Kuopio, Finland.
Tao
T
Li
Department of Applied Physics, University of Eastern Finland, PO Box 1627, FIN-70211, Kuopio, Finland.
Pasi
P
Yli-Pirilä
CSIC, Global Ecology Unit CREAF-CSIC-UAB, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.|CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.
Iolanda
I
Filella
CSIC, Global Ecology Unit CREAF-CSIC-UAB, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.|CREAF, Cerdanyola del Vallès, 08193, Barcelona, Catalonia, Spain.
Joan
J
Llusia
Department of Environmental Science, University of Eastern Finland, PO Box 1627, FIN-70211, Kuopio, Finland.
James D
JD
Blande
D000818:Animals; D001516:Bees / Q000502:physiology*; D035264:Flowers / Q000737:chemistry* / Q000502:physiology; D008401:Gas Chromatography-Mass Spectrometry; D009149:Mustard Plant / Q000737:chemistry* / Q000502:physiology; D010126:Ozone / Q000009:adverse effects* / Q000032:analysis; D054817:Pollination; D055549:Volatile Organic Compounds / Q000737:chemistry*
D055549:Volatile Organic Compounds; D010126:Ozone
Bombus terrestris; Brassica nigra; anisaldehyde; behavioural tests; monoterpenes; p-cymene; phenol