Figure 3: Real-time branch emissions of VOCs together with transpiration (E, mmol m-2 s-1) and net photosynthesis (Anet, µmol m-2s-1) fluxes during a 10-day drought experiment. A branch enclosure was installed on a potted poplar tree and water withheld for the 10-day duration. Daily branch flux patterns of (a ) Methanol (MeOH), Acetic Acid (AA), AA/MeOH emission ratio, (b ) Aerobic fermentation intermediates (acetaldehyde, ethanol, acetone) (c ) CO2 and H2O and the photosynthetic product isoprene. Shaded areas represent the nigh-time where the grow light was switched off.