Monoterpene emissions from conifer tree species (from de novo synthesis and storage pools) play an important role in plant ecology and physiology. During drought stress the two emission sources are affected differently, but they are difficult to separate using conventional measuring techniques. In a recent study published in AoB PLANTS, Lüpke et al. used 13CO2 labelling and an advanced gas exchange measurement system (Tree DEMON) to measure the strength of de novo and pool isoprenoid emissions of Scots pine following drought and rewetting. Both emission types were reduced following drought; however, the de novo emissions were more strongly affected by drought and recovered slower during rewetting. Their study also showed a strongly varying ratio of pools and de novo emissions for the individual isoprenoids. An improved emission standardization algorithm was applied to correctly standardize the emission rates from de novo and pool emissions and to determine the emission potential under different drought stress states.