Saplings of hybrid larch F1 were grown under elevated CO2 and O3.
The rate of total monoterpene emission was significantly decreased by elevated CO2.
However, elevated O3 had no effect on the total monoterpene emission rate.
Relative abundances of highly reactive monoterpenes were smaller under elevated O3.
The higher reactivity with O3 may mitigate oxidative damage in needles of the larch.