History effect of light and temperature on monoterpenoid emissions from Fagus sylvatica L.

Monoterpenoid emissions from Fagus sylvatica L. trees have been measured at light- and temperature-controlled conditions in a growth chamber, using Proton Transfer Reaction Mass Spectrometry (PTR-MS) and the dynamic branch enclosure technique. o synthesized monoterpenoid Standard Emission Factors, obtained by applying the G97 algorithm (Guenther, 1997), varied between 2 and 32 μg gDW−1 h−1 and showed a strong decline in late August and September, probably due to senescence. sponse of monoterpenoid emissions to temperature variations at a constant daily light pattern could be well reproduced with a modified version of the MEGAN algorithm (Guenther et al., 2006), with a typical dependence on the average temperature over the past five days. urnal emissions at constant temperature showed a typical hysteretic behaviour, which could also be adequately described with the modified MEGAN algorithm by taking into account a dependence on the average light levels experienced by the trees during the past 10–13 h. pact of the past light and temperature conditions on the monoterpenoid emissions from F. sylvatica L. was found to be much stronger than assumed in previous algorithms. our experiments were conducted under low light intensity, future studies should aim at confirming and completing the proposed algorithm updates in sunny conditions and natural environments.