Do Oaks With a Provenance Related to Warmer Climates Emit More Isoprene?

The hydrocarbon isoprene plays an important role in atmospheric chemistry, particularly in regards to air pollution and climate change. It is important to know why certain plant species emit isoprene and what factors affect its production in order to predict future air quality. Past research has indicated that isoprene aids in coping with heat stress, so it was hypothesized that source latitude (a proxy for climate) would significantly impact isoprene production by oaks grown in a common location. Twelve bur oaks, Quercus macrocarpa, collected from a latitudinal range (30-45 ̊) and cultivated at the Morton Arboretum were assayed for their isoprene emission rate in the summer of 2014. There was no significant effect of source latitude on isoprene emission rate. As an alternative explanation, the influence of average daily temperature on isoprene emission rate was also tested, but again there was no significant effect. However, slight trends in the anticipated direction suggest that stronger relationships could be revealed if more data are collected.