Thursday, November 20, 2008
Journal Club MTG8: Isoprene emissions
Today's article "The effect of elevated CO2, soil and atmospheric water deficit and seasonal phenology on leaf and ecosystem isoprene emission" by Emiliano Pegoraro describes an experimental biosphere laboratory in that looks at stresses to cottonwood plantations and their responses with respect to isoprenes. The experiment ran over a few years, and looked specifically at the fall of 2000, fall of 2002 and spring of 2003 to cover the range of phenological influences. The plantations were controlled, one with present day CO2 levels and one with elevated CO2 levels. The plantations were both stressed as a result of a vapour pressure deficit (VPD) and drought conditions. The idea was to measure the isoprene emissions under various conditions. The results show a correlation between photosynthetic photon flux density (PPFD) which makes sense as isoprene emissions shutdown with the absence of light. It was interesting that as the drought conditions continued, no matter the CO2 concentration, the isoprene levels tailored off to roughly the same emission rate.
As a side note, I am finally learning all that high school biology I didn't take.