Seminar

Abstract

Methyl halides (CH₃Cl, CH₃Br, CH₃I) and C₂-C₄ alkenes are important for ozone depletion in the stratosphere and ozone creation in the troposphere, respectively, but their terrestrial fluxes are poorly quantified. A major problem in constraining terrestrial sources of methyl halides and C₂-C₄ alkenes is the large temporal variability exhibited by every ecosystem studied thus far. The cause of this variability is unknown, but it generates biases in field sampling and scaling up results. A related question is whether the dominant production mechanism for these compounds is biotic (enzymatic) or abiotic. I will present a hypothesis that methyl halide and light alkene emissions in terrestrial ecosystems are predominantly biogenic, are strongly coupled to each other, and are affected by rapid hormonal shifts in plants associated with transitions between growth stages. Collaborative experiments will be proposed to test the driving factors behind the production and temporal variability of these compounds.