Emissions of biogenic volatile organic compounds from the boreal forest floor and understory: a study by solid-phase microextraction and portable gas chromatography-mass spectrometry.

摘要

Vegetation introduces to the atmosphere a diversity of biogenic volatile organic compounds(BVOCs) which affect atmospheric chemistry, air quality and climate. Understoryemissions might contribute significantly to the total BVOCs budget. In this work, eitherdynamic or static solid-phase microextraction (SPME) combined with portable gas chromatography-massspectrometry were optimised and used for the in-situ measurement ofthe most abundant BVOCs at understory level. The study was performed in summer 2015at the SMEAR II station in Hyyti?l?, Finland. The most abundant BVOCs measured insoil chambers and ambient air were α-pinene and Δ3-carene, and their relative concentrationswere similar in every chamber. These species constituted 80%–90% of the measuredmonoterpenes. Aliphatic aldehydes were also measured, and their amounts were lower insoil chambers than in ambient air. Air BVOC concentrations were markedly higher whenthe wind direction was from SE, which was associated with transportation from nearbysawmills.