Seasonal and diel patterns of biogenic volatile organic compound fluxes in a subarctic tundra

In arctic and subarctic regions, rapid climate changes enhance biogenic volatile organic compound (BVOC) emissions from vegetation, with potentially significant influence on atmospheric processes. However, the seasonal diel patterns of bidirectional exchange (flux) BVOCs remain poorly studied in these regions. Here, we deployed a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) to investigate ecosystem-level BVOC fluxes over growing season tundra heath Abisko, Northern Sweden, quantify two widespread dwarf shrubs high latitudes, Salix myrsinites Betula nana. As expected, ecosystem short-chained oxygenated compounds (e.g., methanol, acetaldehyde acetone) terpenoids isoprene, monoterpenes sesquiterpenes) followed different patterns. For compounds, net dominated peaked early season, while deposition occurred sporadically, particularly at night. contrast, were almost exclusively emitted ecosystem, maxima occurring peak season. At branch level, groups both S. B. nana clear during day. was by isoprene whilst terpene emissions. Methanol, acetone comparable levels similar species. Both responded exponentially enclosure temperature depended light levels. Compared emission models, however, responses steeper for monoterpenes, methanol acetone, but weaker sesquiterpenes. Apart well-known many other BVOCs, such as some carbonyls nitrogen-containing plants contributions variation fluxes. Overall, our study highlights complexity fluxes, which vary seasonally diurnally. Vegetation composition triggered change will shift composition, important implications processes local climate.