In WP1, focused on canopy surface temperature impacts, we conducted field work in Abisko, Sweden, Narsarsuaq, Greenland, and Finse, Norway. Leaf-level studies on tundra shrubs revealed that evergreen and deciduous species differ in temperature responses for photosynthesis and BVOC emissions (Simin et al. 2021, Environ. Exp. Bot.). Plant-scale measurements on dwarf birch and grey willow across an elevation gradient assessed relationships between canopy height, plant and environmental traits, and BVOC emissions (Simin et al. 2022, Sci. Total Environ.). Ecosystem-scale measurements showed that a palsa area emitted more BVOCs than a wet fen, while a lake acted as a BVOC sink (Seco et al. 2020, Atmos. Chem. Phys.; Seco et al. 2022, PNAS). Tundra BVOC emissions' strong temperature dependency was evident at the ecosystem scale (Seco et al. 2020, Atmos. Chem. Phys.; Seco et al. 2022, PNAS).
In WP2, focused on insect herbivory, field work was conducted in Abisko, Tromsø, and Narsarsuaq. An experiment using methyl jasmonate (MeJA) to mimic insect herbivory on dwarf birch showed increased BVOC emissions and altered compound profiles, with climate warming amplifying this response (Li et al. 2019, Nat. Plants). The effects of herbivory on dwarf birch BVOC emissions varied under different environments (Rieksta et al. 2021, Glob. Change Biol.; Rieksta et al. 2023, Plant Environ. Interact.). Experiments indicated a positive relationship between the number of feeding larvae and BVOC emissions from mountain birch (Rieksta et al. 2020, Front. Plant Sci.). Gall-infestation caused less changes in BVOC emissions from Arctic willows (Swanson et al. 2021, Sci. Total Environ.).
In WP3, focused on permafrost thaw emissions, we showed that thawing permafrost releases BVOCs, especially ethanol and methanol, with lower atmospheric emissions due to microbial uptake during passage through the active layer (Kramshøj et al. 2018, Nat. Commun.). Microbial uptake is efficient for all BVOCs in all soils (Albers et al. 2018, Biogeosciences; Rinnan & Albers 2020, JGR Biogeosci.). The uptake rate increases with higher BVOC availability (Jiao et al. 2023, Soil Biol. Biochem.). Soil water content, affecting oxygen levels, also influences BVOC emissions (Kramshøj et al. 2019, Glob. Change Biol.). Emissions vary over the growing season and between landscape types (Jiao et al. 2023, Geoderma).
WP4 assessed temperature sensitivity of BVOC emissions in Alpine ecosystems beyond the Arctic, with field measurements in Ecuador, Bolivia, and Costa Rica. Comparisons of BVOC emissions in control and warming treatments in local Alpine vegetation are under analysis (Chan et al., in preparation; Smart et al., in preparation).
WP5’s modelling work analyzed Pan-Arctic tundra BVOC emissions under different climate scenarios and their impacts on atmospheric chemistry (Tang et al. 2023, npj Clim. Atmos. Sci.). A review article summarized current knowledge and identified gaps in modelling soil BVOC processes (Tang et al. 2019, Rev. Geophys.). New leaf temperature algorithms were developed using data from WP1 (Simin et al. 2021, Environ. Exp. Bot.) and ecosystem data were used for model validation (Seco et al. 2020, Atmos. Chem. Phys.). Herbivory-BVOC emission relationships were assessed to develop algorithms for model improvement (Tang et al., in preparation).
