Periodic Reporting for period 1 - ELATE (Exchange of Light alkenes and Alkyl halides from Arctic Tundra Ecosystem)
Période du rapport: 2023-01-01 au 2024-12-31
Anthropogenic climate change is driving unprecedented warming across Arctic and permafrost-affected regions, leading to thawing soils, shifts in vegetation, and altered soil biogeochemistry. These changes can profoundly affect the exchange of volatile organic compounds (VOCs) between soils and the atmosphere. While VOCs make up a relatively small portion of total carbon flux compared with carbon dioxide or methane, they play a significant role in atmospheric chemistry, contributing to ozone formation and secondary aerosol production.
This project aims to clarify how Arctic and permafrost-affected soils can simultaneously act as sources and sinks of VOCs—particularly light alkenes and alkyl halides, as well as other key compounds—under both current conditions and plausible future climate scenarios. It pursued four overarching objectives: (1) characterize the capacity of these soils to emit or absorb relevant VOCs, (2) determine how environmental drivers such as temperature, moisture, and vegetation status influence fluxes, (3) assess the sensitivity of VOC exchanges to simulated warming and elevated CO2, and (4) provide refined parameterizations to inform regional- and global-scale models, thus supporting more accurate projections of climate feedbacks. By advancing our knowledge of VOC dynamics in these sensitive environments, the project delivers insights that can help shape climate response strategies and refine policy measures aimed at combating global climate change.
This project aims to clarify how Arctic and permafrost-affected soils can simultaneously act as sources and sinks of VOCs—particularly light alkenes and alkyl halides, as well as other key compounds—under both current conditions and plausible future climate scenarios. It pursued four overarching objectives: (1) characterize the capacity of these soils to emit or absorb relevant VOCs, (2) determine how environmental drivers such as temperature, moisture, and vegetation status influence fluxes, (3) assess the sensitivity of VOC exchanges to simulated warming and elevated CO2, and (4) provide refined parameterizations to inform regional- and global-scale models, thus supporting more accurate projections of climate feedbacks. By advancing our knowledge of VOC dynamics in these sensitive environments, the project delivers insights that can help shape climate response strategies and refine policy measures aimed at combating global climate change.
WP1: Field Measurements and Historical Dataset Analysis
This work package involved collecting and analyzing soil samples from multiple permafrost-affected sites differing in vegetation cover, temperature profiles, and degrees of thaw. Drawing on both new measurements and reexamined datasets, it investigated how soil properties and microbial activity shape VOC release under changing thermal and moisture conditions. In Jiao et al. (2023, Geoderma), for instance, partially thawed peatlands sometimes showed notably higher terpene emissions, whereas other conditions influenced the overall composition and magnitude of fluxes. These findings highlight the complex interplay between permafrost thaw and VOC release in northern soils.
WP2: Laboratory Incubations Under Global Change Scenarios
This work package used controlled laboratory setups to investigate how Arctic and permafrost-affected soils respond to temperature changes and other environmental factors. By incubating soil samples under varied conditions, it became possible to track real-time production and consumption of different VOCs. These efforts are detailed in Jiao et al. (2023, Soil Biology & Biochemistry), which describes how soils can remove certain VOCs from the headspace, and in Jiao et al. (2025, Communications Earth & Environment), which shows that active layer soils can be important sinks for several compound classes. Taken together, these incubations confirmed that microbial processes and soil properties influence whether these northern soils act as net sources or net sinks, and they provided insights into how ongoing climate changes could shift VOC exchange in high-latitude regions.
WP3: Modeling and Parameterization
This work package focused on integrating experimental insights into global and regional models that represent Arctic soil–atmosphere interactions. A central outcome was the derivation of uptake coefficients for multiple VOCs in active layer soils (Jiao et al., 2025, Communications Earth & Environment), which highlight the potential for simultaneous production and consumption processes in permafrost-affected environments. These coefficients provide an important foundation for including soil uptake dynamics in terrestrial VOC models.
This work package involved collecting and analyzing soil samples from multiple permafrost-affected sites differing in vegetation cover, temperature profiles, and degrees of thaw. Drawing on both new measurements and reexamined datasets, it investigated how soil properties and microbial activity shape VOC release under changing thermal and moisture conditions. In Jiao et al. (2023, Geoderma), for instance, partially thawed peatlands sometimes showed notably higher terpene emissions, whereas other conditions influenced the overall composition and magnitude of fluxes. These findings highlight the complex interplay between permafrost thaw and VOC release in northern soils.
WP2: Laboratory Incubations Under Global Change Scenarios
This work package used controlled laboratory setups to investigate how Arctic and permafrost-affected soils respond to temperature changes and other environmental factors. By incubating soil samples under varied conditions, it became possible to track real-time production and consumption of different VOCs. These efforts are detailed in Jiao et al. (2023, Soil Biology & Biochemistry), which describes how soils can remove certain VOCs from the headspace, and in Jiao et al. (2025, Communications Earth & Environment), which shows that active layer soils can be important sinks for several compound classes. Taken together, these incubations confirmed that microbial processes and soil properties influence whether these northern soils act as net sources or net sinks, and they provided insights into how ongoing climate changes could shift VOC exchange in high-latitude regions.
WP3: Modeling and Parameterization
This work package focused on integrating experimental insights into global and regional models that represent Arctic soil–atmosphere interactions. A central outcome was the derivation of uptake coefficients for multiple VOCs in active layer soils (Jiao et al., 2025, Communications Earth & Environment), which highlight the potential for simultaneous production and consumption processes in permafrost-affected environments. These coefficients provide an important foundation for including soil uptake dynamics in terrestrial VOC models.
Results from this work show that Arctic and permafrost-affected soils can, under certain conditions, either emit or remove significant amounts of VOCs. In some experiments, thawing soils released terpene-rich gases, while in others, active layers acted as sinks for a range of compounds. These findings call attention to the potential for soil processes to affect atmospheric chemistry in areas experiencing rapid climate change. Additional work could examine how other factors, such as freeze–thaw cycles or changing plant communities, influence these fluxes. Refining and validating models with these new data could also strengthen efforts to predict how Arctic soils may respond to continued warming.