BG1.7/CL4.28Soil stocks and atmospheric fluxes of carbon and nitrogen in high-latitude ecosystems (co-organized)
|Convener: Christina Biasi | Co-Conveners: Torben R. Christensen , Maija E. Marushchak , Christina Schädel , Juri Palmtag|
High-latitude ecosystems store more than twice as much carbon in their soils than is currently contained in the atmosphere, and are warming at a rate twice as fast as the rest of the planet. Large parts of these carbon stocks are currently protected from microbial activities in permanently frozen ground. The release of these carbon stocks to the atmosphere in a warmer world in the form of carbon dioxide (CO2) methane (CH4) and volatile organic carbon compounds (VOCs) is largely determining the feedback of Arctic ecosystems to the climate change. However, there is also increasing evidence that nitrous oxide (N2O), a very potent greenhouse gas (GHG), can be released from permafrost soils, with the potential of accelerating the positive feedback loop to climate change from high-latitude ecosystems. Emission patterns and magnitude of N2O are much less studied from high-latitude ecosystems than CO2 or CH4 emissions, and detailed process knowledge remains sparse. Additionally, little is known on VOC emissions from high latitude soils. One problem in estimating the overall feedback mechanisms from permafrost soils is related to the high spatial variability of high-latitude regions. Understanding this variability is crucial for estimating soil organic carbon and nitrogen storages and their dynamics, ecosystem resilience to climate change, and interactions (i.e. fluxes) between the Earth's four spheres.
This session invites studies from different disciplines, including soil science, geomorphology, biogeochemistry, atmospheric sciences, ecology and remote sensing, that focus on high-latitude, permafrost and periglacial ecosystems. We welcome contributions that provide insights into Arctic greenhouse gas (CO2, CH4, N2O) and reactive gas (VOC) dynamics as well as process studies aiming at mechanistic understanding of carbon and nitrogen stocks and dynamics in permafrost soils. Approaches can range from empirical work to modelling studies, and operate at different scales from microbiological investigation to novel and traditional flux measurements to regional upscaling exercises.