|Abstract Title:||Total and Methylmercury Stocks in Tavvavuoma Permafrost Peatland Sites|
|Presenter Name:||Maria Camila Urrea|
|Session:||Special Session - Climate-Driven Perturbations of Arctic Mercury Cycling|
|Co-Authors:||Maria Camila Urrea,Charlotte Haugk,Gustaf Hugelius,Julia Wagner,Britta Sannel,Sofi Jonsson|
Abstract Information :
Permafrost soils have acted as a sink of mercury (Hg) for thousands of years. As permafrost thaws, hot spots for Hg methylation may develop. This has been exhibited along sampled permafrost thaw gradients (Tarbier et al. 2021), however, the role that permafrost thaw has on the stocks of Hg stored in permafrost soils, remains to be characterized. To address this knowledge gap, we have estimated stocks of total Hg and methylmercury (MeHg) in two permafrost peatland sites in Tavvavuoma, northern Sweden. In total, 39 soil cores were collected from different landscape features: fens, palsas, and peat plateaus. In all landscape features, we observed higher total Hg (THg) concentration in the top 50 cm (?=72.54 ng g?1; range, 1.7-240 ng g?1). When comparing THg, we found higher concentrations in the palsas. For MeHg, we expect to find a higher fraction of THg as MeHg in the fens, due to the wet and anoxic conditions that are favorable for the microbial production of MeHg. This was also supported by the preliminary data from a subset of the cores. Here, we will present the data on THg, MeHg and %MeHg from all the cores together with the estimated stocks of THg and MeHg stocks in two permafrost sites in Tavvavuoma.