Biogeochemical influences on net methylmercury formation proxies along a peatland chronosequence

Microbial Communities Mediating Net Methylmercury Formation Along a Trophic Gradient in a Peatland Chronosequence

“…Moreover, redox variation induced by water regime can also influence Hg speciation and mobilization and consequently Hg bioavailability, resulting in a direct effect on MeHg formation (Beckers et al, 2019;Beckers and Rinklebe, 2017;Frohne et al, 2012;Jonsson et al, 2014;Zhu et al, 2018). Hence it is not surprising that previously reported correlations between peat soil characteristics and net MeHg formation along the chronosequence (Wang et al, 2020(Wang et al, , 2021) may be explained by peat-soil control of microbial community composition or some type of interplay (Fig. 2, Table S9).…”

Post-depositional Hg transformation processes in an open boreal peatland constrained by Hg stable isotopes

“…It has been shown that reduced NOM possess a much higher potential to both reduce Hg II and back-oxidize Hg 0 than oxidized NOM 63 . The reduction of Hg II is expected to be very slow due to its exceptionally strong complex formation with thiol groups in NOM 64 , and possible formation of the only slightly soluble mineral β-HgS (metacinnabar) in the sulfidic environment of peatland soils in the region 65 .…”

Microbial communities mediating net methylmercury formation along a trophic gradient in a peatland chronosequence

“…S1 in the Supplementary Information (SI)). More detailed information on the site, clean sampling and sample preparation is given elsewhere (Wang et al, 2020(Wang et al, , 2021. Briefly, the chronosequence features a natural gradient of trophic status and hydrogeochemistry with respect to vegetation composition and other geochemical and geomorphological features.…”

“…young, intermediate and old peatlands) to gradual changes in concentrations of THg and MeHg in solid peat, with higher MeHg but lower THg observed in the nutrient-rich younger peatlands (Wang et al, 2020). The apparently higher net MeHg formation in younger peatlands was attributed to the higher availability of organic matter and appropriate electron acceptors as well as the higher IHg solubility enhanced by the formation of Hg-polysulfide compounds in the younger peatlands (Wang et al, 2021). We also investigated whether vascular plant removal would impact Hg methylation within peatlands along the chronosequence by reducing the availability of readily available organic matter (i.e.…”