|Abstract Title:||Vegetation Patterns Influence Mercury Accumulation in Permafrost Peatlands|
|Presenter Name:||Charlotte Haugk|
|Company/Institution:||Department for Environmental Science, Stockholm University|
|Session:||Special Session - Climate-Driven Perturbations of Arctic Mercury Cycling|
|Co-Authors:||Charlotte Haugk,Sofi Jonsson,Britta Sannel,Brach Anica,Gustaf Hugelius,Peter Kuhry,Brittany Tarbier|
Abstract Information :
Northern peatlands act as a globally important sink for atmospheric mercury (Hg). The factors that control permafrost soil Hg distribution are however not well understood. To investigate these patterns in permafrost peatlands, we characterized nine peat cores with contrasting accumulation histories (epigenetic and syngenetic permafrost accumulation) from west-central Canada, the Hudson Bay Lowlands and sites in northern Fennoscandia. In all cores, highest total mercury (THg) concentrations were found close to the peat surface with a maximum THg of around 200 ng Hg g-1 d.w-1. Earlier studies using plant macrofossil analysis have revealed that the peat in these cores accumulated under different vegetation regimes. Higher concentrations of THg were observed in rootlet layers, which indicates dry conditions and slower peat accumulation rates. Tracers of charcoal, indicative of fires, did not correlate with lower concentrations of THg. Our study suggests historical vegetation patterns may drive accumulated concentrations of THg.