RESEARCH ARTICLE Organic horizon and mineral soil mercury along three clear-cut forest chronosequences across the northeastern USA Justin B. Richardson 1,2 & Chelsea L. Petrenko 1,3 & Andrew J. Friedland 1 Received: 29 May 2017 /Accepted: 26 September 2017 # Springer-Verlag GmbH Germany 2017 Abstract Mercury (Hg) is a globally distributed pollutant trace metal that has been increasing in terrestrial environments due to rising anthropogenic emissions. Vegetation plays an important role in Hg sequestration in forested environments, but increasing tree removal for biofuels and wood products may affect this process. The long-term effect of clear-cutting on forest soil Hg remains uncertain, since most studies are limited to measuring changes for < 10 years following a single harvest event. The chronosequence approach, which substi- tutes space for time using forest stands of different ages since clear-cutting, allows for investigation of processes occurring over decades to centuries. Here, we utilized three clear-cut forest soil chronosequences across the northeastern USA to understand Hg accumulation and retention over several de- cades. Total Hg concentrations and pools were quantified for five soil depth increments along three chronosequences. Our results showed Hg concentrations and pools decreased in the initial 20 years following clear-cutting. Mineral soil Hg pools decreased 21–53% (7–14 mg m -2 ) between 1–5-year-old stands and 15–25-year-old stands but mineral soil Hg pools recovered in 55–140-year-old stands to similar values as mea- sured in 1–5-year-old stands. Our study is one of the first to demonstrate a decrease and recovery in Hg pool size. These changes in Hg did not correspond with changes in bulk den- sity, soil C, or pH. We utilized a simple two-box model to determine how different Hg fluxes affected organic and min- eral soil horizon Hg pools. Our simple model suggests that changes in litterfall and volatilization rates could have caused the observed changes in organic horizon Hg pools. However, only increases in leaching could reproduce observed decreases to mineral soil Hg pools. Further studies are needed to deter- mine the mechanism of Hg loss from forest soils following clear-cutting. Keywords Trace metal . Pollution . Forest harvest . Soil disturbance . Mineral soil . Biogeochemistry Introduction Mercury (Hg) is a globally distributed pollutant trace metal, found widely in terrestrial ecosystems due to anthropogenic emissions (Smith-Downey et al. 2010; Streets et al. 2017) as well as natural emissions (Hylander and Meili 2003). Mercury is sourced to the atmosphere from geologic and human emis- sions as both gaseous and particulate phases (Miller et al. 2005; Driscoll et al. 2007). After emission and transport in the atmosphere, Hg is deposited as gaseous aerosols, dry par- ticulates, or dissolved ions in precipitation (Miller et al. 2005; Mitchell et al. 2008; Obrist et al. 2011; Yu et al. 2014). Global atmospheric deposition rates of Hg have been increasing since the Industrial Revolution due to human pollution from artisan- al gold mining and coal combustion (Kamman and Engstrom 2002; Hylander and Meili 2003; Driscoll et al. 2007; Streets et al. 2017). Mercury can be lost from forest soils via two main Responsible editor: Philippe Garrigues Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11356-017-0356-9) contains supplementary material, which is available to authorized users. * Justin B. Richardson Justin.B.Richardson.GR@dartmouth.edu 1 Environmental Studies Program, Dartmouth College, Hanover, NH 03755, USA 2 Earth and Atmospheric Sciences Department, Cornell University, Ithaca, NY 14850, USA 3 Department of Ecology and Evolutionary Biology, Dartmouth College, Hanover, NH 03755, USA Environ Sci Pollut Res DOI 10.1007/s11356-017-0356-9