Mercury cycling in boreal ecosystems: The long-term effect of acid rain constituents on peatland pore water methylmercury concentrations

Citation
Ba. Branfireun et al., Mercury cycling in boreal ecosystems: The long-term effect of acid rain constituents on peatland pore water methylmercury concentrations, GEOPHYS R L, 28(7), 2001, pp. 1227-1230
Citations number
22
Categorie Soggetti
Earth Sciences
Journal title
GEOPHYSICAL RESEARCH LETTERS
ISSN journal
00948276 → ACNP
Volume
28
Issue
7
Year of publication
2001
Pages
1227 - 1230
Database
ISI
SICI code
0094-8276(20010401)28:7<1227:MCIBET>2.0.ZU;2-2
Abstract
Sulphate-reducing bacteria have been identified as primary methylators of m ercury (Hg) in the laboratory and in field investigations. However, no stud ies have investigated the effect of long-term deposition of sulphate on met hylmercury (MeHg) dynamics in peatlands, which are known to be significant sources of MeHg to downstream waters in the boreal forest zone. As an ancil lary experiment to a larger project investigating the effects of acid rain constituents on peatland carbon dynamics, the influence of experimentally e levated Na2SO4 and/or NH4NO3 deposition on peat pore water MeHg concentrati ons was determined using a simple mesocosm experimental design. After three years, additions of S in amounts equivalent to the 1980s dry and wet depos ition in Southern Sweden resulted in peat pore water MeHg concentrations up to six times above background levels. Elevated N loads had no effect on po re water MeHg concentrations.