Bayreuther Institut für Terrestrische Ökosystemforschung
>> internal Site
BFÖ 83: Schwesig, D: Biogeochemistry of Mercury and Methylmercury in Two Forested Catchments in Bavaria, Germany (14.5 Euro)
Mercury (Hg) and methylmercury (MeHg) are global pollutants, but little information is available on their biogeochemistry in forested catchments of Central Europe. The objectives of this study were to investigate input and output fluxes of total Hg (Hg
) and MeHg in a deciduous and a coniferous catchment in Bavaria (Germany), and to estimate pools and mobility of these compounds at the catchment scale, and particularly in the forest floor. Furthermore, the role of wetlands as internal sources of MeHg, and the bioaccumulation of Hg
and MeHg in aquatic biota were studied.
In both catchments, input and output fluxes of Hg compounds were investigated. Several soil profiles were sampled to estimate pools of Hg compounds in the catchments. In the coniferous catchment fluxes of Hg
and MeHg with forest floor percolates were measured. The potential of a wetland soil in the coniferous catchment to produce MeHg was investigated in a laboratory experiment under varying incubation conditions, using stable isotope addition and isotope-specific detection of MeHg. Mosses and insect larvae of a creek in the coniferous catchment were analyzed for contents of Hg
, MeHg, and isotope composition of carbon and nitrogen.
In summary it was shown that forested catchments act as a sink for both MeHg and Hg
, without considerable differences in the input/output ratio between the species Hg
and MeHg at the annual catchment scale. Nevertheless, differences in transport and mobility of both species were important at smaller scales, e.g. the forest floor. Pools of both compounds in the soils seem to be of higher importance for the output of MeHg and Hg
than the current deposition. Besides the large pools, transformation processes can strongly influence the output by runoff, especially of MeHg. Slight changes in runoff concentrations of both compounds can strongly affect the aquatic biota, due to high bioconcentration factors of MeHg and Hg
Zurück zur Übersicht
powered by BayCMS © 2015
University of Bayreuth,
Diese Webseite verwendet Cookies.