Importance of vegetation type for mercury sequestration in the northern Swedish mire, Rödmossamyran

Downwash of atmospherically deposited trace metals in peat and the influence of rainfall intensity: An experimental test

“…2a) varies between the sphagnum lawn and the dominant fen section of the mire, but is consistent between cores from the same area (Rydberg et al, 2010;Hansson et al, 2014a). In those studies the lower level of decomposition in the sphagnum (0.05-0.06 g cm −3 ) versus the fen (0.07 to 0.10 g cm −3 ) peat is also supported by analyses of C/N ratios and light transmission.…”

“…Field and laboratory measured pH values of the peat pore water have been in the range 3.5-4.0. For a more detailed description of the mire, including peat stratigraphy, see Rydberg et al (2010). Based on climate data from the Swedish Meteorological and Hydrological Institute (SMHI.se) the mean (defined as the period 1961-1990) annual temperature for Umeå is 3°C and the mean annual precipitation is 600 mm, but annual rainfall has varied from 400 to 1020 mm year −1 .…”

“…Our objective in this study was to further test the importance of downwashing for trace metals in peat, beyond that of 7 Be, based on a controlled experimental setup. We used a set of 13 peat cores collected from Rödmossamyran, a site we have studied both for radiometric tracers ( 7 Be, 210 Pb, 137 Cs and 241 Am) (Hansson et al, 2014a,b) and Hg (Rydberg et al, 2010).…”

Preferential degradation of polyphenols from Sphagnum – 4-Isopropenylphenol as a proxy for past hydrological conditions in Sphagnum-dominated peat

“…The absence of markers for lichens (3-methoxy-5-methylphenol) and pine and the very low 424 abundance of the marker for graminoids (ferulic acid methyl ester) in the peat samples (Section 425 2.4) indicate a complete dominance by Sphagnum and prevailing wet conditions, which is in 426 agreement with the present-day situation at the centre of the mire (Rydberg et al, 2010). This 427 notwithstanding, the peat has a substantial contribution from (di)methoxyphenols (Table 2) Sphagnum in the RMM peat core, it is very unlikely that the variation in 4-isopropenylphenol 507 (from 0.21 to 2.85% TIC; Fig.…”

Reconstructing historical Pb and Hg pollution in NW Spain using multiple cores from the Chao de Lamoso bog (Xistral Mountains)

“…At least in core CHL13, the anomalously low 206 Pb/ 207 Pb ratios suggest that not all differences in the Pb records are the result of differences in atmospheric inputs, and some other peat characteristics (i.e. plant composition of the peat; Rydberg et al, 2010) or post-depositional processes (i.e. local enhanced accumulation or decomposition, remobilization; MacKenzie et al, 1998) may be involved.…”