Atmospheric Pb and Ti Accumulation Rates from Sphagnum Moss: Dependence upon Plant Productivity

Abstract

The accumulation rates of atmospheric Pb and Ti were obtained using the production rates of Sphagnum mosses collected in four ombrotrophic bogs from two regions of southern Germany: Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Surfaces of Sphagnum carpets were marked with plastic mesh and one year later the production of plant matter was harvested. Metal concentrations were determined in acid digests using sector field ICP-MS employing well established analytical procedures. Up to 12 samples (40 x 40 cm) were collected per site, and 6-10 sites were investigated per bog. Variations within a given sampling site were in the range 2.3-4x for Pb concentrations, 1.8-2.5x for Ti concentrations, 3-8.3x for Pb/Ti, 5.6-7.8x for Pb accumulation rates, and 2.3-6.4x for Ti accumulation rates. However, the median values of these parameters for the sites (6-10 per bog) were quite consistent. The mosses from the bogs in NBF exhibited significantly greater productivity (187-202 g m(-2) a(-1)) compared to the OB peat bogs (71-91 g m(-2) a(-1)), and these differences had a pronounced effect on the Pb and Ti accumulation rates. Highly productive mosses showed no indication of a "dilution effect" of Pb or Ti concentrations, suggesting that more productive plants were simply able to accumulate more particles from the air. The median rates of net Pb accumulation by the mosses are in excellent agreement with the fluxes obtained by direct atmospheric measurements at nearby monitoring stations in both regions (EMEP and MAPESI data).

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

“…Considering the presence of ericaceous shrubs, but no overhanging pine, at site F1, this is in good agreement with a number of studies reporting that an increased interception area, i.e., a canopy, will increase mercury deposition (Lindberg et al, 1998;Zhang et al, 2009). It has also been reported that a higher plant growth rate can increase the interception of metals (Kempter et al, 2010), and because the vertical peat accumulation for site S1 and F1 is similar, but the decomposition slightly higher in the latter (as indicated by the bulk density), the F1-site likely has a slightly higher plant growth rate, which can contribute to the difference in deposition between the two sites. However, mercury concentrations between the two sites differ by 42-61% for living mosses, 63% for the topmost peat and 77-96% for mercury inventories, which are all greater than the 33% difference indicated by the unsupported 210 Pb inventories.…”

SphagnumMosses from 21 Ombrotrophic Bogs in the Athabasca Bituminous Sands Region Show No Significant Atmospheric Contamination of “Heavy Metals”

“…7 A recent study of Sphagnum moss from four bogs in two regions of southern Germany (DE) showed that accumulation rates obtained from Pb analysis of Sphagnum were in good agreement with direct deposition measurements for the same regions. 8 …”

Inductively Coupled Plasma Mass Spectrometry

“…221 Results from two different sampling sites in Germany were compared and attention was paid to both intrasite and species-dependent variation. Important for drawing meaningful ecological considerations is that the accumulation was seen to largely depend on the annual dry-matter production rate of the mosses.…”