12 research outputs found
Heavy metal and nitrogen concentrations in mosses are declining across Europe whilst some “hotspots” remain in 2010
In recent decades, naturally growing mosses have been used successfully as biomonitors of atmospheric deposition of heavy metals and nitrogen. Since 1990, the European moss survey has been repeated at five-yearly intervals. In 2010, the lowest concentrations of metals and nitrogen in mosses were generally found in northern Europe, whereas the highest concentrations were observed in (south-)eastern Europe for metals and the central belt for nitrogen. Averaged across Europe, since 1990, the median concentration in mosses has declined the most for lead (77%), followed by vanadium (55%), cadmium (51%), chromium (43%), zinc (34%), nickel (33%), iron (27%), arsenic (21%, since 1995), mercury (14%, since 1995) and copper (11%). Between 2005 and 2010, the decline ranged from 6% for copper to 36% for lead; for nitrogen the decline was 5%. Despite the Europe-wide decline, no changes or increases have been observed between 2005 and 2010 in some (regions of) countries
Country-specific correlations across Europe between modelled atmospheric cadmium and lead deposition and concentrations in mosses
Previous analyses at the European scale have shown that cadmium and lead concentrations in mosses are
primarily determined by the total deposition of these metals. Further analyses in the current study show
that Spearman rank correlations between the concentration in mosses and the deposition modelled by
the European Monitoring and Evaluation Programme (EMEP) are country and metal-specific. Significant
positive correlations were found for about two thirds or more of the participating countries in 1990,
1995, 2000 and 2005 (except for Cd in 1990). Correlations were often not significant and sometimes
negative in countries where mosses were only sampled in a relatively small number of EMEP grids.
Correlations frequently improved when only data for EMEP grids with at least three moss sampling sites
per grid were included. It was concluded that spatial patterns and temporal trends agree reasonably well
between lead and cadmium concentrations in mosses and modelled atmospheric deposition
Nitrogen concentrations in mosses indicate the spatial distribution of atmospheric nitrogen deposition in Europe
In 2005/6, nearly 3000 moss samples from (semi-)natural location across 16 European countries were
collected for nitrogen analysis. The lowest total nitrogen concentrations in mosses (<0.8%) were
observed in northern Finland and northern UK. The highest concentrations (>1.6%) were found in parts
of Belgium, France, Germany, Slovakia, Slovenia and Bulgaria. The asymptotic relationship between the
nitrogen concentrations in mosses and EMEP modelled nitrogen deposition (averaged per
50 km x 50 km grid) across Europe showed less scatter when there were at least five moss sampling sites
per grid. Factors potentially contributing to the scatter are discussed. In Switzerland, a strong (r2 = 0.91)
linear relationship was found between the total nitrogen concentration in mosses and measured sitespecific
bulk nitrogen deposition rates. The total nitrogen concentrations in mosses complement
deposition measurements, helping to identify areas in Europe at risk from high nitrogen deposition at
a high spatial resolution