Moss-specific accumulation of atmospheric element deposition?

This article presents statistical analyses of elements concentrations in mosses which were collected in 1990, 1995, 2000, 2005 and 2015 throughout Germany at 592, 1026, 1028, 726 and 400 sites, respectively, and chemically analysed according to harmonised methods throughout Europe. The evaluations intended to examine whether the element concentrations are specific to moss species and whether conversion factors should be used. Such observations and recommendations have so far been limited to spatially confined areas with relatively few moss samples and were derived from studies without methodological harmonisation. The data collected 1990-2015 across Germany was analysed by percentile statistics. The samplings from 2015 were additionally evaluated by bivariate correlation analyses and multivariate techniques to identify and rank the statistical relevance of site-specific and regional characteristics for the concentrations of 12 heavy metals and nitrogen in mosses. The strongest predictor for Cd, Cu, Ni, Pb, Zn and N concentrations was the sampled moss species. In 2015, the atmospheric deposition showed a lower predictive power compared to earlier campaigns. However, the present study does not refute the hypothesis of moss species-specific element concentrations which are in the range of local and metrological variance. It is therefore advisable to continue dispensing with conversion factors.