Does heavy metal deposition affect nutrient uptake by moss Pleurozium schreberi?

Heavy metals may influence chemical composition of plants, and thus shape elemental stoichiometry of plant communities. That is because some physiological processes aiming at neutralization of contaminant toxicity require increased acquisition of some nutrients (e.g. N, S, P or Ca). The aim of the study was to evaluate the heavy metal deposition in Poland using moss Pleurozium schreberi as a bioindicator, and check whether C/N, C/S, C/P and Ca/Mg ratios in mosses correspond with the accumulation of heavy metals. Heavy metal concentrations in mosses were highly variable across the study area – southern parts of the country, industrialized and densely populated, were the most contaminated. There were significant correlations between nutrient ratios and metal accumulation in mosses. Mosses seem to take 1) more N, P and S under Cu contamination, and 2) more Ca under Zn contamination. This increased acquisition of nutrients, mainly N and Ca, may be a response to higher toxicity of heavy metals. Further studies are required to exclude other causes for observed relationships.