Element concentrations in the forest moss Hylocomium splendens: variation associated with altitude, net primary production and soil chemistry.

Net primary production (NPP) of the forest moss Hylocomium splendens increased significantly along an elevational gradient in the southern Alps of Italy. Extracellularly bound metals (Al, Ca, Co, Cr, Fe, Ni, Mo, Ni, Pb) showed declining concentrations in moss tissue with increasing altitude, presumably because the amount of exchange sites on the cell wall increases less than total biomass. Concentrations of intracellular elements did not vary (Cd, Cu, Mg, Na, Zn), or even increased (K) with altitude. The observed patterns were always independent of precipitation amount and soil concentrations of exchangeable elements. A higher soil nutrient status only enhanced K uptake by the moss. We concluded that variations in moss NPP, associated with elevational gradients, may significantly affect estimates of atmospheric deposition based on moss analysis in mountainous regions.