Trace Metals in High Elevation Forest Soils in Maine.

Trace metals in mountain ecosystems of the northeastern United States have received considerable attention in recent years as researchers examine the effects of atmospheric deposition on the health and function of forests.  High elevation soils are particularly sensitive to changes in atmospheric chemistry due to higher deposition of pollutants by wet and dry deposition, interception of wet cloud moisture, the formation of rime ice, and the tenacity of highly organic soils to retain trace metals.   The purpose of this research project was to assess concentrations and spatial and temporal changes in trace metal concentrations on six mountains in Maine.  This was done by collecting organic and surface mineral soil samples along an elevational gradient, and analyzing the samples for various trace metals, including As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V and Zn.  The data were analyzed for trends in metal concentration with elevation.  This data was also compared with data collected from the same sites 11 and 28 years ago to assess changes in metal concentration, and therefore atmospheric deposition, over time.  Preliminary results show that most metals are below EPA acceptable limits, and generally show a slight increase in trace metal concentration with increasing elevation.