This study compares the vertical distribution of elements in an A_p soil horizon from 1990 and 1998 in a pitch pine forest in North Haven, CT.  The soil was divided into eight depth classes and each was analyzed for ten elements by both amount and concentration.  Generally, the concentrations in forest floors decreased while concentrations within mineral soil increased.
        Within the forest floor, the amounts and concentrations decreased for: lead, zinc, copper, potassium, and phosphorous.  A greater forest floor mass caused the concentrations of aluminum and iron to decrease even though amounts increased.  Magnesium, calcium, and manganese increased in both amount and concentration.
        Within the mineral soil, two general patterns of distributions were seen.  Lead and copper decreased smoothly with depth in both 1990 and, at higher levels, in 1998.  In the intervening eight years, lead increased in certain intermediate depths, while copper increased throughout the entire profile, with larger increases at shallower depths.  This pattern of distribution probably occurs because lead and copper pollution at this site is so high that the majority of the element is not affected by the system's natural soil organization processes and instead decrease smoothly with depth.  Decreasing forest floor levels will hopefully eventually cause a corresponding decrease in the mineral soil.
        The other dominant pattern of distribution reflects an early stage of chemical podzolization, the segregation of soil horizons that creates the visible soil horizons common to New England.  Low amounts and concentrations are present in the upper 2 cm, suggesting the incipient formation of an E horizon.  The amounts of the elements increase to a depth of 6-8 cm, where a "bulge" of elements was seen.  At this depth, elements are accumulating to form a B_hs horizon.  Beneath this "bulge", most elements decreased with depth.  This pattern of distribution is true, with slight variations, of zinc, magnesium, manganese, potassium, aluminum, phosphorous, and iron.  Between 1990 and 1998, the amounts of these elements increased between 0-8 cm, but below the zone of accumulation, the amounts were equivalent.
         One focus of this study was to verify the downward movement of lead reported by other researchers (Friedland et. al., 1992; Herrick and Friedland, 1990; Craig, 1991).  We found that lead increased between 4-16 cm.  The estimated rate of lead movement in this acidic sandy soil, (calculated using the median of the thickness divisions) is 12 mm/year.  This directional migration rate is a measure of the time required for lead to move downward through the mineral soil.  This rate falls within the 3-19 mm/yr range found by Miller and Friedland (1994).  Assuming this rate stays constant in the pure sand parent material, it will take several hundred years for the lead to migrate to the water table.
        The decrease in forest floor concentrations provides hope that measures such as the Clean Air Act of 1972 have reduced emissions of metals.  Hopefully, continued attempts to reduce pollution will further reduce amounts in the forest floor, and these reductions will spread downward into the mineral soil.
          Analyzing the changes in amounts and concentrations of various depth classes provide a window into the unseen chemical processes occurring in the soil, especially podzolization.  By studying this process on a formerly plowed site, pedogenesis processes are able to be clearly seen, and the movement of other minerals is not as affected by diverse soil layers as it would be in a site with fully developed soil horizons.  This study illustrates the usefulness of temporal comparisons to discover patterns that suggest the underlying processes.  We hope that this study serves as an intermediate data point.  Continued monitoring of this site will allow for the long-term patterns of soil development and pollution movement to be seen more clearly.