Lead Sequestration and Species Redistribution During Soil Organic Matter Decomposition

@article{citeulike:2883529, abstract = {Abstract: The turnover of soil organic matter (SOM) maintains a dynamic chemical environment in the forest floor that can impact metal speciation on relatively short timescales. Here we measure the speciation of Pb in controlled and natural organic (O) soil horizons to quantify changes in metal partitioning during SOM decomposition in different forest litters. We provide a link between the sequestration of pollutant Pb in O-horizons, estimated by forest floor Pb inventories, and speciation using synchrotron-based X-ray fluorescence and X-ray absorption spectroscopy. When Pb was introduced to fresh forest Oi samples, it adsorbed primarily to SOM surfaces, but as decomposition progressed over two years in controlled experiments, up to 60\% of the Pb was redistributed to pedogenic birnessite and ferrihydrite surfaces. In addition, a significant fraction of pollutant Pb in natural soil profiles was associated with similar mineral phases (\~{}2035\%) and SOM (\~{}6580\%). Conifer forests have at least 2-fold higher Pb burdens in the forest floor relative to deciduous forests due to more efficient atmospheric scavenging and slower organic matter turnover. We demonstrate that pedogenic minerals play an important role in surface soil Pb sequestration, particularly in deciduous forests, and should be considered in any assessment of pollutant Pb mobility.}, address = {Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire 03755, and Environmental Studies Program, Dartmouth College, Hanover, New Hampshire 03755, and USGS, Woods Hole Science Center, 384 Woods Hole Road, Woods Hole, MA, 02543}, author = {Schroth, Andrew W. and Bostick, Benjamin C. and Kaste, James M. and Friedland, Andrew J. }, citeulike-article-id = {2883529}, doi = {http://dx.doi.org/10.1021/es703002b}, journal = {Environ. Sci. Technol.}, month = {May}, number = {10}, pages = {3627--3633}, posted-at = {2008-06-11 19:21:10}, priority = {2}, title = {Lead Sequestration and Species Redistribution During Soil Organic Matter Decomposition}, url = {http://dx.doi.org/10.1021/es703002b}, volume = {42}, year = {2008} }

TY - JOUR ID - citeulike:2883529 L3 - citeulike-article-id:2883529 TI - Lead Sequestration and Species Redistribution During Soil Organic Matter Decomposition JF - Environ. Sci. Technol. VL - 42 IS - 10 SP - 3627 EP - 3633 AD - Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire 03755, and Environmental Studies Program, Dartmouth College, Hanover, New Hampshire 03755, and USGS, Woods Hole Science Center, 384 Woods Hole Road, Woods Hole, MA, 02543 N2 - Abstract: The turnover of soil organic matter (SOM) maintains a dynamic chemical environment in the forest floor that can impact metal speciation on relatively short timescales. Here we measure the speciation of Pb in controlled and natural organic (O) soil horizons to quantify changes in metal partitioning during SOM decomposition in different forest litters. We provide a link between the sequestration of pollutant Pb in O-horizons, estimated by forest floor Pb inventories, and speciation using synchrotron-based X-ray fluorescence and X-ray absorption spectroscopy. When Pb was introduced to fresh forest Oi samples, it adsorbed primarily to SOM surfaces, but as decomposition progressed over two years in controlled experiments, up to 60% of the Pb was redistributed to pedogenic birnessite and ferrihydrite surfaces. In addition, a significant fraction of pollutant Pb in natural soil profiles was associated with similar mineral phases (~2035%) and SOM (~6580%). Conifer forests have at least 2-fold higher Pb burdens in the forest floor relative to deciduous forests due to more efficient atmospheric scavenging and slower organic matter turnover. We demonstrate that pedogenic minerals play an important role in surface soil Pb sequestration, particularly in deciduous forests, and should be considered in any assessment of pollutant Pb mobility. AU - Schroth, Andrew AU - Bostick, Benjamin AU - Kaste, James AU - Friedland, Andrew PY - 2008/05/15/ UR - http://dx.doi.org/10.1021/es703002b ER -