Sulfur species behavior in soil organic matter during decomposition
Schroth, Andrew W.
Bostick, Benjamin C.
Kaste, James M.
Mitchell, Myron J.
Friedland, Andrew J.
MetadataShow full item record
Soil organic matter (SOM) is a primary reservoir of terrestrial sulfur (S), but its role in the global S cycle remains poorly understood. We examine S speciation by X-ray absorption near-edge structure (XANES) spectroscopy to describe S species behavior during SOM decomposition. Sulfur species in SOM were best represented by organic sulfide, sulfoxide, sulfonate, and sulfate. The highest fraction of S in litter was organic sulfide, but as decomposition progressed, relative fractions of sulfonate and sulfate generally increased. Over 6-month laboratory incubations, organic sulfide was most reactive, suggesting that a fraction of this species was associated with a highly labile pool of SOM. During humification, relative concentrations of sulfoxide consistently decreased, demonstrating the importance of sulfoxide as a reactive S phase in soil. Sulfonate fractional abundance increased during humification irrespective of litter type, illustrating its relative stability in soils. The proportion of S species did not differ systematically by litter type, but organic sulfide became less abundant in conifer SOM during decomposition, while sulfate fractional abundance increased. Conversely, deciduous SOM exhibited lesser or nonexistent shifts in organic sulfide and sulfate fractions during decomposition, possibly suggesting that S reactivity in deciduous litter is coupled to rapid C mineralization and independent of S speciation. All trends were consistent in soils across study sites. We conclude that S reactivity is related to speciation in SOM, particularly in conifer forests, and S species fractions in SOM change during decomposition. Our data highlight the importance of intermediate valence species (sulfoxide and sulfonate) in the pedochemical cycling of organic bound S.
Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 112 (2007): G04011, doi:10.1029/2007JG000538.
Showing items related by title, author, creator and subject.
Marine sedimentary organic matter : delineation of marine and terrestrial sources through radiocarbon dating; and the role of organic sulfur in early petroleum generation Benitez-Nelson, Bryan C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1996-05)This thesis details two years of research conducted with the guidance and support of three advisors: Dr. J. K. Whelan, Dr. J. S. Seewald and Dr. T. I. Eglinton. Each of the three chapters represents a different, ...
Impact of circulation on export production, dissolved organic matter, and dissolved oxygen in the ocean : results from Phase II of the Ocean Carbon-cycle Model Intercomparison Project (OCMIP-2) Najjar, Raymond G.; Jin, X.; Louanchi, F.; Aumont, Olivier; Caldeira, Ken; Doney, Scott C.; Dutay, J.-C.; Follows, Michael J.; Gruber, Nicolas; Joos, Fortunat; Lindsay, Keith; Maier-Reimer, Ernst; Matear, Richard J.; Matsumoto, K.; Monfray, Patrick; Mouchet, Anne; Orr, James C.; Plattner, Gian-Kasper; Sarmiento, Jorge L.; Schlitzer, Reiner; Slater, Richard D.; Weirig, Marie-France; Yamanaka, Yasuhiro; Yool, Andrew (American Geophysical Union, 2007-08-08)Results are presented of export production, dissolved organic matter (DOM) and dissolved oxygen simulated by 12 global ocean models participating in the second phase of the Ocean Carbon-cycle Model Intercomparison Project. ...
Characterization of dissolved organic matter in Lake Superior and its watershed using ultrahigh resolution mass spectrometry Minor, Elizabeth C.; Steinbring, Carla J.; Longnecker, Krista; Kujawinski, Elizabeth B. (2011-11-14)With the advent of ultrahigh resolution mass spectrometry, recent studies have begun to resolve molecular-level relationships between terrestrial and aquatic dissolved organic matter (DOM) in rivers, estuaries, ...