119-7 The Intimate Life of Soil Carbon.



Monday, October 17, 2011: 4:00 PM
Henry Gonzalez Convention Center, Room 212B, Concourse Level

Peter Nico1, Marco Keiluweit2, Markus Kleber3, Jennifer Pett-Ridge4, Jeremy Bougoure4, David Myrold5 and Lydia Zeglin5, (1)Earth Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA
(2)Ag & Life Sciences Bldg, Rm 3017, Oregon State University, Corvallis, OR
(3)Dept. Crop and Soil Science, Oregon State University, Corvallis, OR
(4)Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA
(5)Oregon State University, Corvallis, OR
There is not doubt that differences in soil carbon dynamics can have macroscopic impacts on soil function and the global C cycle.  However, to understand the mechanistic details of C cycling these processes must be investigated at the micro-scale, the scale at which soil microbiota and soil mineral components are of comparable size and interact directly. It is this intimate life of soil carbon that we seek to understand using a combination of micro-analytical techniques and isotopic labeling.  Specifically, we have recently applied this approach to studying the micro-scale dynamics of 13C- and 15N-labeled chitin during a 3-week incubation into fungi-dominated microenvironments in O/A-horizons of old-growth forest soils adapted to rapid cycling of amino sugars. Our results show that microbial transformation and the subsequent association of amide N with Fe (oxyhydr)oxides occurs within weeks, emphasizing the potential importance of hydroxylated Fe oxide surfaces in microbially-mediated cycling of C and N in organic soil horizons.
See more from this Division: S02 Soil Chemistry
See more from this Session: Symposium--Mineral/Organic Interactions Across Time and Space: III Molecular Scale