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Register Number: 66279
Title: Soil Carbon Responses to Elevated Atmospheric CO2
Principal Investigator: Jastrow, Julie
Institution Address: Argonne, IL 60439-4843
Awarded Amount to Date and B&R Code :
FY 2013$409 kKP170201
FY 2012$430 kKP170201
FY 2011$384 kKP170201
FY 2010$350 kKP1702010
DOE Program Manager: Dan Stover
BER Division: Climate and Environmental Sciences
Research Area: Terrestrial Ecosystem Science
Abstract Submit Date: 09/30/2013
Project Term: 10/01/2009 - 09/30/2013
Abstract: Determining the potential carbon sink strength of terrestrial ecosystems requires better understanding and improved quantitation of processes involved in soil carbon storage and turnover. Some soil carbon is stabilized because of its biochemical recalcitrance. More labile carbon can be physically protected from decomposition by incorporation into soil aggregates or chemically protected by association with soil minerals. The processes involved in soil aggregate formation and turnover form the theoretical basis for isolating measurable carbon pools with functionally meaningful relationships to soil carbon dynamics. We use physicochemical fractionation techniques, stable carbon isotopes, long-term incubations, and compound-specific isotope analysis of biopolymer structures to evaluate the dynamics, sources, and stability of functional soil carbon pools and their responses to atmospheric CO2 enrichment. Studies carried out at free air CO2 enrichment (FACE) facilities use repeated measurements over time and isotopic tracers available at these sites to investigate fundamental questions regarding potential saturation of soil carbon protection mechanisms, the effects of changes in input availability and source, the stability and longevity of accrued carbon, and the influence of species-specific responses and edaphic properties on soil carbon dynamics in ecosystems exposed to atmospheric CO2 enrichment. An important goal of this research is to contribute data and process knowledge to help parameterize and validate soil organic matter simulation models, thereby allowing extrapolation of results to the broader scales needed to predict the role of terrestrial ecosystems in continental and global carbon cycles.