Pore-scale Carbon Biogeochemical Processes in Soils and Their Impact to Climate Models
EMSL Project ID
46906
Abstract
Carbon (C) flux from terrestrial soils is an important component in Earth System Models (ESMs) to simulate global carbon cycling and its effect on climate changes. One major challenge to reliably estimate the carbon flux from soils is the role of soil microbial communities and biogeochemical processes in regulating soil organic carbon release and stability, especially under changing climate conditions. Significant uncertainties exist currently regarding which biogeochemical processes control C fate and transport in soils; and how these processes manifest at different scales under variable environmental conditions. The objectives of this proposed study are to: 1) identify biogeochemical mechanisms controlling the balance between C accrual and mineralization at the pore and molecular scales to inform predictions of C cycling during cellulose and lignin decomposition in a native soil; 2) develop process-based models to describe microbial metabolisms and their coupling with abiotic geochemical reactions and physical transport processes; and 3) investigate and establish scaling relationships for upscaling process-based models from the pore to continuum scales that can be incorporated in large scale systems. The scaled models will be evaluated against field measurements and will be compared with current biogeochemical models in ESMs. The research will provide fundamental insights into the biogeochemical mechanisms in regulating the soil carbon cycling and will provide process-based models that incorporate fundamental mechanisms of soil biogeochemical processes and effectively describe carbon flux to and from atmosphere that can be incorporated in the ESMs for more accurately predicting global carbon cycling and climate changes.The proposed research requires using EMSL facilities of: 1) SEM, TEM and NMR for structural identification of microbial metabolic products and their associations with aqueous and solid phases; 2) microfluidic facility to investigate the coupling of pore-scale processes (diffusion and biogeochemical reactions) that regulate the effective metabolic rates, C transformation, and species reactive transport, and to evaluate process-based models under controlled chemical and transport conditions; and 3) X-ray computerized tomography and NMR facilities for characterizing pore and grain structures in soil aggregates and columns for upscaling investigations.
Project Details
Project type
Exploratory Research
Start Date
2012-04-27
End Date
2013-04-28
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Yang X, C Liu, J Shang, Y Fang, and VL Bailey. 2014. "A Unified Multi-Scale Model for Pore-Scale Flow Simulations in Soils." Soil Science Society of America Journal 78(1):108-118. doi:10.2136/sssaj2013.05.0190