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Pore- to Core-Scale Research to Inform Ecosystem-Scale Soil C Biogeochemistry


EMSL Project ID
49369

Abstract

The spatial separation of soil organic carbon (SOC), microbes, and extracellular activity is an important mechanism of SOC protection in soils that exists at the soil pore (micron-mm) scale. The microbial processes that control soil C metabolism, and emit greenhouse gases (GHG) to the atmosphere encompass a wide range of chemical compounds, reactions, and products. Potentially labile SOC may be isolated in soil pores, protected from these metabolic processes. We are particularly interested in the role played by hydrology in connecting soil pores and increasing the availability of physically isolated SOC. We hypothesize that the SOC protection mechanisms described in Earth system models (ESMs) are dependent on stable soil conditions, and changing hydrologic connectivity through increased water saturation or disturbance will increase SOC mineralization and GHG fluxes to the atmosphere. We focus our application for EMSL resources on chemical characterization of soil C fractions, physical characterization of pore-scale soil structure, and computational tools to integrate our data for the development of new models of soil C dynamics. The proposed research requests high-resolution chemical and physical characterization to study how soil C is stored in soil macropore networks, and rigorously link soil physical structure, water movement, and C chemistry to elucidate pore-scale mechanisms of soil C protection and metabolism. By coupling new knowledge of the physical and chemical protection of soil organic C with transport simulations, we will develop mechanistic models of soil C dynamics in soil that reflect pore-scale processes and that could therefore increase the predictive power of ecosystem models under changing conditions such as presented by a changing climate.

Project Details

Project type
Large-Scale EMSL Research
Start Date
2016-10-01
End Date
2018-09-30
Status
Closed

Team

Principal Investigator

Vanessa Bailey
Institution
Pacific Northwest National Laboratory

Team Members

Nicole Zavoshy
Institution
Pacific Northwest National Laboratory

Ashly Smith
Institution
Pacific Northwest National Laboratory

Zhifeng Yan
Institution
Tianjin University

Lisa Bramer
Institution
Pacific Northwest National Laboratory

William Nelson
Institution
Pacific Northwest National Laboratory

Aaron Phillips
Institution
Pacific Northwest National Laboratory

Benjamin Bond-Lamberty
Institution
Pacific Northwest National Laboratory

Darren Curtis
Institution
Pacific Northwest National Laboratory

Tamas Varga
Institution
Environmental Molecular Sciences Laboratory

Lee Ann McCue
Institution
Environmental Molecular Sciences Laboratory

Chongxuan Liu
Institution
Pacific Northwest National Laboratory

Related Publications

Bailey VL, AP Smith, MM Tfaily, SJ Fansler, and B Bond-Lamberty. 2017. "Differences in Soluble Organic Carbon Chemistry in Pore Waters Sampled from Different Pore Size Domains." Soil Biology and Biochemistry 107:133-143. doi:10.1016/j.soilbio.2016.11.025
Smith AP, B Bond-Lamberty, BW Benscoter, MM Tfaily, R Hinkle, C Liu, and VL Bailey. 2017. "Shifts in pore connectivity from precipitation versus groundwater rewetting increases soil carbon loss after drought." Nature Communications 8:Article No. 1335. doi:10.1038/s41467-017-01320-x
Yan Z., B. Bond-Lamberty, K. Todd-Brown, V.L. Bailey, and C. Liu. 2018. "A moisture function of soil heterotrophic respiration that incorporates microscale processes." Nature Communications 9. PNNL-SA-126718. doi:10.1038/s41467-018-04971-6
Yan Z, C Liu, Y Liu, and VL Bailey. 2017. "Multiscale Investigation on Biofilm Distribution and its Impact on Macroscopic Biogeochemical Reaction Rates." Water Resources Research 53(11):8698-8714. doi:10.1002/2017WR020570