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Temporal Dynamics of Microbial Traits Driving Divergent Patterns of Carbon Flow During Surface Litter Decomposition


EMSL Project ID
60007

Abstract

Microbially-driven surface litter decomposition is an important terrestrial ecosystem process creating soil organic carbon that serves as an essential carbon sink. Climate change projections show that litter decomposition rates will increase with rising temperatures with more carbon released as carbon dioxide (CO2) to the atmosphere and less carbon stored in soils. The proposed work builds on a foundation of research conducted through a DOE BER-funded SFA where we apply a "common garden" experimental approach to isolate microbial community composition as the single independent variable to identify microbial effect traits that create substantial variation in carbon cycling. Our overarching goal is to investigate the influence of microbial community composition on the temporal dynamics of carbon cycling during surface litter decomposition. We are expanding the impact of prior work be extending the timescale of analysis beyond 6 weeks to 1 year. We recently completed a one year grass litter decomposition experiment inoculated with soil microbial communities that exhibited contrasting patterns of carbon cycling, producing either low or high quantities of dissolved organic carbon (DOC). Through our proposed collaboration with JGI and EMSL, we will gain substantial insights into mechanisms that underpin the contrasting carbon cycling patterns by characterizing the temporal dynamics of 1) DOC composition using GC-MS and FTICR-MS metabolomics (EMSL), 2) total microbial community composition and activity using metatransciptomics (JGI), and 3) the spatial organization of major microbial taxa directly associated with decomposing grass litter using rRNA-FISH probes with confocal and super resolution fluorescent microscopy (EMSL). This research supports DOE BER's mission to understand how microorganisms influence their environment especially as it relates to terrestrial carbon cycling. The proposed work will enable us to decipher community features and physiological mechanisms that underpin persistent differences in carbon cycling, supporting future efforts to steer microbial communities for enhanced soil carbon storage.

Project Details

Project type
FICUS Research
Start Date
2021-10-01
End Date
N/A
Status
Active

Team

Principal Investigator

Marie Kroeger
Institution
Los Alamos National Laboratory

Co-Investigator(s)

John Dunbar
Institution
Los Alamos National Laboratory

Team Members

La Verne Gallegos-Graves
Institution
Los Alamos National Laboratory

Buck Hanson
Institution
Los Alamos National Laboratory

Michaeline Albright
Institution
Los Alamos National Laboratory

Patrick Chain
Institution
Los Alamos National Laboratory

Demosthenes Morales
Institution
Los Alamos National Laboratory

Sanna Sevanto
Institution
Los Alamos National Laboratory