Stoichiometrically coupled carbon and nitrogen cycling in the MIcrobial-MIneral Carbon Stabilization model version 1.0 (MIMICS-CN v1.0)

Details

• Journal Title:
  Geoscientific Model Development
• Personal Author:
  Kyker-Snowman, Emily ; Wieder, William R. ; Frey, Serita D. ; Grandy, A. Stuart
• NOAA Program & Office:
  NESDIS (National Environmental Satellite, Data, and Information Service) ; NCEI (National Centers for Environmental Information)
• Description:
  Explicit consideration of microbial physiology in soil biogeochemical models that represent coupled carbon–nitrogen dynamics presents opportunities to deepen understanding of ecosystem responses to environmental change. The MIcrobial-MIneral Carbon Stabilization (MIMICS) model explicitly represents microbial physiology and physicochemical stabilization of soil carbon (C) on regional and global scales. Here we present a new version of MIMICS with coupled C and nitrogen (N) cycling through litter, microbial, and soil organic matter (SOM) pools. The model was parameterized and validated against C and N data from the Long-Term Inter-site Decomposition Experiment Team (LIDET; six litter types, 10 years of observations, and 13 sites across North America). The model simulates C and N losses from litterbags in the LIDET study with reasonable accuracy (C: R2=0.63; N: R2=0.29), which is comparable with simulations from the DAYCENT model that implicitly represents microbial activity (C: R2=0.67; N: R2=0.30). Subsequently, we evaluated equilibrium values of stocks (total soil C and N, microbial biomass C and N, inorganic N) and microbial process rates (soil heterotrophic respiration, N mineralization) simulated by MIMICS-CN across the 13 simulated LIDET sites against published observations from other continent-wide datasets. We found that MIMICS-CN produces equilibrium values in line with measured values, showing that the model generates plausible estimates of ecosystem soil biogeochemical dynamics across continental-scale gradients. MIMICS-CN provides a platform for coupling C and N projections in a microbially explicit model, but experiments still need to identify the physiological and stoichiometric characteristics of soil microbes, especially under environmental change scenarios.
• Source:
  Geoscientific Model Development, 13(9), 4413-4434
• DOI:
  https://doi.org/10.5194/gmd-13-4413-2020
• ISSN:
  1991-9603
• Format:
  pdf
• Publisher:
  Copernicus GmbH
• Document Type:
  Journal Article
• License:
  https://creativecommons.org/licenses/by/4.0/
• Rights Information:
  CC BY
• Compliance:
  Library
• Main Document Checksum:
  urn:sha-512:f6eab179cda520f5ee0ece1fc1a8956598cf3ada2c2f3a64b548fcc96996455657883f0c93b63ab970a970cb8d012db391c88167ed938a189e7641b8e27f51b0
• Download URL:
  https://repository.library.noaa.gov/view/noaa/69793/noaa_69793_DS1.pdf
• File Type:
  [PDF - 3.08 MB ]