Research Highlights

Recent highlights of our science

Responses of two nonlinear microbial models to warming and increased carbon input

February 18, 2016

Objective

Improve understanding of significance of soil microbial processes in soil carbon responses to climate change.

Approach

  • Compared two nonlinear microbial models: one based on reverse Michaelis–Menton kinetics (model A) and the other on regular Michaelis–Menton kinetics (model B).
  • Used analytic approximations and numerical solutions to test CO2 efflux of both models.

Half-life (a, b) and period (c, d) in units of year for model A (a, c) and B (b, d). The purple region represents non-oscillatory region for model A in (c), and a period greater than 30 years for model B in (d).

Results/Impacts

  • We found oscillatory responses of C pools to small perturbations in initial pool sizes, which dampen faster in model A than in model B.
  • Soil warming always decreased C storage in model A, but in model B it predominantly decreased C storage in cool regions and increased C in warm regions.
  • Sensitivity of maximum CO2 efflux to increased C input increased with soil temperature in model A but decreased with increased soil temperature in model B.

Wang, Y. P., J. Jiang, B. Chen-Charpentier, F. B. Agusto, A. Hastings, Forrest M. Hoffman, M. Rasmussen, M. J. Smith, K. Todd-Brown, Y. Wang, X. Xu, and Y. Q. Luo. February 18, 2016. “Responses of Two Nonlinear Microbial Models to Warming and Increased Carbon Input.” Biogeosci., 13(4):887–902. doi:10.5194/bg-13-887-2016.