Concurrent and lagged impacts of an anomalously warm year on autotrophic and heterotrophic components of soil respiration: a deconvolution analysis

Authors


Author for correspondence:
Xuhui Zhou
Tel: +1 405 325 8578
Email: zxuhui14@ou.edu

Summary

  • Partitioning soil respiration into autotrophic (RA) and heterotrophic (RH) components is critical for understanding their differential responses to climate warming.
  • Here, we used a deconvolution analysis to partition soil respiration in a pulse warming experiment. We first conducted a sensitivity analysis to determine which parameters can be identified by soil respiration data. A Markov chain Monte Carlo technique was then used to optimize those identifiable parameters in a terrestrial ecosystem model. Finally, the optimized parameters were employed to quantify RA and RH in a forward analysis.
  • Our results displayed that more than one-half of parameters were constrained by daily soil respiration data. The optimized model simulation showed that warming stimulated RH and had little effect on RA in the first 2 months, but decreased both RH and RA during the remainder of the treatment and post-treatment years. Clipping of above-ground biomass stimulated the warming effect on RH but not on RA. Overall, warming decreased RA and RH significantly, by 28.9% and 24.9%, respectively, during the treatment year and by 27.3% and 33.3%, respectively, during the post-treatment year, largely as a result of decreased canopy greenness and biomass.
  • Lagged effects of climate anomalies on soil respiration and its components are important in assessing terrestrial carbon cycle feedbacks to climate warming.

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