Gene-informed decomposition model predicts lower soil carbon loss due to persistent microbial adaptation to warming

Authors: GUO, XUE - Tsinghua University; GAO, QUN - Tsinghua University; YUAN, MENGTING - University Of California; WANG, GANGSHENG - University Of Oklahoma; ZHOU, XISHU - Central South University; FENG, JIAJIE - University Of Oklahoma; SHI, ZHOU - University Of Oklahoma; Hale, Lauren; WU, LINWEI - University Of Oklahoma; ZHOU, AIFEN - University Of Oklahoma; TIAN, RENMAO - University Of Oklahoma; LIU, FEIFEI - Northern Arizona University; WU, BO - University Of Oklahoma; CHEN, LIJUN - University Of Oklahoma; JUNG, CHANG GYO - Northern Arizona University; NIU, SHULI - Chinese Academy Of Agricultural Sciences; LI, DEJUN - Chinese Academy Of Agricultural Sciences; XU, XIA - University Of Oklahoma; JIANG, LIFEN - Northern Arizona University; ESCALAS, ARTHUR - University Of Oklahoma; WU, LIYOU - University Of Oklahoma; HE, ZHILI - University Of Oklahoma; VAN NOSTRAND, JOY - University Of Oklahoma; NING, DALIANG - University Of Oklahoma; LIU, XUEDUAN - Central South University; YANG, YUNFENG - Tsinghua University; SCHUUR, EDWARD - Northern Arizona University; KONSTANTINIDIS, KONSTANTINOST - Georgia Institute Of Technology; COLE, JAMES - Michigan State University; PENTON, C. RYAN - Arizona State University; LUO, YIQI - Northern State University; TIEDJE, JAMES - Arizona State University; ZHOU, JIZHONG - University Of Oklahoma

Submitted to: Nature Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2020
Publication Date: 8/29/2020
Citation: Guo, X., Gao, Q., Yuan, M., Wang, G., Zhou, X., Feng, J., Shi, Z., Hale, L.E., Wu, L., Zhou, A., Tian, R., Liu, F., Wu, B., Chen, L., Jung, C., Niu, S., Li, D., Xu, X., Jiang, L., Escalas, A., Wu, L., He, Z., Van Nostrand, J.D., Ning, D., Liu, X., Yang, Y., Schuur, E.A., Konstantinidis, K., Cole, J.R., Penton, C., Luo, Y., Tiedje, J.M., Zhou, J. 2020. Gene-informed decomposition model predicts lower soil carbon loss due to persistent microbial adaptation to warming. Nature Communications. 11. Article 4897. https://doi.org/10.1038/s41467-020-18706-z.
DOI: https://doi.org/10.1038/s41467-020-18706-z

Interpretive Summary: Microbial decomposition rates of soil organic carbon (SOC) and litter (i.e. heterotrophic respiration) have shown short-term increases in response to warmer temperatures, which if persistent on a grand scale, could greatly enhance greenhouse gas emissions and provide a net positive feedback to climate warming. This 7-year study revealed that thermal adaptation of heterotrophic respiration dampened this response and was attributed to shifts in microbial community structure and soil moisture losses. Incorporating relative abundances of microbial genes involved in SOC decomposition into Earth Systems Models improved accuracy and reduced uncertainty. This enhanced model should be assessed across wider biomes to evaluate its suitability to improve prediction accuracy of ecosystem feedbacks to climate warming.

Technical Abstract: Soil microbial respiration is an important source of uncertainty in projecting future climate and carbon (C) cycle feedbacks. However, its feedbacks to climate warming and underlying microbial mechanisms are still poorly understood. Here we show that the temperature sensitivity of soil microbial respiration (e.g., Q10) in a temperate grassland ecosystem persistently decreases by 12.0±3.7% across 7 years of warming. Also, the shifts of microbial communities play critical roles in regulating thermal adaptation of soil respiration. Incorporating microbial functional gene abundance data into a microbially-enabled ecosystem model significantly improves the modeling performance of soil microbial respiration by 5–19%, and reduces model parametric uncertainty by 55–71%. In addition, modeling analyses show that the microbial thermal adaptation can lead to considerably less heterotrophic respiration (11.6±7.5%), and hence less soil C loss. If such microbially mediated dampening effects occur generally across different spatial and temporal scales, the potential positive feedback of soil microbial respiration in response to climate warming may be less than previously predicted.