Biotic responses buffer warming-induced soil organic carbon loss in Arctic tundra

• Published in: Global Change Biology
• Main Authors: Liang, Junyi, Xia, Jiangyang East China Normal Univ. , Shanghai . Tiantong National Station of Forest Ecosystem, Research Center for Global Change and Ecological Forecasting, School of Ecological and Environmental Sciences; Inst. of Eco-Chongming , Shanghai, Shi, Zheng Univ. of Oklahoma, Norman, OK . Dept. of Microbiology and Plant Biology, Jiang, Lifen Univ. of Oklahoma, Norman, OK . Dept. of Microbiology and Plant Biology; Northern Arizona Univ., Flagstaff, AZ . Center for Ecosystem Science and Society and Dept. of Biological Sciences, Ma, Shuang Univ. of Oklahoma, Norman, OK . Dept. of Microbiology and Plant Biology; Northern Arizona Univ., Flagstaff, AZ . Center for Ecosystem Science and Society and Dept. of Biological Sciences, Lu, Xingjie Univ. of Oklahoma, Norman, OK . Dept. of Microbiology and Plant Biology; Northern Arizona Univ., Flagstaff, AZ . Center for Ecosystem Science and Society and Dept. of Biological Sciences, Mauritz, Marguerite Northern Arizona Univ., Flagstaff, AZ . Center for Ecosystem Science and Society and Dept. of Biological Sciences, Natali, Susan M. Woods Hole Research Center, Falmouth, MA, Pegoraro, Elaine Northern Arizona Univ., Flagstaff, AZ . Center for Ecosystem Science and Society and Dept. of Biological Sciences, Penton, Christopher Ryan Arizona State Univ., Mesa, AZ . College of Integrative Sciences and Arts; Arizona State Univ., Tempe, AZ . Center for Fundamental and Applied Microbiomics, Biodesign Inst., Plaza, César Northern Arizona Univ., Flagstaff, AZ . Center for Ecosystem Science and Society and Dept. of Biological Sciences; Univ. Rey Juan Carlos, Mostoles . Dept. de Biologıa y Geologıa, Fısica y Quımica Inorganica, Escuela Superior de Ciencias Experimentales y Tecnologıa,; Consejo Superior de Investigaciones Cientificas , Madrid . Inst. de Ciencias Agrarias, Salmon, Verity G. Oak Ridge National Lab. , Oak Ridge, TN . Environmental Sciences Division and Climate Change Science Inst., Celis, Gerardo Northern Arizona Univ., Flagstaff, AZ . Center for Ecosystem Science and Society and Dept. of Biological Sciences, Cole, James R. Michigan State Univ., East Lansing, MI . Dept. of Plant, Soil and Microbial Sciences, Center for Microbial Ecology, Konstantinidis, Konstantinos T. Georgia Inst. of Technology, Atlanta, GA . School of Civil and Environmental Engineering and School of Biology, Tiedje, James M. Michigan State Univ., East Lansing, MI . Dept. of Plant, Soil and Microbial Sciences, Center for Microbial Ecology, Zhou, Jizhong Univ. of Oklahoma, Norman, OK . Dept. of Microbiology and Plant Biology; Univ. of Oklahoma, Norman, OK . Inst. for Environmental Genomics; Tsinghua Univ., Beijing . State Key Joint Lab. of Environment Simulation and Pollution Control, School of Environment; Lawrence Berkeley National Lab. , Berkeley, CA . Earth and Environmental Sciences, Schuur, Edward A. G. Northern Arizona Univ., Flagstaff, AZ . Center for Ecosystem Science and Society and Dept. of Biological Sciences, Luo, Yiqi Univ. of Oklahoma, Norman, OK . Dept. of Microbiology and Plant Biology; Northern Arizona Univ., Flagstaff, AZ . Center for Ecosystem Science and Society and Dept. of Biological Sciences; Tsinghua Univ., Beijing . Dept. of Earth System Science
• Language: unknown
• Published: 2023
• Subjects: 54 ENVIRONMENTAL SCIENCES; Arctic; permafrost; Tundra; Alaska
• Online Access: http://www.osti.gov/servlets/purl/1468031; https://www.osti.gov/biblio/1468031; https://doi.org/10.1111/gcb.14325

Climate warming can result in both abiotic (e.g., permafrost thaw) and biotic (e.g., microbial functional genes) changes in Arctic tundra. Recent research has incorporated dynamic permafrost thaw in Earth system models (ESMs) and indicates that Arctic tundra could be a significant future carbon (C) source due to the enhanced decomposition of thawed deep soil C. However, warming-induced biotic changes may influence biologically related parameters and the consequent projections in ESMs. How model parameters associated with biotic responses will change under warming and to what extent these changes affect projected C budgets have not been carefully examined. Here in this study, we synthesized six data sets over 5 years from a soil warming experiment at the Eight Mile Lake, Alaska, into the Terrestrial ECOsystem (TECO) model with a probabilistic inversion approach. The TECO model used multiple soil layers to track dynamics of thawed soil under different treatments. Our results show that warming increased light use efficiency of vegetation photosynthesis but decreased baseline (i.e., environment-corrected) turnover rates of SOC in both the fast and slow pools in comparison with those under control. Moreover, the parameter changes generally amplified over time, suggesting processes of gradual physiological acclimation and functional gene shifts of both plants and microbes. The TECO model predicted that field warming from 2009 to 2013 resulted in cumulative C losses of 224 or 87 g/m 2 , respectively, without or with changes in those parameters. Thus, warming-induced parameter changes reduced predicted soil C loss by 61%. Our study suggests that it is critical to incorporate biotic changes in ESMs to improve the model performance in predicting C dynamics in permafrost regions.