Fig. 1: Warming effects on soil variables and ecosystem C fluxes.

a Air and soil surface (7.5 cm) temperatures averaged from 2010 to 2016. b Soil moisture averaged from 2010 to 2016. c Ecosystem C fluxes, which were estimated on the basis of the C amount from CO₂ emissions averaged from 2010 to 2016. GPP, gross primary productivity; ER, ecosystem respiration; NEE, net ecosystem C exchange. Positive values indicate C sink, and negative values represent C source. d in situ soil respirations averaged from 2010 to 2016. R_a, autotrophic respiration; R_h, heterotrophic respiration; R_t, soil total respiration. e Decomposition rate of standard cellulose filter paper (mass loss) in the field determined in 2016. f Apparent and model-derived temperature sensitivity (Q₁₀) of heterotrophic respiration (R_h) averaged from 2010 to 2016. Apparent Q₁₀ is estimated by fitting the curve of R_h versus soil temperature based on the Q₁₀ method. Model-derived Q₁₀ is derived by calibrating the MEND model. Error bars represent standard errors of the means (n = 4 field plots examined over seven repeated measures from 2010 to 2016). The differences between warming and control were tested by the two-sided repeated measures ANOVA, indicated by *** when p < 0.01, ** when p < 0.05, * when p < 0.10. Source data are provided as a Source Data file.