Fig. 1

The absolute abundances of various taxa, measured by 16S rRNA genes, after incubation with ¹³C-vanillin, determined by quantitative polymerase chain reaction (qPCR) and amplicon sequencing. a The numbers of total ¹²C- and ¹³C-labeled 16S rRNA gene copies in ¹³C-vanillin incubated samples (n = 3, biological replicates of warmed or control samples). b The circular maximum likelihood phylogenetic tree of the ¹³C-labeled active decomposer operational taxonomic units (OTUs). Relative abundance is the modified sequence number in heavy fractions (MSNH; see the “Methods” section for details) of the OTU (n = 3, biological replicates of warmed or control samples), c The number of ¹³C-labeled 16S rRNA gene copies of Burkholderia (n = 3, biological replicates of warmed or control samples). d The number of ¹³C-labeled 16S rRNA gene copies of α-Proteobacteria (n = 3, biological replicates of warmed or control samples). *0.01 < P ≤ 0.05 and **0.001 < P ≤ 0.01, as determined by a two-tailed t test. W, warmed soils; C, unwarmed/control soils. Data are shown as mean ± standard error