Fig. 5: Changes in carbon degradation gene abundance by soil layer during extended thaw incubation.

Normalized gene abundance (GPM; mean ± SD) of KEGG Tier IV metabolism pathways related to organic carbon degradation including (A) aromatic compound degradation, (B) benzoate degradation, (C) aminobenzoate degradation, (D) fluorobenzoate degradation, (E) pyruvate metabolism, and (F) methane metabolism derived from the active-layer, transition-zone, and permafrost metagenomes. Significant differences were determined between incubation time points within each soil layer microbiome (ANOVA; ***p < 0.001, **p < 0.01, *p < 0.05).