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Page 10 of 21 Artyukhov et al. Carbon Footprints 2026, 5, 8
Figure 3. Soil basal respiration rate (µg C-CO 2 /g per hour) at different stages of incubation at 25 and 10 °C [mean ± SD (n = 3)]. Ya_Р1,
Ya_Р2 - soils of the southern hypoarctic tundras of the Yamal Peninsula. RI_С2-RI_С6 - soils of the mountain tundras of the Polar Urals.
Sal_C1, Gk_С7, Lb_С8 - soils of the forest-tundra of the Lower Ob region (Figure was created using Origin Pro 2024 software). SD:
Standard deviation.
The variability in PMC and basal respiration rates across the studied soils can be attributed to differences in
their physicochemical properties. As shown in Supplementary Tables 1-2, soils with the highest
mineralization potentials (e.g., the Oao horizon of Sal_C1 and the TE horizon of Gk_C7) are characterized
by a high SOC content and an acidic pH. The high SOC content provides a substantial substrate pool for
microbial metabolism . The acidic pH in these organic horizons may select for specialized microbial
[50]
communities adapted to such conditions . In contrast, mineral soils (e.g., Ya_P2) with lower SOC content,
[51]
finer texture, and potentially higher clay content likely stabilize organic matter through organo-mineral
associations, reducing the accessibility of substrates to microbes and resulting in lower PMC values and
mineralization intensities . Furthermore, the cryoturbated horizons showed distinct patterns, likely due to
[52]
the physical disruption of soil aggregates and the incorporation of fresh organic material into deeper, colder
layers, which aligns with the observed inverse temperature response in some samples .
[53]
