Table 1. Chemical composition and organic matter degradation parameters of the active layer (AL) and permafrost (PF) samples at five sites.
| Site | Layer | Sample size |
Hydrolysable lipids (mg g−1
OC) |
Lignin-derived phenols (mg g−1
OC) |
Degradation parameters |
|||||
|---|---|---|---|---|---|---|---|---|---|---|
| Cutin-derived compounds | Suberin-derived compounds | Vanillyls | Cinnamyls | Syringyls | ω-C16/∑C16 | (Ad/Al)v | (Ad/Al)s | |||
| YY | AL | 3 | 9.9 (9.5–10.4) | 31.8 (30.9–32.9) | 5.4 (4.7–6.2) | 9.3 (7.9–10.4) | 5.1 (4.3–5.8) | 0.3 (0.3–0.4) | 1.0 (0.9–1.1) | 1.0 (0.9–1.1) |
| PF | 3 | 4.0 (3.3–5.0) | 17.8 (15.7–20.6) | 0.8 (0.4–1.1) | 0.6 (0.3–0.8) | 0.8 (0.4–1.1) | 0.2 (0.2–0.3) | 0.7 (0.5–0.8) | 0.5 (0.4–0.6) | |
| CMH | AL | 3 | 10.3 (9.6–11.6) | 32.8 (30.9–35.1) | 3.8 (3.8–3.9) | 7.3 (5.6–8.3) | 4.3 (4.2–4.4) | 0.3 (0.3–0.3) | 0.6 (0.6–0.6) | 0.5 (0.5–0.5) |
| PF | 3 | 11.7 (10.2–12.9) | 45.0 (37.0–51.5) | 4.3 (4.0–4.5) | 9.1 (8.3–9.7) | 4.9 (4.5–5.1) | 0.2 (0.2–0.3) | 0.6 (0.5–0.7) | 0.5 (0.4–0.6) | |
| HSX | AL | 3 | 1.9 (1.3–2.4) | 6.4 (5.1–7.5) | 1.5 (1.3–1.8) | 1.0 (0.7–1.4) | 1.3 (1.2–1.5) | 0.3 (0.3–0.4) | 0.6 (0.5–0.7) | 0.5 (0.4–0.5) |
| PF | 3 | 0.8 (0.6–1.1) | 2.0 (1.4–2.7) | 0.9 (0.7–1.1) | 0.08 (0.06–0.1) | 0.4 (0.4–0.5) | 0.6 (0.4–0.8) | 0.4 (0.4–0.5) | 0.2 (0.1–0.2) | |
| WQ | AL | 3 | 9.6 (9.0–10.3) | 41.6 (40.3–43.3) | 4.9 (3.8–5.5) | 4.5 (2.8–5.5) | 3.8 (2.9–4.3) | 0.4 (0.4–0.4) | 1.0 (1.0–1.0) | 0.8 (0.8–0.8) |
| PF | 3 | 2.8 (2.2–3.5) | 20.7 (19.7–21.7) | 3.0 (2.9–3.1) | 1.3 (1.2–1.5) | 2.4 (2.3–2.4) | 0.6 (0.4–0.7) | 0.6 (0.6–0.6) | 0.5 (0.5–0.5) | |
| KLSK | AL | 3 | 7.2 (4.6–8.6) | 9.6 (8.1–10.7) | 6.5 (6.2–6.9) | 3.8 (3.0–4.2) | 5.9 (5.0–6.9) | 0.2 (0.2–0.3) | 0.5 (0.4–0.5) | 0.4 (0.4–0.5) |
| PF | 3 | 0.08 (0.05–0.10) | 7.9 (6.3–9.0) | 0.5 (0.4–0.6) | 0.07 (0.05–0.09) | 0.5 (0.4–0.5) | 0.9 (0.8–1.0) | 0.3 (0.3–0.3) | 0.2 (0.2–0.2) | |
The five sites are Youyun (YY) and Changmahe (CMH) in Maqin County, Huashixia (HSX) in Maduo County, Wenquan (WQ) in Xinghai County and Kunlunshankou (KLSK) in Geermu. ω-C16/∑C16 is the ratio of ω-hydroxy C16 acid to the total of ω-hydroxyalkanoic acid, n-alkane-α, ω-dioic acid, and mid-chain-substituted acids with 16 carbons; (Ad/Al)v is the ratio of vanillic acid to vanillin; (Ad/Al)s is the ratio of syringic acid to syringaldehyde. The interquartile range is presented in parentheses.