Table 1 Pollution and soil characteristics along longitudinal and depth gradients.
Sampling date | Distance from oil seep (m) | Depth (cm) | Extractable organic matter, EOM (mg g−1) | Hydrocarbon index, HI (mg g−1) | Carbon preference index, CPI | TOC (mg g−1) | N (mg g−1) | C/N | pH | |
|---|---|---|---|---|---|---|---|---|---|---|
GUN0 | May 2016 | 0 | 0–5 | 119.2 ± 21.9 a | 73.7 ± 26.3 a | 1.0 | 142 | 3.5 | 40.3 | 6.88 |
GUN2 | 2 | 0–5 | 11.7 ± 0.9 b | 3.2 ± 0.2 b | 6.2 | 80 | 4.8 | 16.6 | 7.00 | |
GUN4 | 4 | 0–5 | 3.0 ± 0.2 b | 0.9 ± 0.1 b | 10.0 | 61 | 4.1 | 14.8 | 6.05 | |
GUN10 | 10 | 0–5 | 3.2 ± 0.8 b | 1.0 ± 0.3 b | 10.8 | 42 | 2.8 | 15.1 | 5.76 | |
GUN15 | 15 | 0–5 | 1.8 ± 0.2 b | 0.4 ± 0.1 b | 9.7 | 43 | 3.0 | 14.4 | 5.51 | |
ETV0 | May 2016 | 0 | 0–5 | 118.6 ± 44.6 a | 35.3 ± 13.3 a | 1.0 | 154 | 3.5 | 43.8 | 6.09 |
ETV2 | 2 | 0–5 | 48.7 ± 20.2 ab | 11.2 ± 5.6 ab | 2.3 | 103 | 3.8 | 27.0 | 6.14 | |
ETV4 | 4 | 0–5 | 20.9 ± 14.4 ab | 3.7 ± 2.5 b | 3.1 | 57 | 2.4 | 23.7 | 6.03 | |
ETV10 | 10 | 0–5 | 6.3 ± 4.4 b | 0.5 ± 0.2 b | 6.4 | 23 | 1.4 | 16.9 | 5.77 | |
ETV15 | 15 | 0–5 | 14.8 ± 9.4 ab | 0.5 ± 0.1 b | 6.2 | 27 | 1.7 | 15.7 | 5.19 | |
ETV0_P0-2 | May 2017 | 0 | 0–2 | 108.9 ± 9.0 ab | 42.3 ± 1.9 a | na | 141 ± 2 a | 3.1 ± 0.2 a | 46.2 ± 2.8 ab | na |
ETV0_P2-5 | 0 | 2–5 | 113.0 ± 18.2 a | 24.9 ± 3.1 b | na | 142 ± 19 a | 3.8 ± 0.5 a | 37.6 ± 1.1 ab | na | |
ETV0_P5-15 | 0 | 5–15 | 73.0 ± 27.3 bc | 11.6 ± 5.1 c | na | 42 ± 9 b | 1.7 ± 0.4 ab | 25.4 ± 0.8 b | na | |
ETV0_P15-30 | 0 | 15–30 | 31.7 ± 19.5 c | 5.6 ± 3.7 c | na | 13 ± 3 b | 0.4 ± 0.2 b | 51.5 ± 19.6 a | na |
