Table 2 Soil NH +4 –N, NO −3 –N, SON (soluble organic N) in water extracts, SON/TSN (total soluble N) and SON/TN (total N) in adjacent natural secondary forest (SF) stands and larch plantation (LP) stands
Sampling time | Soil depth (cm) | Forest type | SON (μg g−1) | NH +4 –N (μg g−1) | NO −3 –N (μg g−1) | SON/TSN (%) | SON/TN (%) |
|---|---|---|---|---|---|---|---|
Jun 2010 | 0–5 | SF | 123.4 ± 22.4* | 6.3 ± 0.9 | 56.8 ± 7.8 | 64.9 ± 4.0 | 2.1 ± 0.4 |
LP | 71.1 ± 25.5 | 6.4 ± 0.9 | 39.7 ± 3.1 | 53.4 ± 11.3 | 1.8 ± 0.3 | ||
5–15 | SF | 19.4 ± 4.8 | 5.4 ± 0.3 | 20.4 ± 1.4* | 41.0 ± 6.8 | 0.5 ± 0.1 | |
LP | 7.4 ± 1.7 | 5.2 ± 0.8 | 10.9 ± 1.3 | 30.6 ± 4.2 | 0.4 ± 0.1 | ||
Oct 2010 | 0–5 | SF | 97.5 ± 9.4* | 1.9 ± 0.3 | 34.5 ± 8.1 | 73.0 ± 4.4 | 1.6 ± 0.2 |
LP | 61.1 ± 5.5 | 1.5 ± 0.3 | 25.3 ± 1.2 | 69.1 ± 2.5 | 1.5 ± 0.2 | ||
5–15 | SF | 11.7 ± 3.3 | 1.7 ± 0.2 | 11.9 ± 2.1* | 44.8 ± 7.5 | 0.3 ± 0.1 | |
LP | 4.8 ± 1.1 | 2.4 ± 0.4 | 6.4 ± 0.7 | 33.8 ± 5.2 | 0.2 ± 0.0 |