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Table 1 Soil N concentrations, δ15N values, C concentrations, δ13C in the Oa+e horizon and mineral horizon (0–20 cm) in four treatments

From: Effects of long-term nitrogen addition on the δ15N and δ13C of Larix gmelinii and soil in a boreal forest

Soil horizons Soil properties N addition treatments
CK LN MN HN
Oa+e horizons Total N (g kg−1) 1.65 ± 0.12b 1.77 ± 0.07b 1.85 ± 0.32a 1.96 ± 0.10a
δ15N (‰) − 1.47 ± 0.52b − 0.89 ± 0.19ab − 0.25 ± 0.58a − 0.48 ± 0.10a
Total C (g kg−1) 39.92 ± 4.21a 42.64 ± 1.90a 39.12 ± 6.21a 42.60 ± 1.12a
δ13C (‰) − 29.13 ± 0.11a − 28.96 ± 0.28a − 29.16 ± 0.28a − 29.15 ± 0.20a
NH4+–N (mg kg−1) 45.54 ± 12.39b 85.12 ± 15.99ab 186.28 ± 85.75a 166.32 ± 85.43a
NO3–N (mg kg−1) 9.88 ± 0.90b 9.66 ± 0.54b 17.52 ± 3.21a 14.11 ± 3.46ab
Mineral horizons Total N (g kg−1) 0.19 ± 0.03b 0.21 ± 0.03b 0.29 ± 0.04a 0.26 ± 0.04ab
 0–10 cm δ15N (‰) 5.54 ± 0.93a 4.77 ± 0.69a 5.03 ± 0.70a 4.47 ± 0.55a
Total C (g kg−1) 5.15 ± 1.29a 4.07 ± 1.61a 4.02 ± 1.13a 5.13 ± 2.67a
δ13C (‰) − 26.54 ± 0.30a − 26.75 ± 0.25a − 26.28 ± 0.19a − 26.70 ± 0.17a
NH4+–N (mg kg−1) 6.14 ± 0.72b 8.01 ± 3.01b 13.47 ± 3.47a 12.64 ± 2.19a
NO3–N (mg kg−1) 1.70 ± 0.21c 2.74 ± 0.16bc 3.14 ± 0.42b 5.02 ± 2.06a
 10–20 cm Total N (g kg−1) 0.08 ± 0.01a 0.08 ± 0.03a 0.08 ± 0.02a 0.09 ± 0.04a
δ15N (‰) 5.93 ± 0.36a 5.90 ± 0.87a 5.87 ± 0.72a 5.13 ± 0.52a
Total C (g kg−1) 1.41 ± 0.71a 1.26 ± 0.07a 1.18 ± 0.48a 1.18 ± 0.44a
δ13C (‰) − 26.00 ± 0.44a − 25.98 ± 0.03a − 26.11 ± 0.38a − 26.12 ± 0.25a
NH4+–N (mg kg−1) 3.52 ± 1.59a 4.05 ± 1.46a 4.78 ± 0.73a 4.54 ± 1.52a
NO3–N (mg kg−1) 2.23 ± 0.75a 2.47 ± 0.41a 2.78 ± 0.52a 2.37 ± 0.45a
  1. Alphabet indicates the significant difference among different N addition treatments. Tukey’s HSD test (p < 0.05)