Soil enzyme activities as potential indicators of soluble organic nitrogen pools in forest ecosystems of Northeast China

Table 1 The selected soil and microbial properties in adjacent natural secondary forest (SF) stands and larch plantation (LP) stands

Sampling time	Soil depth (cm)	Forest type	Soil organic C (g kg⁻¹)	Total N (g kg⁻¹)	C/N	MBC (mg kg⁻¹)	MBN (mg kg⁻¹)	Soil pH
Jun 2010	0–5	SF	65.8 ± 2.9*	6.0 ± 0.3*	11.0 ± 0.3	958.6 ± 71.3*	153.8 ± 16.4*	6.3 ± 0.2*
	0–5	LP	43.7 ± 1.6	3.9 ± 0.2	11.2 ± 0.2	562.7 ± 25.3	90.1 ± 5.2	5.4 ± 0.1
	5–15	SF	36.4 ± 3.0*	3.6 ± 0.4*	10.2 ± 0.2	548.0 ± 55.5*	95.4 ± 10.0*	5.8 ± 0.2
	5–15	LP	20.9 ± 2.1	2.1 ± 0.3	10.0 ± 0.2	353.0 ± 20.9	46.0 ± 6.9	5.3 ± 0.1
Oct 2010	0–5	SF	66.1 ± 2.3*	6.0 ± 0.3*	11.0 ± 0.4	737.9 ± 58.1*	116.4 ± 10.3*	ND
	0–5	LP	44.4 ± 2.2	4.1 ± 0.3	11.0 ± 0.3	410.6 ± 12.3	67.7 ± 4.8	ND
	5–15	SF	36.9 ± 2.7*	3.7 ± 0.3*	10.0 ± 0.2	392.6 ± 32.6*	66.4 ± 5.3*	ND
	5–15	LP	21.4 ± 2.6	2.2 ± 0.3	10.1 ± 0.3	243.0 ± 13.5	35.1 ± 4.6	ND

MBC microbial biomass C; MBN microbial biomass N. Values shown in tables are means ± standard errors (n = 4). ND denotes not determined
*P < 0.05 levels, significant differences between the secondary forest and larch plantation of the corresponding depth

ISSN: 1297-966X