TABLE 2.

Soil physical and chemical characteristics in the rhizosphere and bulk soil along the age gradient of Chinese fir plantation in subtropical China.

Location	Stand age (years)	pH	Moisture	TC (g kg–1)	TN (g kg–1)	TP (g kg–1)	NH4+–N (mg kg–1)	NO3––N (mg kg–1)	DOC (mg kg–1)	DON (mg kg–1)	AP (mg kg–1)
Rhizosphere	7	4.44 ± 0.05a	29.75 ± 0.55b	20.15 ± 0.27a	1.32 ± 0.003a	0.30 ± 0.01a	4.74 ± 0.31a	1.46 ± 0.29c	201.58 ± 13.44a	27.15 ± 2.33a	2.28 ± 0.45a
	15	4.29 ± 0.06ab	33.98 ± 1.06a	19.44 ± 0.92a	1.45 ± 0.07a	0.29 ± 0.01a	3.00 ± 0.19b	9.65 ± 1.15a	267.92 ± 24.05a	24.63 ± 4.59a	2.06 ± 0.06a
	24	4.19 ± 0.02c	36.01 ± 1.49a	21.62 ± 1.29a	1.40 ± 0.09a	0.31 ± 0.01a	4.71 ± 0.26a	6.70 ± 1.05ab	112.76 ± 13.87b	30.79 ± 1.46a	1.98 ± 0.19a
	34	4.20 ± 0.05bc	30.12 ± 0.74b	18.62 ± 1.49a	1.32 ± 0.14a	0.23 ± 0.02b	5.48 ± 0.23a	4.71 ± 0.43bc	70.78 ± 14.08b	24.94 ± 2.92a	1.74 ± 0.11a
Bulk	7	4.51 ± 0.02a	30.10 ± 0.68b	19.85 ± 0.54a	1.32 ± 0.04a	0.31 ± 0.02a	6.12 ± 0.47a	1.73 ± 0.39c	70.18 ± 12.74ab	32.26 ± 2.35a	2.69 ± 0.29a
	15	4.46 ± 0.07ab	34.87 ± 0.86a	18.10 ± 0.93a	1.36 ± 0.06a	0.31 ± 0.02a	3.29 ± 0.13b	9.60 ± 0.56a	85.34 ± 7.66ab	42.03 ± 2.69a	2.57 ± 0.45a
	24	4.28 ± 0.06c	34.55 ± 1.34a	19.23 ± 1.45a	1.28 ± 0.06a	0.32 ± 0.005a	5.70 ± 0.11a	7.22 ± 0.78ab	93.15 ± 10.29a	34.93 ± 5.80a	1.84 ± 0.11a
	34	4.41 ± 0.04bc	30.39 ± 0.29b	18.38 ± 1.48a	1.34 ± 0.11a	0.22 ± 0.01b	5.65 ± 0.41a	4.60 ± 0.16bc	54.12 ± 3.42b	28.54 ± 5.09a	1.79 ± 0.29a

Values are the means ± SE (n = 4). Different letters indicate significant differences among different stand ages in rhizosphere or bulk soil (p < 0.05).