Table 1. Soil physical and chemical characteristics (0–10 cm) in the tropical forest before the start of fertilization (conducted in September 2009).

Variables	aN	aP	aNP	Control
pH(H2O)	3.97 ± 0.05	3.95 ± 0.05	4.02 ± 0.09	3.99 ± 0.06
SOC (%)	2.90 ± 0.12	2.86 ± 0.27	2.90 ± 0.17	2.54 ± 0.16
Total N(g kg−1)	2.34 ± 0.21	2.66 ± 0.10	2.68 ± 0.19	2.71 ± 0.15
Total P(g kg−1)	0.38 ± 0.02	0.42 ± 0.02	0.43 ± 0.03	0.40 ± 0.03
Available-P(mg kg−1)	3.79 ± 0.42	4.06 ± 0.37	3.70 ± 0.60	4.10 ± 0.56
NO3−-N(mg kg−1)	2.72 ± 0.11	2.68 ± 0.31	2.35 ± 0.33	2.88 ± 0.35
NH4+-N(mg kg−1)	1.85 ± 0.13	1.81 ± 0.11	2.03 ± 0.17	2.12 ± 0.12

Note: Data are expressed as means ± SE (n = 5). aN: N addition treatment; aP: P addition treatment; aNP: N and P co-addition treatment.