Reduced turnover rate of topsoil organic carbon in old-growth forests: a case study in subtropical China

Forest Ecosystems

Table 2 Soil properties of the upper 30-cm in different forests

Forest	PF	MF	BF
SOC (g·kg^− 1)	10.52 ± 0.39^b	18.82 ± 1.09^a	18.29 ± 0.61^a
ROC (g·kg^− 1)	3.29 ± 0.14^b	5.37 ± 0.41^a	4.83 ± 0.25^a
RI (%)	71.06 ± 0.45^b	72.62 ± 1.22^ab	75.10 ± 0.51^a
MBC (mg·kg^− 1)	142.40 ± 7.73^b	247.73 ± 27.40^a	236.94 ± 22.74^a
TN (g·kg^− 1)	0.83 ± 0.02^b	1.34 ± 0.06^a	1.48 ± 0.05^a
AN (mg·kg^− 1)	65.80 ± 3.83^c	132.07 ± 4.64^b	154.03 ± 5.55^a
C/N	11.87 ± 0.23^b	13.28 ± 0.23^a	12.05 ± 0.11^b
SWC (%)	15.86 ± 0.52^b	24.06 ± 0.97^a	25.10 ± 0.58^a
pH	4.05 ± 0.01^a	3.95 ± 0.03^b	3.91 ± 0.02^b
MWD (mm)	172.96 ± 19.02^b	321.30 ± 17.79^a	256.39 ± 22.52^a
BD (g·cm^− 3)	1.45 ± 0.06^a	1.23 ± 0.03^b	1.21 ± 0.04^b

Values are the mean ± standard error (n = 8; for the BD, n = 3). PF P. massoniana forest; MF coniferous and broadleaved mixed forest; BF monsoon evergreen broadleaved forest; SOC soil organic carbon; ROC readily oxidized organic carbon; RI recalcitrance index; MBC microbial biomass carbon; TN total nitrogen; AN available nitrogen; C/N the ratio of carbon to nitrogen; SWC soil water content; MWD mean weight diameter of soil aggregates; BD bulk density. Different lowercase letters indicate significant differences among different forests (p < 0.05)