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

Forest Ecosystems

Table 1 Concentrations and isotope abundance (δ¹³C) of soil organic carbon (SOC) in the upper 30 cm depth of different forests

Forest	Depth (cm)	SOC (g·kg^− 1)	δ¹³C (‰)
PF	0–10	18.56 ± 0.84^Ba	−25.10 ± 0.20^Ac
	10–20	7.63 ± 0.54^Bb	−22.46 ± 0.35^Ab
	20–30	5.37 ± 0.39^Cc	− 21.38 ± 0.28^Aa
MF	0–10	29.36 ± 2.53^Aa	− 25.77 ± 0.27^Ab
	10–20	14.62 ± 0.82^Ab	−22.94 ± 0.24^Aa
	20–30	8.82 ± 0.13^Bc	− 22.00 ± 0.59^Aa
BF	0–10	28.43 ± 0.94^Aa	−27.31 ± 0.17^Bb
	10–20	15.89 ± 0.56^Ab	−25.93 ± 0.34^Ba
	20–30	10.56 ± 0.52^Ac	− 25.04 ± 0.35^Ba

Values are the mean ± standard error (n = 8). PF P. massoniana forest; MF coniferous and broadleaved mixed forest; BF monsoon evergreen broadleaved forest. Different lowercase letters indicate significant differences among three depths in the same forest (p < 0.05). Different capital letters indicate significant differences among three forest types of the same depth (p < 0.05)