Linkage of microbial living communities and residues to soil organic carbon accumulation along a forest restoration gradient in southern China

Forest Ecosystems

Table 2 Soil and microbial properties between the four forest restoration stages

	Forest restoration stages
	F14		F49		F70		UF
Soil layer	Topsoil	Subsoil	Topsoil	Subsoil	Topsoil	Subsoil	Topsoil	Subsoil
Soil properties
pH	4.75 ± 0.07^A	4.78 ± 0.06^a	4.43 ± 0.04^C	4.50 ± 0.03^b	4.59 ± 0.03^B	4.57 ± 0.01^b	4.50 ± 0.04^BC	4.50 ± 0.04^b
BD (g·cm^− 3)	1.35 ± 0.01^A	1.47 ± 0.02^a	1.11 ± 0.01^C	1.42 ± 0.00^a	1.27 ± 0.03^B	1.29 ± 0.02^b	1.26 ± 0.01^B	1.43 ± 0.01^a
Sand (%)	77.69 ± 0.35^A	70.62 ± 0.45^a	24.08 ± 0.94^C	19.78 ± 0.41^c	16.85 ± 0.66^D	16.23 ± 1.14^d	43.93 ± 0.87^B	45.88 ± 0.97^b
Silt (%)	18.17 ± 0.31^A	23.85 ± 0.18^c	61.82 ± 1.16^B	65.38 ± 0.44^a	66.88 ± 0.69^A	66.49 ± 0.87^a	44.75 ± 0.71^C	43.67 ± 0.97^b
Clay (%)	4.14 ± 0.29^C	5.53 ± 0.30^d	14.10 ± 0.84^A	14.84 ± 0.26^b	16.27 ± 0.53^A	17.28 ± 0.55^a	11.32 ± 0.72^B	10.45 ± 0.24^c
Soil microbial PLFAs (nmol·g^− 1)
Bacterial PLFA	6.44 ± 0.32^B	4.10 ± 0.17^b	3.56 ± 0.39^C	2.42 ± 0.27^b	8.75 ± 0.52^A	2.98 ± 0.11^b	9.24 ± 0.72^A	11.46 ± 1.07^a
Fungal PLFA	0.60 ± 0.03^BC	0.49 ± 0.05^b	0.42 ± 0.07^C	0.28 ± 0.06^b	0.97 ± 0.04^A	0.36 ± 0.02^b	0.81 ± 0.07^AB	1.42 ± 0.14^a
Soil amino sugar parameters (mg·kg^− 1)
GluN	316.84 ± 29.77^D	116.65 ± 10.93^d	415.66 ± 7.28^C	298.97 ± 12.31^c	502.64 ± 10.01^B	320.89 ± 3.82^b	598.21 ± 5.09^A	336.84 ± 7.53^a
MurA	27.83 ± 4.17	12.83 ± 1.75^b	27.95 ± 1.39	21.38 ± 1.24^a	26.03 ± 2.14	20.87 ± 1.04^a	27.76 ± 3.50	20.31 ± 1.64^a
GalN	92.86 ± 17.68^C	33.37 ± 3.38^c	141.06 ± 4.95^B	104.14 ± 5.57^b	152.56 ± 1.63^B	110.10 ± 2.10^b	176.67 ± 3.77^A	133.24 ± 3.56^a

Different uppercase and lowercase letters indicate significant differences in topsoil and subsoil between the four restoration stages at the P < 0.05 level. Values are means ± SE (n = 6). Abbreviations: BD bulk density; GalN galactosamine; GluN glucosamine; MurA muramic acid