A meta-analysis of changes in soil organic carbon stocks after afforestation with deciduous broadleaved, sempervirent broadleaved, and conifer tree species

Table 3 Pearson correlation coefficients between the rate of SOC stock change and influencing factors

	Soil depth	Initial SOC stock	Mean annual temperature	Mean annual precipitation	N
Total	0–20	− 0.296**	− 0.127*	− 0.252**	261
	20–40	− 0.413**	− 0.06	− 0.172*	168
	40–60	− 0.164	− 0.185*	− 0.075	115
Deciduous broadleaved	0–20	0.135	− 0.051	0.08	101
	20–40	0.289*	− 0.203	0.24	48
	40–60	− 0.109	0.219	0.529**	38
Sempervirent broadleaved	0–20	− 0.08	0.103	− 0.057	62
	20–40	− 0.026	− 0.114	− 0.151	48
	40–60	0.168	− 0.369*	0.01	37
Sempervirent conifer	0–20	− 0.511**	− 0.09	− 0.399**	98
	20–40	− 0.611**	− 0.005	− 0.226	72
	40–60	− 0.471**	− 0.022	0.02	40

* and ** indicate that correlation is significant at the 0.05 level (2-tailed) and 0.01 level (2-tailed), respectively

ISSN: 1297-966X