红壤侵蚀区不同植被恢复模式土壤有机碳含量、密度及储量分布特征

[Objective]To clarify the distribution characteristics of soil organic carbon in different vegetation restoration modes in the red soil erosion area.[Method]Taking six types of forest stands after 27 years of artificial vegetation restoration and reconstruction as the research objects,and natural restoration sites without artificial disturbance were used as controls.20×20 m standard sample plots were set up,and soil samples were collected from 0～10 cm,10～20 cm,20～30 cm,and 30～40 cm soil layers to determine their organic carbon content,soil capacity,and other physicochemical properties to investigate the distribution characteristics in the red soil erosion area,and to estimate the carbon storage capacity of soil layers in the study area.[Result](1)Compared with the natural restoration site,the SOC content of all six artificial vegetation restoration modes increased significantly(p<0.05),and the SOC content of the 0～20 cm soil layer also differed significantly(p<0.05)among the different artificial vegetation restoration modes,which showed that SS>MES>RES＞RMS>PE＞PM.There was no significant difference in SOC content in the 20～40 cm soil layer.(2)The distribution patterns of soil organic carbon content in different soil layers of the seven vegetation restoration modes in the study area were basically the same,and all showed a trend of decreasing SOC content with increasing soil depth,but the magnitude of SOC reduction in different vegetation restoration modes was different,among which the magnitude of reduction was the largest in the pure forest of Schima superba and the smallest in the natural restoration site.(3)The pattern of change in soil organic carbon density was generally consistent with the pattern of change in soil organic carbon content(r = 0.978,p<0.01,Pearson two-tailed test).Soil moisture content,bulk density,porosity and total nitrogen had significant effects on soil organic carbon.(4)The organic carbon stock in the 0～40 cm soil layer within 85.85 hm2 of the study area was 7317.87 Mg C.The largest organic carbon stock was 1840.58 Mg C in the MES,and the smallest organic carbon stock was 432.97 Mg C in the RMS.[Conclusion]Artificial vegetation restoration and rehabilitation are effective in red soil erosion areas,and in the future construction of the study area,preference should be given to dominant tree species such as mullein in order to enhance soil carbon sequestration capacity.