Effects of different vegetation restoration strategy on organic carbon and its fractions in manganese mine tailings pond
This study investigated the characteristics of organic carbon and its fractions in manganese tailings under different vegetation restoration strategies.It provided a scientific basis for selecting vegetation restoration strategies for the manganese tailing pond.A field experiment was conducted at a manganese tailing pond in Guilin,Guangxi.Five vegetation restoration strategies were set up(Q:Monoculture Celosia argentea L.;M:Monoculture Miscanthus sinensis A.;D:Monoculture Hylodesmum podocarpum H.;DQ:C.argentea and H.podocarpum intercropping;DM:M.sinensis and H.podocarpum intercropping.),and natural vegetation restoration was used as a control(CK).After vegetation restoration,tailings were collected for analysis of total organic carbon and its fractions.The results indicate that:(1)After vegetation restoration,the total organic carbon content in the tailings increased by 15.0％to 290％compared to CK.The total organic carbon content in different treatments was in the order of DQ＞D＞Q＞DM＞M,with the DQ treatment reached 6.94 g kg-1.(2)Vegetation restoration increased the easily oxidizable organic carbon(EOC)by 46.2％to 258％,dissolved organic carbon content(DOC)by 259％to 519％,microbial biomass carbon(MBC)by 51.4％to 459％,and recalcitrant organic carbon content(ROC)by 10.5％to 295％.Notably,DOC,MBC and ROC in the DQ were significantly higher than those in Q and D(p＜0.05).(3)Vegetation restoration led to an increase in the carbon pool management index(CPMI)of tailings.Specifically,the increase in DQ was the most significant,with its CPMI increasing by 236％compared to CK,and it was higher than D and Q.The CPMI of DM was higher than M but lower than D.(4)Redundancy analysis showed that total nitrogen and active calcium explained 88.8％and 83.8％of the variance in organic carbon and its components,respectively,indicating that these are the key factors regulating total organic carbon and its components in tailings under vegetation restoration.In conclusion,vegetation restoration can effectively improve the organic carbon and component content of the tailings.Compared with monocropping,reasonable intercropping strategies increased the carbon sequestration efficiency and improved the quality of the tailings.C.argentea and H.podocarpum intercropping is a suitable vegetation restoration strategy for tailings.The results of this study can provide a reference for enhancing the carbon sequestration function and improving the quality of tailings ponds.
manganese tailingsvegetation restorationorganic carboncarbon fractionscarbon pool management index
万方数据
维普
