Effects Of Different Management Practices On Soil Carbon Pool And Accumulation Of Phytolith Accluded Carbon In Moso Bamboo Forests

Moso bamboo(Phyllostachys heterocycla var.pubescens)has a great potential in carbon sequestration,Phytolith-occluded carbon(Phyt OC),a promising long-term biogeochemical carbon sequestration mode,plays a crucial role in the global carbon cycle and the regulation of atmospheric CO₂.However,it is not clear what effects the different management practices will have on carbon sequestration.Therefore we selected three parts as the research objects,i.e.soil,leaves and litter,and four management practices,including control(CK),compound fertilizer(CF),silicon fertilizer(SiF)and cut.The main research results are as follows:(1)Soil physical and chemical properties and nutrient elements:the management practices had litter influence on p H,and significant difference were only formed between silicon fertilizer and cut on the bulk density of the 20?40 soil layer(P<0.05).In terms of nutrients,the difference between alkaline hydrolysis nitrogen and available phosphorus content of the 0?20cm soil layer under compound fertilizer and silicon fertilizer was significant(P<0.05).(2)SOC content and storage:the application of SiF significantly increased the SOC content of the two soil layers compared with CK,respectively,while the application of CF and cut reduced the SOC content,but did not form a significant difference(P>0.05).The content(storage)of the 0?20cm soil layer can be ranked as:SiF>CK>cut>CF,and the 20?40 soil layer varied as a following trend:SiF>CK>CF>cut.(3)C and N content and C/N in leaves and litters:the change range of C and N content under four management practices were 420.74?432.94 mg·g^-1 and 22.38?26.32 mg·g^-1,the range of C/N is16.73?19.75.The order of C content under four management practices is cut>CK>SiF>CF,the order of N content is cut>CF>CK>SiF,and the order of C/N can be ranked as SiF>CK>CF>cut.(4)Phytolith content,Phyt OC content and storage:in soil,though compared with CK,phytolith content?Phyt OC content and storage had all increased,while only the application of SiF increased significantly(P<0.05);in leaves,all three practices had increased phytolith content,but only second-degree leaves under SiF and first-degree leaves under cut had significant increases(P<0.05);in litter,there were no significant difference in phytolith content under other three management practices compared with CK(P>0.05),the Phyt OC storage between cut and CK formed a significant difference P<0.05).(5)In the entire Moso bamboo forest ecosystem(soil+leaves+litter),Phyt OC storage under all three management practices increased and reached a significant level compared with CK(P<0.05).The overall increment ranked as SiF(102%)>CF(34.4%)>cut(26.9%).The effects of different management practices on the accumulation of PhytOC changed with stand age.From the above results,the following conclusions can be drawn:different management practices can affect the accumulation of SOC and Phyt OC in Moso bamboo forests.With regard to the current three practices,the application of SiF has greater carbon sequestration potential.