[Objective]In order to understand the impact of replanting different broad-leaved tree species on soil carbon storage in Pinus massoniana forests,a study was conducted to identify an effective carbon sequestration model for the broadleaf transformation of P.massoniana plantations.[Method]Within the state-owned forest farm in Dushan county,Guizhou province,a representative artificially planted pure forest of P.massoniana with similar forest structure was selected.After selective logging,Cinnamomum camphora,Phoebe zhennan,Choerospondias axillaris,and Liriodendron chinense of broad-leaved tree species were replanted in the same forest plot for 8-14 a.Three plots were designated for each condition,with a total of 15 plots,and soil samples of 0-20,20-40,and 40-60 cm were collected for determination of soil physiochemical properties and active organic carbon components,using the pure forest of P.massoniana without replanting the broad-leaved trees as the control.[Result]Replanting different broad-leaved tree species had varying effects on soil carbon pools,with significant effects on the 0-20 cm soil layer and smaller effects on deeper soil layers.The range of soil carbon storage changes in the 0-60 cm layer was approximately 1.39-12.77 kg·m-2,with the highest soil carbon storage observed in pure forests of P.massoniana and P.massoniana+C.axillaris,reaching 212.35 and 203.51 kg·m-2,respectively,while the P.massoniana and C.camphora forest had the lowest soil carbon storage,approximately 100.78 kg·m-2.Replanting broad-leaved trees significantly reduced soil pH but increased microbial biomass carbon(MBC).In the 0-20 cm soil layer,the soil organic carbon and total nitrogen significantly increased in the P.massoniana+C.axillaris forest.Although soil carbon storage decreased in the short term after replanting broad-leaved trees,soil nitrogen storage did not significantly change.The replanting of P.zhennan significantly increased soil carbon pool activity and carbon pool activity index,while the replanting of C.axillaris significantly improved soil carbon pool stability.[Conclusion]Prioritizing the selection of deciduous broad-leaved tree species with high initial lignin/N values in the leaf effectively enhanced the soil carbon and nitrogen retention capacity of pure P.massoniana forests.The transformation of pure P.massoniana forests into broad-leaved forests had a minor short-term effect on soil nitrogen storage.After a certain degree of decline in soil carbon stocks,it might require a recovery period of fifteen years or more.
关键词
马尾松人工纯林/碳氮固存/补植阔叶树/短期效应
Key words
Pinus massoniana artificial pure forest/carbon and nitrogen sequestration/replanting broad-leaved trees/short-term effects
维普
万方数据