Variation Of Soil Organic Carbon Mineralization And Microbial Community Characteristics After Moso Bamboo’s Invasion Into And Replacement Of Broadleaf Forests

Soil microorganisms drive the interactions between plants and invaded soil,also affect the adaptability and competitiveness of invasive plants.This study combined with field and pot experiments to investigate the effects of Moso bamboo invading broadleaf forest on soil carbon mineralization and microbial community characteristics.The soil carbon mineralization rates were measured by the alkali trapping method.The structural and functional diversity of soil bacterial and fungal communities were analyzed by terminal restriction fragment length polymorphism(T-RFLP),High-throughput sequencing,and real-time quantitative PCR techniques.This study aimed to explore bacterial and fungal communities’ roles in soil organic carbon mineralization under Moso bamboo invasion..The results of field experiments show that:1.The invasion of Moso bamboo increased soil p H,the contents of organic carbon,microbial biomass carbon,and water-soluble carbon.The organic carbon mineralization in the bamboo forest soil was 81% higher than broadleaf forest in autumn.2.The abundance of bacterial and fungal community in the soil of bamboo forest was higher than broadleaf forest,and the abundance of fungal community in the soil of bamboo forest was 20% and 80% higher than broadleaf forest in spring and autumn,respectively and was positively correlated with carbon mineralization.The soil bacterial and fungal community composition in a bamboo forest and broadleaf forest were different.The seasonal variation of bacterial community composition was significant,and the fungal community showed the difference before and after the invasion in stands.RDA results showed that the soil fungal community composition was significantly affected by p H,organic carbon mineralization rate,microbial entropy carbon,and invertase activity;however,a close relationship was found between the fungal community composition and carbon mineralization.The results of the pot experiment showed that:1.The soil p H,organic carbon,microbial biomass carbon,β-glucosidase,and cellulase activities were all higher in the soil planted with bamboo than soil planted with broadleaf tree species.Moreover,the total organic carbon mineralization under bamboo planted soil was 10%,33%,and 22% higher than Cinnamomum camphora,Schimba superba,and Quercus glauca planted soils.2.The abundance of fungal community in the soil planted with bamboo was 63% and140% higher than that grown with Cinomum camphora and Quercus glauca;however,the fungal community diversity in the soil planted with bamboo was significantly lower than planted with broadleaf tree species.The PCo A and RDA results showed that soil bacterial community response to tree species was more sensitive than that of the fungal community.The fungal community was significantly correlated with soil p H,organic carbon content,and carbon mineralization rate;moreover,they showed a positive correlation between the fungal community and carbon mineralization in bamboo planted soil,contrasting the bacterial community.The results showed that the carbon mineralization rate in the soil of bamboo forest and bamboo was higher than that in the broadleaf forest and soil planted with broadleaf tree species,and the succession of soil fungal community was the fundamental reason to increase carbon mineralization amount.