Effects Of Different Forest Regeneration Methods On Soil Microbial Diversity And Enzyme Activity In The Middle Subtropical

Soil microbial diversity affects soil carbon and nutrient sequestration,and the interac-tion between soil microorganisms and plant soil also affects many important functions of forest ecosystem.Soil microbial composition and function are often affected by land use intensification.Soil microbial and enzyme activities are affected by changes in above-ground and underground habitats,changing their carbon use strategies.Microorganisms affect soil carbon cycle and carbon sink function.Forest regeneration affects the above-ground and underground biodiversity and nutrient cycling process.Artificial natural regen-eration plays an important role in the process of nutrient accumulation and carbon sink.However,the study on microbial community dynamics of forest regeneration in the middle subtropical zone is not deep enough.Therefore,in order to study the changes of forest re-newal methods on microbial dynamics,three forest renewal methods:Castanopsis carlesii human renewal forest（AR）,Castanopsis carlesii plantation（CC）and Cunninghamia Lan-ceolata plantation（CL）and Castanopsis carlesii secondary forest（CT）were selected as the control.The main results are as follows:（1）Forest regeneration significantly affects soil environmental factors.Castanopsis carlesii human regeneration forest has higher carbon sequestration capacity than Chinese fir artificial forest,and the soil organic carbon of Castanopsis carlesii human regeneration forest is significantly higher than that of the two plantations.Microbial biomass and micro-bial biomass entropy are also affected by forest regeneration mode.Soil microbial biomass carbon and nitrogen of Castanopsis carlesii human regeneration forest are higher than those of other forest types.The microbial entropy carbon content of Cunninghamial Lanceolata plantation is high,and its utilization of soil carbon is insufficient.The activity contents of AP,βG and NAG enzymes in different forest renewal patterns ranged from 156.65 to 647.23,3.03 to 20.34 and 3.48 to 26.51 nmol·g^-1h^-1.βG:NAG（0.65～0.89）higher thanβG:AP（0.02～0.04）and NAG:AP（0.04～0.07）,ecological enzyme activity and metering ratio were different in different forest regeneration methods.Soil enzyme activity was significantly affected by carbon and p H.（2）The bacterial and fungal communities were detected by 16S rRNA and its rRNA gene sequencing.The results showed that forest regeneration significantly changed the community composition of bacteria and fungi,and the abundance and diversity of fungal community responded more strongly to forest regeneration.The diversity of bacteria and fungi in different forest regeneration methods was different.The community diversity abun-dance of Castanopsis carlesii human regeneration forest was closer to that of natural forest,and the results were inconsistent in rainy season and dry season.Eutrophic bacteria were enriched in rainy season and oligotrophic bacteria were enriched in dry season;The content of Basidiomycota in Castanopsis carlesii forest was higher than that of other forest types in dry season and rainy season.The bacterial community of Castanopsis carlesii human regeneration promoting forest changes the process of bacteria using nutrients to participate in carbon and nutrient cycle.The content of Basidiomycota in the forest was higher,and the community responded more strongly to the changes of aboveground litter and root sys-tem than other single plantation.Environmental factors such as p H affected the structure of soil microbial community,and enzyme activity affected the structure and abundance of soil fungal community.In conclusion,we studied the diversity of microbial communities in different regener-ation modes of middle subtropical forests,and discussed the adaptation strategies of micro-bial communities to environmental changes and the functional feedback of microorganisms.Secondly,we applied soil microbial enzyme activity to further understand the soil ecologi-cal process involved by microorganisms.Therefore,this study provides some data and the-oretical reference for understanding the diversity and activity of soil microorganisms in different regeneration forest types in the middle subtropical zone.