Study On Soil Microorganisms And Enzyme Activities In Different Forest Ages

In order to clarify the evolution characteristics of soil chemical properties,microorganisms and enzyme activities in different ages of Phoebe bournei plantations,to provide scientific basis for improving the soil quality of Phoebe bournei plantations and sustainable management of Phoebe bournei plantations.In this paper,three standard plots of 12 standard plots were set up for each of four forest ages:5 years,10 years,15 years,and 40 years.The soil samples were collected to determine the 21 chemical properties of the soil in the plots.Indicators,4 enzyme activity indicators and 3 microbial biomass indicators,and soil fungal and bacterial sequencing data of Fujian Nannan plantation forests.Correlation analysis and factor analysis were used to conduct research on soil microorganisms and enzyme activities of Fujian Nannan forests.The main conclusions are as follows(1)Soil chemical property indicators between different forest ages:pH,organic carbon,total nitrogen,total phosphorus,total potassium,hydrolyzed nitrogen and available phosphorus,calcium,magnesium,iron,manganese,copper,zinc,boron,and There were significant differences in the contents of heavy metals aluminum,barium,cobalt,cadmium,chromium,lead,nickel and vanadium(p<0.05).The content of total potassium and available iron in the soil of 5-year-old southern Fujian plantations is abundant,and the contents of available phosphorus,available calcium,magnesium,manganese,zinc,and boron,and heavy metals barium and cobalt are generally low The content of hydrolyzed nitrogen and available boron in the soil of the 10-year-old southern Fujian plantation is abundant,and the contents of total nitrogen,total phosphorus,total potassium,heavy metals cadmium,lead and nickel are generally low The soil pH,total nitrogen,and available phosphorus,calcium,magnesium,manganese,zinc,and heavy metals barium cobalt and cadmium are abundant in the 15-year-old southern Fujian plantation,and the contents of available copper,iron and heavy metals aluminum,chromium are generally low.The content of total phosphorus,available copper and heavy metals aluminum,chromium,lead,nickel,and vanadium in the soil of the 40-year-old southern Fujian plantation is rich,and the contents of organic carbon and hydrolyzed nitrogen are generally low(2)Soil enzyme activity and microbial biomass indicators between different forest ages:urease,invertase,catalase,acid phosphatase,and microbial biomass C,N,and P all have significant differences(p<0.05).Among them,the soil urease activities were higher in the 40-year-old southern Fujian plantation,while the activities were lower in invertase and acid phosphatase.Soil invertase and acid phosphatase activities were higher in 5-year-old southern Fujian plantations.The urease and catalase activity of the soil in the 15-year-old South Fujian plantation was low.Soil catalase activities were higher in 10-year-old southern Fujian plantations The contents of microbial biomass C,N,and P all increased with the increase of forest age,and the order of their size was 40 years old>15 years old>10 years old>5 years old(3)There is a significant correlation between soil properties of Paulownia forests of different ages.Soil enzyme activities and microbial biomass are also significantly related to soil chemical properties.Soil chemical properties are total nitrogen,total phosphorus,available phosphorus and pH,effective calcium,Magnesium,manganese and zinc and heavy metal elements cadmium,barium and lead are sensitive factors for soil enzyme activity and microbial biomass changes(4)Bacterial community structure and diversity are significantly different in different ages of Phoebe nannanensis plantations(p<0.05),among which Proteobacteria(30.87%),Acidobacteria(26.98%),and Curvularia(16.49%).And Actinomycota(9.80%)were the main dominant Mycoplasma in Fujian Nannan plantation.The relative abundance of P.aeruginosa and GAL15 in the 10-year-old Fujian Nannan plantation was significantly higher than that of the 5-year and 15-year-old Fujian Nannan plantation.Born in Phoebe nannanensis in 15 and 40 years The bacterial diversity index Simpson evenness index,Ace richness index,and Chaol richness index of Phoebe bournei plantation were all significantly higher than those of other forest age types at 15 years old(5)Soil bacterial structure and diversity are significantly correlated with soil chemical properties.Soil chemical properties total nitrogen,total phosphorus,available phosphorus,available manganese and boron,and heavy metal elements cadmium,barium,and cobalt are sensitive to changes in soil bacterial structure Factors;soil chemical properties:total nitrogen,total phosphorus,pH,available manganese,copper and iron,and heavy metal elements barium and cobalt are all sensitive factors for changes in soil bacterial diversity.(6)The structure and diversity of fungal communities were significantly different in different ages of Phoebe bournei plantations(p<0.05),among which the basidiomycota(36.04%),ascomycota(28.50%),and zygomycota(2.38%).As the main dominant mycoplasma of Phoebe nannanensis plantation,the relative abundance of Basidiomycota and Ascomycota in the 10-year-old Fujian Phoebe plantation is significantly higher than other forest ages.The relative abundance is significantly lower than other forest ages.Among the fungal diversity in southern Fujian plantations,Shannon evenness index of 15-year-old Fujian Nannan plantation was significantly lower than other forest ages,while Simpson evenness index was significantly higher than other forest ages,and Ace richness index of 40-year-old Fujian Nannan plantation was significantly higher than The Chaol richness index of 15-year,5-year and 40-year-old Phoebe nannanensis plantations was significantly higher than that of 10-year and 15-year.(7)The structure and diversity of soil fungi are significantly related to soil chemical properties.Soil chemical properties such as organic carbon,hydrolyzed nitrogen,pH,available iron,manganese and zinc,and heavy metal elements barium and cobalt are sensitive factors for changes in soil fungal structure.Soil chemical properties Organic carbon,available phosphorus,pH,available copper and iron,and heavy metal elements nickel,chromium,and aluminum are all sensitive factors for changes in soil fungal diversity.