The Different Soil Microbial Characteristics Of Moso Bamboo And Chinese Fir As Well As Its Affecting Mechanism

The sustainable development of forest resources is not only a requirement for the development of the national economy,but also a guarantee for a good ecological environment.Numerous literature reports that long-term continuous planting of eucalyptus,eucalyptus,fir,poplar and other plantations showed obvious obstacles to continuous planting,which seriously affected my country’s timber production and ecological security.However,Phyllostachys pubescens,which is also a plantation,did not have similar continuous planting obstacles.phenomenon.The long-term effects of different forest stands on the soil may be different,and the biological fertility of soil is an important indicator of soil health.In vivo bacteria in plants may affect root exudates through plant metabolism,thereby affecting rhizosphere soil microbes.Cunninghamia lanceolata and Phyllostachys pubescens are distributed in the same climatic zone.In order to explore the differences in the structure of the soil and plant micro-community in the two forests,forest land surveys and control experiments were carried OTU,and high-throughput techniques were used to analyze the community composition and diversity of bacteria and fungi.The forest land survey used natural broad-leaved forest as the control to compare the physical and chemical properties and microbial differences between the pure forests of Phyllostachys edulis and Cunninghamia lanceolata.The control test used Schima superba(broad-leaved trees)as the control.One-year-old Phyllostachys edulis and Cunninghamia lanceolata were planted.One year later,the basic soil was analyzed and compared.Index differences in properties,composition of root exudates,soil microorganisms in the root zone,and endophytic bacteria in plant leaves and roots.The main results are as follows:(1)The results of the forest land survey showed that the Shannon diversity and Inv Simpson uniformity index of soil bacteria and fungi in Phyllostachys edulis forests were significantly higher than that of Chinese fir forests(P<0.05),and even higher than that of broad-leaved forests.The Berger-Parker index of dominant species diversity was significantly higher than that of Chinese fir forests.It is higher than that of the moso bamboo forest(P<0.05),indicating that the bacteria and fungi composing the soil of the moso bamboo forest are not only diverse in species but also evenly distributed.The total OTU and unique OTU numbers of soil bacteria and fungi in Phyllostachys pubescens forests are much higher than those of Chinese fir forests and broad-leaved forests.The phylum classification levels of soil bacteria and fungi in Phyllostachys pubescens forests and broad-leaved forests are smaller than those of Chinese fir forests,but PCo A analysis results based on OTU It shows that the difference between the Phyllostachys pubescens forest and the broad-leaved forest is the biggest.The soil Actinobacteria(13.13%)of the Phyllostachys pubescens forest were higher than the broad-leaved forest and Chinese fir forest,and the Basidiomycota(23%)fungi were significantly higher(P<0.05)than the broad-leaved forest and Chinese fir forest.The soil Chloroflexi bacteria(24.42%)and Mortierellomycota fungi(45%)in the Chinese fir forest were significantly higher(P<0.05)than the Phyllostachys pubescens forest and broad-leaved forest.The results of RDA combined with the physical and chemical properties of the soil showed that the lower nutrient level of the Chinese fir forest soil is one of the reasons for the formation of its special microbial community,while the relatively rich nutrient content and higher p H of the Phyllostachys edulis forest soil is conducive to the formation of rich and diverse good Microbial structure.In conclusion,the rich diversity of soil bacteria in the Phyllostachys pubescens forest is the main reason to ensure the sustainable and healthy growth of bamboo.(2)One year after planting,the results of soil microbes in the root zone showed that the diversity,uniformity and richness index of soil bacteria in the root zone of the three plants increased significantly compared with the native soil,while the diversity index of dominant species was lower than the original one.Bottom soil.The most dominant order species classified by soil order in the root zone for 1 year are more abundant than the background,but it inherits the dominant order of Acidobacteria and Proteobacteria in the background broad-leaved forest soil to a large extent.Different plants also have significant differences in the enrichment of fungi of each dominant order.Schima superba and Phyllostachys pubescens are better at enriching Ascomycota fungi,and Chinese fir is better at enriching Basidiomycota fungi.The Pco A results based on OTU showed that the three plant soil bacteria and fungi samples were clearly separated,and the difference between Phyllostachys pubescens and Chinese fir was the largest.The root exudates of different plants are significantly different.The three plant common compounds account for only 15.7% of the total,and they have different dominant specific compounds.(3)Changes of plant endophytes before and after planting.The PCo A results based on OTU showed that the distribution of roots,leaf bacteria and fungi of the three plants before and after planting was similar,but the repeated aggregation in the plant group was more obvious after one year of planting.Among them,Schima superba is more different from Phyllostachys edulis and Chinese fir.Plant endophytic bacteria are more affected by environmental factors,while endophytic fungi are more affected by plants.From the perspective of mutual colonization with soil microorganisms,endophytic bacteria are more affected by spatial distance,and have less mutual influence with soil microorganisms.Endophytic fungi are easier to colonize in the soil through biological infection and other methods.Combining the results of the three aspects,it can be seen that whether from the root zone soil bacterial and fungal species composition,or root exudates,Chinese fir colonization has a strong enrichment effect on dominant bacteria,but it also reduces the root zone soil microbial diversity.The results of forest land surveys also reflect this phenomenon;moso bamboo is easier to maintain the stability of microorganisms in its soil root zone due to its uniform species diversity,and from the perspective of species composition,moso bamboo has a microbial community structure similar to broad-leaved.