| Ecological stoichiometry is a scientific method to study the relationship and dynamic balance between energy and chemical elements（C、N、P）in ecosystems.Studying the ecological stoichiometric characteristics of soil under different vegetation types can reveal the coupling relationship between ecological process elements and the energy balance of ecosystems.Guizhou Mount Fanjing Nature Reserve has a well preserved subtropical primary ecosystem,which is a typical old-growth forest ecosystem.There are evergreen broad-leaved forest,coniferous and broad-leaved mixed forest,evergreen and deciduous broad-leaved mixed forest,deciduous broad-leaved forest,dwarf forest and other forest vegetation types.In recent years,with the rapid development of the local tourism industry and the intensification of human activities,the forest ecosystem of Mount Fanjing has been severely disrupted to varying degrees.To reveal the soil ecological stoichiometry characteristics and the impact of soil microorganisms under different vegetation types in Mount Fanjing,and to explore the relationship between soil ecological stoichiometry and microorganisms under the forest of Mount Fanjing,in order to provide basic data for the protection of the forest ecosystem in Mount Fanjing.Based on the Ecological stoichiometry theory,the main research results of this study are as follows:（1）The total nutrient content of 0-20 cm soil under different vegetation types of Mount Fanjing was significantly higher than that of 20-40 cm soil,indicating that the soil nutrients under different vegetation types of Mount Fanjing Nature Reserve had obvious agglomeration effects.There were significant differences between soil total soil nutrients and available nutrients under different vegetation types（p<0.05）,and deciduous broadleaved forests had the largest organic carbon（SOC）and total phosphorus（TP）contents among different vegetation types.Evergreen broadleaf forest soil had the highest carbon-to-nitrogen ratio（C/N）.The nitrogen-to-phosphorus ratio（N/P）of soil in coniferous and broad-wide mixed forest was between 14 and 16,indicating that the growth of plants in mixed coniferous forest was constrained by N and P.The N/P of the other four vegetation was less than fourteen,indicating that the growth of understory vegetation in these four vegetation types was mainly restricted by N element.Under different vegetation types of Fanjing Mountain,SOC was positively correlated with C/P and C/N（p<0.05）.TP was negatively correlated with C/P and N/P（p<0.05）.TN was significantly positively correlated with N/P（p<0.05）and negatively correlated with C/N（p<0.05）.（2）Under different vegetation types of Mount Fanjing,soil microbial biomass carbon,nitrogen and phosphorus surface polymerization effect was obvious,and the ratio of soil microbial biomass carbon-phosphorus(C/Pmic)between 0-20 cm and20-40 cm showed that the>evergreen broadleaved forest>deciduous broadleaved forest>coniferous broadleaf mixed forest>evergreen deciduous broadleaf mixed forest Dwarf forest indicates that soil microorganisms in dwarf forest have a greater ability to release P element in the process of mineralization SOC,which in turn affects the content of phosphorus（MBP）of their own soil microbial biomass.The nitrogen-to-phosphorus ratio(N/Pmic)of soil microbial biomass in dwarf forests was lower at 0-20 cm and 20-40 cm,indicating that the demand for N by plants in dwarf forests was greater than the demand for P.（3）The dominant flora of soil bacteria under different vegetation types in Mount Fanjing are Acidobacteriota,Proteobacteria,and Actinobacteriota.The richness and diversity of soil microbial communities of 0-20 cm under different vegetation types were as evergreen deciduous broad-leaved mixed forest>coniferous broad-leaved mixed forest>deciduous broad-leaved forest>dwarf forest>evergreen broad-leaved forest,and the richness and diversity of 20-40 cm microbial community were as follows:deciduous broad-leaved forest>mixed coniferous and broad-leaved forest>evergreen deciduous broad-leaved mixed forest>evergreen broad-leaved forest>dwarf forest.The number of 0-20 cm soil microbial OTUs was higher than that of 20-40 cm soil microbial OTUs,and the number of 0-20 cm and 20-40 cm soil OTUs were all shown as evergreen deciduous broad-leaved mixed forest>coniferous broad-leaved mixed forest>evergreen broad-leaved forest>deciduous broad-leaved forest>dwarf forest,indicating that evergreen deciduous broad-leaved mixed forest and coniferous broad-leaved mixed forest were more suitable for the growth of multiple microorganisms.（4）β-glucosidase and leucine aminopeptidase activities were highest in evergreen broadleaf forests,acid phosphatase and N-acetyl-β-D-glucosidase activities were highest in coniferous mixed forests,and leucine aminopeptidase and N-acetyl-β-D-glucosidase activities were lowest in deciduous broadleaf forest soils.The correlation analysis between soil,microbial biomass and soil enzyme stoichiometry of different vegetation types in Mount Fanjing shows that there is a highly significant positive correlation between N/Pmicand C/Pmicin 0-20 cm soil of different vegetation types in Fanjing Mountain（p<0.001）,C/Nmicand C/N are highly significant positive correlation（p<0.001）,and EEA C/P and C/N are significantly positive correlation（p<0.05）;There is a highly significant positive correlation between N/Pmic and C/Pmic in 20-40cm soil（p<0.001）. |
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