Spatial Variability Of Ecological Stoichiometry Of Microbial Biomass Carbon,Nitrogen And Phosphorus In Rhizosphere Soil Tea At Wufeng

Soil microbial biomass is the active component of organic carbon in soil and is the source and sink center of soil carbon,nitrogen and phosphorus.Microorganisms respond to changes in habitats sensitively and participate in the mineralization and retention of nutrients to regulate the flow of carbon,nitrogen and phosphorus in the soil.Therefore,the ecostoichiometric characteristics of soil microbial biomass carbon,nitrogen and phosphorus are a useful tool for evaluating the nutritional constraints of terrestrial ecosystems.However,soil microbial biomass is sensitive to changes in habitat.The spatial changes of soil microbial carbon,nitrogen,and phosphorus may affect its eco-stoichiometric characteristics of carbon,nitrogen,and phosphorus,however,there was little information on the spatial variation of soil stoichiometric of microbial biomass,carbon,nitrogen,and phosphorus.In this study,rhizosphere soil of tea tree was selected to study ecostoichiometric characteristics of microbial biomass carbon,nitrogen,phosphorus and its key driving factor with an altitude of 800m-1400 m Caihuatai in Caihua,Wufeng,Yichang,Hubei Province.The results were as follows:The coefficient of variation of rhizosphere soil water content was 5.88%,which belonged to weak variability,and the coefficient of variation of p H was 9.47%,which belonged to low variation.The average values of OC,TN,and TP in rhizosphere soil were 34.00 g / kg,3.25 g / kg,and 1.04 g / kg,respectively.The coefficients of variation were 12.03%,9.23%,and 23.08%,respectively.The average values of C: N,C: P and N: P in rhizosphere soil were 10.45,35.06 and 3.34,respectively,and the coefficients of variation were 7.56%,33.29%,and 31.74%,respectively.These results indicated that the soil carbon,nitrogen and phosphorus content and their ecostoichiometric ratio are in a moderate degree of variation.The average values of MBC,MBN and MBP in rhizosphere soil were 441.15 mg / kg,85.51 mg / kg and 7.96 mg / kg,respectively,and the coefficients of variation were 45.69%,43.52% and 51.01%,respectively.The average values of MBC: MBN,MBC: MBP and MBN: MBP in rhizosphere soil were 6.62,73.86 and 12.81,respectively,and the coefficients of variation were 70.09%,82.79% and 55.27%,respectively.These results indicated that although the degree of variation of soil microbial biomass and its ecostoichiometric ratio was also a moderate degree of variation,the intensity of variation was higher than that of soil carbon,nitrogen,phosphorus and its ecostoichiometric ratio.Among the trace elements B,Mn,Fe,Cu,Zn,and Se,except that Fe was weakly variable,the remaining trace elements were all of medium intensity variation.Geostatistical analysis results showed that OC,C: N,C: P,N: P had a small range and strong spatial autocorrelation,TN had a large range and strong spatial autocorrelation,TP had a small range and very weak spatial correlation.In addition,structural factors are the main influencing factors of spatial variability of soil OC,TN and carbon,nitrogen and phosphorus eco-stoichiometric ratios.It showed that MBC,MBN,MBC: MBN,MBC: MBP,MBN: MBP had small scope and strong spatial autocorrelation,and MBP had small scope and weak spatial correlation.Effective Mn and effective Se had a small range and strong spatial autocorrelation,effective Cu had a large range and strong spatial autocorrelation,effective B,effective Fe and effective Zn had a small range and weak spatial correlation.This reflected that structural factors(soil parent material,topography,soil type,etc.)significantly affected Mn,Cu,and Se.Fe,B,while Zn were greatly affected by random factors(such as fertilization,etc.),resulting in their correlation within a small distance range.Redundancy analysis showed that the elevation factor explained the microbial biomass C,N,P and its eco-stoichiometric ratio to 45.5%,followed by the effective Mn content to the microbial biomass C,N,P and its eco-stoichiometric ratio to 14.5%,including The interpretation of water to microbial biomass carbon,nitrogen and phosphorus and its eco-stoichiometric ratio reached 13.9%,C / P to microbial biomass carbon,nitrogen and phosphorus and its eco-stoichiometric ratio reached 7.8%,and p H to microbial biomass carbon,nitrogen and phosphorus The explanation of its eco-stoichiometric ratio reached 3.9%.This showed that the spatial variation of altitude was a key driving factor that affected the spatial variability of rhizosphere soil microbial biomass carbon,nitrogen and phosphorus and its eco-stoichiometric ratio.