Carbon, Nitrogen And Phosphorus Content And Ecological Stoichiometry Characteristics Of Spartina Alterniflora In The Tidal Flat Wetland Of Jiaozhou Bay

The tidal flat wetland is pivot between the sea and land.The wetland concentration distribution characteristic of C,N,P is vital of the wetland ecosystem and global biogeochemical cycle.This study selected the tidal flat wetland in Jiaozhou Bay as the research area,take the Spartina alterniflora eco-belt as the research object.Explored the temporal and spatial changes of C,N,P element content on the Spartina alterniflora,soil and litter;and,by comparing the spatial and temporal distribution of C,N and P in 2015and 2016,to inquiry the inter-annual variability in main nutrient,analysed the influence of soil physical to the main nutrient in the wetland.In order to provide the basic data of main nutrient cycle to Jiaozhou Bay,and can offer help for the wetland ecological stiochiometry and global biogeochemical cycle.?1?The seasonal dynamics of the biomass of Spartina alterniflora in the tideland wetland of Jiaozhou Bay,showed an increasing trend,followed by a decline,with the highest in autumn and lowest in spring.The biomass and carbon storage of the different components of plants showed the highest stem,followed by leaves,and the least roots,among which the carbon storage in autumn and winter was higher than that in spring and summer.?2?The C content of plant components was expressed as leaf>stem>root,and the seasonal dynamics were higher in autumn and lower in spring.The N content of each component is leaf>root>stem,and the seasonal distribution characteristics are higher in spring and lower in autumn.The P content distribution of different components was leaf>root>stem,and the seasonal distribution characteristics were the lowest in winter?2.84 g/kg?and was the highest in summer?3.96 g/kg?.The distribution characteristics of carbon,nitrogen,and phosphorus in litter of Spartina alterniflora were larger in winter and smaller in spring.?3?The TOC content of the soil in the tidal flat wetland of Jiaozhou Bay varied from3.86 to 11.30 g/kg,with an average of 8.03 g/kg.The vertical spatial distribution showed a trend of decreasing,and the surface TOC content was higher than the bottom layer.The TOC content of grass soil was significantly higher than mudflat soil;it was higher in winter,spring than in summer and autumn.The TN content of tidal flat wetland in Jiaozhou Bay ranged from 0.30 to 0.84 g/kg,with an average of 0.59 g/kg.The vertical spatial distribution showed a downward trend overall,and winter was significantly higher than other seasons;NH⁴⁺-N content The range of variation ranged from 2.83 to 15.60mg/kg with an average of 9.23 mg/kg.The overall NH⁴⁺-N content was lower in summer and higher in spring and autumn.The vertical distribution of NH⁴-N content is the same as grass soil.The content of TN and NH⁴⁺-N in grass soil was higher than that in mudflat soil.The soil TP content was 0.28⁰.76 g/kg.With the increase of soil depth,the content of TP decreased.The contents of AP in grass soil and mudflat soil were in the range of13.72²4.90 mg/kg and 14.68²8.80 mg/kg,respectively.The average values were 19.19mg/kg and 23.25 mg/kg.The AP content in grass soil was significantly lower than that in mudflat soil.?4?The C:N,C:P,and N:P in the wetland soil fluctuate within 7.03³1.28,9.23³1.56,and 0.71².57,respectively.The average values of the corresponding stoichiometric ratios are 15.07,18.45,and 1.35,respectively.The performance is C:P>C:N>N:P.C:N are all in the range of 10 to 20,indicating that the soil nitrogen content in the study area can meet the nutritional needs of soil microorganisms.N:P less than 14indicates that the main limiting nutrient element in the study area is N element,the degree of mineralization of soil nutrients is low,and the richness of plant species is low.?5?The main factors influencing the grass soil nutrient contents change in the Jiaozhou Bay is salinity,water rates,and pH,there is correlation between ecological stoichiometry of grass soil and salinity and water rates?P<0.05?;The main factors influence the change of mudflat soil nutrient content is water content,besides the pH and salinity of mudflat soil significantly associates with ecological stoichiometry?P<0.05?.