Jiaozhou Bay Wetland Ecosystem Carbon And Nitrogen And Phosphorus Content Of Ecological Stoichiometry Characteristics

The tidal flat wetland is a hub between the land and sea. The wetland soil and concentration distribution characteristics of carbon (C), nitrogen (N), phosphorus (P) in the plants and its ecological chemometrics affect the wetland ecosystem and global biogeochemical cycle. This study selected the tidal flat wetland in the Dagu estuary of the Jiaozhou bay as a study area, explored the C, N and P balance and coupling and characteristics of ecological chemometrics in the reed wetland with different flooding frequencies, in the alkaline wetland with different water and salt gradient and in the offshore naked flat soil and advantage plants, and analyzed impacts of physical and chemical properties of different soil on its characteristics of ecological chemometrics, so as to reveal the response mechanism of the tidal flat wetland ecosystem for tide, water, salt and so on. It can offer help for basic researches on the wetland ecological stoichiometry, the wetland restoration and management, and global biogeochemical cycle.The conclusions are as follows:(1) The content distributions of soil carbon, nitrogen and phosphorus are different in different types of tidal flat wetland. In the reed wetland, the content distribution ranges of soil carbon, nitrogen, phosphorus, are respectively5.73～15.07g/kg,0.46～0.84g/kg,0.03～0.39g/kg and the average values are respectively8.93g/kg,0.61g/kg,0.15g/kg. In the alkaline wetland, the content distribution ranges of soil carbon, nitrogen, phosphorus are respectively2.80～12.42g/kg,0.52～2.19g/kg,2.19～1.00g/kg and the average values are respectively7.36g/kg,1.10g/kg,0.66g/kg. In the offshore naked flat, the content distribution ranges of soil carbon, nitrogen, phosphorus are respectively9.51～12.88g/kg,0.98～1.46g/kg,1.46～0.89g/kg and the average values are respectively11.76g/kg,1.24g/kg,0.75g/kg.(2) The ecological stoichiometric ratios are different. In the reed wetland, the changing ranges of soil C/N, C/P, N/P are respectively11.50～29.05,80.19～506.22,4.44～38.24, and the average values are17.10,182.60,11.60, respectively. In the alkaline wetland, the changing ranges of soil C/N, C/P, N/P are respectively3.37～17.83,11.79～116.39and116.39～12.47, and the average values are8.62,33.47,4.21, respectively. In the offshore naked flat, the changing ranges of soil C/N, C/P, N/P are respectively8.84～14.31,33.14～54.18and54.18～5.27, and the average values are11.26,41.10,3.74, respectively.(3) In different types of wetland soil of tidal flat wetland, main influencing factors of ecological stoichiometry are different. In the reed wetland, pH, the salinity and the moisture content are the main influencing factors; in the alkaline wetland, main influencing factors are pH, the salinity and the moisture content; in the offshore naked flat, it is the salinity.(4) The carbon, nitrogen and phosphorus contents of different plants are different. The changing ranges of carbon, nitrogen and phosphorus contents in reed stems are respectively449.07～597.26g/kg,6.45～17.31g/kg,17.31～1.83g/kg, and the average values are521.44g/kg,11.23g/kg,1.57g/kg, respectively. The changing ranges of carbon, nitrogen, phosphorus contents in reed leaves are respectively439.68～627.43g/kg,19.57～42.96g/kg,42.96～4.18g/kg, and the average values are538.34g/kg,29.83g/kg,3.14g/kg. The changing ranges of carbon, nitrogen, phosphorus contents in the suaeda glauca are respectively193.56～458.22g/kg,7.70～14.87g/kg,14.87～2.89g/kg, and the average values are310.74g/kg,10.73g/kg,2.06g/kg. The changing ranges of carbon, nitrogen and phosphorus in the spartina anglica are respectively346.75～389.36g/kg,8.95～12.36g/kg,12.364.35g/kg, and the average values are368.31g/kg,10.65g/kg,3.55g/kg.(5) Different plants have different ecological stoichiometric ratios. The changing ranges of C/N, C/P, N/P contents in the reed stems are respectively37.36-76.14,724.68～1098.06and1098.06～19.40, and the average values are56.74,868.30,15.77, respectively. The changing ranges of C/N, C/P, N/P contents in the reed leaves are respectively15.26～30.06,348.52～550.81and550.81～26.25, and the average values are21.76,453.57,21.23, respectively. The changing ranges of C/N, C/P, N/P contents in the suaeda glauca are respectively22.27～53.94,272.03502.54and502.54～14.32, and the average values are34.53,389.60,11.76, respectively. The changing ranges of C/N, C/P, N/P contents in the spartina anglica are respectively34.18～46.51,222.52～380.76and380.76～9.28, and the average values are40.90,275.80,6.79, respectively.(6) Changes of soil physical and chemical properties will inevitably affect ecological chemometrics characteristics of carbon, nitrogen, phosphorus of wetland plants. As for the reeds, pH has certain influences on C, C/N of reed stems; the soil bulk density has certain influences on N, C/N of reed leaves. In terms of suaeda glauca, the soil pH is significantly related with C in the suaeda glauca and is great significantly related with C/P in the suaeda glauca; the soil salinity is significantly related with C/N in the suaeda glauca; the soil moisture content is significantly negative related with N/P in the suaeda glauca. In terms of spartina anglica, the soil salinity is significantly related with the C content of spartina anglica and is great significantly related with the P content; the soil moisture content is great significantly related with the C, P, C/N and N/P of spartina anglica; the soil bulk density is also significantly related with the C and P content of spartina anglica.