Ecological stoichiometric characteristics of carbon, nitrogen and phosphorus in the soil and leaves of Tamarix austromongolica of the wetland in Lanzhou section of the Yellow River

  Objective  By analyzing the ecological stoichiometric characteristics of soil and leaves of the dominant plant Tamarix austromongolica under different conditions in the wetland of Lanzhou section of the Yellow River, this study explored the ecological adaptability and growth limiting factors of T. austromongolica, providing a theoretical basis for the management and ecological conservation of the wetland plant T. austromongolica.

  Method  We selected 4 typical sampling points in Lanzhou section of the Yellow River from west to east in turn, namely wetland near Langao Group along the Yellow River (Ⅰ), Yintan Wetland Park (Ⅱ), wetland near the Fable Garden along the Yellow River (Ⅲ), and Yantan Tanjianzi Wetland Park (Ⅳ) to study the eco-stoichiometric characteristics of soils and leaves of T. austromongolica.

  Result  The average contents of C, N and P were 10.66, 0.16 and 0.24 g/kg, respectively in wetland soil in Lanzhou section of the Yellow River. The contents of C, N and P decreased from west to east, while the C∶N, C∶P and N∶P were opposite. P content in Ⅰ was significantly higher, and C∶P in Ⅳ was significantly higher than that in other sampling points. The average contents of C, N and P in T. austromongolica leaves were 364.60, 29.95 and 1.02 g/kg, respectively. There was no significant difference in C content of T. austromongolica leaves among the four sampling points. The contents of N and P decreased from west to east, while the C∶N, C∶P and N∶P were on the contrary. The N and P contents of Ⅰ were significantly higher than those of other sampling points. Correlation analysis showed that the contents of C, N and P in soil were significantly positively correlated, the contents of N and P in T. austromongolica leaves were significantly positively correlated, and the contents of N and P, C∶P and N∶P between soil and T. austromongolica leaves were significantly positively correlated, respectively. The leaf N∶P of T. austromongolica in various sampling points was higher than 20.

  Conclusion  The growth of T. austromongolica in Lanzhou section of the Yellow River wetland is limited by P. It is suggested that the adjustment of plant community structure and the return of fallen leaves should be strengthened in wetland conservation and management to improve the nutrient limitation.