Leaf carbon, nitrogen and phosphorus stoichiometry of Tamarix chinensis Lour. in the Laizhou Bay coastal wetland, China

With the studies of ecological stoichiometry changing from global to regional and smaller scales, it is of great significance to know how, for a single species in a typical ecosystem, the carbon (C), nitrogen (N) and phosphorus (P) stoichiometry varies with the seasons and responds to environmental stresses. In this study, taking T. chinensis (Tamarix chinensis Lour.) in the Laizhou Bay coastal wetland as a test object, seasonal variations in leaf C, N and P stoichiometry and their correlations with soil salt were analyzed. The results showed that leaf C, N and P contents and the ratios of C:N, C:P and N:P of T. chinensis exhibited large variations. The leaf C, N and P contents were 388.56-472.07, 18.39-32.86 and 1.02-3.16 g kg−1, respectively. Also, the ratios of C:N, C:P and N:P were 11.83-24.78, 125.98-425.98 and 8.62-23.66, respectively. The seasonal variation of the leaf C content presented an increasing trend while the leaf N and P contents indicated a trend of first increasing and later decreasing. However, a trend contrary to the leaf N and P was observed for the ratios of leaf C:N, C:P and N:P. There was a significant negative correlation between leaf P content and soil salt. Conversely, a positive correlation was found between the ratios of leaf C:P, N:P and soil salt. Generally, T. chinensis in the Laizhou Bay wetland took a defensive life-history strategy during the growth process. The growth of T. chinensis was limited by N at the beginning of the growing season, and by P in the middle and final stages of the growing season.