C, N and P stoichiometric characteristics in leaves of Suaeda salsa during different growth phase in coastal wetlands of China
滨海盐地碱蓬不同生长阶段叶片C、N、P化学计量特征

Aims Suaeda salsa is a typical species in coastal wetlands, and understanding change in its stoichiometric characteristics would help to assess its health status and target conservation efforts. We investigated which nutrient factor restricts its growth and proposed theories for protecting and managing coastal wetland by comparing the C, N and P stoichiometric characteristics of S. salsa in different growth periods. Methods We collected S. salsa leaves in different growth phases from June to November 2010 in Yancheng coastal wetlands, Jiangsu Province. The C, N and P contents of the leaves were measured. Data were analyzed by correlation analysis between N content and C:N and P content and C:P. N content and P content were also analyzed. Important findings Leaf C content of S. salsa had significant differences among three different growth phases, with the lowest in the growth phase and the highest in the decline phase. Leaf N content in the decline phase is significantly lower than in the mature and growth phases, and no significant difference of leaf P content was found. C:N and C:P were gradually increasing in the growth period while N:P showed a gradually decreasing trend. Correlation analysis indicated that C:N and C:P were negatively correlated with corresponding N, P content in three different phases. N content was positively linearly correlated with P content, indicating consistent demand of N and P by S. salsa. Furthermore, N is a restrictive factor for S. salsa in coastal wetlands during its growth and development.