Response of different organs’ stoichiometry of Phragmites australis to soil salinity in arid marshes, China

Soil salinization, an important and increasingly prevalent issue in arid regions, influences plant growth and carbon (C): nitrogen (N): phosphorus (P) stoichiometry patterns by limiting nutrient access. Plant C:N:P stoichiometry patterns and response to soil salinity among organs (e.g., leaves, stems and roots) reflect plants’ trade-offs between access to resources and their adaptation strategies to different habitats. Common in marshes of arid middle-lower reaches of the Shule River Basin, China, Phragmites australis (Cav.) Trin. Ex Steud. (P. australis), is often the dominant species. The effects of soil salinity on the C:N:P stoichiometry among organs of P. australis were investigated in this study. The average N and P concentrations in leaves (19.09 ± 0.63 and 0.98 ± 0.05 g·kg−1, respectively) were significantly greater than those in roots (3.16 ± 0.16 and 0.76 ± 0.05 g·kg−1, respectively) and stems (3.80 ± 0.16 and 0.55 ± 0.05 g·kg−1, respectively) (P 0.05). The N:P ratio in leaves (20.89 ± 0.81) was significantly greater than those in stems (8.95 ± 0.67) and roots (5.11 ± 0.49), while C:N and C:P ratios (22.33 ± 0.82 and 469.25 ± 26.81, respectively) were significantly lower than those in stems (114.56 ± 4.93 and 1014.49 ± 86.57, respectively) and roots (144.58 ± 8.25 and 693.00 ± 74.18, respectively) (P