Abstract: We analyzed the C, N and P concentrations and stoichiometric ratios (C∶N∶P) in roots, stems, and leaves of Kandelia candel, Bruguiera gymnorrhiza, Aegiceras corniculatum and Acanthus ilicifolius in Zhangjiang Estuary, subtropical China. The C concentrations in stems and leaves were significantly higher than those in roots of K. candel, A. corniculatum, and A. ilicifolius. The N and P concentrations ofK. candel, B. gymnorrhiza, and A. corniculatum were the highest in leaves, followed by stems and roots. In A. corniculatum and A. ilicifolius, the variation coefficient of stem C concentrations was significantly lower than that of roots and leaves. The variation coefficient of N concentration in K. candel, B. gymnorrhiza, A. ilicifoliusand that of P concentration in K. candel, B. gymnorrhiza, A. corniculatumwere the lowest in leaves. InK. candel, B. gymnorrhiza, and A. ilicifolius, the variation coefficient of C∶N ratio was significantly higher in roots and stems than that in leaves. Among the four mangrove species, foliar and root P concentrations in A. ilicifoliuswere significantly higher than those in the other species, and stem P in A. ilicifoliuswas slightly higher than in the other species. The variation coefficients of C, N, P concentrations in roots and C and P concentrations in leaves were higher in A. ilicifoliusthan in other species. C∶N∶P ratio in leaves (151∶9∶1) of four mangrove species was significantly lower than that in roots (187∶4∶1) or stems (239∶5∶1), suggesting that ecological stoichiometry of leaves was relatively stable. Our results provide theoretical basis for the large-caleresearch of ecological stoichiometry of mangrove and a scientific guidance for the conservation and sustainable management of mangrove plants.

Key words: Pararcyplera microptera meridionalis, cold hardiness, supercooling point, lethal temperature, lethal time.