Abstract:Field studies on carbon (C), nitrogen (N) and phosphorus (P) stoichiometry of submersed macrophytes commonly focus on mesotrophic or eutrophic waters, while plant stoichiometric characteristics in oligotrophic waters, which may be different from those in mesotrophic or eutrophic waters, are rarely involved. This work aimed to study the stoichiometric characteristics of submersed macrophytes in an oligotrophic lake, the Lake Fuxian, which is of great significance for comprehensive understandings of elemental biogeochemical cycles in lakes. We conducted a field investigation on the distribution of submersed macrophytes in the Lake Fuxian and measured the morphological and C, N and P stoichiometric characteristic of nine common submersed macrophyte species. Intraspecific and interspecific coefficients of variation (CV) of stoichiometric characteristics of the sampled plants were also compared. The results revealed that submersed macrophytes distributed mainly in the shallow water depths (ranging from 0.5 m to 14.0 m with a mean value of 3.6 m) in the Lake Fuxian. The mean values of C, N and P contents in the aboveground parts of the nine species were 381.89, 18.59 and 2.13 mg/g, respectively, with an average N:P ratio of 9.21. The C, N and P contents of the plants were significantly positively correlated. Interspecific CV of the C, N and P contents and the C:N and C:P ratios were higher than the intraspecific CV, while intraspecific CV was higher than the interspecific N:P ratio. The C contents and N:P ratios of submersed macrophytes in the Lake Fuxian were higher than most of those in the middle and lower reaches of the Yangtze River. The results indicated that the growth of submersed macrophytes in the Lake Fuxian was potentially limited by P.