Abstract: Taking the native Phragmites australis and invasive Spartina alterniflora in Minjiang River estuary as test objectives, this paper studied the seasonal dynamics of their biomass and nitrogen- and phosphorus absorption efficiency. A typical single-peak curve was presented for the seasonal dynamics of aboveground biomass and nitrogen- and phosphorus absorption efficiency of the two species. P. australis had the maximum aboveground biomass (219533 g·m-2) in summer, while S. alterniflora had it (367002 g·m-2) in autumn. The total nitrogen (TN) and total phosphorus (TP) contents of P australis reached the peak (2106 g·m-2 of TN and 112 g·m-2 of TP) in summer and in autumn, respectively, while those of S. alterniflora all reached the peak (2676 g·m-2 of TN and 323 g·m-2 of TP) in autumn. Both of the two species had a higher absorption efficiency in TN than in TP (P<001), and S. alterniflora had a significantly higher absorption efficiency of TN and TP than P. australis (P<0.05). To some extent, the N/P, C/N, and C/P ratios of plants could indicate the nitrogen- and phosphorus absorption efficiency of the plants.

Key words: Hucho taimen, compensatory growth, starvation and re-feeding, feeding frequency, coefficient of variation.