Abstract: From November 2012 to July 2014, a survey on macrobenthos at three habitats (mangrove, Spartina alterniflora and natural tidal flat) in the tidal flat of Maoyan Island was quarterly conducted to compare their species composition, biomass, secondary productivity, and P/B values. The results showed that the biomass of macrobenthos was in order of mangrove (16.58±6.21 g·m^-2) > S. alterniflora (14.16±13.87 g·m^-2) > natural tidal flat (9.97±6.43 g·m^-2). The biomass of each habitat was lowest in winter. Twoway ANOVA analysis showed that the three habitats had no significant differences in biomass (P=0.276), but different seasons did have (P=0.042). In addition, biomass varied greatly among ten sites (P=0.000) and different seasons (P=0.032). The secondary productivity of macrobenthos was in order of mangrove (10.60 g AFDW·m^-2·a^-1) > natural tidal flat (9.00 g AFDW·m^-2·a^-1) > S. alterniflora (8.99 g AFDW·m^-2·a^-1), and the secondary productivity of macrobenthos at each habitat was lowest in winter. The P/B value of the natural tidal flat was highest (0.90), followed by mangrove and S. alterniflora (0.64 for both). The P/B values in spring and winter were higher than in summer and autumn. Collectively, the mangrove habitats in Maoyan Island had higher secondary productivity, and planting mangrove to take the place of S. alterniflora would be an efficient way to control its invasion.

Key words: individual reproductive fitness, fitness coefficient, natural population, sexual reproduction, regeneration., Toona ciliata var. pubescens