Diversity patterns in intertidal communities of three southern islands of Changshan archipelago
长山列岛南部三岛岩相潮间带群落多样性格局

The diversity pattern of intertidal communities in 3 southern islands of Changshan archipelago were studied.The results showed that the community appearance and structure in rocky intertidal zones of 3 islands were regimented by dominant species Chthamalus challengeri, Ostrea spp., macro algae and Littorina brevicula ,while in gravel intertidal zones of Southern Changshan and Daheishan regimented by Chthamalus challengeri, Littorina brevicula, Ostrea spp., and in Northern Changshan,by Chthamalus challengeri , macro algae and Gaetice depressus .There existed no obvious difference in community structures of rocky intertidal zones among 3 islands, which was demonstrated by the similarity in first 5 dominant species and their dominance ranks in the community. However,a significant difference was achieved in gravel intertidal communities,in which, the dominant species in the community at Northern Changshan differed greatly from that of others. The community diversity in R, J, D B, D IV , H B' and H IV' in rocky intertidal communities among 3 islands showed a great coincidence, Northern Changshan> Southern Changshan>Daheishan, however,little coincident results weree found among gravel intertidal communities. It was found that there existed a higher community diversity in gravel intertidal communities at Daheishan and Southern Changshan than at Northern Changshan where existed the highest species evenness.The community diversity was generally higher in gravel intertidal communities than in rocky intertidal ones. The variation in community compositions, stuctures and diversities were resulted mainly from topographical heterogeneities, substratum heterogeneities, hydrodynamics, water eutrophication and human disturbance in intertidal zones.